"Reapply r268521 "[InstCombine] Canonicalize icmp instructions based on dominating conditions.""
This reapplies commit r268521, that was reverted in r268530 due to a test failure in select-implied.ll
Modified the test case to reflect the new change.
llvm-svn: 268557
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 417b752..a2eb151 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -127,6 +127,18 @@
.inverse();
}
+ConstantRange ConstantRange::makeExactICmpRegion(CmpInst::Predicate Pred,
+ const APInt &C) {
+ // Computes the exact range that is equal to both the constant ranges returned
+ // by makeAllowedICmpRegion and makeSatisfyingICmpRegion. This is always true
+ // when RHS is a singleton such as an APInt and so the assert is valid.
+ // However for non-singleton RHS, for example ult [2,5) makeAllowedICmpRegion
+ // returns [0,4) but makeSatisfyICmpRegion returns [0,2).
+ //
+ assert(makeAllowedICmpRegion(Pred, C) == makeSatisfyingICmpRegion(Pred, C));
+ return makeAllowedICmpRegion(Pred, C);
+}
+
ConstantRange
ConstantRange::makeGuaranteedNoWrapRegion(Instruction::BinaryOps BinOp,
const ConstantRange &Other,