[InstCombine] Support ssub.sat canonicalization for non-splats
Extend ssub.sat(X, C) -> sadd.sat(X, -C) canonicalization to also
support non-splat vector constants. This is done by generalizing
the implementation of the isNotMinSignedValue() helper to return
true for constants that are non-splat, but don't contain any
signed min elements.
Differential Revision: https://reviews.llvm.org/D55011
llvm-svn: 348072
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index f0b09e1..a023b6d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2104,11 +2104,10 @@
}
// ssub.sat(X, C) -> sadd.sat(X, -C) if C != MIN
- // TODO: Support non-splat C.
- const APInt *C;
- if (IID == Intrinsic::ssub_sat && match(Arg1, m_APInt(C)) &&
- !C->isMinSignedValue()) {
- Value *NegVal = ConstantInt::get(II->getType(), -*C);
+ Constant *C;
+ if (IID == Intrinsic::ssub_sat && match(Arg1, m_Constant(C)) &&
+ C->isNotMinSignedValue()) {
+ Value *NegVal = ConstantExpr::getNeg(C);
return replaceInstUsesWith(
*II, Builder.CreateBinaryIntrinsic(
Intrinsic::sadd_sat, Arg0, NegVal));