[llvm-commits] [llvm] r67211 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll

[Chris Lattner]

Author: lattner
Date: Wed Mar 18 11:32:19 2009
New Revision: 67211

URL: http://llvm.org/viewvc/llvm-project?rev=67211&view=rev
Log:
Fix PR3826 - InstComb assert with vector shift, by not calling ComputeNumSignBits on a vector.

Added:
    llvm/trunk/test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=67211&r1=67210&r2=67211&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Wed Mar 18 11:32:19 2009
@@ -7029,15 +7029,16 @@
       return ReplaceInstUsesWith(I, CSI);
   
   // See if we can turn a signed shr into an unsigned shr.
-  if (!isa<VectorType>(I.getType()) &&
-      MaskedValueIsZero(Op0,
+  if (!isa<VectorType>(I.getType())) {
+    if (MaskedValueIsZero(Op0,
                       APInt::getSignBit(I.getType()->getPrimitiveSizeInBits())))
-    return BinaryOperator::CreateLShr(Op0, I.getOperand(1));
+      return BinaryOperator::CreateLShr(Op0, I.getOperand(1));
 
-  // Arithmetic shifting an all-sign-bit value is a no-op.
-  unsigned NumSignBits = ComputeNumSignBits(Op0);
-  if (NumSignBits == Op0->getType()->getPrimitiveSizeInBits())
-    return ReplaceInstUsesWith(I, Op0);
+    // Arithmetic shifting an all-sign-bit value is a no-op.
+    unsigned NumSignBits = ComputeNumSignBits(Op0);
+    if (NumSignBits == Op0->getType()->getPrimitiveSizeInBits())
+      return ReplaceInstUsesWith(I, Op0);
+  }
 
   return 0;
 }

Added: llvm/trunk/test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll?rev=67211&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2009-03-18-vector-ashr-crash.ll Wed Mar 18 11:32:19 2009
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis
+; PR3826
+
+define void @0(<4 x i16>*, <4 x i16>*) {
+	%3 = alloca <4 x i16>*		; <<4 x i16>**> [#uses=1]
+	%4 = load <4 x i16>* null, align 1		; <<4 x i16>> [#uses=1]
+	%5 = ashr <4 x i16> %4, <i16 5, i16 5, i16 5, i16 5>		; <<4 x i16>> [#uses=1]
+	%6 = load <4 x i16>** %3		; <<4 x i16>*> [#uses=1]
+	store <4 x i16> %5, <4 x i16>* %6, align 1
+	ret void
+}