From 9f7f83b861f6d03df81c440364ba10f55f6447d5 Mon Sep 17 00:00:00 2001 From: Anton Korobeynikov Date: Wed, 25 Aug 2010 07:50:11 +0000 Subject: [PATCH] Fix nasty mingw32 bug, which e.g. prevented llvm-gcc bootstrap there. Mark _alloca call as clobberring EFLAGS, otherwise some DCE might remove other flags-clobberring stuff (e.g. cmp instructions) occuring after _alloca call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112034 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86ISelLowering.cpp | 3 ++- lib/Target/X86/X86InstrInfo.td | 7 ++++--- lib/Target/X86/X86RegisterInfo.cpp | 6 ++++-- 3 files changed, 10 insertions(+), 6 deletions(-) diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 7adaf9728d7..dc1bab32f25 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -8930,7 +8930,8 @@ X86TargetLowering::EmitLoweredMingwAlloca(MachineInstr *MI, .addReg(X86::EAX, RegState::Implicit) .addReg(X86::ESP, RegState::Implicit) .addReg(X86::EAX, RegState::Define | RegState::Implicit) - .addReg(X86::ESP, RegState::Define | RegState::Implicit); + .addReg(X86::ESP, RegState::Define | RegState::Implicit) + .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit); MI->eraseFromParent(); // The pseudo instruction is gone now. return BB; diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td index 60af8ed4c57..84fde71f2e6 100644 --- a/lib/Target/X86/X86InstrInfo.td +++ b/lib/Target/X86/X86InstrInfo.td @@ -580,9 +580,10 @@ def VASTART_SAVE_XMM_REGS : I<0, Pseudo, // The main point of having separate instruction are extra unmodelled effects // (compared to ordinary calls) like stack pointer change. -def MINGW_ALLOCA : I<0, Pseudo, (outs), (ins), - "# dynamic stack allocation", - [(X86MingwAlloca)]>; +let Defs = [EAX, ESP, EFLAGS], Uses = [ESP] in + def MINGW_ALLOCA : I<0, Pseudo, (outs), (ins), + "# dynamic stack allocation", + [(X86MingwAlloca)]>; } // Nop diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index 746e3fa7b5c..56ddfb03ecb 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -1109,7 +1109,8 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { .addImm(NumBytes); BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32)) .addExternalSymbol("_alloca") - .addReg(StackPtr, RegState::Define | RegState::Implicit); + .addReg(StackPtr, RegState::Define | RegState::Implicit) + .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit); } else { // Save EAX BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r)) @@ -1121,7 +1122,8 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { .addImm(NumBytes - 4); BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32)) .addExternalSymbol("_alloca") - .addReg(StackPtr, RegState::Define | RegState::Implicit); + .addReg(StackPtr, RegState::Define | RegState::Implicit) + .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit); // Restore EAX MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),