================
@@ -9110,6 +9111,41 @@ void
LoopVectorizationPlanner::adjustRecipesForReductions(
continue;
const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
+ // Adjust AnyOf reductions; replace the reduction phi for the selected
value
+ // with a boolean reduction phi node to check if the condition is true in
+ // any iteration. The final value is selected by the final
+ // ComputeReductionResult.
+ if (RecurrenceDescriptor::isAnyOfRecurrenceKind(
+ RdxDesc.getRecurrenceKind())) {
+ auto *Select = cast<VPRecipeBase>(*find_if(PhiR->users(), [](VPUser *U) {
+ return isa<VPWidenSelectRecipe>(U) ||
+ (isa<VPReplicateRecipe>(U) &&
+ cast<VPReplicateRecipe>(U)->getUnderlyingInstr()->getOpcode()
==
+ Instruction::Select);
+ }));
+ VPValue *Cmp = Select->getOperand(0);
+ // If the compare is checking the reduction PHI node, adjust it to check
+ // the start value.
+ if (VPRecipeBase *CmpR = Cmp->getDefiningRecipe()) {
+ for (unsigned I = 0; I != CmpR->getNumOperands(); ++I)
+ if (CmpR->getOperand(I) == PhiR)
+ CmpR->setOperand(I, PhiR->getStartValue());
+ }
+ VPBuilder::InsertPointGuard Guard(Builder);
+ Builder.setInsertPoint(Select);
+
+ // If the true value of the select is the reduction phi, the new value is
+ // selected if the negated condition is true in any iteration.
+ if (Select->getOperand(1) == PhiR)
+ Cmp = Builder.createNot(Cmp);
----------------
ayalz wrote:
As Mel pointed out, this case of "Red = cond ? PhiR : Other" where a single
false cond suffices for the result to be Other, could be considered an `AllOf`
reduction starting with true using createAnd() instead of createOr(), resulting
in "AND(conds) ? Start : Other".
Negating cond swaps the operands and translates into the "Red = !cond ? Other :
PhiR" form of an `AnyOf` reduction starting with false and using createOr(),
where a single true !cond suffices for the result to be Other, resulting in
"OR(!conds) ? Other : Start".
https://github.com/llvm/llvm-project/pull/78304
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