[llvm-commits] [llvm] r88841 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/compare-signs.ll
Nick Lewycky
nicholas at mxc.ca
Sat Nov 14 23:47:32 PST 2009
Author: nicholas
Date: Sun Nov 15 01:47:32 2009
New Revision: 88841
URL: http://llvm.org/viewvc/llvm-project?rev=88841&view=rev
Log:
Revert r88830 and r88831 which appear to have caused a selfhost buildbot some
grief. I suspect this patch merely exposed a bug else.
Modified:
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
llvm/trunk/test/Transforms/InstCombine/compare-signs.ll
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=88841&r1=88840&r2=88841&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sun Nov 15 01:47:32 2009
@@ -8539,34 +8539,6 @@
}
}
- // icmp ne A, B is equal to xor A, B when A and B only really have one bit.
- // It is also profitable to transform icmp eq into not(xor(A, B)) because that
- // may lead to additional simplifications.
- if (CI.getType() == ICI->getOperand(0)->getType()) {
- if (const IntegerType *ITy = dyn_cast<IntegerType>(CI.getType())) {
- Value *LHS = ICI->getOperand(0);
- Value *RHS = ICI->getOperand(1);
-
- uint32_t BitWidth = ITy->getBitWidth();
- APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0);
- APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0);
- APInt TypeMask(APInt::getAllOnesValue(BitWidth));
- ComputeMaskedBits(LHS, TypeMask, KnownZeroLHS, KnownOneLHS);
- ComputeMaskedBits(RHS, TypeMask, KnownZeroRHS, KnownOneRHS);
-
- if (KnownZeroLHS.countLeadingOnes() == BitWidth-1 &&
- KnownZeroRHS.countLeadingOnes() == BitWidth-1) {
- if (!DoXform) return ICI;
-
- Value *Xor = Builder->CreateXor(LHS, RHS);
- if (ICI->isTrueWhenEqual())
- Xor = Builder->CreateXor(Xor, ConstantInt::get(ITy, 1));
- Xor->takeName(ICI);
- return ReplaceInstUsesWith(CI, Xor);
- }
- }
- }
-
return 0;
}
Modified: llvm/trunk/test/Transforms/InstCombine/compare-signs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/compare-signs.ll?rev=88841&r1=88840&r2=88841&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/compare-signs.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/compare-signs.ll Sun Nov 15 01:47:32 2009
@@ -1,4 +1,5 @@
; RUN: opt %s -instcombine -S | FileCheck %s
+; XFAIL: *
; PR5438
; TODO: This should also optimize down.
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