[llvm] c2b7f09 - [SLP] make invalid operand explicit for extra arg in reduction matching; NFC

[Sanjay Patel via llvm-commits]

Author: Sanjay Patel
Date: 2021-07-09T15:32:12-04:00
New Revision: c2b7f09d8c276c83f3af5123a0ca55d62b0ffaab

URL: https://github.com/llvm/llvm-project/commit/c2b7f09d8c276c83f3af5123a0ca55d62b0ffaab
DIFF: https://github.com/llvm/llvm-project/commit/c2b7f09d8c276c83f3af5123a0ca55d62b0ffaab.diff

LOG: [SLP] make invalid operand explicit for extra arg in reduction matching; NFC

This makes it clearer when we have encountered the extra arg.
Also, we may need to adjust the way the operand iteration
works when handling logical and/or.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 246f755eac03..04ee349396cd 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -7288,6 +7288,8 @@ class HorizontalReduction {
   /// The type of reduction operation.
   RecurKind RdxKind;
 
+  const unsigned INVALID_OPERAND_INDEX = std::numeric_limits<unsigned>::max();
+
   static bool isCmpSelMinMax(Instruction *I) {
     return match(I, m_Select(m_Cmp(), m_Value(), m_Value())) &&
            RecurrenceDescriptor::isMinMaxRecurrenceKind(getRdxKind(I));
@@ -7322,7 +7324,7 @@ class HorizontalReduction {
       // in this case.
       // Do not perform analysis of remaining operands of ParentStackElem.first
       // instruction, this whole instruction is an extra argument.
-      ParentStackElem.second = getNumberOfOperands(ParentStackElem.first);
+      ParentStackElem.second = INVALID_OPERAND_INDEX;
     } else {
       // We ran into something like:
       // ParentStackElem.first += ... + ExtraArg + ...
@@ -7636,7 +7638,7 @@ class HorizontalReduction {
       bool IsReducedValue = TreeRdxKind != RdxKind;
 
       // Postorder visit.
-      if (IsReducedValue || EdgeToVisit == getNumberOfOperands(TreeN)) {
+      if (IsReducedValue || EdgeToVisit >= getNumberOfOperands(TreeN)) {
         if (IsReducedValue)
           ReducedVals.push_back(TreeN);
         else {