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-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp38
1 files changed, 20 insertions, 18 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 151216860fd..eafb32b1b83 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2105,24 +2105,26 @@ Instruction *InstCombiner::foldICmpShrConstant(ICmpInst &ICI, Instruction *LHSI,
Instruction *InstCombiner::foldICmpUDivConstant(ICmpInst &Cmp,
Instruction *UDiv,
const APInt *C) {
- // FIXME: This check restricts all folds under here to scalar types.
- if (ConstantInt *DivLHS = dyn_cast<ConstantInt>(UDiv->getOperand(0))) {
- Value *X = UDiv->getOperand(1);
- const APInt &C2 = DivLHS->getValue();
- assert(C2 != 0 && "udiv 0, X should have been simplified already.");
- // (icmp ugt (udiv C2, X), C1) -> (icmp ule X, C2/(C1+1))
- if (Cmp.getPredicate() == ICmpInst::ICMP_UGT) {
- assert(!C->isMaxValue() &&
- "icmp ugt X, UINT_MAX should have been simplified already.");
- return new ICmpInst(ICmpInst::ICMP_ULE, X,
- ConstantInt::get(X->getType(), C2.udiv(*C + 1)));
- }
- // (icmp ult (udiv C2, X), C1) -> (icmp ugt X, C2/C1)
- if (Cmp.getPredicate() == ICmpInst::ICMP_ULT) {
- assert(C != 0 && "icmp ult X, 0 should have been simplified already.");
- return new ICmpInst(ICmpInst::ICMP_UGT, X,
- ConstantInt::get(X->getType(), C2.udiv(*C)));
- }
+ const APInt *C2;
+ if (!match(UDiv->getOperand(0), m_APInt(C2)))
+ return nullptr;
+
+ assert(C2 != 0 && "udiv 0, X should have been simplified already.");
+
+ // (icmp ugt (udiv C2, Y), C) -> (icmp ule Y, C2/(C+1))
+ Value *Y = UDiv->getOperand(1);
+ if (Cmp.getPredicate() == ICmpInst::ICMP_UGT) {
+ assert(!C->isMaxValue() &&
+ "icmp ugt X, UINT_MAX should have been simplified already.");
+ return new ICmpInst(ICmpInst::ICMP_ULE, Y,
+ ConstantInt::get(Y->getType(), C2->udiv(*C + 1)));
+ }
+
+ // (icmp ult (udiv C2, Y), C) -> (icmp ugt Y, C2/C)
+ if (Cmp.getPredicate() == ICmpInst::ICMP_ULT) {
+ assert(C != 0 && "icmp ult X, 0 should have been simplified already.");
+ return new ICmpInst(ICmpInst::ICMP_UGT, Y,
+ ConstantInt::get(Y->getType(), C2->udiv(*C)));
}
return nullptr;
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