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| author | Craig Topper <craig.topper@intel.com> | 2018-03-01 00:08:38 +0000 |
|---|---|---|
| committer | Yi Kong <yikong@google.com> | 2018-03-27 16:41:38 -0700 |
| commit | 5154c3238e4c7df6c62294dd338e76a3afb9a621 (patch) | |
| tree | 3795c4c276a0350e0a32294d139a1112b21da2df | |
| parent | f08e14a6c79bf8fc7998e74f05f479cfcc54ce70 (diff) | |
| download | llvm-5154c3238e4c7df6c62294dd338e76a3afb9a621.tar.gz | |
[X86] Make sure we don't combine (fneg (fma X, Y, Z)) to a target specific node when there are no FMA instructions.
This would cause a 'cannot select' error at isel when we should have emitted a lib call and an xor.
Fixes PR36553.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326393 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 2 | ||||
| -rw-r--r-- | test/CodeGen/X86/pr36553.ll | 20 |
2 files changed, 21 insertions, 1 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 6600cc5dfb3..01a5f467a4f 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -34321,7 +34321,7 @@ static SDValue combineFneg(SDNode *N, SelectionDAG &DAG, // If we're negating an FMA node, then we can adjust the // instruction to include the extra negation. unsigned NewOpcode = 0; - if (Arg.hasOneUse()) { + if (Arg.hasOneUse() && Subtarget.hasAnyFMA()) { switch (Arg.getOpcode()) { case ISD::FMA: NewOpcode = X86ISD::FNMSUB; break; case X86ISD::FMSUB: NewOpcode = X86ISD::FNMADD; break; diff --git a/test/CodeGen/X86/pr36553.ll b/test/CodeGen/X86/pr36553.ll new file mode 100644 index 00000000000..827f80a3e07 --- /dev/null +++ b/test/CodeGen/X86/pr36553.ll @@ -0,0 +1,20 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py +; RUN: llc < %s -mtriple=x86_64-apple-darwin10 | FileCheck %s + +; Make sure we don't crash because we negated an fma when we didn't have any fma instructions. + +define float @pr36553(float %a, float %b, float %c) nounwind { +; CHECK-LABEL: pr36553: +; CHECK: ## %bb.0: ## %entry +; CHECK-NEXT: pushq %rax +; CHECK-NEXT: callq _fmaf +; CHECK-NEXT: xorps {{.*}}(%rip), %xmm0 +; CHECK-NEXT: popq %rax +; CHECK-NEXT: retq +entry: + %0 = tail call float @llvm.fma.f32(float %a, float %b, float %c) + %sub = fsub float -0.000000e+00, %0 + ret float %sub +} + +declare float @llvm.fma.f32(float, float, float) |