It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
new file mode 100644
index 0000000..07a96d3
--- /dev/null
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -0,0 +1,437 @@
+//===-- X86ISelLowering.h - X86 DAG Lowering Interface ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the interfaces that X86 uses to lower LLVM code into a
+// selection DAG.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef X86ISELLOWERING_H
+#define X86ISELLOWERING_H
+
+#include "X86Subtarget.h"
+#include "X86RegisterInfo.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+
+namespace llvm {
+  namespace X86ISD {
+    // X86 Specific DAG Nodes
+    enum NodeType {
+      // Start the numbering where the builtin ops leave off.
+      FIRST_NUMBER = ISD::BUILTIN_OP_END+X86::INSTRUCTION_LIST_END,
+
+      /// SHLD, SHRD - Double shift instructions. These correspond to
+      /// X86::SHLDxx and X86::SHRDxx instructions.
+      SHLD,
+      SHRD,
+
+      /// FAND - Bitwise logical AND of floating point values. This corresponds
+      /// to X86::ANDPS or X86::ANDPD.
+      FAND,
+
+      /// FOR - Bitwise logical OR of floating point values. This corresponds
+      /// to X86::ORPS or X86::ORPD.
+      FOR,
+
+      /// FXOR - Bitwise logical XOR of floating point values. This corresponds
+      /// to X86::XORPS or X86::XORPD.
+      FXOR,
+
+      /// FSRL - Bitwise logical right shift of floating point values. These
+      /// corresponds to X86::PSRLDQ.
+      FSRL,
+
+      /// FILD, FILD_FLAG - This instruction implements SINT_TO_FP with the
+      /// integer source in memory and FP reg result.  This corresponds to the
+      /// X86::FILD*m instructions. It has three inputs (token chain, address,
+      /// and source type) and two outputs (FP value and token chain). FILD_FLAG
+      /// also produces a flag).
+      FILD,
+      FILD_FLAG,
+
+      /// FP_TO_INT*_IN_MEM - This instruction implements FP_TO_SINT with the
+      /// integer destination in memory and a FP reg source.  This corresponds
+      /// to the X86::FIST*m instructions and the rounding mode change stuff. It
+      /// has two inputs (token chain and address) and two outputs (int value
+      /// and token chain).
+      FP_TO_INT16_IN_MEM,
+      FP_TO_INT32_IN_MEM,
+      FP_TO_INT64_IN_MEM,
+
+      /// FLD - This instruction implements an extending load to FP stack slots.
+      /// This corresponds to the X86::FLD32m / X86::FLD64m. It takes a chain
+      /// operand, ptr to load from, and a ValueType node indicating the type
+      /// to load to.
+      FLD,
+
+      /// FST - This instruction implements a truncating store to FP stack
+      /// slots. This corresponds to the X86::FST32m / X86::FST64m. It takes a
+      /// chain operand, value to store, address, and a ValueType to store it
+      /// as.
+      FST,
+
+      /// FP_GET_RESULT - This corresponds to FpGETRESULT pseudo instruction
+      /// which copies from ST(0) to the destination. It takes a chain and
+      /// writes a RFP result and a chain.
+      FP_GET_RESULT,
+
+      /// FP_SET_RESULT - This corresponds to FpSETRESULT pseudo instruction
+      /// which copies the source operand to ST(0). It takes a chain+value and
+      /// returns a chain and a flag.
+      FP_SET_RESULT,
+
+      /// CALL/TAILCALL - These operations represent an abstract X86 call
+      /// instruction, which includes a bunch of information.  In particular the
+      /// operands of these node are:
+      ///
+      ///     #0 - The incoming token chain
+      ///     #1 - The callee
+      ///     #2 - The number of arg bytes the caller pushes on the stack.
+      ///     #3 - The number of arg bytes the callee pops off the stack.
+      ///     #4 - The value to pass in AL/AX/EAX (optional)
+      ///     #5 - The value to pass in DL/DX/EDX (optional)
+      ///
+      /// The result values of these nodes are:
+      ///
+      ///     #0 - The outgoing token chain
+      ///     #1 - The first register result value (optional)
+      ///     #2 - The second register result value (optional)
+      ///
+      /// The CALL vs TAILCALL distinction boils down to whether the callee is
+      /// known not to modify the caller's stack frame, as is standard with
+      /// LLVM.
+      CALL,
+      TAILCALL,
+      
+      /// RDTSC_DAG - This operation implements the lowering for 
+      /// readcyclecounter
+      RDTSC_DAG,
+
+      /// X86 compare and logical compare instructions.
+      CMP, TEST, COMI, UCOMI,
+
+      /// X86 SetCC. Operand 1 is condition code, and operand 2 is the flag
+      /// operand produced by a CMP instruction.
+      SETCC,
+
+      /// X86 conditional moves. Operand 1 and operand 2 are the two values
+      /// to select from (operand 1 is a R/W operand). Operand 3 is the
+      /// condition code, and operand 4 is the flag operand produced by a CMP
+      /// or TEST instruction. It also writes a flag result.
+      CMOV,
+
+      /// X86 conditional branches. Operand 1 is the chain operand, operand 2
+      /// is the block to branch if condition is true, operand 3 is the
+      /// condition code, and operand 4 is the flag operand produced by a CMP
+      /// or TEST instruction.
+      BRCOND,
+
+      /// Return with a flag operand. Operand 1 is the chain operand, operand
+      /// 2 is the number of bytes of stack to pop.
+      RET_FLAG,
+
+      /// REP_STOS - Repeat fill, corresponds to X86::REP_STOSx.
+      REP_STOS,
+
+      /// REP_MOVS - Repeat move, corresponds to X86::REP_MOVSx.
+      REP_MOVS,
+
+      /// LOAD_PACK Load a 128-bit packed float / double value. It has the same
+      /// operands as a normal load.
+      LOAD_PACK,
+
+      /// LOAD_UA Load an unaligned 128-bit value. It has the same operands as
+      /// a normal load.
+      LOAD_UA,
+
+      /// GlobalBaseReg - On Darwin, this node represents the result of the popl
+      /// at function entry, used for PIC code.
+      GlobalBaseReg,
+
+      /// Wrapper - A wrapper node for TargetConstantPool,
+      /// TargetExternalSymbol, and TargetGlobalAddress.
+      Wrapper,
+
+      /// WrapperRIP - Special wrapper used under X86-64 PIC mode for RIP
+      /// relative displacements.
+      WrapperRIP,
+
+      /// S2VEC - X86 version of SCALAR_TO_VECTOR. The destination base does not
+      /// have to match the operand type.
+      S2VEC,
+
+      /// PEXTRW - Extract a 16-bit value from a vector and zero extend it to
+      /// i32, corresponds to X86::PEXTRW.
+      PEXTRW,
+
+      /// PINSRW - Insert the lower 16-bits of a 32-bit value to a vector,
+      /// corresponds to X86::PINSRW.
+      PINSRW,
+
+      /// FMAX, FMIN - Floating point max and min.
+      ///
+      FMAX, FMIN,
+
+      /// FRSQRT, FRCP - Floating point reciprocal-sqrt and reciprocal
+      /// approximation.  Note that these typically require refinement
+      /// in order to obtain suitable precision.
+      FRSQRT, FRCP,
+
+      // Thread Local Storage
+      TLSADDR, THREAD_POINTER,
+
+      // Exception Handling helpers
+      EH_RETURN
+    };
+  }
+
+ /// Define some predicates that are used for node matching.
+ namespace X86 {
+   /// isPSHUFDMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to PSHUFD.
+   bool isPSHUFDMask(SDNode *N);
+
+   /// isPSHUFHWMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to PSHUFD.
+   bool isPSHUFHWMask(SDNode *N);
+
+   /// isPSHUFLWMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to PSHUFD.
+   bool isPSHUFLWMask(SDNode *N);
+
+   /// isSHUFPMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to SHUFP*.
+   bool isSHUFPMask(SDNode *N);
+
+   /// isMOVHLPSMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVHLPS.
+   bool isMOVHLPSMask(SDNode *N);
+
+   /// isMOVHLPS_v_undef_Mask - Special case of isMOVHLPSMask for canonical form
+   /// of vector_shuffle v, v, <2, 3, 2, 3>, i.e. vector_shuffle v, undef,
+   /// <2, 3, 2, 3>
+   bool isMOVHLPS_v_undef_Mask(SDNode *N);
+
+   /// isMOVLPMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVLP{S|D}.
+   bool isMOVLPMask(SDNode *N);
+
+   /// isMOVHPMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVHP{S|D}
+   /// as well as MOVLHPS.
+   bool isMOVHPMask(SDNode *N);
+
+   /// isUNPCKLMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to UNPCKL.
+   bool isUNPCKLMask(SDNode *N, bool V2IsSplat = false);
+
+   /// isUNPCKHMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to UNPCKH.
+   bool isUNPCKHMask(SDNode *N, bool V2IsSplat = false);
+
+   /// isUNPCKL_v_undef_Mask - Special case of isUNPCKLMask for canonical form
+   /// of vector_shuffle v, v, <0, 4, 1, 5>, i.e. vector_shuffle v, undef,
+   /// <0, 0, 1, 1>
+   bool isUNPCKL_v_undef_Mask(SDNode *N);
+
+   /// isUNPCKH_v_undef_Mask - Special case of isUNPCKHMask for canonical form
+   /// of vector_shuffle v, v, <2, 6, 3, 7>, i.e. vector_shuffle v, undef,
+   /// <2, 2, 3, 3>
+   bool isUNPCKH_v_undef_Mask(SDNode *N);
+
+   /// isMOVLMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVSS,
+   /// MOVSD, and MOVD, i.e. setting the lowest element.
+   bool isMOVLMask(SDNode *N);
+
+   /// isMOVSHDUPMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVSHDUP.
+   bool isMOVSHDUPMask(SDNode *N);
+
+   /// isMOVSLDUPMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a shuffle of elements that is suitable for input to MOVSLDUP.
+   bool isMOVSLDUPMask(SDNode *N);
+
+   /// isSplatMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a splat of a single element.
+   bool isSplatMask(SDNode *N);
+
+   /// isSplatLoMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a splat of zero element.
+   bool isSplatLoMask(SDNode *N);
+
+   /// getShuffleSHUFImmediate - Return the appropriate immediate to shuffle
+   /// the specified isShuffleMask VECTOR_SHUFFLE mask with PSHUF* and SHUFP*
+   /// instructions.
+   unsigned getShuffleSHUFImmediate(SDNode *N);
+
+   /// getShufflePSHUFHWImmediate - Return the appropriate immediate to shuffle
+   /// the specified isShuffleMask VECTOR_SHUFFLE mask with PSHUFHW
+   /// instructions.
+   unsigned getShufflePSHUFHWImmediate(SDNode *N);
+
+   /// getShufflePSHUFKWImmediate - Return the appropriate immediate to shuffle
+   /// the specified isShuffleMask VECTOR_SHUFFLE mask with PSHUFLW
+   /// instructions.
+   unsigned getShufflePSHUFLWImmediate(SDNode *N);
+ }
+
+  //===--------------------------------------------------------------------===//
+  //  X86TargetLowering - X86 Implementation of the TargetLowering interface
+  class X86TargetLowering : public TargetLowering {
+    int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
+    int RegSaveFrameIndex;            // X86-64 vararg func register save area.
+    unsigned VarArgsGPOffset;         // X86-64 vararg func int reg offset.
+    unsigned VarArgsFPOffset;         // X86-64 vararg func fp reg offset.
+    int ReturnAddrIndex;              // FrameIndex for return slot.
+    int BytesToPopOnReturn;           // Number of arg bytes ret should pop.
+    int BytesCallerReserves;          // Number of arg bytes caller makes.
+  public:
+    X86TargetLowering(TargetMachine &TM);
+
+    // Return the number of bytes that a function should pop when it returns (in
+    // addition to the space used by the return address).
+    //
+    unsigned getBytesToPopOnReturn() const { return BytesToPopOnReturn; }
+
+    // Return the number of bytes that the caller reserves for arguments passed
+    // to this function.
+    unsigned getBytesCallerReserves() const { return BytesCallerReserves; }
+ 
+    /// getStackPtrReg - Return the stack pointer register we are using: either
+    /// ESP or RSP.
+    unsigned getStackPtrReg() const { return X86StackPtr; }
+    
+    /// LowerOperation - Provide custom lowering hooks for some operations.
+    ///
+    virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
+
+    virtual SDOperand PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
+
+    virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
+                                                       MachineBasicBlock *MBB);
+
+    /// getTargetNodeName - This method returns the name of a target specific
+    /// DAG node.
+    virtual const char *getTargetNodeName(unsigned Opcode) const;
+
+    /// 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.
+    virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
+                                                uint64_t Mask,
+                                                uint64_t &KnownZero, 
+                                                uint64_t &KnownOne,
+                                                const SelectionDAG &DAG,
+                                                unsigned Depth = 0) const;
+    
+    SDOperand getReturnAddressFrameIndex(SelectionDAG &DAG);
+
+    ConstraintType getConstraintType(const std::string &Constraint) const;
+     
+    std::vector<unsigned> 
+      getRegClassForInlineAsmConstraint(const std::string &Constraint,
+                                        MVT::ValueType VT) const;
+    /// isOperandValidForConstraint - Return the specified operand (possibly
+    /// modified) if the specified SDOperand is valid for the specified target
+    /// constraint letter, otherwise return null.
+    SDOperand isOperandValidForConstraint(SDOperand Op, char ConstraintLetter,
+                                          SelectionDAG &DAG);
+    
+    /// getRegForInlineAsmConstraint - Given a physical register constraint
+    /// (e.g. {edx}), return the register number and the register class for the
+    /// register.  This should only be used for C_Register constraints.  On
+    /// error, this returns a register number of 0.
+    std::pair<unsigned, const TargetRegisterClass*> 
+      getRegForInlineAsmConstraint(const std::string &Constraint,
+                                   MVT::ValueType VT) const;
+    
+    /// isLegalAddressingMode - Return true if the addressing mode represented
+    /// by AM is legal for this target, for a load/store of the specified type.
+    virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
+
+    /// isShuffleMaskLegal - Targets can use this to indicate that they only
+    /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
+    /// By default, if a target supports the VECTOR_SHUFFLE node, all mask
+    /// values are assumed to be legal.
+    virtual bool isShuffleMaskLegal(SDOperand Mask, MVT::ValueType VT) const;
+
+    /// isVectorClearMaskLegal - Similar to isShuffleMaskLegal. This is
+    /// used by Targets can use this to indicate if there is a suitable
+    /// VECTOR_SHUFFLE that can be used to replace a VAND with a constant
+    /// pool entry.
+    virtual bool isVectorClearMaskLegal(std::vector<SDOperand> &BVOps,
+                                        MVT::ValueType EVT,
+                                        SelectionDAG &DAG) const;
+  private:
+    /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
+    /// make the right decision when generating code for different targets.
+    const X86Subtarget *Subtarget;
+    const MRegisterInfo *RegInfo;
+
+    /// X86StackPtr - X86 physical register used as stack ptr.
+    unsigned X86StackPtr;
+
+    /// X86ScalarSSE - Select between SSE2 or x87 floating point ops.
+    bool X86ScalarSSE;
+
+    SDNode *LowerCallResult(SDOperand Chain, SDOperand InFlag, SDNode*TheCall,
+                            unsigned CallingConv, SelectionDAG &DAG);
+        
+    // C and StdCall Calling Convention implementation.
+    SDOperand LowerCCCArguments(SDOperand Op, SelectionDAG &DAG,
+                                bool isStdCall = false);
+    SDOperand LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC);
+
+    // X86-64 C Calling Convention implementation.
+    SDOperand LowerX86_64CCCArguments(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerX86_64CCCCallTo(SDOperand Op, SelectionDAG &DAG,unsigned CC);
+
+    // Fast and FastCall Calling Convention implementation.
+    SDOperand LowerFastCCArguments(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFastCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC);
+
+    SDOperand LowerBUILD_VECTOR(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerEXTRACT_VECTOR_ELT(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerINSERT_VECTOR_ELT(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerSCALAR_TO_VECTOR(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerConstantPool(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerGlobalAddress(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerGlobalTLSAddress(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerExternalSymbol(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerShift(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerSINT_TO_FP(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFP_TO_SINT(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFABS(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFNEG(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFCOPYSIGN(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerSETCC(SDOperand Op, SelectionDAG &DAG, SDOperand Chain);
+    SDOperand LowerSELECT(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerBRCOND(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerMEMSET(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerMEMCPY(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerJumpTable(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerDYNAMIC_STACKALLOC(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerREADCYCLCECOUNTER(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerVASTART(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerVACOPY(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerINTRINSIC_WO_CHAIN(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerRETURNADDR(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFRAMEADDR(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerFRAME_TO_ARGS_OFFSET(SDOperand Op, SelectionDAG &DAG);
+    SDOperand LowerEH_RETURN(SDOperand Op, SelectionDAG &DAG);
+  };
+}
+
+#endif    // X86ISELLOWERING_H