add uadd_ov/usub_ov to apint, consolidate constant folding
logic to use the new APInt methods. Among other things this
implements rdar://8501501 - llvm.smul.with.overflow.i32 should constant fold
which comes from "clang -ftrapv", originally brought to my attention from PR8221.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116457 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index ca68988..3807314 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -2053,6 +2053,12 @@
return Res;
}
+APInt APInt::uadd_ov(const APInt &RHS, bool &Overflow) const {
+ APInt Res = *this+RHS;
+ Overflow = Res.ult(RHS);
+ return Res;
+}
+
APInt APInt::ssub_ov(const APInt &RHS, bool &Overflow) const {
APInt Res = *this - RHS;
Overflow = isNonNegative() != RHS.isNonNegative() &&
@@ -2060,6 +2066,12 @@
return Res;
}
+APInt APInt::usub_ov(const APInt &RHS, bool &Overflow) const {
+ APInt Res = *this+RHS;
+ Overflow = Res.ugt(RHS);
+ return Res;
+}
+
APInt APInt::sdiv_ov(const APInt &RHS, bool &Overflow) const {
// MININT/-1 --> overflow.
Overflow = isMinSignedValue() && RHS.isAllOnesValue();