[llvm] r226245 - Fix Reassociate handling of constant in presence of undef float

[Mehdi Amini]

Author: mehdi_amini
Date: Thu Jan 15 21:00:58 2015
New Revision: 226245

URL: http://llvm.org/viewvc/llvm-project?rev=226245&view=rev
Log:
Fix Reassociate handling of constant in presence of undef float

http://reviews.llvm.org/D6993

Added:
    llvm/trunk/test/Transforms/Reassociate/crash2.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp?rev=226245&r1=226244&r2=226245&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp Thu Jan 15 21:00:58 2015
@@ -917,10 +917,13 @@ void Reassociate::RewriteExprTree(Binary
 /// version of the value is returned, and BI is left pointing at the instruction
 /// that should be processed next by the reassociation pass.
 static Value *NegateValue(Value *V, Instruction *BI) {
-  if (ConstantFP *C = dyn_cast<ConstantFP>(V))
-    return ConstantExpr::getFNeg(C);
-  if (Constant *C = dyn_cast<Constant>(V))
+  if (Constant *C = dyn_cast<Constant>(V)) {
+    if (C->getType()->isFPOrFPVectorTy()) {
+      return ConstantExpr::getFNeg(C);
+    }
     return ConstantExpr::getNeg(C);
+  }
+
 
   // We are trying to expose opportunity for reassociation.  One of the things
   // that we want to do to achieve this is to push a negation as deep into an

Added: llvm/trunk/test/Transforms/Reassociate/crash2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/crash2.ll?rev=226245&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Reassociate/crash2.ll (added)
+++ llvm/trunk/test/Transforms/Reassociate/crash2.ll Thu Jan 15 21:00:58 2015
@@ -0,0 +1,25 @@
+; RUN: opt -reassociate %s -S -o - | FileCheck %s
+
+; Reassociate pass used to crash on these example
+
+
+define float @undef1() {
+wrapper_entry:
+; CHECK-LABEL: @undef1
+; CHECK: ret float fadd (float undef, float fadd (float undef, float fadd (float fsub (float -0.000000e+00, float undef), float fsub (float -0.000000e+00, float undef))))
+  %0 = fadd fast float undef, undef
+  %1 = fsub fast float undef, %0
+  %2 = fadd fast float undef, %1
+  ret float %2
+}
+
+define void @undef2() {
+wrapper_entry:
+; CHECK-LABEL: @undef2
+; CHECK: unreachable
+  %0 = fadd fast float undef, undef
+  %1 = fadd fast float %0, 1.000000e+00
+  %2 = fsub fast float %0, %1
+  %3 = fmul fast float %2, 2.000000e+00
+  unreachable
+}