[llvm-commits] [llvm] r67662 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/2009-03-24-InfLoop.ll
Chris Lattner
sabre at nondot.org
Tue Mar 24 17:28:58 PDT 2009
Author: lattner
Date: Tue Mar 24 19:28:58 2009
New Revision: 67662
URL: http://llvm.org/viewvc/llvm-project?rev=67662&view=rev
Log:
Fix PR3874 by restoring a condition I removed, but making it more
precise than it used to be.
Added:
llvm/trunk/test/Transforms/InstCombine/2009-03-24-InfLoop.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=67662&r1=67661&r2=67662&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Tue Mar 24 19:28:58 2009
@@ -6582,7 +6582,8 @@
// preferable because it allows the C<<Y expression to be hoisted out
// of a loop if Y is invariant and X is not.
if (Shift && Shift->hasOneUse() && RHSV == 0 &&
- ICI.isEquality() && !Shift->isArithmeticShift()) {
+ ICI.isEquality() && !Shift->isArithmeticShift() &&
+ !isa<Constant>(Shift->getOperand(0))) {
// Compute C << Y.
Value *NS;
if (Shift->getOpcode() == Instruction::LShr) {
Added: llvm/trunk/test/Transforms/InstCombine/2009-03-24-InfLoop.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2009-03-24-InfLoop.ll?rev=67662&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2009-03-24-InfLoop.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2009-03-24-InfLoop.ll Tue Mar 24 19:28:58 2009
@@ -0,0 +1,9 @@
+; PR3874
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis
+ define i1 @test(i32 %x) {
+ %A = lshr i32 3968, %x
+ %B = and i32 %A, 1
+ %C = icmp eq i32 %B, 0
+ ret i1 %C
+ }
+
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