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author | Owen Anderson <resistor@mac.com> | 2010-07-14 23:33:51 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2010-07-14 23:33:51 +0000 |
commit | bd129a746058dc5d8da089f1351ff417de3114e7 (patch) | |
tree | 0c809169211f9fc5c468c9c0550cdc42fe0bf235 /lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | |
parent | 14904ce25ccca82ef23b53274f48057d65417ef5 (diff) | |
download | llvm-bd129a746058dc5d8da089f1351ff417de3114e7.tar.gz llvm-bd129a746058dc5d8da089f1351ff417de3114e7.tar.bz2 llvm-bd129a746058dc5d8da089f1351ff417de3114e7.tar.xz |
Add instcombine transforms to optimize tests of multiple bits of the same value into a single larger comparison.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108378 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 3f4a857c41..57cd76dab0 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -472,6 +472,24 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *NewOr = Builder->CreateOr(Val, Val2); return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } + + // (icmp ne (A & C1) 0) & (icmp ne (A & C2), 0) --> + // (icmp eq (A & (C1|C2)), (C1|C2)) + if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) { + Instruction *I1 = dyn_cast<Instruction>(Val); + Instruction *I2 = dyn_cast<Instruction>(Val2); + if (I1 && I1->getOpcode() == Instruction::And && + I2 && I2->getOpcode() == Instruction::And && + I1->getOperand(0) == I1->getOperand(0)) { + ConstantInt *CI1 = dyn_cast<ConstantInt>(I1->getOperand(1)); + ConstantInt *CI2 = dyn_cast<ConstantInt>(I2->getOperand(1)); + if (CI1 && CI2) { + Constant *ConstOr = ConstantExpr::getOr(CI1, CI2); + Value *NewAnd = Builder->CreateAnd(I1->getOperand(0), ConstOr); + return Builder->CreateICmp(ICmpInst::ICMP_EQ, NewAnd, ConstOr); + } + } + } } // From here on, we only handle: |