Re-commit r151623 with fix. Only issue special no-return calls if it's a direct call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151645 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARM.td b/lib/Target/ARM/ARM.td
index 076424e..16af8cf 100644
--- a/lib/Target/ARM/ARM.td
+++ b/lib/Target/ARM/ARM.td
@@ -89,6 +89,11 @@
"AvoidCPSRPartialUpdate", "true",
"Avoid CPSR partial update for OOO execution">;
+// Some processors perform return stack prediction. CodeGen should avoid issue
+// "normal" call instructions to callees which do not return.
+def FeatureHasRAS : SubtargetFeature<"ras", "HasRAS", "true",
+ "Has return address stack">;
+
/// Some M architectures don't have the DSP extension (v7E-M vs. v7M)
def FeatureDSPThumb2 : SubtargetFeature<"t2dsp", "Thumb2DSP", "true",
"Supports v7 DSP instructions in Thumb2">;
@@ -204,13 +209,14 @@
// V7a Processors.
def : Processor<"cortex-a8", CortexA8Itineraries,
[ProcA8, HasV7Ops, FeatureNEON, FeatureDB,
- FeatureDSPThumb2]>;
+ FeatureDSPThumb2, FeatureHasRAS]>;
def : Processor<"cortex-a9", CortexA9Itineraries,
[ProcA9, HasV7Ops, FeatureNEON, FeatureDB,
- FeatureDSPThumb2]>;
+ FeatureDSPThumb2, FeatureHasRAS]>;
def : Processor<"cortex-a9-mp", CortexA9Itineraries,
[ProcA9, HasV7Ops, FeatureNEON, FeatureDB,
- FeatureDSPThumb2, FeatureMP]>;
+ FeatureDSPThumb2, FeatureMP,
+ FeatureHasRAS]>;
// V7M Processors.
def : ProcNoItin<"cortex-m3", [HasV7Ops,
diff --git a/lib/Target/ARM/ARMAsmPrinter.cpp b/lib/Target/ARM/ARMAsmPrinter.cpp
index 8d93420..9d8c97a 100644
--- a/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -1343,6 +1343,60 @@
}
return;
}
+ case ARM::BMOVPCBr9_CALL:
+ case ARM::BMOVPCB_CALL: {
+ {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::MOVr);
+ TmpInst.addOperand(MCOperand::CreateReg(ARM::LR));
+ TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
+ // Add predicate operands.
+ TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
+ TmpInst.addOperand(MCOperand::CreateReg(0));
+ // Add 's' bit operand (always reg0 for this)
+ TmpInst.addOperand(MCOperand::CreateReg(0));
+ OutStreamer.EmitInstruction(TmpInst);
+ }
+ {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::Bcc);
+ const GlobalValue *GV = MI->getOperand(0).getGlobal();
+ MCSymbol *GVSym = Mang->getSymbol(GV);
+ const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
+ TmpInst.addOperand(MCOperand::CreateExpr(GVSymExpr));
+ // Add predicate operands.
+ TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
+ TmpInst.addOperand(MCOperand::CreateReg(0));
+ OutStreamer.EmitInstruction(TmpInst);
+ }
+ return;
+ }
+ case ARM::t2BMOVPCBr9_CALL:
+ case ARM::t2BMOVPCB_CALL: {
+ {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::tMOVr);
+ TmpInst.addOperand(MCOperand::CreateReg(ARM::LR));
+ TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
+ // Add predicate operands.
+ TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
+ TmpInst.addOperand(MCOperand::CreateReg(0));
+ OutStreamer.EmitInstruction(TmpInst);
+ }
+ {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::t2B);
+ const GlobalValue *GV = MI->getOperand(0).getGlobal();
+ MCSymbol *GVSym = Mang->getSymbol(GV);
+ const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
+ TmpInst.addOperand(MCOperand::CreateExpr(GVSymExpr));
+ // Add predicate operands.
+ TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
+ TmpInst.addOperand(MCOperand::CreateReg(0));
+ OutStreamer.EmitInstruction(TmpInst);
+ }
+ return;
+ }
case ARM::MOVi16_ga_pcrel:
case ARM::t2MOVi16_ga_pcrel: {
MCInst TmpInst;
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index aa51ced..8ad7136 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1286,7 +1286,7 @@
SDValue
ARMTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
- bool &isTailCall,
+ bool doesNotRet, bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
@@ -1582,12 +1582,20 @@
if (Subtarget->isThumb()) {
if ((!isDirect || isARMFunc) && !Subtarget->hasV5TOps())
CallOpc = ARMISD::CALL_NOLINK;
+ else if (doesNotRet && isDirect && !isARMFunc &&
+ Subtarget->hasRAS() && !Subtarget->isThumb1Only())
+ // "mov lr, pc; b _foo" to avoid confusing the RSP
+ CallOpc = ARMISD::CALL_NOLINK;
else
CallOpc = isARMFunc ? ARMISD::CALL : ARMISD::tCALL;
} else {
- CallOpc = (isDirect || Subtarget->hasV5TOps())
- ? (isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL)
- : ARMISD::CALL_NOLINK;
+ if (!isDirect && !Subtarget->hasV5TOps()) {
+ CallOpc = ARMISD::CALL_NOLINK;
+ } else if (doesNotRet && isDirect && Subtarget->hasRAS())
+ // "mov lr, pc; b _foo" to avoid confusing the RSP
+ CallOpc = ARMISD::CALL_NOLINK;
+ else
+ CallOpc = isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL;
}
std::vector<SDValue> Ops;
@@ -2080,7 +2088,8 @@
std::pair<SDValue, SDValue> CallResult =
LowerCallTo(Chain, (Type *) Type::getInt32Ty(*DAG.getContext()),
false, false, false, false,
- 0, CallingConv::C, false, /*isReturnValueUsed=*/true,
+ 0, CallingConv::C, /*isTailCall=*/false,
+ /*doesNotRet=*/false, /*isReturnValueUsed=*/true,
DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl);
return CallResult.first;
}
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index a72a476..7f12293 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -462,7 +462,7 @@
virtual SDValue
LowerCall(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
- bool &isTailCall,
+ bool doesNotRet, bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 1c2976d..6f510ba 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -1951,6 +1951,13 @@
def BMOVPCRX_CALL : ARMPseudoInst<(outs), (ins tGPR:$func, variable_ops),
8, IIC_Br, [(ARMcall_nolink tGPR:$func)]>,
Requires<[IsARM, NoV4T, IsNotIOS]>;
+
+ // mov lr, pc; b if callee is marked noreturn to avoid confusing the
+ // return stack predictor.
+ def BMOVPCB_CALL : ARMPseudoInst<(outs),
+ (ins bl_target:$func, variable_ops),
+ 8, IIC_Br, [(ARMcall_nolink tglobaladdr:$func)]>,
+ Requires<[IsARM, IsNotIOS]>;
}
let isCall = 1,
@@ -1993,6 +2000,12 @@
def BMOVPCRXr9_CALL : ARMPseudoInst<(outs), (ins tGPR:$func, variable_ops),
8, IIC_Br, [(ARMcall_nolink tGPR:$func)]>,
Requires<[IsARM, NoV4T, IsIOS]>;
+
+ // mov lr, pc; b if callee is marked noreturn to avoid confusing the
+ // return stack predictor.
+ def BMOVPCBr9_CALL : ARMPseudoInst<(outs),(ins bl_target:$func, variable_ops),
+ 8, IIC_Br, [(ARMcall_nolink tglobaladdr:$func)]>,
+ Requires<[IsARM, IsIOS]>;
}
let isBranch = 1, isTerminator = 1 in {
@@ -4897,6 +4910,12 @@
Requires<[IsARM, IsNotIOS]>;
def : ARMPat<(ARMcall texternalsym:$func), (BLr9 texternalsym:$func)>,
Requires<[IsARM, IsIOS]>;
+def : ARMPat<(ARMcall_nolink texternalsym:$func),
+ (BMOVPCB_CALL texternalsym:$func)>,
+ Requires<[IsARM, IsNotIOS]>;
+def : ARMPat<(ARMcall_nolink texternalsym:$func),
+ (BMOVPCBr9_CALL texternalsym:$func)>,
+ Requires<[IsARM, IsIOS]>;
// zextload i1 -> zextload i8
def : ARMPat<(zextloadi1 addrmode_imm12:$addr), (LDRBi12 addrmode_imm12:$addr)>;
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 88b6a2f..e8984e1 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -3277,6 +3277,38 @@
Requires<[IsThumb2, IsIOS]>;
}
+let isCall = 1,
+ // On non-IOS platforms R9 is callee-saved.
+ Defs = [LR], Uses = [SP] in {
+ // mov lr, pc; b if callee is marked noreturn to avoid confusing the
+ // return stack predictor.
+ def t2BMOVPCB_CALL : tPseudoInst<(outs),
+ (ins t_bltarget:$func, variable_ops),
+ 6, IIC_Br, [(ARMcall_nolink tglobaladdr:$func)]>,
+ Requires<[IsThumb, IsNotIOS]>;
+}
+
+let isCall = 1,
+ // On IOS R9 is call-clobbered.
+ // R7 is marked as a use to prevent frame-pointer assignments from being
+ // moved above / below calls.
+ Defs = [LR], Uses = [R7, SP] in {
+ // mov lr, pc; b if callee is marked noreturn to avoid confusing the
+ // return stack predictor.
+ def t2BMOVPCBr9_CALL : tPseudoInst<(outs),
+ (ins t_bltarget:$func, variable_ops),
+ 6, IIC_Br, [(ARMcall_nolink tglobaladdr:$func)]>,
+ Requires<[IsThumb, IsIOS]>;
+}
+
+// Direct calls
+def : T2Pat<(ARMcall_nolink texternalsym:$func),
+ (t2BMOVPCB_CALL texternalsym:$func)>,
+ Requires<[IsThumb, IsNotIOS]>;
+def : T2Pat<(ARMcall_nolink texternalsym:$func),
+ (t2BMOVPCBr9_CALL texternalsym:$func)>,
+ Requires<[IsThumb, IsIOS]>;
+
// IT block
let Defs = [ITSTATE] in
def t2IT : Thumb2XI<(outs), (ins it_pred:$cc, it_mask:$mask),
diff --git a/lib/Target/ARM/ARMSelectionDAGInfo.cpp b/lib/Target/ARM/ARMSelectionDAGInfo.cpp
index 3113b62..e2530d0 100644
--- a/lib/Target/ARM/ARMSelectionDAGInfo.cpp
+++ b/lib/Target/ARM/ARMSelectionDAGInfo.cpp
@@ -189,6 +189,7 @@
0, // number of fixed arguments
TLI.getLibcallCallingConv(RTLIB::MEMSET), // call conv
false, // is tail call
+ false, // does not return
false, // is return val used
DAG.getExternalSymbol(TLI.getLibcallName(RTLIB::MEMSET),
TLI.getPointerTy()), // callee
diff --git a/lib/Target/ARM/ARMSubtarget.h b/lib/Target/ARM/ARMSubtarget.h
index 58ff8fb..c94795f 100644
--- a/lib/Target/ARM/ARMSubtarget.h
+++ b/lib/Target/ARM/ARMSubtarget.h
@@ -125,6 +125,10 @@
/// CPSR setting instruction.
bool AvoidCPSRPartialUpdate;
+ /// HasRAS - Some processors perform return stack prediction. CodeGen should
+ /// avoid issue "normal" call instructions to callees which do not return.
+ bool HasRAS;
+
/// HasMPExtension - True if the subtarget supports Multiprocessing
/// extension (ARMv7 only).
bool HasMPExtension;
@@ -214,6 +218,7 @@
bool isFPOnlySP() const { return FPOnlySP; }
bool prefers32BitThumb() const { return Pref32BitThumb; }
bool avoidCPSRPartialUpdate() const { return AvoidCPSRPartialUpdate; }
+ bool hasRAS() const { return HasRAS; }
bool hasMPExtension() const { return HasMPExtension; }
bool hasThumb2DSP() const { return Thumb2DSP; }