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| author | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-04-27 18:02:12 +0000 |
|---|---|---|
| committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-04-27 18:02:12 +0000 |
| commit | 4d4c54d29ff911f59fe2be1a31331dbcbb741f5f (patch) | |
| tree | 7462985c701c756423fce2663a8820dee00f7223 /lib/Transforms/Scalar | |
| parent | 595dd5af1438141dde4f19225d5b57170c651731 (diff) | |
| download | external_llvm-4d4c54d29ff911f59fe2be1a31331dbcbb741f5f.zip external_llvm-4d4c54d29ff911f59fe2be1a31331dbcbb741f5f.tar.gz external_llvm-4d4c54d29ff911f59fe2be1a31331dbcbb741f5f.tar.bz2 | |
Fix a XOR reassociation bug.
When Reassociator optimize "(x | C1)" ^ "(X & C2)", it may swap the two
subexpressions, however, it forgot to swap cached constants (of C1 and C2)
accordingly.
rdar://13739160
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180676 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar')
| -rw-r--r-- | lib/Transforms/Scalar/Reassociate.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index fc3b38e..a3c241d 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -1195,9 +1195,6 @@ bool Reassociate::CombineXorOpnd(Instruction *I, XorOpnd *Opnd1, XorOpnd *Opnd2, if (X != Opnd2->getSymbolicPart()) return false; - const APInt &C1 = Opnd1->getConstPart(); - const APInt &C2 = Opnd2->getConstPart(); - // This many instruction become dead.(At least "Opnd1 ^ Opnd2" will die.) int DeadInstNum = 1; if (Opnd1->getValue()->hasOneUse()) @@ -1215,6 +1212,8 @@ bool Reassociate::CombineXorOpnd(Instruction *I, XorOpnd *Opnd1, XorOpnd *Opnd2, if (Opnd2->isOrExpr()) std::swap(Opnd1, Opnd2); + const APInt &C1 = Opnd1->getConstPart(); + const APInt &C2 = Opnd2->getConstPart(); APInt C3((~C1) ^ C2); // Do not increase code size! @@ -1230,6 +1229,8 @@ bool Reassociate::CombineXorOpnd(Instruction *I, XorOpnd *Opnd1, XorOpnd *Opnd2, } else if (Opnd1->isOrExpr()) { // Xor-Rule 3: (x | c1) ^ (x | c2) = (x & c3) ^ c3 where c3 = c1 ^ c2 // + const APInt &C1 = Opnd1->getConstPart(); + const APInt &C2 = Opnd2->getConstPart(); APInt C3 = C1 ^ C2; // Do not increase code size @@ -1244,6 +1245,8 @@ bool Reassociate::CombineXorOpnd(Instruction *I, XorOpnd *Opnd1, XorOpnd *Opnd2, } else { // Xor-Rule 4: (x & c1) ^ (x & c2) = (x & (c1^c2)) // + const APInt &C1 = Opnd1->getConstPart(); + const APInt &C2 = Opnd2->getConstPart(); APInt C3 = C1 ^ C2; Res = createAndInstr(I, X, C3); } |