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path: root/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
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Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
-rw-r--r--lib/Transforms/InstCombine/InstCombineAndOrXor.cpp6
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 8ddaa16ee0..86673f8096 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1464,8 +1464,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (Value *V = SimplifyOrInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
-
-
+
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(I))
@@ -1474,7 +1473,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
ConstantInt *C1 = 0; Value *X = 0;
// (X & C1) | C2 --> (X | C2) & (C1|C2)
+ // iff (C1 & C2) == 0.
if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) &&
+ (RHS->getValue() & C1->getValue()) != 0 &&
Op0->hasOneUse()) {
Value *Or = Builder->CreateOr(X, RHS);
Or->takeName(Op0);
@@ -1497,6 +1498,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
+
if (isa<PHINode>(Op0))
if (Instruction *NV = FoldOpIntoPhi(I))
return NV;