It's not safe to fold a load from GV stub or constantpool into a two-address use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49002 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2008-03-31 23:19:51 +00:00
parent 82b53cd2ba
commit 427f4c106a
3 changed files with 51 additions and 2 deletions

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@ -757,8 +757,9 @@ bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI,
if (FilterFoldedOps(MI, Ops, MRInfo, FoldOps))
return false;
// Can't fold a load from fixed stack slot into a two address instruction.
if (isSS && DefMI && (MRInfo & VirtRegMap::isMod))
// The only time it's safe to fold into a two address instruction is when
// it's folding reload and spill from / into a spill stack slot.
if (DefMI && (MRInfo & VirtRegMap::isMod))
return false;
MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(*mf_, MI, FoldOps, Slot)

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@ -1825,7 +1825,15 @@ X86InstrInfo::foldMemoryOperand(MachineInstr *MI, unsigned i,
MI->getOperand(0).getReg() == MI->getOperand(1).getReg()) {
OpcodeTablePtr = &RegOp2MemOpTable2Addr;
isTwoAddrFold = true;
// Can't write back to CPI or a GV stub.
if (MOs[3].isCPI() ||
(MOs[3].isGlobal() && isGVStub(MOs[3].getGlobal(), TM)))
return NULL;
} else if (i == 0) { // If operand 0
// Can't write back to CPI or a GV stub.
if (MOs[3].isCPI() ||
(MOs[3].isGlobal() && isGVStub(MOs[3].getGlobal(), TM)))
return NULL;
if (MI->getOpcode() == X86::MOV16r0)
NewMI = MakeM0Inst(*this, X86::MOV16mi, MOs, MI);
else if (MI->getOpcode() == X86::MOV32r0)

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@ -0,0 +1,40 @@
; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -relocation-model=pic -disable-fp-elim | grep add | grep 12 | not grep non_lazy_ptr
; Don't fold re-materialized load into a two address instruction
%"struct.Smarts::Runnable" = type { i32 (...)**, i32 }
%struct.__sbuf = type { i8*, i32 }
%"struct.std::ios_base" = type { i32 (...)**, i32, i32, i32, i32, i32, %"struct.std::ios_base::_Callback_list"*, %struct.__sbuf, [8 x %struct.__sbuf], i32, %struct.__sbuf*, %"struct.std::locale" }
%"struct.std::ios_base::_Callback_list" = type { %"struct.std::ios_base::_Callback_list"*, void (i32, %"struct.std::ios_base"*, i32)*, i32, i32 }
%"struct.std::locale" = type { %"struct.std::locale::_Impl"* }
%"struct.std::locale::_Impl" = type { i32, %"struct.Smarts::Runnable"**, i32, %"struct.Smarts::Runnable"**, i8** }
@_ZTVSt9basic_iosIcSt11char_traitsIcEE = external constant [4 x i32 (...)*] ; <[4 x i32 (...)*]*> [#uses=1]
@_ZTTSt19basic_ostringstreamIcSt11char_traitsIcESaIcEE = external constant [4 x i8*] ; <[4 x i8*]*> [#uses=1]
@_ZTVSt19basic_ostringstreamIcSt11char_traitsIcESaIcEE = external constant [10 x i32 (...)*] ; <[10 x i32 (...)*]*> [#uses=2]
@_ZTVSt15basic_streambufIcSt11char_traitsIcEE = external constant [16 x i32 (...)*] ; <[16 x i32 (...)*]*> [#uses=1]
@_ZTVSt15basic_stringbufIcSt11char_traitsIcESaIcEE = external constant [16 x i32 (...)*] ; <[16 x i32 (...)*]*> [#uses=1]
define void @_GLOBAL__I__ZN5Pooma5pinfoE() nounwind {
entry:
store i32 (...)** getelementptr ([10 x i32 (...)*]* @_ZTVSt19basic_ostringstreamIcSt11char_traitsIcESaIcEE, i32 0, i32 8), i32 (...)*** null, align 4
%tmp96.i.i142.i = call i8* @_Znwm( i32 180 ) nounwind ; <i8*> [#uses=2]
call void @_ZNSt8ios_baseC2Ev( %"struct.std::ios_base"* null ) nounwind
store i32 (...)** getelementptr ([4 x i32 (...)*]* @_ZTVSt9basic_iosIcSt11char_traitsIcEE, i32 0, i32 2), i32 (...)*** null, align 4
store i32 (...)** null, i32 (...)*** null, align 4
%ctg2242.i.i163.i = getelementptr i8* %tmp96.i.i142.i, i32 0 ; <i8*> [#uses=1]
%tmp150.i.i164.i = load i8** getelementptr ([4 x i8*]* @_ZTTSt19basic_ostringstreamIcSt11char_traitsIcESaIcEE, i32 0, i64 2), align 4 ; <i8*> [#uses=1]
%tmp150151.i.i165.i = bitcast i8* %tmp150.i.i164.i to i32 (...)** ; <i32 (...)**> [#uses=1]
%tmp153.i.i166.i = bitcast i8* %ctg2242.i.i163.i to i32 (...)*** ; <i32 (...)***> [#uses=1]
store i32 (...)** %tmp150151.i.i165.i, i32 (...)*** %tmp153.i.i166.i, align 4
%tmp159.i.i167.i = bitcast i8* %tmp96.i.i142.i to i32 (...)*** ; <i32 (...)***> [#uses=1]
store i32 (...)** getelementptr ([10 x i32 (...)*]* @_ZTVSt19basic_ostringstreamIcSt11char_traitsIcESaIcEE, i32 0, i32 3), i32 (...)*** %tmp159.i.i167.i, align 4
store i32 (...)** getelementptr ([16 x i32 (...)*]* @_ZTVSt15basic_streambufIcSt11char_traitsIcEE, i32 0, i32 2), i32 (...)*** null, align 4
call void @_ZNSt6localeC1Ev( %"struct.std::locale"* null ) nounwind
store i32 (...)** getelementptr ([16 x i32 (...)*]* @_ZTVSt15basic_stringbufIcSt11char_traitsIcESaIcEE, i32 0, i32 2), i32 (...)*** null, align 4
unreachable
}
declare i8* @_Znwm(i32)
declare void @_ZNSt8ios_baseC2Ev(%"struct.std::ios_base"*)
declare void @_ZNSt6localeC1Ev(%"struct.std::locale"*) nounwind