[llvm] [CVP] Refactor `processMinMaxIntrinsic` to use context-sensitive information (PR #82596)

[Nikita Popov via llvm-commits]

================
@@ -530,15 +530,23 @@ static bool processAbsIntrinsic(IntrinsicInst *II, LazyValueInfo *LVI) {
 // See if this min/max intrinsic always picks it's one specific operand.
 static bool processMinMaxIntrinsic(MinMaxIntrinsic *MM, LazyValueInfo *LVI) {
   CmpInst::Predicate Pred = CmpInst::getNonStrictPredicate(MM->getPredicate());
-  LazyValueInfo::Tristate Result = LVI->getPredicateAt(
-      Pred, MM->getLHS(), MM->getRHS(), MM, /*UseBlockValue=*/true);
-  if (Result == LazyValueInfo::Unknown)
-    return false;
-
-  ++NumMinMax;
-  MM->replaceAllUsesWith(MM->getOperand(!Result));
-  MM->eraseFromParent();
-  return true;
+  ConstantRange LHS_CR = LVI->getConstantRangeAtUse(MM->getOperandUse(0),
+                                                    /*UndefAllowed*/ true);
----------------
nikic wrote:

Shouldn't this be UndefAllowed=false?

https://github.com/llvm/llvm-project/pull/82596