[ValueTracking] Add support for non-splat vecs in cmpExcludesZero

Just a small QOL change.

Author: goldsteinn

llvm/lib/Analysis/ValueTracking.cpp

@@ -567,11 +567,24 @@ static bool cmpExcludesZero(CmpInst::Predicate Pred, const Value *RHS) {
 
   // All other predicates - rely on generic ConstantRange handling.
   const APInt *C;
-  if (!match(RHS, m_APInt(C)))
+  auto Zero = APInt::getZero(RHS->getType()->getScalarSizeInBits());
+  if (match(RHS, m_APInt(C))) {
+    ConstantRange TrueValues = ConstantRange::makeExactICmpRegion(Pred, *C);
+    return !TrueValues.contains(Zero);
+  }
+
+  auto *VC = dyn_cast<ConstantDataVector>(RHS);
+  if (VC == nullptr)
     return false;
 
-  ConstantRange TrueValues = ConstantRange::makeExactICmpRegion(Pred, *C);
-  return !TrueValues.contains(APInt::getZero(C->getBitWidth()));
+  for (unsigned ElemIdx = 0, NElem = VC->getNumElements(); ElemIdx < NElem;
+       ++ElemIdx) {
+    ConstantRange TrueValues = ConstantRange::makeExactICmpRegion(
+        Pred, VC->getElementAsAPInt(ElemIdx));
+    if (TrueValues.contains(Zero))
+      return false;
+  }
+  return true;
 }
 
 static bool isKnownNonZeroFromAssume(const Value *V, const SimplifyQuery &Q) {

llvm/test/Analysis/ValueTracking/known-non-zero.ll

@@ -1163,11 +1163,7 @@ define i1 @sdiv_known_non_zero_fail(i8 %x, i8 %y) {
 
 define <2 x i1> @cmp_excludes_zero_with_nonsplat_vec(<2 x i8> %a, <2 x i8> %b) {
 ; CHECK-LABEL: @cmp_excludes_zero_with_nonsplat_vec(
-; CHECK-NEXT:    [[C:%.*]] = icmp sge <2 x i8> [[A:%.*]], <i8 1, i8 4>
-; CHECK-NEXT:    [[S:%.*]] = select <2 x i1> [[C]], <2 x i8> [[A]], <2 x i8> <i8 4, i8 5>
-; CHECK-NEXT:    [[AND:%.*]] = or <2 x i8> [[S]], [[B:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[AND]], zeroinitializer
-; CHECK-NEXT:    ret <2 x i1> [[R]]
+; CHECK-NEXT:    ret <2 x i1> zeroinitializer
 ;
   %c = icmp sge <2 x i8> %a, <i8 1, i8 4>
   %s = select <2 x i1> %c, <2 x i8> %a, <2 x i8> <i8 4, i8 5>