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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-07-24 20:23:50 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-07-24 20:23:50 +0000 |
| commit | b09701db9e74298912164d988ddf40bb1b5ec19b (patch) | |
| tree | 1c65cf745cfb57ce5c07981c3c942ae5e6251fd0 | |
| parent | f6275309994dea2ec852c1f539875ae643646ec5 (diff) | |
| download | external_llvm-b09701db9e74298912164d988ddf40bb1b5ec19b.zip external_llvm-b09701db9e74298912164d988ddf40bb1b5ec19b.tar.gz external_llvm-b09701db9e74298912164d988ddf40bb1b5ec19b.tar.bz2 | |
Correctly handle <undef> tied uses when rewriting after a split.
This fixes PR10463. A two-address instruction with an <undef> use
operand was incorrectly rewritten so the def and use no longer used the
same register, violating the tie constraint.
Fix this by always rewriting <undef> operands with the register a def
operand would use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135885 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/SplitKit.cpp | 12 | ||||
| -rw-r--r-- | test/CodeGen/X86/crash.ll | 25 |
2 files changed, 29 insertions, 8 deletions
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp index d607e37..46a43d8 100644 --- a/lib/CodeGen/SplitKit.cpp +++ b/lib/CodeGen/SplitKit.cpp @@ -938,15 +938,11 @@ void SplitEditor::rewriteAssigned(bool ExtendRanges) { continue; } - // <undef> operands don't really read the register, so just assign them to - // the complement. - if (MO.isUse() && MO.isUndef()) { - MO.setReg(Edit->get(0)->reg); - continue; - } - + // <undef> operands don't really read the register, so it doesn't matter + // which register we choose. When the use operand is tied to a def, we must + // use the same register as the def, so just do that always. SlotIndex Idx = LIS.getInstructionIndex(MI); - if (MO.isDef()) + if (MO.isDef() || MO.isUndef()) Idx = MO.isEarlyClobber() ? Idx.getUseIndex() : Idx.getDefIndex(); // Rewrite to the mapped register at Idx. diff --git a/test/CodeGen/X86/crash.ll b/test/CodeGen/X86/crash.ll index b5b1ad4..db1e999 100644 --- a/test/CodeGen/X86/crash.ll +++ b/test/CodeGen/X86/crash.ll @@ -316,3 +316,28 @@ declare void @_ZNSt6vectorIN4llvm11MachineMoveESaIS1_EE13_M_insert_auxEN9__gnu_c declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind + +; PR10463 +; Spilling a virtual register with <undef> uses. +define void @autogen_239_1000() { +BB: + %Shuff = shufflevector <8 x double> undef, <8 x double> undef, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 undef, i32 undef> + br label %CF + +CF: + %B16 = frem <8 x double> zeroinitializer, %Shuff + %E19 = extractelement <8 x double> %Shuff, i32 5 + br i1 undef, label %CF, label %CF75 + +CF75: + br i1 undef, label %CF75, label %CF76 + +CF76: + store double %E19, double* undef + br i1 undef, label %CF76, label %CF77 + +CF77: + %B55 = fmul <8 x double> %B16, undef + br label %CF77 +} + |