[PATCH] D29756: [X86][btver2] PR31902: Fix a crash in combineOrCmpEqZeroToCtlzSrl under fast math.

[pierre gousseau via Phabricator via llvm-commits]

pgousseau created this revision.
Herald added a subscriber: igorb.

In combineOrCmpEqZeroToCtlzSrl, replace "getConstantOperand == 0" by "isNullConstant" to account for floating point constants.


https://reviews.llvm.org/D29756

Files:
  lib/Target/X86/X86ISelLowering.cpp
  test/CodeGen/X86/lzcnt-zext-cmp.ll


Index: test/CodeGen/X86/lzcnt-zext-cmp.ll
===================================================================
--- test/CodeGen/X86/lzcnt-zext-cmp.ll
+++ test/CodeGen/X86/lzcnt-zext-cmp.ll
@@ -341,3 +341,34 @@
   %lor.ext = zext i1 %0 to i32
   ret i32 %lor.ext
 }
+
+; PR31902 Fix a crash in combineOrCmpEqZeroToCtlzSrl under fast math.
+define i32 @test_zext_cmp11(double %a, double %b) "no-nans-fp-math"="true" {
+; CHECK-LABEL: test_zext_cmp11:
+; CHECK:       # BB#0: # %entry
+; CHECK-NEXT:    vxorps %xmm2, %xmm2, %xmm2
+; CHECK-NEXT:    vucomisd %xmm2, %xmm0
+; CHECK-NEXT:    sete %al
+; CHECK-NEXT:    vucomisd %xmm2, %xmm1
+; CHECK-NEXT:    sete %cl
+; CHECK-NEXT:    orb %al, %cl
+; CHECK-NEXT:    movzbl %cl, %eax
+; CHECK-NEXT:    retq
+;
+; NOFASTLZCNT-LABEL: test_zext_cmp11:
+; NOFASTLZCNT:       # BB#0: # %entry
+; NOFASTLZCNT-NEXT:    vxorps %xmm2, %xmm2, %xmm2
+; NOFASTLZCNT-NEXT:    vucomisd %xmm2, %xmm0
+; NOFASTLZCNT-NEXT:    sete %al
+; NOFASTLZCNT-NEXT:    vucomisd %xmm2, %xmm1
+; NOFASTLZCNT-NEXT:    sete %cl
+; NOFASTLZCNT-NEXT:    orb %al, %cl
+; NOFASTLZCNT-NEXT:    movzbl %cl, %eax
+; NOFASTLZCNT-NEXT:    retq
+entry:
+  %cmp = fcmp fast oeq double %a, 0.000000e+00
+  %cmp1 = fcmp fast oeq double %b, 0.000000e+00
+  %0 = or i1 %cmp, %cmp1
+  %conv = zext i1 %0 to i32
+  ret i32 %conv
+}
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -31137,7 +31137,7 @@
     return N->getOpcode() == X86ISD::SETCC && N->hasOneUse() &&
            X86::CondCode(N->getConstantOperandVal(0)) == X86::COND_E &&
            N->getOperand(1).getOpcode() == X86ISD::CMP &&
-           N->getOperand(1).getConstantOperandVal(1) == 0 &&
+           isNullConstant(N->getOperand(1).getOperand(1)) &&
            N->getOperand(1).getValueType().bitsGE(MVT::i32);
   };
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D29756.87785.patch
Type: text/x-patch
Size: 1929 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170209/7de49a1c/attachment.bin>