[llvm-commits] [llvm] r158166 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineSelect.cpp test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll

[Nadav Rotem]

Author: nadav
Date: Thu Jun  7 15:28:57 2012
New Revision: 158166

URL: http://llvm.org/viewvc/llvm-project?rev=158166&view=rev
Log:
Fix a bug in FoldSelectOpOp. Bitcast ops may change the number of vector elements, which may disagree with the select condition type.


Added:
    llvm/trunk/test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll
Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=158166&r1=158165&r2=158166&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Thu Jun  7 15:28:57 2012
@@ -129,6 +129,12 @@
     if (TI->isCast()) {
       if (TI->getOperand(0)->getType() != FI->getOperand(0)->getType())
         return 0;
+      // The select condition may be a vector. We may only change the operand
+      // type if the vector width remains the same (and matches the condition).
+      Type *CondTy = SI.getCondition()->getType();
+      if (CondTy->isVectorTy() && CondTy->getVectorNumElements() !=
+          FI->getOperand(0)->getType()->getVectorNumElements())
+        return 0;
     } else {
       return 0;  // unknown unary op.
     }

Added: llvm/trunk/test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll?rev=158166&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2012-6-7-vselect-bitcast.ll Thu Jun  7 15:28:57 2012
@@ -0,0 +1,11 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; CHECK: bitcast
+
+define void @foo(<16 x i8> %a, <16 x i8> %b, <4 x i32>* %c) {
+  %aa = bitcast <16 x i8> %a to <4 x i32>
+  %bb = bitcast <16 x i8> %b to <4 x i32>
+  %select_v = select <4 x i1> zeroinitializer, <4 x i32> %aa, <4 x i32> %bb
+  store <4 x i32> %select_v, <4 x i32>* %c, align 4
+  ret void
+}
+