| //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This implements the TargetLowering class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Target/TargetAsmInfo.h" |
| #include "llvm/Target/TargetLowering.h" |
| #include "llvm/Target/TargetSubtarget.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetRegisterInfo.h" |
| #include "llvm/GlobalVariable.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/CodeGen/MachineFrameInfo.h" |
| #include "llvm/CodeGen/SelectionDAG.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/Support/MathExtras.h" |
| using namespace llvm; |
| |
| namespace llvm { |
| TLSModel::Model getTLSModel(const GlobalValue *GV, Reloc::Model reloc) { |
| bool isLocal = GV->hasLocalLinkage(); |
| bool isDeclaration = GV->isDeclaration(); |
| // FIXME: what should we do for protected and internal visibility? |
| // For variables, is internal different from hidden? |
| bool isHidden = GV->hasHiddenVisibility(); |
| |
| if (reloc == Reloc::PIC_) { |
| if (isLocal || isHidden) |
| return TLSModel::LocalDynamic; |
| else |
| return TLSModel::GeneralDynamic; |
| } else { |
| if (!isDeclaration || isHidden) |
| return TLSModel::LocalExec; |
| else |
| return TLSModel::InitialExec; |
| } |
| } |
| } |
| |
| /// InitLibcallNames - Set default libcall names. |
| /// |
| static void InitLibcallNames(const char **Names) { |
| Names[RTLIB::SHL_I16] = "__ashlhi3"; |
| Names[RTLIB::SHL_I32] = "__ashlsi3"; |
| Names[RTLIB::SHL_I64] = "__ashldi3"; |
| Names[RTLIB::SHL_I128] = "__ashlti3"; |
| Names[RTLIB::SRL_I16] = "__lshrhi3"; |
| Names[RTLIB::SRL_I32] = "__lshrsi3"; |
| Names[RTLIB::SRL_I64] = "__lshrdi3"; |
| Names[RTLIB::SRL_I128] = "__lshrti3"; |
| Names[RTLIB::SRA_I16] = "__ashrhi3"; |
| Names[RTLIB::SRA_I32] = "__ashrsi3"; |
| Names[RTLIB::SRA_I64] = "__ashrdi3"; |
| Names[RTLIB::SRA_I128] = "__ashrti3"; |
| Names[RTLIB::MUL_I16] = "__mulhi3"; |
| Names[RTLIB::MUL_I32] = "__mulsi3"; |
| Names[RTLIB::MUL_I64] = "__muldi3"; |
| Names[RTLIB::MUL_I128] = "__multi3"; |
| Names[RTLIB::SDIV_I16] = "__divhi3"; |
| Names[RTLIB::SDIV_I32] = "__divsi3"; |
| Names[RTLIB::SDIV_I64] = "__divdi3"; |
| Names[RTLIB::SDIV_I128] = "__divti3"; |
| Names[RTLIB::UDIV_I16] = "__udivhi3"; |
| Names[RTLIB::UDIV_I32] = "__udivsi3"; |
| Names[RTLIB::UDIV_I64] = "__udivdi3"; |
| Names[RTLIB::UDIV_I128] = "__udivti3"; |
| Names[RTLIB::SREM_I16] = "__modhi3"; |
| Names[RTLIB::SREM_I32] = "__modsi3"; |
| Names[RTLIB::SREM_I64] = "__moddi3"; |
| Names[RTLIB::SREM_I128] = "__modti3"; |
| Names[RTLIB::UREM_I16] = "__umodhi3"; |
| Names[RTLIB::UREM_I32] = "__umodsi3"; |
| Names[RTLIB::UREM_I64] = "__umoddi3"; |
| Names[RTLIB::UREM_I128] = "__umodti3"; |
| Names[RTLIB::NEG_I32] = "__negsi2"; |
| Names[RTLIB::NEG_I64] = "__negdi2"; |
| Names[RTLIB::ADD_F32] = "__addsf3"; |
| Names[RTLIB::ADD_F64] = "__adddf3"; |
| Names[RTLIB::ADD_F80] = "__addxf3"; |
| Names[RTLIB::ADD_PPCF128] = "__gcc_qadd"; |
| Names[RTLIB::SUB_F32] = "__subsf3"; |
| Names[RTLIB::SUB_F64] = "__subdf3"; |
| Names[RTLIB::SUB_F80] = "__subxf3"; |
| Names[RTLIB::SUB_PPCF128] = "__gcc_qsub"; |
| Names[RTLIB::MUL_F32] = "__mulsf3"; |
| Names[RTLIB::MUL_F64] = "__muldf3"; |
| Names[RTLIB::MUL_F80] = "__mulxf3"; |
| Names[RTLIB::MUL_PPCF128] = "__gcc_qmul"; |
| Names[RTLIB::DIV_F32] = "__divsf3"; |
| Names[RTLIB::DIV_F64] = "__divdf3"; |
| Names[RTLIB::DIV_F80] = "__divxf3"; |
| Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv"; |
| Names[RTLIB::REM_F32] = "fmodf"; |
| Names[RTLIB::REM_F64] = "fmod"; |
| Names[RTLIB::REM_F80] = "fmodl"; |
| Names[RTLIB::REM_PPCF128] = "fmodl"; |
| Names[RTLIB::POWI_F32] = "__powisf2"; |
| Names[RTLIB::POWI_F64] = "__powidf2"; |
| Names[RTLIB::POWI_F80] = "__powixf2"; |
| Names[RTLIB::POWI_PPCF128] = "__powitf2"; |
| Names[RTLIB::SQRT_F32] = "sqrtf"; |
| Names[RTLIB::SQRT_F64] = "sqrt"; |
| Names[RTLIB::SQRT_F80] = "sqrtl"; |
| Names[RTLIB::SQRT_PPCF128] = "sqrtl"; |
| Names[RTLIB::LOG_F32] = "logf"; |
| Names[RTLIB::LOG_F64] = "log"; |
| Names[RTLIB::LOG_F80] = "logl"; |
| Names[RTLIB::LOG_PPCF128] = "logl"; |
| Names[RTLIB::LOG2_F32] = "log2f"; |
| Names[RTLIB::LOG2_F64] = "log2"; |
| Names[RTLIB::LOG2_F80] = "log2l"; |
| Names[RTLIB::LOG2_PPCF128] = "log2l"; |
| Names[RTLIB::LOG10_F32] = "log10f"; |
| Names[RTLIB::LOG10_F64] = "log10"; |
| Names[RTLIB::LOG10_F80] = "log10l"; |
| Names[RTLIB::LOG10_PPCF128] = "log10l"; |
| Names[RTLIB::EXP_F32] = "expf"; |
| Names[RTLIB::EXP_F64] = "exp"; |
| Names[RTLIB::EXP_F80] = "expl"; |
| Names[RTLIB::EXP_PPCF128] = "expl"; |
| Names[RTLIB::EXP2_F32] = "exp2f"; |
| Names[RTLIB::EXP2_F64] = "exp2"; |
| Names[RTLIB::EXP2_F80] = "exp2l"; |
| Names[RTLIB::EXP2_PPCF128] = "exp2l"; |
| Names[RTLIB::SIN_F32] = "sinf"; |
| Names[RTLIB::SIN_F64] = "sin"; |
| Names[RTLIB::SIN_F80] = "sinl"; |
| Names[RTLIB::SIN_PPCF128] = "sinl"; |
| Names[RTLIB::COS_F32] = "cosf"; |
| Names[RTLIB::COS_F64] = "cos"; |
| Names[RTLIB::COS_F80] = "cosl"; |
| Names[RTLIB::COS_PPCF128] = "cosl"; |
| Names[RTLIB::POW_F32] = "powf"; |
| Names[RTLIB::POW_F64] = "pow"; |
| Names[RTLIB::POW_F80] = "powl"; |
| Names[RTLIB::POW_PPCF128] = "powl"; |
| Names[RTLIB::CEIL_F32] = "ceilf"; |
| Names[RTLIB::CEIL_F64] = "ceil"; |
| Names[RTLIB::CEIL_F80] = "ceill"; |
| Names[RTLIB::CEIL_PPCF128] = "ceill"; |
| Names[RTLIB::TRUNC_F32] = "truncf"; |
| Names[RTLIB::TRUNC_F64] = "trunc"; |
| Names[RTLIB::TRUNC_F80] = "truncl"; |
| Names[RTLIB::TRUNC_PPCF128] = "truncl"; |
| Names[RTLIB::RINT_F32] = "rintf"; |
| Names[RTLIB::RINT_F64] = "rint"; |
| Names[RTLIB::RINT_F80] = "rintl"; |
| Names[RTLIB::RINT_PPCF128] = "rintl"; |
| Names[RTLIB::NEARBYINT_F32] = "nearbyintf"; |
| Names[RTLIB::NEARBYINT_F64] = "nearbyint"; |
| Names[RTLIB::NEARBYINT_F80] = "nearbyintl"; |
| Names[RTLIB::NEARBYINT_PPCF128] = "nearbyintl"; |
| Names[RTLIB::FLOOR_F32] = "floorf"; |
| Names[RTLIB::FLOOR_F64] = "floor"; |
| Names[RTLIB::FLOOR_F80] = "floorl"; |
| Names[RTLIB::FLOOR_PPCF128] = "floorl"; |
| Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2"; |
| Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2"; |
| Names[RTLIB::FPROUND_F80_F32] = "__truncxfsf2"; |
| Names[RTLIB::FPROUND_PPCF128_F32] = "__trunctfsf2"; |
| Names[RTLIB::FPROUND_F80_F64] = "__truncxfdf2"; |
| Names[RTLIB::FPROUND_PPCF128_F64] = "__trunctfdf2"; |
| Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi"; |
| Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi"; |
| Names[RTLIB::FPTOSINT_F32_I128] = "__fixsfti"; |
| Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi"; |
| Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi"; |
| Names[RTLIB::FPTOSINT_F64_I128] = "__fixdfti"; |
| Names[RTLIB::FPTOSINT_F80_I32] = "__fixxfsi"; |
| Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi"; |
| Names[RTLIB::FPTOSINT_F80_I128] = "__fixxfti"; |
| Names[RTLIB::FPTOSINT_PPCF128_I32] = "__fixtfsi"; |
| Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi"; |
| Names[RTLIB::FPTOSINT_PPCF128_I128] = "__fixtfti"; |
| Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi"; |
| Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi"; |
| Names[RTLIB::FPTOUINT_F32_I128] = "__fixunssfti"; |
| Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi"; |
| Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi"; |
| Names[RTLIB::FPTOUINT_F64_I128] = "__fixunsdfti"; |
| Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi"; |
| Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi"; |
| Names[RTLIB::FPTOUINT_F80_I128] = "__fixunsxfti"; |
| Names[RTLIB::FPTOUINT_PPCF128_I32] = "__fixunstfsi"; |
| Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi"; |
| Names[RTLIB::FPTOUINT_PPCF128_I128] = "__fixunstfti"; |
| Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf"; |
| Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf"; |
| Names[RTLIB::SINTTOFP_I32_F80] = "__floatsixf"; |
| Names[RTLIB::SINTTOFP_I32_PPCF128] = "__floatsitf"; |
| Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf"; |
| Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf"; |
| Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf"; |
| Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf"; |
| Names[RTLIB::SINTTOFP_I128_F32] = "__floattisf"; |
| Names[RTLIB::SINTTOFP_I128_F64] = "__floattidf"; |
| Names[RTLIB::SINTTOFP_I128_F80] = "__floattixf"; |
| Names[RTLIB::SINTTOFP_I128_PPCF128] = "__floattitf"; |
| Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf"; |
| Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf"; |
| Names[RTLIB::UINTTOFP_I32_F80] = "__floatunsixf"; |
| Names[RTLIB::UINTTOFP_I32_PPCF128] = "__floatunsitf"; |
| Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf"; |
| Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf"; |
| Names[RTLIB::UINTTOFP_I64_F80] = "__floatundixf"; |
| Names[RTLIB::UINTTOFP_I64_PPCF128] = "__floatunditf"; |
| Names[RTLIB::UINTTOFP_I128_F32] = "__floatuntisf"; |
| Names[RTLIB::UINTTOFP_I128_F64] = "__floatuntidf"; |
| Names[RTLIB::UINTTOFP_I128_F80] = "__floatuntixf"; |
| Names[RTLIB::UINTTOFP_I128_PPCF128] = "__floatuntitf"; |
| Names[RTLIB::OEQ_F32] = "__eqsf2"; |
| Names[RTLIB::OEQ_F64] = "__eqdf2"; |
| Names[RTLIB::UNE_F32] = "__nesf2"; |
| Names[RTLIB::UNE_F64] = "__nedf2"; |
| Names[RTLIB::OGE_F32] = "__gesf2"; |
| Names[RTLIB::OGE_F64] = "__gedf2"; |
| Names[RTLIB::OLT_F32] = "__ltsf2"; |
| Names[RTLIB::OLT_F64] = "__ltdf2"; |
| Names[RTLIB::OLE_F32] = "__lesf2"; |
| Names[RTLIB::OLE_F64] = "__ledf2"; |
| Names[RTLIB::OGT_F32] = "__gtsf2"; |
| Names[RTLIB::OGT_F64] = "__gtdf2"; |
| Names[RTLIB::UO_F32] = "__unordsf2"; |
| Names[RTLIB::UO_F64] = "__unorddf2"; |
| Names[RTLIB::O_F32] = "__unordsf2"; |
| Names[RTLIB::O_F64] = "__unorddf2"; |
| } |
| |
| /// getFPEXT - Return the FPEXT_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getFPEXT(MVT OpVT, MVT RetVT) { |
| if (OpVT == MVT::f32) { |
| if (RetVT == MVT::f64) |
| return FPEXT_F32_F64; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// getFPROUND - Return the FPROUND_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getFPROUND(MVT OpVT, MVT RetVT) { |
| if (RetVT == MVT::f32) { |
| if (OpVT == MVT::f64) |
| return FPROUND_F64_F32; |
| if (OpVT == MVT::f80) |
| return FPROUND_F80_F32; |
| if (OpVT == MVT::ppcf128) |
| return FPROUND_PPCF128_F32; |
| } else if (RetVT == MVT::f64) { |
| if (OpVT == MVT::f80) |
| return FPROUND_F80_F64; |
| if (OpVT == MVT::ppcf128) |
| return FPROUND_PPCF128_F64; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getFPTOSINT(MVT OpVT, MVT RetVT) { |
| if (OpVT == MVT::f32) { |
| if (RetVT == MVT::i32) |
| return FPTOSINT_F32_I32; |
| if (RetVT == MVT::i64) |
| return FPTOSINT_F32_I64; |
| if (RetVT == MVT::i128) |
| return FPTOSINT_F32_I128; |
| } else if (OpVT == MVT::f64) { |
| if (RetVT == MVT::i32) |
| return FPTOSINT_F64_I32; |
| if (RetVT == MVT::i64) |
| return FPTOSINT_F64_I64; |
| if (RetVT == MVT::i128) |
| return FPTOSINT_F64_I128; |
| } else if (OpVT == MVT::f80) { |
| if (RetVT == MVT::i32) |
| return FPTOSINT_F80_I32; |
| if (RetVT == MVT::i64) |
| return FPTOSINT_F80_I64; |
| if (RetVT == MVT::i128) |
| return FPTOSINT_F80_I128; |
| } else if (OpVT == MVT::ppcf128) { |
| if (RetVT == MVT::i32) |
| return FPTOSINT_PPCF128_I32; |
| if (RetVT == MVT::i64) |
| return FPTOSINT_PPCF128_I64; |
| if (RetVT == MVT::i128) |
| return FPTOSINT_PPCF128_I128; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getFPTOUINT(MVT OpVT, MVT RetVT) { |
| if (OpVT == MVT::f32) { |
| if (RetVT == MVT::i32) |
| return FPTOUINT_F32_I32; |
| if (RetVT == MVT::i64) |
| return FPTOUINT_F32_I64; |
| if (RetVT == MVT::i128) |
| return FPTOUINT_F32_I128; |
| } else if (OpVT == MVT::f64) { |
| if (RetVT == MVT::i32) |
| return FPTOUINT_F64_I32; |
| if (RetVT == MVT::i64) |
| return FPTOUINT_F64_I64; |
| if (RetVT == MVT::i128) |
| return FPTOUINT_F64_I128; |
| } else if (OpVT == MVT::f80) { |
| if (RetVT == MVT::i32) |
| return FPTOUINT_F80_I32; |
| if (RetVT == MVT::i64) |
| return FPTOUINT_F80_I64; |
| if (RetVT == MVT::i128) |
| return FPTOUINT_F80_I128; |
| } else if (OpVT == MVT::ppcf128) { |
| if (RetVT == MVT::i32) |
| return FPTOUINT_PPCF128_I32; |
| if (RetVT == MVT::i64) |
| return FPTOUINT_PPCF128_I64; |
| if (RetVT == MVT::i128) |
| return FPTOUINT_PPCF128_I128; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getSINTTOFP(MVT OpVT, MVT RetVT) { |
| if (OpVT == MVT::i32) { |
| if (RetVT == MVT::f32) |
| return SINTTOFP_I32_F32; |
| else if (RetVT == MVT::f64) |
| return SINTTOFP_I32_F64; |
| else if (RetVT == MVT::f80) |
| return SINTTOFP_I32_F80; |
| else if (RetVT == MVT::ppcf128) |
| return SINTTOFP_I32_PPCF128; |
| } else if (OpVT == MVT::i64) { |
| if (RetVT == MVT::f32) |
| return SINTTOFP_I64_F32; |
| else if (RetVT == MVT::f64) |
| return SINTTOFP_I64_F64; |
| else if (RetVT == MVT::f80) |
| return SINTTOFP_I64_F80; |
| else if (RetVT == MVT::ppcf128) |
| return SINTTOFP_I64_PPCF128; |
| } else if (OpVT == MVT::i128) { |
| if (RetVT == MVT::f32) |
| return SINTTOFP_I128_F32; |
| else if (RetVT == MVT::f64) |
| return SINTTOFP_I128_F64; |
| else if (RetVT == MVT::f80) |
| return SINTTOFP_I128_F80; |
| else if (RetVT == MVT::ppcf128) |
| return SINTTOFP_I128_PPCF128; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or |
| /// UNKNOWN_LIBCALL if there is none. |
| RTLIB::Libcall RTLIB::getUINTTOFP(MVT OpVT, MVT RetVT) { |
| if (OpVT == MVT::i32) { |
| if (RetVT == MVT::f32) |
| return UINTTOFP_I32_F32; |
| else if (RetVT == MVT::f64) |
| return UINTTOFP_I32_F64; |
| else if (RetVT == MVT::f80) |
| return UINTTOFP_I32_F80; |
| else if (RetVT == MVT::ppcf128) |
| return UINTTOFP_I32_PPCF128; |
| } else if (OpVT == MVT::i64) { |
| if (RetVT == MVT::f32) |
| return UINTTOFP_I64_F32; |
| else if (RetVT == MVT::f64) |
| return UINTTOFP_I64_F64; |
| else if (RetVT == MVT::f80) |
| return UINTTOFP_I64_F80; |
| else if (RetVT == MVT::ppcf128) |
| return UINTTOFP_I64_PPCF128; |
| } else if (OpVT == MVT::i128) { |
| if (RetVT == MVT::f32) |
| return UINTTOFP_I128_F32; |
| else if (RetVT == MVT::f64) |
| return UINTTOFP_I128_F64; |
| else if (RetVT == MVT::f80) |
| return UINTTOFP_I128_F80; |
| else if (RetVT == MVT::ppcf128) |
| return UINTTOFP_I128_PPCF128; |
| } |
| return UNKNOWN_LIBCALL; |
| } |
| |
| /// InitCmpLibcallCCs - Set default comparison libcall CC. |
| /// |
| static void InitCmpLibcallCCs(ISD::CondCode *CCs) { |
| memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL); |
| CCs[RTLIB::OEQ_F32] = ISD::SETEQ; |
| CCs[RTLIB::OEQ_F64] = ISD::SETEQ; |
| CCs[RTLIB::UNE_F32] = ISD::SETNE; |
| CCs[RTLIB::UNE_F64] = ISD::SETNE; |
| CCs[RTLIB::OGE_F32] = ISD::SETGE; |
| CCs[RTLIB::OGE_F64] = ISD::SETGE; |
| CCs[RTLIB::OLT_F32] = ISD::SETLT; |
| CCs[RTLIB::OLT_F64] = ISD::SETLT; |
| CCs[RTLIB::OLE_F32] = ISD::SETLE; |
| CCs[RTLIB::OLE_F64] = ISD::SETLE; |
| CCs[RTLIB::OGT_F32] = ISD::SETGT; |
| CCs[RTLIB::OGT_F64] = ISD::SETGT; |
| CCs[RTLIB::UO_F32] = ISD::SETNE; |
| CCs[RTLIB::UO_F64] = ISD::SETNE; |
| CCs[RTLIB::O_F32] = ISD::SETEQ; |
| CCs[RTLIB::O_F64] = ISD::SETEQ; |
| } |
| |
| TargetLowering::TargetLowering(TargetMachine &tm) |
| : TM(tm), TD(TM.getTargetData()) { |
| // All operations default to being supported. |
| memset(OpActions, 0, sizeof(OpActions)); |
| memset(LoadExtActions, 0, sizeof(LoadExtActions)); |
| memset(TruncStoreActions, 0, sizeof(TruncStoreActions)); |
| memset(IndexedModeActions, 0, sizeof(IndexedModeActions)); |
| memset(ConvertActions, 0, sizeof(ConvertActions)); |
| memset(CondCodeActions, 0, sizeof(CondCodeActions)); |
| |
| // Set default actions for various operations. |
| for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) { |
| // Default all indexed load / store to expand. |
| for (unsigned IM = (unsigned)ISD::PRE_INC; |
| IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) { |
| setIndexedLoadAction(IM, (MVT::SimpleValueType)VT, Expand); |
| setIndexedStoreAction(IM, (MVT::SimpleValueType)VT, Expand); |
| } |
| |
| // These operations default to expand. |
| setOperationAction(ISD::FGETSIGN, (MVT::SimpleValueType)VT, Expand); |
| setOperationAction(ISD::CONCAT_VECTORS, (MVT::SimpleValueType)VT, Expand); |
| } |
| |
| // Most targets ignore the @llvm.prefetch intrinsic. |
| setOperationAction(ISD::PREFETCH, MVT::Other, Expand); |
| |
| // ConstantFP nodes default to expand. Targets can either change this to |
| // Legal, in which case all fp constants are legal, or use addLegalFPImmediate |
| // to optimize expansions for certain constants. |
| setOperationAction(ISD::ConstantFP, MVT::f32, Expand); |
| setOperationAction(ISD::ConstantFP, MVT::f64, Expand); |
| setOperationAction(ISD::ConstantFP, MVT::f80, Expand); |
| |
| // These library functions default to expand. |
| setOperationAction(ISD::FLOG , MVT::f64, Expand); |
| setOperationAction(ISD::FLOG2, MVT::f64, Expand); |
| setOperationAction(ISD::FLOG10,MVT::f64, Expand); |
| setOperationAction(ISD::FEXP , MVT::f64, Expand); |
| setOperationAction(ISD::FEXP2, MVT::f64, Expand); |
| setOperationAction(ISD::FLOG , MVT::f32, Expand); |
| setOperationAction(ISD::FLOG2, MVT::f32, Expand); |
| setOperationAction(ISD::FLOG10,MVT::f32, Expand); |
| setOperationAction(ISD::FEXP , MVT::f32, Expand); |
| setOperationAction(ISD::FEXP2, MVT::f32, Expand); |
| |
| // Default ISD::TRAP to expand (which turns it into abort). |
| setOperationAction(ISD::TRAP, MVT::Other, Expand); |
| |
| IsLittleEndian = TD->isLittleEndian(); |
| UsesGlobalOffsetTable = false; |
| ShiftAmountTy = PointerTy = getValueType(TD->getIntPtrType()); |
| ShiftAmtHandling = Undefined; |
| memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*)); |
| memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray)); |
| maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8; |
| allowUnalignedMemoryAccesses = false; |
| benefitFromCodePlacementOpt = false; |
| UseUnderscoreSetJmp = false; |
| UseUnderscoreLongJmp = false; |
| SelectIsExpensive = false; |
| IntDivIsCheap = false; |
| Pow2DivIsCheap = false; |
| StackPointerRegisterToSaveRestore = 0; |
| ExceptionPointerRegister = 0; |
| ExceptionSelectorRegister = 0; |
| BooleanContents = UndefinedBooleanContent; |
| SchedPreferenceInfo = SchedulingForLatency; |
| JumpBufSize = 0; |
| JumpBufAlignment = 0; |
| IfCvtBlockSizeLimit = 2; |
| IfCvtDupBlockSizeLimit = 0; |
| PrefLoopAlignment = 0; |
| |
| InitLibcallNames(LibcallRoutineNames); |
| InitCmpLibcallCCs(CmpLibcallCCs); |
| |
| // Tell Legalize whether the assembler supports DEBUG_LOC. |
| const TargetAsmInfo *TASM = TM.getTargetAsmInfo(); |
| if (!TASM || !TASM->hasDotLocAndDotFile()) |
| setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand); |
| } |
| |
| TargetLowering::~TargetLowering() {} |
| |
| /// computeRegisterProperties - Once all of the register classes are added, |
| /// this allows us to compute derived properties we expose. |
| void TargetLowering::computeRegisterProperties() { |
| assert(MVT::LAST_VALUETYPE <= 32 && |
| "Too many value types for ValueTypeActions to hold!"); |
| |
| // Everything defaults to needing one register. |
| for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) { |
| NumRegistersForVT[i] = 1; |
| RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i; |
| } |
| // ...except isVoid, which doesn't need any registers. |
| NumRegistersForVT[MVT::isVoid] = 0; |
| |
| // Find the largest integer register class. |
| unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE; |
| for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg) |
| assert(LargestIntReg != MVT::i1 && "No integer registers defined!"); |
| |
| // Every integer value type larger than this largest register takes twice as |
| // many registers to represent as the previous ValueType. |
| for (unsigned ExpandedReg = LargestIntReg + 1; ; ++ExpandedReg) { |
| MVT EVT = (MVT::SimpleValueType)ExpandedReg; |
| if (!EVT.isInteger()) |
| break; |
| NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1]; |
| RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg; |
| TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1); |
| ValueTypeActions.setTypeAction(EVT, Expand); |
| } |
| |
| // Inspect all of the ValueType's smaller than the largest integer |
| // register to see which ones need promotion. |
| unsigned LegalIntReg = LargestIntReg; |
| for (unsigned IntReg = LargestIntReg - 1; |
| IntReg >= (unsigned)MVT::i1; --IntReg) { |
| MVT IVT = (MVT::SimpleValueType)IntReg; |
| if (isTypeLegal(IVT)) { |
| LegalIntReg = IntReg; |
| } else { |
| RegisterTypeForVT[IntReg] = TransformToType[IntReg] = |
| (MVT::SimpleValueType)LegalIntReg; |
| ValueTypeActions.setTypeAction(IVT, Promote); |
| } |
| } |
| |
| // ppcf128 type is really two f64's. |
| if (!isTypeLegal(MVT::ppcf128)) { |
| NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64]; |
| RegisterTypeForVT[MVT::ppcf128] = MVT::f64; |
| TransformToType[MVT::ppcf128] = MVT::f64; |
| ValueTypeActions.setTypeAction(MVT::ppcf128, Expand); |
| } |
| |
| // Decide how to handle f64. If the target does not have native f64 support, |
| // expand it to i64 and we will be generating soft float library calls. |
| if (!isTypeLegal(MVT::f64)) { |
| NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64]; |
| RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64]; |
| TransformToType[MVT::f64] = MVT::i64; |
| ValueTypeActions.setTypeAction(MVT::f64, Expand); |
| } |
| |
| // Decide how to handle f32. If the target does not have native support for |
| // f32, promote it to f64 if it is legal. Otherwise, expand it to i32. |
| if (!isTypeLegal(MVT::f32)) { |
| if (isTypeLegal(MVT::f64)) { |
| NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64]; |
| RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64]; |
| TransformToType[MVT::f32] = MVT::f64; |
| ValueTypeActions.setTypeAction(MVT::f32, Promote); |
| } else { |
| NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32]; |
| RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32]; |
| TransformToType[MVT::f32] = MVT::i32; |
| ValueTypeActions.setTypeAction(MVT::f32, Expand); |
| } |
| } |
| |
| // Loop over all of the vector value types to see which need transformations. |
| for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE; |
| i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) { |
| MVT VT = (MVT::SimpleValueType)i; |
| if (!isTypeLegal(VT)) { |
| MVT IntermediateVT, RegisterVT; |
| unsigned NumIntermediates; |
| NumRegistersForVT[i] = |
| getVectorTypeBreakdown(VT, |
| IntermediateVT, NumIntermediates, |
| RegisterVT); |
| RegisterTypeForVT[i] = RegisterVT; |
| |
| // Determine if there is a legal wider type. |
| bool IsLegalWiderType = false; |
| MVT EltVT = VT.getVectorElementType(); |
| unsigned NElts = VT.getVectorNumElements(); |
| for (unsigned nVT = i+1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) { |
| MVT SVT = (MVT::SimpleValueType)nVT; |
| if (isTypeLegal(SVT) && SVT.getVectorElementType() == EltVT && |
| SVT.getVectorNumElements() > NElts) { |
| TransformToType[i] = SVT; |
| ValueTypeActions.setTypeAction(VT, Promote); |
| IsLegalWiderType = true; |
| break; |
| } |
| } |
| if (!IsLegalWiderType) { |
| MVT NVT = VT.getPow2VectorType(); |
| if (NVT == VT) { |
| // Type is already a power of 2. The default action is to split. |
| TransformToType[i] = MVT::Other; |
| ValueTypeActions.setTypeAction(VT, Expand); |
| } else { |
| TransformToType[i] = NVT; |
| ValueTypeActions.setTypeAction(VT, Promote); |
| } |
| } |
| } |
| } |
| } |
| |
| const char *TargetLowering::getTargetNodeName(unsigned Opcode) const { |
| return NULL; |
| } |
| |
| |
| MVT TargetLowering::getSetCCResultType(MVT VT) const { |
| return getValueType(TD->getIntPtrType()); |
| } |
| |
| |
| /// getVectorTypeBreakdown - Vector types are broken down into some number of |
| /// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32 |
| /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack. |
| /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86. |
| /// |
| /// This method returns the number of registers needed, and the VT for each |
| /// register. It also returns the VT and quantity of the intermediate values |
| /// before they are promoted/expanded. |
| /// |
| unsigned TargetLowering::getVectorTypeBreakdown(MVT VT, |
| MVT &IntermediateVT, |
| unsigned &NumIntermediates, |
| MVT &RegisterVT) const { |
| // Figure out the right, legal destination reg to copy into. |
| unsigned NumElts = VT.getVectorNumElements(); |
| MVT EltTy = VT.getVectorElementType(); |
| |
| unsigned NumVectorRegs = 1; |
| |
| // FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we |
| // could break down into LHS/RHS like LegalizeDAG does. |
| if (!isPowerOf2_32(NumElts)) { |
| NumVectorRegs = NumElts; |
| NumElts = 1; |
| } |
| |
| // Divide the input until we get to a supported size. This will always |
| // end with a scalar if the target doesn't support vectors. |
| while (NumElts > 1 && !isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) { |
| NumElts >>= 1; |
| NumVectorRegs <<= 1; |
| } |
| |
| NumIntermediates = NumVectorRegs; |
| |
| MVT NewVT = MVT::getVectorVT(EltTy, NumElts); |
| if (!isTypeLegal(NewVT)) |
| NewVT = EltTy; |
| IntermediateVT = NewVT; |
| |
| MVT DestVT = getRegisterType(NewVT); |
| RegisterVT = DestVT; |
| if (DestVT.bitsLT(NewVT)) { |
| // Value is expanded, e.g. i64 -> i16. |
| return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits()); |
| } else { |
| // Otherwise, promotion or legal types use the same number of registers as |
| // the vector decimated to the appropriate level. |
| return NumVectorRegs; |
| } |
| |
| return 1; |
| } |
| |
| /// getWidenVectorType: given a vector type, returns the type to widen to |
| /// (e.g., v7i8 to v8i8). If the vector type is legal, it returns itself. |
| /// If there is no vector type that we want to widen to, returns MVT::Other |
| /// When and where to widen is target dependent based on the cost of |
| /// scalarizing vs using the wider vector type. |
| MVT TargetLowering::getWidenVectorType(MVT VT) const { |
| assert(VT.isVector()); |
| if (isTypeLegal(VT)) |
| return VT; |
| |
| // Default is not to widen until moved to LegalizeTypes |
| return MVT::Other; |
| } |
| |
| /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate |
| /// function arguments in the caller parameter area. This is the actual |
| /// alignment, not its logarithm. |
| unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const { |
| return TD->getCallFrameTypeAlignment(Ty); |
| } |
| |
| SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table, |
| SelectionDAG &DAG) const { |
| if (usesGlobalOffsetTable()) |
| return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy()); |
| return Table; |
| } |
| |
| bool |
| TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const { |
| // Assume that everything is safe in static mode. |
| if (getTargetMachine().getRelocationModel() == Reloc::Static) |
| return true; |
| |
| // In dynamic-no-pic mode, assume that known defined values are safe. |
| if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC && |
| GA && |
| !GA->getGlobal()->isDeclaration() && |
| !GA->getGlobal()->isWeakForLinker()) |
| return true; |
| |
| // Otherwise assume nothing is safe. |
| return false; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Optimization Methods |
| //===----------------------------------------------------------------------===// |
| |
| /// ShrinkDemandedConstant - Check to see if the specified operand of the |
| /// specified instruction is a constant integer. If so, check to see if there |
| /// are any bits set in the constant that are not demanded. If so, shrink the |
| /// constant and return true. |
| bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op, |
| const APInt &Demanded) { |
| DebugLoc dl = Op.getDebugLoc(); |
| |
| // FIXME: ISD::SELECT, ISD::SELECT_CC |
| switch (Op.getOpcode()) { |
| default: break; |
| case ISD::XOR: |
| case ISD::AND: |
| case ISD::OR: { |
| ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1)); |
| if (!C) return false; |
| |
| if (Op.getOpcode() == ISD::XOR && |
| (C->getAPIntValue() | (~Demanded)).isAllOnesValue()) |
| return false; |
| |
| // if we can expand it to have all bits set, do it |
| if (C->getAPIntValue().intersects(~Demanded)) { |
| MVT VT = Op.getValueType(); |
| SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0), |
| DAG.getConstant(Demanded & |
| C->getAPIntValue(), |
| VT)); |
| return CombineTo(Op, New); |
| } |
| |
| break; |
| } |
| } |
| |
| return false; |
| } |
| |
| /// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the |
| /// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening |
| /// cast, but it could be generalized for targets with other types of |
| /// implicit widening casts. |
| bool |
| TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op, |
| unsigned BitWidth, |
| const APInt &Demanded, |
| DebugLoc dl) { |
| assert(Op.getNumOperands() == 2 && |
| "ShrinkDemandedOp only supports binary operators!"); |
| assert(Op.getNode()->getNumValues() == 1 && |
| "ShrinkDemandedOp only supports nodes with one result!"); |
| |
| // Don't do this if the node has another user, which may require the |
| // full value. |
| if (!Op.getNode()->hasOneUse()) |
| return false; |
| |
| // Search for the smallest integer type with free casts to and from |
| // Op's type. For expedience, just check power-of-2 integer types. |
| const TargetLowering &TLI = DAG.getTargetLoweringInfo(); |
| unsigned SmallVTBits = BitWidth - Demanded.countLeadingZeros(); |
| if (!isPowerOf2_32(SmallVTBits)) |
| SmallVTBits = NextPowerOf2(SmallVTBits); |
| for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) { |
| MVT SmallVT = MVT::getIntegerVT(SmallVTBits); |
| if (TLI.isTruncateFree(Op.getValueType(), SmallVT) && |
| TLI.isZExtFree(SmallVT, Op.getValueType())) { |
| // We found a type with free casts. |
| SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT, |
| DAG.getNode(ISD::TRUNCATE, dl, SmallVT, |
| Op.getNode()->getOperand(0)), |
| DAG.getNode(ISD::TRUNCATE, dl, SmallVT, |
| Op.getNode()->getOperand(1))); |
| SDValue Z = DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), X); |
| return CombineTo(Op, Z); |
| } |
| } |
| return false; |
| } |
| |
| /// SimplifyDemandedBits - Look at Op. At this point, we know that only the |
| /// DemandedMask bits of the result of Op are ever used downstream. If we can |
| /// use this information to simplify Op, create a new simplified DAG node and |
| /// return true, returning the original and new nodes in Old and New. Otherwise, |
| /// analyze the expression and return a mask of KnownOne and KnownZero bits for |
| /// the expression (used to simplify the caller). The KnownZero/One bits may |
| /// only be accurate for those bits in the DemandedMask. |
| bool TargetLowering::SimplifyDemandedBits(SDValue Op, |
| const APInt &DemandedMask, |
| APInt &KnownZero, |
| APInt &KnownOne, |
| TargetLoweringOpt &TLO, |
| unsigned Depth) const { |
| unsigned BitWidth = DemandedMask.getBitWidth(); |
| assert(Op.getValueSizeInBits() == BitWidth && |
| "Mask size mismatches value type size!"); |
| APInt NewMask = DemandedMask; |
| DebugLoc dl = Op.getDebugLoc(); |
| |
| // Don't know anything. |
| KnownZero = KnownOne = APInt(BitWidth, 0); |
| |
| // Other users may use these bits. |
| if (!Op.getNode()->hasOneUse()) { |
| if (Depth != 0) { |
| // If not at the root, Just compute the KnownZero/KnownOne bits to |
| // simplify things downstream. |
| TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth); |
| return false; |
| } |
| // If this is the root being simplified, allow it to have multiple uses, |
| // just set the NewMask to all bits. |
| NewMask = APInt::getAllOnesValue(BitWidth); |
| } else if (DemandedMask == 0) { |
| // Not demanding any bits from Op. |
| if (Op.getOpcode() != ISD::UNDEF) |
| return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType())); |
| return false; |
| } else if (Depth == 6) { // Limit search depth. |
| return false; |
| } |
| |
| APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut; |
| switch (Op.getOpcode()) { |
| case ISD::Constant: |
| // We know all of the bits for a constant! |
| KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue() & NewMask; |
| KnownZero = ~KnownOne & NewMask; |
| return false; // Don't fall through, will infinitely loop. |
| case ISD::AND: |
| // If the RHS is a constant, check to see if the LHS would be zero without |
| // using the bits from the RHS. Below, we use knowledge about the RHS to |
| // simplify the LHS, here we're using information from the LHS to simplify |
| // the RHS. |
| if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { |
| APInt LHSZero, LHSOne; |
| TLO.DAG.ComputeMaskedBits(Op.getOperand(0), NewMask, |
| LHSZero, LHSOne, Depth+1); |
| // If the LHS already has zeros where RHSC does, this and is dead. |
| if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| // If any of the set bits in the RHS are known zero on the LHS, shrink |
| // the constant. |
| if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask)) |
| return true; |
| } |
| |
| if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask, |
| KnownZero2, KnownOne2, TLO, Depth+1)) |
| return true; |
| assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); |
| |
| // If all of the demanded bits are known one on one side, return the other. |
| // These bits cannot contribute to the result of the 'and'. |
| if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(1)); |
| // If all of the demanded bits in the inputs are known zeros, return zero. |
| if ((NewMask & (KnownZero|KnownZero2)) == NewMask) |
| return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType())); |
| // If the RHS is a constant, see if we can simplify it. |
| if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask)) |
| return true; |
| // If the operation can be done in a smaller type, do so. |
| if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) |
| return true; |
| |
| // Output known-1 bits are only known if set in both the LHS & RHS. |
| KnownOne &= KnownOne2; |
| // Output known-0 are known to be clear if zero in either the LHS | RHS. |
| KnownZero |= KnownZero2; |
| break; |
| case ISD::OR: |
| if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask, |
| KnownZero2, KnownOne2, TLO, Depth+1)) |
| return true; |
| assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); |
| |
| // If all of the demanded bits are known zero on one side, return the other. |
| // These bits cannot contribute to the result of the 'or'. |
| if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(1)); |
| // If all of the potentially set bits on one side are known to be set on |
| // the other side, just use the 'other' side. |
| if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask)) |
| return TLO.CombineTo(Op, Op.getOperand(1)); |
| // If the RHS is a constant, see if we can simplify it. |
| if (TLO.ShrinkDemandedConstant(Op, NewMask)) |
| return true; |
| // If the operation can be done in a smaller type, do so. |
| if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) |
| return true; |
| |
| // Output known-0 bits are only known if clear in both the LHS & RHS. |
| KnownZero &= KnownZero2; |
| // Output known-1 are known to be set if set in either the LHS | RHS. |
| KnownOne |= KnownOne2; |
| break; |
| case ISD::XOR: |
| if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2, |
| KnownOne2, TLO, Depth+1)) |
| return true; |
| assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); |
| |
| // If all of the demanded bits are known zero on one side, return the other. |
| // These bits cannot contribute to the result of the 'xor'. |
| if ((KnownZero & NewMask) == NewMask) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| if ((KnownZero2 & NewMask) == NewMask) |
| return TLO.CombineTo(Op, Op.getOperand(1)); |
| // If the operation can be done in a smaller type, do so. |
| if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) |
| return true; |
| |
| // If all of the unknown bits are known to be zero on one side or the other |
| // (but not both) turn this into an *inclusive* or. |
| // e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0 |
| if ((NewMask & ~KnownZero & ~KnownZero2) == 0) |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(), |
| Op.getOperand(0), |
| Op.getOperand(1))); |
| |
| // Output known-0 bits are known if clear or set in both the LHS & RHS. |
| KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2); |
| // Output known-1 are known to be set if set in only one of the LHS, RHS. |
| KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2); |
| |
| // If all of the demanded bits on one side are known, and all of the set |
| // bits on that side are also known to be set on the other side, turn this |
| // into an AND, as we know the bits will be cleared. |
| // e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2 |
| if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known |
| if ((KnownOne & KnownOne2) == KnownOne) { |
| MVT VT = Op.getValueType(); |
| SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT); |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT, |
| Op.getOperand(0), ANDC)); |
| } |
| } |
| |
| // If the RHS is a constant, see if we can simplify it. |
| // for XOR, we prefer to force bits to 1 if they will make a -1. |
| // if we can't force bits, try to shrink constant |
| if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { |
| APInt Expanded = C->getAPIntValue() | (~NewMask); |
| // if we can expand it to have all bits set, do it |
| if (Expanded.isAllOnesValue()) { |
| if (Expanded != C->getAPIntValue()) { |
| MVT VT = Op.getValueType(); |
| SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0), |
| TLO.DAG.getConstant(Expanded, VT)); |
| return TLO.CombineTo(Op, New); |
| } |
| // if it already has all the bits set, nothing to change |
| // but don't shrink either! |
| } else if (TLO.ShrinkDemandedConstant(Op, NewMask)) { |
| return true; |
| } |
| } |
| |
| KnownZero = KnownZeroOut; |
| KnownOne = KnownOneOut; |
| break; |
| case ISD::SELECT: |
| if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2, |
| KnownOne2, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); |
| |
| // If the operands are constants, see if we can simplify them. |
| if (TLO.ShrinkDemandedConstant(Op, NewMask)) |
| return true; |
| |
| // Only known if known in both the LHS and RHS. |
| KnownOne &= KnownOne2; |
| KnownZero &= KnownZero2; |
| break; |
| case ISD::SELECT_CC: |
| if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2, |
| KnownOne2, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); |
| |
| // If the operands are constants, see if we can simplify them. |
| if (TLO.ShrinkDemandedConstant(Op, NewMask)) |
| return true; |
| |
| // Only known if known in both the LHS and RHS. |
| KnownOne &= KnownOne2; |
| KnownZero &= KnownZero2; |
| break; |
| case ISD::SHL: |
| if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { |
| unsigned ShAmt = SA->getZExtValue(); |
| SDValue InOp = Op.getOperand(0); |
| |
| // If the shift count is an invalid immediate, don't do anything. |
| if (ShAmt >= BitWidth) |
| break; |
| |
| // If this is ((X >>u C1) << ShAmt), see if we can simplify this into a |
| // single shift. We can do this if the bottom bits (which are shifted |
| // out) are never demanded. |
| if (InOp.getOpcode() == ISD::SRL && |
| isa<ConstantSDNode>(InOp.getOperand(1))) { |
| if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) { |
| unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue(); |
| unsigned Opc = ISD::SHL; |
| int Diff = ShAmt-C1; |
| if (Diff < 0) { |
| Diff = -Diff; |
| Opc = ISD::SRL; |
| } |
| |
| SDValue NewSA = |
| TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType()); |
| MVT VT = Op.getValueType(); |
| return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT, |
| InOp.getOperand(0), NewSA)); |
| } |
| } |
| |
| if (SimplifyDemandedBits(Op.getOperand(0), NewMask.lshr(ShAmt), |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| KnownZero <<= SA->getZExtValue(); |
| KnownOne <<= SA->getZExtValue(); |
| // low bits known zero. |
| KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue()); |
| } |
| break; |
| case ISD::SRL: |
| if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { |
| MVT VT = Op.getValueType(); |
| unsigned ShAmt = SA->getZExtValue(); |
| unsigned VTSize = VT.getSizeInBits(); |
| SDValue InOp = Op.getOperand(0); |
| |
| // If the shift count is an invalid immediate, don't do anything. |
| if (ShAmt >= BitWidth) |
| break; |
| |
| // If this is ((X << C1) >>u ShAmt), see if we can simplify this into a |
| // single shift. We can do this if the top bits (which are shifted out) |
| // are never demanded. |
| if (InOp.getOpcode() == ISD::SHL && |
| isa<ConstantSDNode>(InOp.getOperand(1))) { |
| if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) { |
| unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue(); |
| unsigned Opc = ISD::SRL; |
| int Diff = ShAmt-C1; |
| if (Diff < 0) { |
| Diff = -Diff; |
| Opc = ISD::SHL; |
| } |
| |
| SDValue NewSA = |
| TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType()); |
| return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT, |
| InOp.getOperand(0), NewSA)); |
| } |
| } |
| |
| // Compute the new bits that are at the top now. |
| if (SimplifyDemandedBits(InOp, (NewMask << ShAmt), |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| KnownZero = KnownZero.lshr(ShAmt); |
| KnownOne = KnownOne.lshr(ShAmt); |
| |
| APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt); |
| KnownZero |= HighBits; // High bits known zero. |
| } |
| break; |
| case ISD::SRA: |
| // If this is an arithmetic shift right and only the low-bit is set, we can |
| // always convert this into a logical shr, even if the shift amount is |
| // variable. The low bit of the shift cannot be an input sign bit unless |
| // the shift amount is >= the size of the datatype, which is undefined. |
| if (DemandedMask == 1) |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(), |
| Op.getOperand(0), Op.getOperand(1))); |
| |
| if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { |
| MVT VT = Op.getValueType(); |
| unsigned ShAmt = SA->getZExtValue(); |
| |
| // If the shift count is an invalid immediate, don't do anything. |
| if (ShAmt >= BitWidth) |
| break; |
| |
| APInt InDemandedMask = (NewMask << ShAmt); |
| |
| // If any of the demanded bits are produced by the sign extension, we also |
| // demand the input sign bit. |
| APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt); |
| if (HighBits.intersects(NewMask)) |
| InDemandedMask |= APInt::getSignBit(VT.getSizeInBits()); |
| |
| if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| KnownZero = KnownZero.lshr(ShAmt); |
| KnownOne = KnownOne.lshr(ShAmt); |
| |
| // Handle the sign bit, adjusted to where it is now in the mask. |
| APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt); |
| |
| // If the input sign bit is known to be zero, or if none of the top bits |
| // are demanded, turn this into an unsigned shift right. |
| if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits) { |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT, |
| Op.getOperand(0), |
| Op.getOperand(1))); |
| } else if (KnownOne.intersects(SignBit)) { // New bits are known one. |
| KnownOne |= HighBits; |
| } |
| } |
| break; |
| case ISD::SIGN_EXTEND_INREG: { |
| MVT EVT = cast<VTSDNode>(Op.getOperand(1))->getVT(); |
| |
| // Sign extension. Compute the demanded bits in the result that are not |
| // present in the input. |
| APInt NewBits = APInt::getHighBitsSet(BitWidth, |
| BitWidth - EVT.getSizeInBits()) & |
| NewMask; |
| |
| // If none of the extended bits are demanded, eliminate the sextinreg. |
| if (NewBits == 0) |
| return TLO.CombineTo(Op, Op.getOperand(0)); |
| |
| APInt InSignBit = APInt::getSignBit(EVT.getSizeInBits()); |
| InSignBit.zext(BitWidth); |
| APInt InputDemandedBits = APInt::getLowBitsSet(BitWidth, |
| EVT.getSizeInBits()) & |
| NewMask; |
| |
| // Since the sign extended bits are demanded, we know that the sign |
| // bit is demanded. |
| InputDemandedBits |= InSignBit; |
| |
| if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| |
| // If the sign bit of the input is known set or clear, then we know the |
| // top bits of the result. |
| |
| // If the input sign bit is known zero, convert this into a zero extension. |
| if (KnownZero.intersects(InSignBit)) |
| return TLO.CombineTo(Op, |
| TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,EVT)); |
| |
| if (KnownOne.intersects(InSignBit)) { // Input sign bit known set |
| KnownOne |= NewBits; |
| KnownZero &= ~NewBits; |
| } else { // Input sign bit unknown |
| KnownZero &= ~NewBits; |
| KnownOne &= ~NewBits; |
| } |
| break; |
| } |
| case ISD::ZERO_EXTEND: { |
| unsigned OperandBitWidth = Op.getOperand(0).getValueSizeInBits(); |
| APInt InMask = NewMask; |
| InMask.trunc(OperandBitWidth); |
| |
| // If none of the top bits are demanded, convert this into an any_extend. |
| APInt NewBits = |
| APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask; |
| if (!NewBits.intersects(NewMask)) |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl, |
| Op.getValueType(), |
| Op.getOperand(0))); |
| |
| if (SimplifyDemandedBits(Op.getOperand(0), InMask, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| KnownZero.zext(BitWidth); |
| KnownOne.zext(BitWidth); |
| KnownZero |= NewBits; |
| break; |
| } |
| case ISD::SIGN_EXTEND: { |
| MVT InVT = Op.getOperand(0).getValueType(); |
| unsigned InBits = InVT.getSizeInBits(); |
| APInt InMask = APInt::getLowBitsSet(BitWidth, InBits); |
| APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits); |
| APInt NewBits = ~InMask & NewMask; |
| |
| // If none of the top bits are demanded, convert this into an any_extend. |
| if (NewBits == 0) |
| return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl, |
| Op.getValueType(), |
| Op.getOperand(0))); |
| |
| // Since some of the sign extended bits are demanded, we know that the sign |
| // bit is demanded. |
| APInt InDemandedBits = InMask & NewMask; |
| InDemandedBits |= InSignBit; |
| InDemandedBits.trunc(InBits); |
| |
| if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero, |
| KnownOne, TLO, Depth+1)) |
| return true; |
| KnownZero.zext(BitWidth); |
| KnownOne.zext(BitWidth); |
| |
| // If the sign bit is known zero, convert this to a zero extend. |
| if (KnownZero.intersects(InSignBit)) |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl, |
| Op.getValueType(), |
| Op.getOperand(0))); |
| |
| // If the sign bit is known one, the top bits match. |
| if (KnownOne.intersects(InSignBit)) { |
| KnownOne |= NewBits; |
| KnownZero &= ~NewBits; |
| } else { // Otherwise, top bits aren't known. |
| KnownOne &= ~NewBits; |
| KnownZero &= ~NewBits; |
| } |
| break; |
| } |
| case ISD::ANY_EXTEND: { |
| unsigned OperandBitWidth = Op.getOperand(0).getValueSizeInBits(); |
| APInt InMask = NewMask; |
| InMask.trunc(OperandBitWidth); |
| if (SimplifyDemandedBits(Op.getOperand(0), InMask, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| KnownZero.zext(BitWidth); |
| KnownOne.zext(BitWidth); |
| break; |
| } |
| case ISD::TRUNCATE: { |
| // Simplify the input, using demanded bit information, and compute the known |
| // zero/one bits live out. |
| APInt TruncMask = NewMask; |
| TruncMask.zext(Op.getOperand(0).getValueSizeInBits()); |
| if (SimplifyDemandedBits(Op.getOperand(0), TruncMask, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| KnownZero.trunc(BitWidth); |
| KnownOne.trunc(BitWidth); |
| |
| // If the input is only used by this truncate, see if we can shrink it based |
| // on the known demanded bits. |
| if (Op.getOperand(0).getNode()->hasOneUse()) { |
| SDValue In = Op.getOperand(0); |
| unsigned InBitWidth = In.getValueSizeInBits(); |
| switch (In.getOpcode()) { |
| default: break; |
| case ISD::SRL: |
| // Shrink SRL by a constant if none of the high bits shifted in are |
| // demanded. |
| if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1))){ |
| APInt HighBits = APInt::getHighBitsSet(InBitWidth, |
| InBitWidth - BitWidth); |
| HighBits = HighBits.lshr(ShAmt->getZExtValue()); |
| HighBits.trunc(BitWidth); |
| |
| if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) { |
| // None of the shifted in bits are needed. Add a truncate of the |
| // shift input, then shift it. |
| SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl, |
| Op.getValueType(), |
| In.getOperand(0)); |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, |
| Op.getValueType(), |
| NewTrunc, |
| In.getOperand(1))); |
| } |
| } |
| break; |
| } |
| } |
| |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| break; |
| } |
| case ISD::AssertZext: { |
| MVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT(); |
| APInt InMask = APInt::getLowBitsSet(BitWidth, |
| VT.getSizeInBits()); |
| if (SimplifyDemandedBits(Op.getOperand(0), InMask & NewMask, |
| KnownZero, KnownOne, TLO, Depth+1)) |
| return true; |
| assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); |
| KnownZero |= ~InMask & NewMask; |
| break; |
| } |
| case ISD::BIT_CONVERT: |
| #if 0 |
| // If this is an FP->Int bitcast and if the sign bit is the only thing that |
| // is demanded, turn this into a FGETSIGN. |
| if (NewMask == MVT::getIntegerVTSignBit(Op.getValueType()) && |
| MVT::isFloatingPoint(Op.getOperand(0).getValueType()) && |
| !MVT::isVector(Op.getOperand(0).getValueType())) { |
| // Only do this xform if FGETSIGN is valid or if before legalize. |
| if (!TLO.AfterLegalize || |
| isOperationLegal(ISD::FGETSIGN, Op.getValueType())) { |
| // Make a FGETSIGN + SHL to move the sign bit into the appropriate |
| // place. We expect the SHL to be eliminated by other optimizations. |
| SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, Op.getValueType(), |
| Op.getOperand(0)); |
| unsigned ShVal = Op.getValueType().getSizeInBits()-1; |
| SDValue ShAmt = TLO.DAG.getConstant(ShVal, getShiftAmountTy()); |
| return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, Op.getValueType(), |
| Sign, ShAmt)); |
| } |
| } |
| #endif |
| break; |
| case ISD::ADD: |
| case ISD::MUL: |
| case ISD::SUB: { |
| // Add, Sub, and Mul don't demand any bits in positions beyond that |
| // of the highest bit demanded of them. |
| APInt LoMask = APInt::getLowBitsSet(BitWidth, |
| BitWidth - NewMask.countLeadingZeros()); |
| if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2, |
| KnownOne2, TLO, Depth+1)) |
| return true; |
| if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2, |
| KnownOne2, TLO, Depth+1)) |
| return true; |
| // See if the operation should be performed at a smaller bit width. |
| if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) |
| return true; |
| } |
| // FALL THROUGH |
| default: |
| // Just use ComputeMaskedBits to compute output bits. |
| TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth); |
| break; |
| } |
| |
| // If we know the value of all of the demanded bits, return this as a |
| // constant. |
| if ((NewMask & (KnownZero|KnownOne)) == NewMask) |
| return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType())); |
| |
| return false; |
| } |
| |
| /// computeMaskedBitsForTargetNode - Determine which of the bits specified |
| /// in Mask are known to be either zero or one and return them in the |
| /// KnownZero/KnownOne bitsets. |
| void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op, |
| const APInt &Mask, |
| APInt &KnownZero, |
| APInt &KnownOne, |
| const SelectionDAG &DAG, |
| unsigned Depth) const { |
| assert((Op.getOpcode() >= ISD::BUILTIN_OP_END || |
| Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || |
| Op.getOpcode() == ISD::INTRINSIC_W_CHAIN || |
| Op.getOpcode() == ISD::INTRINSIC_VOID) && |
| "Should use MaskedValueIsZero if you don't know whether Op" |
| " is a target node!"); |
| KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0); |
| } |
| |
| /// ComputeNumSignBitsForTargetNode - This method can be implemented by |
| /// targets that want to expose additional information about sign bits to the |
| /// DAG Combiner. |
| unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op, |
| unsigned Depth) const { |
| assert((Op.getOpcode() >= ISD::BUILTIN_OP_END || |
| Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || |
| Op.getOpcode() == ISD::INTRINSIC_W_CHAIN || |
| Op.getOpcode() == ISD::INTRINSIC_VOID) && |
| "Should use ComputeNumSignBits if you don't know whether Op" |
| " is a target node!"); |
| return 1; |
| } |
| |
| /// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly |
| /// one bit set. This differs from ComputeMaskedBits in that it doesn't need to |
| /// determine which bit is set. |
| /// |
| static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) { |
| // A left-shift of a constant one will have exactly one bit set, because |
| // shifting the bit off the end is undefined. |
| if (Val.getOpcode() == ISD::SHL) |
| if (ConstantSDNode *C = |
| dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0))) |
| if (C->getAPIntValue() == 1) |
| return true; |
| |
| // Similarly, a right-shift of a constant sign-bit will have exactly |
| // one bit set. |
| if (Val.getOpcode() == ISD::SRL) |
| if (ConstantSDNode *C = |
| dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0))) |
| if (C->getAPIntValue().isSignBit()) |
| return true; |
| |
| // More could be done here, though the above checks are enough |
| // to handle some common cases. |
| |
| // Fall back to ComputeMaskedBits to catch other known cases. |
| MVT OpVT = Val.getValueType(); |
| unsigned BitWidth = OpVT.getSizeInBits(); |
| APInt Mask = APInt::getAllOnesValue(BitWidth); |
| APInt KnownZero, KnownOne; |
| DAG.ComputeMaskedBits(Val, Mask, KnownZero, KnownOne); |
| return (KnownZero.countPopulation() == BitWidth - 1) && |
| (KnownOne.countPopulation() == 1); |
| } |
| |
| /// SimplifySetCC - Try to simplify a setcc built with the specified operands |
| /// and cc. If it is unable to simplify it, return a null SDValue. |
| SDValue |
| TargetLowering::SimplifySetCC(MVT VT, SDValue N0, SDValue N1, |
| ISD::CondCode Cond, bool foldBooleans, |
| DAGCombinerInfo &DCI, DebugLoc dl) const { |
| SelectionDAG &DAG = DCI.DAG; |
| |
| // These setcc operations always fold. |
| switch (Cond) { |
| default: break; |
| case ISD::SETFALSE: |
| case ISD::SETFALSE2: return DAG.getConstant(0, VT); |
| case ISD::SETTRUE: |
| case ISD::SETTRUE2: return DAG.getConstant(1, VT); |
| } |
| |
| if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) { |
| const APInt &C1 = N1C->getAPIntValue(); |
| if (isa<ConstantSDNode>(N0.getNode())) { |
| return DAG.FoldSetCC(VT, N0, N1, Cond, dl); |
| } else { |
| // If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an |
| // equality comparison, then we're just comparing whether X itself is |
| // zero. |
| if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) && |
| N0.getOperand(0).getOpcode() == ISD::CTLZ && |
| N0.getOperand(1).getOpcode() == ISD::Constant) { |
| unsigned ShAmt = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue(); |
| if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && |
| ShAmt == Log2_32(N0.getValueType().getSizeInBits())) { |
| if ((C1 == 0) == (Cond == ISD::SETEQ)) { |
| // (srl (ctlz x), 5) == 0 -> X != 0 |
| // (srl (ctlz x), 5) != 1 -> X != 0 |
| Cond = ISD::SETNE; |
| } else { |
| // (srl (ctlz x), 5) != 0 -> X == 0 |
| // (srl (ctlz x), 5) == 1 -> X == 0 |
| Cond = ISD::SETEQ; |
| } |
| SDValue Zero = DAG.getConstant(0, N0.getValueType()); |
| return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0), |
| Zero, Cond); |
| } |
| } |
| |
| // If the LHS is '(and load, const)', the RHS is 0, |
| // the test is for equality or unsigned, and all 1 bits of the const are |
| // in the same partial word, see if we can shorten the load. |
| if (DCI.isBeforeLegalize() && |
| N0.getOpcode() == ISD::AND && C1 == 0 && |
| N0.getNode()->hasOneUse() && |
| isa<LoadSDNode>(N0.getOperand(0)) && |
| N0.getOperand(0).getNode()->hasOneUse() && |
| isa<ConstantSDNode>(N0.getOperand(1))) { |
| LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0)); |
| uint64_t bestMask = 0; |
| unsigned bestWidth = 0, bestOffset = 0; |
| if (!Lod->isVolatile() && Lod->isUnindexed() && |
| // FIXME: This uses getZExtValue() below so it only works on i64 and |
| // below. |
| N0.getValueType().getSizeInBits() <= 64) { |
| unsigned origWidth = N0.getValueType().getSizeInBits(); |
| // We can narrow (e.g.) 16-bit extending loads on 32-bit target to |
| // 8 bits, but have to be careful... |
| if (Lod->getExtensionType() != ISD::NON_EXTLOAD) |
| origWidth = Lod->getMemoryVT().getSizeInBits(); |
| uint64_t Mask =cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue(); |
| for (unsigned width = origWidth / 2; width>=8; width /= 2) { |
| uint64_t newMask = (1ULL << width) - 1; |
| for (unsigned offset=0; offset<origWidth/width; offset++) { |
| if ((newMask & Mask) == Mask) { |
| if (!TD->isLittleEndian()) |
| bestOffset = (origWidth/width - offset - 1) * (width/8); |
| else |
| bestOffset = (uint64_t)offset * (width/8); |
| bestMask = Mask >> (offset * (width/8) * 8); |
| bestWidth = width; |
| break; |
| } |
| newMask = newMask << width; |
| } |
| } |
| } |
| if (bestWidth) { |
| MVT newVT = MVT::getIntegerVT(bestWidth); |
| if (newVT.isRound()) { |
| MVT PtrType = Lod->getOperand(1).getValueType(); |
| SDValue Ptr = Lod->getBasePtr(); |
| if (bestOffset != 0) |
| Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(), |
| DAG.getConstant(bestOffset, PtrType)); |
| unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset); |
| SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr, |
| Lod->getSrcValue(), |
| Lod->getSrcValueOffset() + bestOffset, |
| false, NewAlign); |
| return DAG.getSetCC(dl, VT, |
| DAG.getNode(ISD::AND, dl, newVT, NewLoad, |
| DAG.getConstant(bestMask, newVT)), |
| DAG.getConstant(0LL, newVT), Cond); |
| } |
| } |
| } |
| |
| // If the LHS is a ZERO_EXTEND, perform the comparison on the input. |
| if (N0.getOpcode() == ISD::ZERO_EXTEND) { |
| unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits(); |
| |
| // If the comparison constant has bits in the upper part, the |
| // zero-extended value could never match. |
| if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(), |
| C1.getBitWidth() - InSize))) { |
| switch (Cond) { |
| case ISD::SETUGT: |
| case ISD::SETUGE: |
| case ISD::SETEQ: return DAG.getConstant(0, VT); |
| case ISD::SETULT: |
| case ISD::SETULE: |
| case ISD::SETNE: return DAG.getConstant(1, VT); |
| case ISD::SETGT: |
| case ISD::SETGE: |
| // True if the sign bit of C1 is set. |
| return DAG.getConstant(C1.isNegative(), VT); |
| case ISD::SETLT: |
| case ISD::SETLE: |
| // True if the sign bit of C1 isn't set. |
| return DAG.getConstant(C1.isNonNegative(), VT); |
| default: |
| break; |
| } |
| } |
| |
| // Otherwise, we can perform the comparison with the low bits. |
| switch (Cond) { |
| case ISD::SETEQ: |
| case ISD::SETNE: |
| case ISD::SETUGT: |
| case ISD::SETUGE: |
| case ISD::SETULT: |
| case ISD::SETULE: |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), |
| DAG.getConstant(APInt(C1).trunc(InSize), |
| N0.getOperand(0).getValueType()), |
| Cond); |
| default: |
| break; // todo, be more careful with signed comparisons |
| } |
| } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG && |
| (Cond == ISD::SETEQ || Cond == ISD::SETNE)) { |
| MVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT(); |
| unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits(); |
| MVT ExtDstTy = N0.getValueType(); |
| unsigned ExtDstTyBits = ExtDstTy.getSizeInBits(); |
| |
| // If the extended part has any inconsistent bits, it cannot ever |
| // compare equal. In other words, they have to be all ones or all |
| // zeros. |
| APInt ExtBits = |
| APInt::getHighBitsSet(ExtDstTyBits, ExtDstTyBits - ExtSrcTyBits); |
| if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits) |
| return DAG.getConstant(Cond == ISD::SETNE, VT); |
| |
| SDValue ZextOp; |
| MVT Op0Ty = N0.getOperand(0).getValueType(); |
| if (Op0Ty == ExtSrcTy) { |
| ZextOp = N0.getOperand(0); |
| } else { |
| APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits); |
| ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0), |
| DAG.getConstant(Imm, Op0Ty)); |
| } |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(ZextOp.getNode()); |
| // Otherwise, make this a use of a zext. |
| return DAG.getSetCC(dl, VT, ZextOp, |
| DAG.getConstant(C1 & APInt::getLowBitsSet( |
| ExtDstTyBits, |
| ExtSrcTyBits), |
| ExtDstTy), |
| Cond); |
| } else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) && |
| (Cond == ISD::SETEQ || Cond == ISD::SETNE)) { |
| |
| // SETCC (SETCC), [0|1], [EQ|NE] -> SETCC |
| if (N0.getOpcode() == ISD::SETCC) { |
| bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getZExtValue() != 1); |
| if (TrueWhenTrue) |
| return N0; |
| |
| // Invert the condition. |
| ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get(); |
| CC = ISD::getSetCCInverse(CC, |
| N0.getOperand(0).getValueType().isInteger()); |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC); |
| } |
| |
| if ((N0.getOpcode() == ISD::XOR || |
| (N0.getOpcode() == ISD::AND && |
| N0.getOperand(0).getOpcode() == ISD::XOR && |
| N0.getOperand(1) == N0.getOperand(0).getOperand(1))) && |
| isa<ConstantSDNode>(N0.getOperand(1)) && |
| cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) { |
| // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We |
| // can only do this if the top bits are known zero. |
| unsigned BitWidth = N0.getValueSizeInBits(); |
| if (DAG.MaskedValueIsZero(N0, |
| APInt::getHighBitsSet(BitWidth, |
| BitWidth-1))) { |
| // Okay, get the un-inverted input value. |
| SDValue Val; |
| if (N0.getOpcode() == ISD::XOR) |
| Val = N0.getOperand(0); |
| else { |
| assert(N0.getOpcode() == ISD::AND && |
| N0.getOperand(0).getOpcode() == ISD::XOR); |
| // ((X^1)&1)^1 -> X & 1 |
| Val = DAG.getNode(ISD::AND, dl, N0.getValueType(), |
| N0.getOperand(0).getOperand(0), |
| N0.getOperand(1)); |
| } |
| return DAG.getSetCC(dl, VT, Val, N1, |
| Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ); |
| } |
| } |
| } |
| |
| APInt MinVal, MaxVal; |
| unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits(); |
| if (ISD::isSignedIntSetCC(Cond)) { |
| MinVal = APInt::getSignedMinValue(OperandBitSize); |
| MaxVal = APInt::getSignedMaxValue(OperandBitSize); |
| } else { |
| MinVal = APInt::getMinValue(OperandBitSize); |
| MaxVal = APInt::getMaxValue(OperandBitSize); |
| } |
| |
| // Canonicalize GE/LE comparisons to use GT/LT comparisons. |
| if (Cond == ISD::SETGE || Cond == ISD::SETUGE) { |
| if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true |
| // X >= C0 --> X > (C0-1) |
| return DAG.getSetCC(dl, VT, N0, |
| DAG.getConstant(C1-1, N1.getValueType()), |
| (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT); |
| } |
| |
| if (Cond == ISD::SETLE || Cond == ISD::SETULE) { |
| if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true |
| // X <= C0 --> X < (C0+1) |
| return DAG.getSetCC(dl, VT, N0, |
| DAG.getConstant(C1+1, N1.getValueType()), |
| (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT); |
| } |
| |
| if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal) |
| return DAG.getConstant(0, VT); // X < MIN --> false |
| if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal) |
| return DAG.getConstant(1, VT); // X >= MIN --> true |
| if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal) |
| return DAG.getConstant(0, VT); // X > MAX --> false |
| if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal) |
| return DAG.getConstant(1, VT); // X <= MAX --> true |
| |
| // Canonicalize setgt X, Min --> setne X, Min |
| if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal) |
| return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE); |
| // Canonicalize setlt X, Max --> setne X, Max |
| if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal) |
| return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE); |
| |
| // If we have setult X, 1, turn it into seteq X, 0 |
| if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1) |
| return DAG.getSetCC(dl, VT, N0, |
| DAG.getConstant(MinVal, N0.getValueType()), |
| ISD::SETEQ); |
| // If we have setugt X, Max-1, turn it into seteq X, Max |
| else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1) |
| return DAG.getSetCC(dl, VT, N0, |
| DAG.getConstant(MaxVal, N0.getValueType()), |
| ISD::SETEQ); |
| |
| // If we have "setcc X, C0", check to see if we can shrink the immediate |
| // by changing cc. |
| |
| // SETUGT X, SINTMAX -> SETLT X, 0 |
| if (Cond == ISD::SETUGT && |
| C1 == APInt::getSignedMaxValue(OperandBitSize)) |
| return DAG.getSetCC(dl, VT, N0, |
| DAG.getConstant(0, N1.getValueType()), |
| ISD::SETLT); |
| |
| // SETULT X, SINTMIN -> SETGT X, -1 |
| if (Cond == ISD::SETULT && |
| C1 == APInt::getSignedMinValue(OperandBitSize)) { |
| SDValue ConstMinusOne = |
| DAG.getConstant(APInt::getAllOnesValue(OperandBitSize), |
| N1.getValueType()); |
| return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT); |
| } |
| |
| // Fold bit comparisons when we can. |
| if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && |
| VT == N0.getValueType() && N0.getOpcode() == ISD::AND) |
| if (ConstantSDNode *AndRHS = |
| dyn_cast<ConstantSDNode>(N0.getOperand(1))) { |
| MVT ShiftTy = DCI.isBeforeLegalize() ? |
| getPointerTy() : getShiftAmountTy(); |
| if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3 |
| // Perform the xform if the AND RHS is a single bit. |
| if (isPowerOf2_64(AndRHS->getZExtValue())) { |
| return DAG.getNode(ISD::SRL, dl, VT, N0, |
| DAG.getConstant(Log2_64(AndRHS->getZExtValue()), |
| ShiftTy)); |
| } |
| } else if (Cond == ISD::SETEQ && C1 == AndRHS->getZExtValue()) { |
| // (X & 8) == 8 --> (X & 8) >> 3 |
| // Perform the xform if C1 is a single bit. |
| if (C1.isPowerOf2()) { |
| return DAG.getNode(ISD::SRL, dl, VT, N0, |
| DAG.getConstant(C1.logBase2(), ShiftTy)); |
| } |
| } |
| } |
| } |
| } else if (isa<ConstantSDNode>(N0.getNode())) { |
| // Ensure that the constant occurs on the RHS. |
| return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond)); |
| } |
| |
| if (isa<ConstantFPSDNode>(N0.getNode())) { |
| // Constant fold or commute setcc. |
| SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl); |
| if (O.getNode()) return O; |
| } else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) { |
| // If the RHS of an FP comparison is a constant, simplify it away in |
| // some cases. |
| if (CFP->getValueAPF().isNaN()) { |
| // If an operand is known to be a nan, we can fold it. |
| switch (ISD::getUnorderedFlavor(Cond)) { |
| default: assert(0 && "Unknown flavor!"); |
| case 0: // Known false. |
| return DAG.getConstant(0, VT); |
| case 1: // Known true. |
| return DAG.getConstant(1, VT); |
| case 2: // Undefined. |
| return DAG.getUNDEF(VT); |
| } |
| } |
| |
| // Otherwise, we know the RHS is not a NaN. Simplify the node to drop the |
| // constant if knowing that the operand is non-nan is enough. We prefer to |
| // have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to |
| // materialize 0.0. |
| if (Cond == ISD::SETO || Cond == ISD::SETUO) |
| return DAG.getSetCC(dl, VT, N0, N0, Cond); |
| } |
| |
| if (N0 == N1) { |
| // We can always fold X == X for integer setcc's. |
| if (N0.getValueType().isInteger()) |
| return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT); |
| unsigned UOF = ISD::getUnorderedFlavor(Cond); |
| if (UOF == 2) // FP operators that are undefined on NaNs. |
| return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT); |
| if (UOF == unsigned(ISD::isTrueWhenEqual(Cond))) |
| return DAG.getConstant(UOF, VT); |
| // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO |
| // if it is not already. |
| ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO; |
| if (NewCond != Cond) |
| return DAG.getSetCC(dl, VT, N0, N1, NewCond); |
| } |
| |
| if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && |
| N0.getValueType().isInteger()) { |
| if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB || |
| N0.getOpcode() == ISD::XOR) { |
| // Simplify (X+Y) == (X+Z) --> Y == Z |
| if (N0.getOpcode() == N1.getOpcode()) { |
| if (N0.getOperand(0) == N1.getOperand(0)) |
| return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond); |
| if (N0.getOperand(1) == N1.getOperand(1)) |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond); |
| if (DAG.isCommutativeBinOp(N0.getOpcode())) { |
| // If X op Y == Y op X, try other combinations. |
| if (N0.getOperand(0) == N1.getOperand(1)) |
| return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0), |
| Cond); |
| if (N0.getOperand(1) == N1.getOperand(0)) |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1), |
| Cond); |
| } |
| } |
| |
| if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) { |
| if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) { |
| // Turn (X+C1) == C2 --> X == C2-C1 |
| if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) { |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), |
| DAG.getConstant(RHSC->getAPIntValue()- |
| LHSR->getAPIntValue(), |
| N0.getValueType()), Cond); |
| } |
| |
| // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0. |
| if (N0.getOpcode() == ISD::XOR) |
| // If we know that all of the inverted bits are zero, don't bother |
| // performing the inversion. |
| if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue())) |
| return |
| DAG.getSetCC(dl, VT, N0.getOperand(0), |
| DAG.getConstant(LHSR->getAPIntValue() ^ |
| RHSC->getAPIntValue(), |
| N0.getValueType()), |
| Cond); |
| } |
| |
| // Turn (C1-X) == C2 --> X == C1-C2 |
| if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) { |
| if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) { |
| return |
| DAG.getSetCC(dl, VT, N0.getOperand(1), |
| DAG.getConstant(SUBC->getAPIntValue() - |
| RHSC->getAPIntValue(), |
| N0.getValueType()), |
| Cond); |
| } |
| } |
| } |
| |
| // Simplify (X+Z) == X --> Z == 0 |
| if (N0.getOperand(0) == N1) |
| return DAG.getSetCC(dl, VT, N0.getOperand(1), |
| DAG.getConstant(0, N0.getValueType()), Cond); |
| if (N0.getOperand(1) == N1) { |
| if (DAG.isCommutativeBinOp(N0.getOpcode())) |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), |
| DAG.getConstant(0, N0.getValueType()), Cond); |
| else if (N0.getNode()->hasOneUse()) { |
| assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!"); |
| // (Z-X) == X --> Z == X<<1 |
| SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), |
| N1, |
| DAG.getConstant(1, getShiftAmountTy())); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(SH.getNode()); |
| return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond); |
| } |
| } |
| } |
| |
| if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB || |
| N1.getOpcode() == ISD::XOR) { |
| // Simplify X == (X+Z) --> Z == 0 |
| if (N1.getOperand(0) == N0) { |
| return DAG.getSetCC(dl, VT, N1.getOperand(1), |
| DAG.getConstant(0, N1.getValueType()), Cond); |
| } else if (N1.getOperand(1) == N0) { |
| if (DAG.isCommutativeBinOp(N1.getOpcode())) { |
| return DAG.getSetCC(dl, VT, N1.getOperand(0), |
| DAG.getConstant(0, N1.getValueType()), Cond); |
| } else if (N1.getNode()->hasOneUse()) { |
| assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!"); |
| // X == (Z-X) --> X<<1 == Z |
| SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0, |
| DAG.getConstant(1, getShiftAmountTy())); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(SH.getNode()); |
| return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond); |
| } |
| } |
| } |
| |
| // Simplify x&y == y to x&y != 0 if y has exactly one bit set. |
| // Note that where y is variable and is known to have at most |
| // one bit set (for example, if it is z&1) we cannot do this; |
| // the expressions are not equivalent when y==0. |
| if (N0.getOpcode() == ISD::AND) |
| if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) { |
| if (ValueHasExactlyOneBitSet(N1, DAG)) { |
| Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true); |
| SDValue Zero = DAG.getConstant(0, N1.getValueType()); |
| return DAG.getSetCC(dl, VT, N0, Zero, Cond); |
| } |
| } |
| if (N1.getOpcode() == ISD::AND) |
| if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) { |
| if (ValueHasExactlyOneBitSet(N0, DAG)) { |
| Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true); |
| SDValue Zero = DAG.getConstant(0, N0.getValueType()); |
| return DAG.getSetCC(dl, VT, N1, Zero, Cond); |
| } |
| } |
| } |
| |
| // Fold away ALL boolean setcc's. |
| SDValue Temp; |
| if (N0.getValueType() == MVT::i1 && foldBooleans) { |
| switch (Cond) { |
| default: assert(0 && "Unknown integer setcc!"); |
| case ISD::SETEQ: // X == Y -> ~(X^Y) |
| Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1); |
| N0 = DAG.getNOT(dl, Temp, MVT::i1); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(Temp.getNode()); |
| break; |
| case ISD::SETNE: // X != Y --> (X^Y) |
| N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1); |
| break; |
| case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y |
| case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y |
| Temp = DAG.getNOT(dl, N0, MVT::i1); |
| N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(Temp.getNode()); |
| break; |
| case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X |
| case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X |
| Temp = DAG.getNOT(dl, N1, MVT::i1); |
| N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(Temp.getNode()); |
| break; |
| case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y |
| case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y |
| Temp = DAG.getNOT(dl, N0, MVT::i1); |
| N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp); |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(Temp.getNode()); |
| break; |
| case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X |
| case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X |
| Temp = DAG.getNOT(dl, N1, MVT::i1); |
| N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp); |
| break; |
| } |
| if (VT != MVT::i1) { |
| if (!DCI.isCalledByLegalizer()) |
| DCI.AddToWorklist(N0.getNode()); |
| // FIXME: If running after legalize, we probably can't do this. |
| N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0); |
| } |
| return N0; |
| } |
| |
| // Could not fold it. |
| return SDValue(); |
| } |
| |
| /// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the |
| /// node is a GlobalAddress + offset. |
| bool TargetLowering::isGAPlusOffset(SDNode *N, GlobalValue* &GA, |
| int64_t &Offset) const { |
| if (isa<GlobalAddressSDNode>(N)) { |
| GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N); |
| GA = GASD->getGlobal(); |
| Offset += GASD->getOffset(); |
| return true; |
| } |
| |
| if (N->getOpcode() == ISD::ADD) { |
| SDValue N1 = N->getOperand(0); |
| SDValue N2 = N->getOperand(1); |
| if (isGAPlusOffset(N1.getNode(), GA, Offset)) { |
| ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2); |
| if (V) { |
| Offset += V->getSExtValue(); |
| return true; |
| } |
| } else if (isGAPlusOffset(N2.getNode(), GA, Offset)) { |
| ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1); |
| if (V) { |
| Offset += V->getSExtValue(); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| |
| /// isConsecutiveLoad - Return true if LD (which must be a LoadSDNode) is |
| /// loading 'Bytes' bytes from a location that is 'Dist' units away from the |
| /// location that the 'Base' load is loading from. |
| bool TargetLowering::isConsecutiveLoad(SDNode *LD, SDNode *Base, |
| unsigned Bytes, int Dist, |
| const MachineFrameInfo *MFI) const { |
| if (LD->getOperand(0).getNode() != Base->getOperand(0).getNode()) |
| return false; |
| MVT VT = LD->getValueType(0); |
| if (VT.getSizeInBits() / 8 != Bytes) |
| return false; |
| |
| SDValue Loc = LD->getOperand(1); |
| SDValue BaseLoc = Base->getOperand(1); |
| if (Loc.getOpcode() == ISD::FrameIndex) { |
| if (BaseLoc.getOpcode() != ISD::FrameIndex) |
| return false; |
| int FI = cast<FrameIndexSDNode>(Loc)->getIndex(); |
| int BFI = cast<FrameIndexSDNode>(BaseLoc)->getIndex(); |
| int FS = MFI->getObjectSize(FI); |
| int BFS = MFI->getObjectSize(BFI); |
| if (FS != BFS || FS != (int)Bytes) return false; |
| return MFI->getObjectOffset(FI) == (MFI->getObjectOffset(BFI) + Dist*Bytes); |
| } |
| |
| GlobalValue *GV1 = NULL; |
| GlobalValue *GV2 = NULL; |
| int64_t Offset1 = 0; |
| int64_t Offset2 = 0; |
| bool isGA1 = isGAPlusOffset(Loc.getNode(), GV1, Offset1); |
| bool isGA2 = isGAPlusOffset(BaseLoc.getNode(), GV2, Offset2); |
| if (isGA1 && isGA2 && GV1 == GV2) |
| return Offset1 == (Offset2 + Dist*Bytes); |
| return false; |
| } |
| |
| |
| SDValue TargetLowering:: |
| PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const { |
| // Default implementation: no optimization. |
| return SDValue(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Inline Assembler Implementation Methods |
| //===----------------------------------------------------------------------===// |
| |
| |
| TargetLowering::ConstraintType |
| TargetLowering::getConstraintType(const std::string &Constraint) const { |
| // FIXME: lots more standard ones to handle. |
| if (Constraint.size() == 1) { |
| switch (Constraint[0]) { |
| default: break; |
| case 'r': return C_RegisterClass; |
| case 'm': // memory |
| case 'o': // offsetable |
| case 'V': // not offsetable |
| return C_Memory; |
| case 'i': // Simple Integer or Relocatable Constant |
| case 'n': // Simple Integer |
| case 's': // Relocatable Constant |
| case 'X': // Allow ANY value. |
| case 'I': // Target registers. |
| case 'J': |
| case 'K': |
| case 'L': |
| case 'M': |
| case 'N': |
| case 'O': |
| case 'P': |
| return C_Other; |
| } |
| } |
| |
| if (Constraint.size() > 1 && Constraint[0] == '{' && |
| Constraint[Constraint.size()-1] == '}') |
| return C_Register; |
| return C_Unknown; |
| } |
| |
| /// LowerXConstraint - try to replace an X constraint, which matches anything, |
| /// with another that has more specific requirements based on the type of the |
| /// corresponding operand. |
| const char *TargetLowering::LowerXConstraint(MVT ConstraintVT) const{ |
| if (ConstraintVT.isInteger()) |
| return "r"; |
| if (ConstraintVT.isFloatingPoint()) |
| return "f"; // works for many targets |
| return 0; |
| } |
| |
| /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops |
| /// vector. If it is invalid, don't add anything to Ops. |
| void TargetLowering::LowerAsmOperandForConstraint(SDValue Op, |
| char ConstraintLetter, |
| bool hasMemory, |
| std::vector<SDValue> &Ops, |
| SelectionDAG &DAG) const { |
| switch (ConstraintLetter) { |
| default: break; |
| case 'X': // Allows any operand; labels (basic block) use this. |
| if (Op.getOpcode() == ISD::BasicBlock) { |
| Ops.push_back(Op); |
| return; |
| } |
| // fall through |
| case 'i': // Simple Integer or Relocatable Constant |
| case 'n': // Simple Integer |
| case 's': { // Relocatable Constant |
| // These operands are interested in values of the form (GV+C), where C may |
| // be folded in as an offset of GV, or it may be explicitly added. Also, it |
| // is possible and fine if either GV or C are missing. |
| ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op); |
| GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op); |
| |
| // If we have "(add GV, C)", pull out GV/C |
| if (Op.getOpcode() == ISD::ADD) { |
| C = dyn_cast<ConstantSDNode>(Op.getOperand(1)); |
| GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0)); |
| if (C == 0 || GA == 0) { |
| C = dyn_cast<ConstantSDNode>(Op.getOperand(0)); |
| GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1)); |
| } |
| if (C == 0 || GA == 0) |
| C = 0, GA = 0; |
| } |
| |
| // If we find a valid operand, map to the TargetXXX version so that the |
| // value itself doesn't get selected. |
| if (GA) { // Either &GV or &GV+C |
| if (ConstraintLetter != 'n') { |
| int64_t Offs = GA->getOffset(); |
| if (C) Offs += C->getZExtValue(); |
| Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(), |
| Op.getValueType(), Offs)); |
| return; |
| } |
| } |
| if (C) { // just C, no GV. |
| // Simple constants are not allowed for 's'. |
| if (ConstraintLetter != 's') { |
| // gcc prints these as sign extended. Sign extend value to 64 bits |
| // now; without this it would get ZExt'd later in |
| // ScheduleDAGSDNodes::EmitNode, which is very generic. |
| Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(), |
| MVT::i64)); |
| return; |
| } |
| } |
| break; |
| } |
| } |
| } |
| |
| std::vector<unsigned> TargetLowering:: |
| getRegClassForInlineAsmConstraint(const std::string &Constraint, |
| MVT VT) const { |
| return std::vector<unsigned>(); |
| } |
| |
| |
| std::pair<unsigned, const TargetRegisterClass*> TargetLowering:: |
| getRegForInlineAsmConstraint(const std::string &Constraint, |
| MVT VT) const { |
| if (Constraint[0] != '{') |
| return std::pair<unsigned, const TargetRegisterClass*>(0, 0); |
| assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?"); |
| |
| // Remove the braces from around the name. |
| std::string RegName(Constraint.begin()+1, Constraint.end()-1); |
| |
| // Figure out which register class contains this reg. |
| const TargetRegisterInfo *RI = TM.getRegisterInfo(); |
| for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(), |
| E = RI->regclass_end(); RCI != E; ++RCI) { |
| const TargetRegisterClass *RC = *RCI; |
| |
| // If none of the the value types for this register class are valid, we |
| // can't use it. For example, 64-bit reg classes on 32-bit targets. |
| bool isLegal = false; |
| for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end(); |
| I != E; ++I) { |
| if (isTypeLegal(*I)) { |
| isLegal = true; |
| break; |
| } |
| } |
| |
| if (!isLegal) continue; |
| |
| for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); |
| I != E; ++I) { |
| if (StringsEqualNoCase(RegName, RI->get(*I).AsmName)) |
| return std::make_pair(*I, RC); |
| } |
| } |
| |
| return std::pair<unsigned, const TargetRegisterClass*>(0, 0); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Constraint Selection. |
| |
| /// isMatchingInputConstraint - Return true of this is an input operand that is |
| /// a matching constraint like "4". |
| bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const { |
| assert(!ConstraintCode.empty() && "No known constraint!"); |
| return isdigit(ConstraintCode[0]); |
| } |
| |
| /// getMatchedOperand - If this is an input matching constraint, this method |
| /// returns the output operand it matches. |
| unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const { |
| assert(!ConstraintCode.empty() && "No known constraint!"); |
| return atoi(ConstraintCode.c_str()); |
| } |
| |
| |
| /// getConstraintGenerality - Return an integer indicating how general CT |
| /// is. |
| static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) { |
| switch (CT) { |
| default: assert(0 && "Unknown constraint type!"); |
| case TargetLowering::C_Other: |
| case TargetLowering::C_Unknown: |
| return 0; |
| case TargetLowering::C_Register: |
| return 1; |
| case TargetLowering::C_RegisterClass: |
| return 2; |
| case TargetLowering::C_Memory: |
| return 3; |
| } |
| } |
| |
| /// ChooseConstraint - If there are multiple different constraints that we |
| /// could pick for this operand (e.g. "imr") try to pick the 'best' one. |
| /// This is somewhat tricky: constraints fall into four classes: |
| /// Other -> immediates and magic values |
| /// Register -> one specific register |
| /// RegisterClass -> a group of regs |
| /// Memory -> memory |
| /// Ideally, we would pick the most specific constraint possible: if we have |
| /// something that fits into a register, we would pick it. The problem here |
| /// is that if we have something that could either be in a register or in |
| /// memory that use of the register could cause selection of *other* |
| /// operands to fail: they might only succeed if we pick memory. Because of |
| /// this the heuristic we use is: |
| /// |
| /// 1) If there is an 'other' constraint, and if the operand is valid for |
| /// that constraint, use it. This makes us take advantage of 'i' |
| /// constraints when available. |
| /// 2) Otherwise, pick the most general constraint present. This prefers |
| /// 'm' over 'r', for example. |
| /// |
| static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo, |
| bool hasMemory, const TargetLowering &TLI, |
| SDValue Op, SelectionDAG *DAG) { |
| assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options"); |
| unsigned BestIdx = 0; |
| TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown; |
| int BestGenerality = -1; |
| |
| // Loop over the options, keeping track of the most general one. |
| for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) { |
| TargetLowering::ConstraintType CType = |
| TLI.getConstraintType(OpInfo.Codes[i]); |
| |
| // If this is an 'other' constraint, see if the operand is valid for it. |
| // For example, on X86 we might have an 'rI' constraint. If the operand |
| // is an integer in the range [0..31] we want to use I (saving a load |
| // of a register), otherwise we must use 'r'. |
| if (CType == TargetLowering::C_Other && Op.getNode()) { |
| assert(OpInfo.Codes[i].size() == 1 && |
| "Unhandled multi-letter 'other' constraint"); |
| std::vector<SDValue> ResultOps; |
| TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i][0], hasMemory, |
| ResultOps, *DAG); |
| if (!ResultOps.empty()) { |
| BestType = CType; |
| BestIdx = i; |
| break; |
| } |
| } |
| |
| // This constraint letter is more general than the previous one, use it. |
| int Generality = getConstraintGenerality(CType); |
| if (Generality > BestGenerality) { |
| BestType = CType; |
| BestIdx = i; |
| BestGenerality = Generality; |
| } |
| } |
| |
| OpInfo.ConstraintCode = OpInfo.Codes[BestIdx]; |
| OpInfo.ConstraintType = BestType; |
| } |
| |
| /// ComputeConstraintToUse - Determines the constraint code and constraint |
| /// type to use for the specific AsmOperandInfo, setting |
| /// OpInfo.ConstraintCode and OpInfo.ConstraintType. |
| void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo, |
| SDValue Op, |
| bool hasMemory, |
| SelectionDAG *DAG) const { |
| assert(!OpInfo.Codes.empty() && "Must have at least one constraint"); |
| |
| // Single-letter constraints ('r') are very common. |
| if (OpInfo.Codes.size() == 1) { |
| OpInfo.ConstraintCode = OpInfo.Codes[0]; |
| OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode); |
| } else { |
| ChooseConstraint(OpInfo, hasMemory, *this, Op, DAG); |
| } |
| |
| // 'X' matches anything. |
| if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) { |
| // Labels and constants are handled elsewhere ('X' is the only thing |
| // that matches labels). |
| if (isa<BasicBlock>(OpInfo.CallOperandVal) || |
| isa<ConstantInt>(OpInfo.CallOperandVal)) |
| return; |
| |
| // Otherwise, try to resolve it to something we know about by looking at |
| // the actual operand type. |
| if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) { |
| OpInfo.ConstraintCode = Repl; |
| OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode); |
| } |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Loop Strength Reduction hooks |
| //===----------------------------------------------------------------------===// |
| |
| /// isLegalAddressingMode - Return true if the addressing mode represented |
| /// by AM is legal for this target, for a load/store of the specified type. |
| bool TargetLowering::isLegalAddressingMode(const AddrMode &AM, |
| const Type *Ty) const { |
| // The default implementation of this implements a conservative RISCy, r+r and |
| // r+i addr mode. |
| |
| // Allows a sign-extended 16-bit immediate field. |
| if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1) |
| return false; |
| |
| // No global is ever allowed as a base. |
| if (AM.BaseGV) |
| return false; |
| |
| // Only support r+r, |
| switch (AM.Scale) { |
| case 0: // "r+i" or just "i", depending on HasBaseReg. |
| break; |
| case 1: |
| if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed. |
| return false; |
| // Otherwise we have r+r or r+i. |
| break; |
| case 2: |
| if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed. |
| return false; |
| // Allow 2*r as r+r. |
| break; |
| } |
| |
| return true; |
| } |
| |
| /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant, |
| /// return a DAG expression to select that will generate the same value by |
| /// multiplying by a magic number. See: |
| /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html> |
| SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG, |
| std::vector<SDNode*>* Created) const { |
| MVT VT = N->getValueType(0); |
| DebugLoc dl= N->getDebugLoc(); |
| |
| // Check to see if we can do this. |
| // FIXME: We should be more aggressive here. |
| if (!isTypeLegal(VT)) |
| return SDValue(); |
| |
| APInt d = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue(); |
| APInt::ms magics = d.magic(); |
| |
| // Multiply the numerator (operand 0) by the magic value |
| // FIXME: We should support doing a MUL in a wider type |
| SDValue Q; |
| if (isOperationLegalOrCustom(ISD::MULHS, VT)) |
| Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0), |
| DAG.getConstant(magics.m, VT)); |
| else if (isOperationLegalOrCustom(ISD::SMUL_LOHI, VT)) |
| Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT), |
| N->getOperand(0), |
| DAG.getConstant(magics.m, VT)).getNode(), 1); |
| else |
| return SDValue(); // No mulhs or equvialent |
| // If d > 0 and m < 0, add the numerator |
| if (d.isStrictlyPositive() && magics.m.isNegative()) { |
| Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0)); |
| if (Created) |
| Created->push_back(Q.getNode()); |
| } |
| // If d < 0 and m > 0, subtract the numerator. |
| if (d.isNegative() && magics.m.isStrictlyPositive()) { |
| Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0)); |
| if (Created) |
| Created->push_back(Q.getNode()); |
| } |
| // Shift right algebraic if shift value is nonzero |
| if (magics.s > 0) { |
| Q = DAG.getNode(ISD::SRA, dl, VT, Q, |
| DAG.getConstant(magics.s, getShiftAmountTy())); |
| if (Created) |
| Created->push_back(Q.getNode()); |
| } |
| // Extract the sign bit and add it to the quotient |
| SDValue T = |
| DAG.getNode(ISD::SRL, dl, VT, Q, DAG.getConstant(VT.getSizeInBits()-1, |
| getShiftAmountTy())); |
| if (Created) |
| Created->push_back(T.getNode()); |
| return DAG.getNode(ISD::ADD, dl, VT, Q, T); |
| } |
| |
| /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant, |
| /// return a DAG expression to select that will generate the same value by |
| /// multiplying by a magic number. See: |
| /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html> |
| SDValue TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG, |
| std::vector<SDNode*>* Created) const { |
| MVT VT = N->getValueType(0); |
| DebugLoc dl = N->getDebugLoc(); |
| |
| // Check to see if we can do this. |
| // FIXME: We should be more aggressive here. |
| if (!isTypeLegal(VT)) |
| return SDValue(); |
| |
| // FIXME: We should use a narrower constant when the upper |
| // bits are known to be zero. |
| ConstantSDNode *N1C = cast<ConstantSDNode>(N->getOperand(1)); |
| APInt::mu magics = N1C->getAPIntValue().magicu(); |
| |
| // Multiply the numerator (operand 0) by the magic value |
| // FIXME: We should support doing a MUL in a wider type |
| SDValue Q; |
| if (isOperationLegalOrCustom(ISD::MULHU, VT)) |
| Q = DAG.getNode(ISD::MULHU, dl, VT, N->getOperand(0), |
| DAG.getConstant(magics.m, VT)); |
| else if (isOperationLegalOrCustom(ISD::UMUL_LOHI, VT)) |
| Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT), |
| N->getOperand(0), |
| DAG.getConstant(magics.m, VT)).getNode(), 1); |
| else |
| return SDValue(); // No mulhu or equvialent |
| if (Created) |
| Created->push_back(Q.getNode()); |
| |
| if (magics.a == 0) { |
| assert(magics.s < N1C->getAPIntValue().getBitWidth() && |
| "We shouldn't generate an undefined shift!"); |
| return DAG.getNode(ISD::SRL, dl, VT, Q, |
| DAG.getConstant(magics.s, getShiftAmountTy())); |
| } else { |
| SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q); |
| if (Created) |
| Created->push_back(NPQ.getNode()); |
| NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ, |
| DAG.getConstant(1, getShiftAmountTy())); |
| if (Created) |
| Created->push_back(NPQ.getNode()); |
| NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q); |
| if (Created) |
| Created->push_back(NPQ.getNode()); |
| return DAG.getNode(ISD::SRL, dl, VT, NPQ, |
| DAG.getConstant(magics.s-1, getShiftAmountTy())); |
| } |
| } |
| |
| /// IgnoreHarmlessInstructions - Ignore instructions between a CALL and RET |
| /// node that don't prevent tail call optimization. |
| static SDValue IgnoreHarmlessInstructions(SDValue node) { |
| // Found call return. |
| if (node.getOpcode() == ISD::CALL) return node; |
| // Ignore MERGE_VALUES. Will have at least one operand. |
| if (node.getOpcode() == ISD::MERGE_VALUES) |
| return IgnoreHarmlessInstructions(node.getOperand(0)); |
| // Ignore ANY_EXTEND node. |
| if (node.getOpcode() == ISD::ANY_EXTEND) |
| return IgnoreHarmlessInstructions(node.getOperand(0)); |
| if (node.getOpcode() == ISD::TRUNCATE) |
| return IgnoreHarmlessInstructions(node.getOperand(0)); |
| // Any other node type. |
| return node; |
| } |
| |
| bool TargetLowering::CheckTailCallReturnConstraints(CallSDNode *TheCall, |
| SDValue Ret) { |
| unsigned NumOps = Ret.getNumOperands(); |
| // ISD::CALL results:(value0, ..., valuen, chain) |
| // ISD::RET operands:(chain, value0, flag0, ..., valuen, flagn) |
| // Value return: |
| // Check that operand of the RET node sources from the CALL node. The RET node |
| // has at least two operands. Operand 0 holds the chain. Operand 1 holds the |
| // value. |
| if (NumOps > 1 && |
| IgnoreHarmlessInstructions(Ret.getOperand(1)) == SDValue(TheCall,0)) |
| return true; |
| // void return: The RET node has the chain result value of the CALL node as |
| // input. |
| if (NumOps == 1 && |
| Ret.getOperand(0) == SDValue(TheCall, TheCall->getNumValues()-1)) |
| return true; |
| |
| return false; |
| } |