[llvm] 3c5f073 - [VPlan] Mark VPScalarIVStepsRecipe as not reading/writing memory.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2022-12-04T12:58:46Z
New Revision: 3c5f07349fd8861c505b7f4dc7bfbdbb720d74a5

URL: https://github.com/llvm/llvm-project/commit/3c5f07349fd8861c505b7f4dc7bfbdbb720d74a5
DIFF: https://github.com/llvm/llvm-project/commit/3c5f07349fd8861c505b7f4dc7bfbdbb720d74a5.diff

LOG: [VPlan] Mark VPScalarIVStepsRecipe as not reading/writing memory.

The recipe only computes the inductions steps using its operands. It
does neither read nor write memory.

Split of from D133760.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
    llvm/unittests/Transforms/Vectorize/VPlanTest.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 04513b8d8d101..4e9be35001adf 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -49,6 +49,7 @@ bool VPRecipeBase::mayWriteToMemory() const {
     return cast<Instruction>(getVPSingleValue()->getUnderlyingValue())
         ->mayWriteToMemory();
   case VPBranchOnMaskSC:
+  case VPScalarIVStepsSC:
     return false;
   case VPWidenIntOrFpInductionSC:
   case VPWidenCanonicalIVSC:
@@ -80,6 +81,7 @@ bool VPRecipeBase::mayReadFromMemory() const {
     return cast<Instruction>(getVPSingleValue()->getUnderlyingValue())
         ->mayReadFromMemory();
   case VPBranchOnMaskSC:
+  case VPScalarIVStepsSC:
     return false;
   case VPWidenIntOrFpInductionSC:
   case VPWidenCanonicalIVSC:

diff  --git a/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp b/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
index 34522ad607d71..d4c12eb3fab57 100644
--- a/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
@@ -1080,9 +1080,9 @@ TEST(VPRecipeTest, MayHaveSideEffectsAndMayReadWriteMemory) {
     InductionDescriptor IndDesc;
     VPScalarIVStepsRecipe Recipe(IndDesc, &Op1, &Op2);
     EXPECT_FALSE(Recipe.mayHaveSideEffects());
-    EXPECT_TRUE(Recipe.mayReadFromMemory());
-    EXPECT_TRUE(Recipe.mayWriteToMemory());
-    EXPECT_TRUE(Recipe.mayReadOrWriteMemory());
+    EXPECT_FALSE(Recipe.mayReadFromMemory());
+    EXPECT_FALSE(Recipe.mayWriteToMemory());
+    EXPECT_FALSE(Recipe.mayReadOrWriteMemory());
   }
 
   // The initial implementation is conservative with respect to VPInstructions.