[llvm] e3fbf19 - [SLP] getSpillCost - fully populate IntrinsicCostAttributes to improve cost analysis. (#124129) (REAPPLIED)

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2025-02-03T09:55:41Z
New Revision: e3fbf19eb4428cac03c0e7301512f11f8947d743

URL: https://github.com/llvm/llvm-project/commit/e3fbf19eb4428cac03c0e7301512f11f8947d743
DIFF: https://github.com/llvm/llvm-project/commit/e3fbf19eb4428cac03c0e7301512f11f8947d743.diff

LOG: [SLP] getSpillCost - fully populate IntrinsicCostAttributes to improve cost analysis. (#124129) (REAPPLIED)

We were only constructing the IntrinsicCostAttributes with the arg type info, and not the args themselves, preventing more detailed cost analysis (constant / uniform args etc.)

Just pass the whole IntrinsicInst to the constructor and let it resolve everything it can.

Noticed while having yet another attempt at #63980

Reapplied cleanup now that #125223 and #124984 have landed.

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 da073f38b53fb2..4f83b9cfa18d65 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -12238,18 +12238,12 @@ InstructionCost BoUpSLP::getSpillCost() {
           return false;
         if (II->isAssumeLikeIntrinsic())
           return true;
-        FastMathFlags FMF;
-        SmallVector<Type *, 4> Tys;
-        for (auto &ArgOp : II->args())
-          Tys.push_back(ArgOp->getType());
-        if (auto *FPMO = dyn_cast<FPMathOperator>(II))
-          FMF = FPMO->getFastMathFlags();
-        IntrinsicCostAttributes ICA(II->getIntrinsicID(), II->getType(), Tys,
-                                    FMF);
+        IntrinsicCostAttributes ICA(II->getIntrinsicID(), *II);
         InstructionCost IntrCost =
             TTI->getIntrinsicInstrCost(ICA, TTI::TCK_RecipThroughput);
-        InstructionCost CallCost = TTI->getCallInstrCost(
-            nullptr, II->getType(), Tys, TTI::TCK_RecipThroughput);
+        InstructionCost CallCost =
+            TTI->getCallInstrCost(nullptr, II->getType(), ICA.getArgTypes(),
+                                  TTI::TCK_RecipThroughput);
         return IntrCost < CallCost;
       };