diff options
| author | Benjamin Kramer <benny.kra@googlemail.com> | 2011-04-28 21:38:51 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2011-04-28 21:38:51 +0000 |
| commit | b0884f3f13ca6e5d83e3232d8390a4d58739d57c (patch) | |
| tree | 1f4109b08bcdb9f375f9214aa7bd3704f0f93f14 | |
| parent | 7a2ba2fbe4b0ccaacc2cedbc1bfd2a3764170efe (diff) | |
We require threse bits to be zero, too.
This shouldn't happen in practice because the icmp would be a constant.
Add a check so we don't miscompile code if something goes wrong.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130446 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 75e93127e7..a08446e5d5 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -772,7 +772,7 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2 // where CMAX is the all ones value for the truncated type, - // iff the lower bits of CA are zero. + // iff the lower bits of C2 and CA are zero. if (LHSCC == RHSCC && ICmpInst::isEquality(LHSCC) && LHS->hasOneUse() && RHS->hasOneUse()) { Value *V; @@ -797,7 +797,7 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { // Check that the low bits are zero. APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize); - if ((Low & AndCst->getValue()) == 0) { + if ((Low & AndCst->getValue()) == 0 && (Low & BigCst->getValue()) == 0) { Value *NewAnd = Builder->CreateAnd(V, Low | AndCst->getValue()); APInt N = SmallCst->getValue().zext(BigBitSize) | BigCst->getValue(); Value *NewVal = ConstantInt::get(AndCst->getType()->getContext(), N); |