[ConstantRange] Implement getSignedMin/Max in a less complicated and faster way
Summary: As far as I can tell we should be able to implement these almost the same way we do unsigned, but using signed comparisons and checks for min signed value instead of min unsigned value.
Reviewers: pete, davide, sanjoy
Reviewed By: davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33815
llvm-svn: 305607
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 21d1996..5f44af2 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -284,27 +284,14 @@
}
APInt ConstantRange::getSignedMax() const {
- if (!isWrappedSet()) {
- APInt UpperMinusOne = getUpper() - 1;
- if (getLower().sle(UpperMinusOne))
- return UpperMinusOne;
- return APInt::getSignedMaxValue(getBitWidth());
- }
- if (getLower().isNegative() == getUpper().isNegative())
+ if (isFullSet() || Lower.sgt(Upper))
return APInt::getSignedMaxValue(getBitWidth());
return getUpper() - 1;
}
APInt ConstantRange::getSignedMin() const {
- if (!isWrappedSet()) {
- if (getLower().sle(getUpper() - 1))
- return getLower();
+ if (isFullSet() || (Lower.sgt(Upper) && !getUpper().isMinSignedValue()))
return APInt::getSignedMinValue(getBitWidth());
- }
- if ((getUpper() - 1).slt(getLower())) {
- if (!getUpper().isMinSignedValue())
- return APInt::getSignedMinValue(getBitWidth());
- }
return getLower();
}