[llvm-branch-commits] [llvm] [Vectorizer] fix GEPs incorrectly marked as "inbounds" (PR #120730)

[Florian Mayer via llvm-branch-commits]

https://github.com/fmayer updated https://github.com/llvm/llvm-project/pull/120730

>From 5987219575feabd0eefba5932c21b0eba8ae4fb7 Mon Sep 17 00:00:00 2001
From: Florian Mayer <fmayer at google.com>
Date: Fri, 20 Dec 2024 05:35:56 -0800
Subject: [PATCH 1/3] simplify

Created using spr 1.3.4
---
 llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 0768eccc8aeb35..ffd89466abeea9 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -1986,12 +1986,12 @@ void VPReverseVectorPointerRecipe::execute(VPTransformState &State) {
   // LastLane = 1 - RunTimeVF
   Value *LastLane = Builder.CreateSub(ConstantInt::get(IndexTy, 1), RunTimeVF);
   Value *Ptr = State.get(getOperand(0), VPLane(0));
-  Value *ResultPtr = Builder.CreateGEP(
-      IndexedTy, Ptr, NumElt, "",
-      getGEPNoWrapFlags().withoutInBounds().withoutNoUnsignedSignedWrap());
-  ResultPtr = Builder.CreateGEP(
-      IndexedTy, ResultPtr, LastLane, "",
-      getGEPNoWrapFlags().withoutInBounds().withoutNoUnsignedSignedWrap());
+  Value *ResultPtr =
+      Builder.CreateGEP(IndexedTy, Ptr, NumElt, "",
+                        getGEPNoWrapFlags().withoutNoUnsignedSignedWrap());
+  ResultPtr =
+      Builder.CreateGEP(IndexedTy, ResultPtr, LastLane, "",
+                        getGEPNoWrapFlags().withoutNoUnsignedSignedWrap());
 
   State.set(this, ResultPtr, /*IsScalar*/ true);
 }

>From e4e48cf7e0448f25ccdcdf7d7c262ac880853ddd Mon Sep 17 00:00:00 2001
From: Florian Mayer <fmayer at google.com>
Date: Fri, 20 Dec 2024 05:40:10 -0800
Subject: [PATCH 2/3] address comment

Created using spr 1.3.4
---
 llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index ffd89466abeea9..f97cae215ec087 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -1986,12 +1986,10 @@ void VPReverseVectorPointerRecipe::execute(VPTransformState &State) {
   // LastLane = 1 - RunTimeVF
   Value *LastLane = Builder.CreateSub(ConstantInt::get(IndexTy, 1), RunTimeVF);
   Value *Ptr = State.get(getOperand(0), VPLane(0));
-  Value *ResultPtr =
-      Builder.CreateGEP(IndexedTy, Ptr, NumElt, "",
-                        getGEPNoWrapFlags().withoutNoUnsignedSignedWrap());
-  ResultPtr =
-      Builder.CreateGEP(IndexedTy, ResultPtr, LastLane, "",
-                        getGEPNoWrapFlags().withoutNoUnsignedSignedWrap());
+  // N.B. we deliberately do not use getGEPNoWrapFlags here, because this
+  // transform can invalidate `inbounds`.
+  Value *ResultPtr = Builder.CreateGEP(IndexedTy, Ptr, NumElt, "");
+  ResultPtr = Builder.CreateGEP(IndexedTy, ResultPtr, LastLane, "");
 
   State.set(this, ResultPtr, /*IsScalar*/ true);
 }

>From 88971013ce379e6a7259544666c40c65410c4f00 Mon Sep 17 00:00:00 2001
From: Florian Mayer <fmayer at google.com>
Date: Fri, 20 Dec 2024 06:12:55 -0800
Subject: [PATCH 3/3] address

Created using spr 1.3.4
---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 5 +++--
 llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp  | 8 ++++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 1f6996cd9c1f49..65de01471a91ef 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8436,10 +8436,11 @@ VPRecipeBuilder::tryToWidenMemory(Instruction *I, ArrayRef<VPValue *> Operands,
         Ptr->getUnderlyingValue()->stripPointerCasts());
     VPSingleDefRecipe *VectorPtr;
     if (Reverse)
+      // N.B. we deliberately do pass getGEPNoWrapFlags here, because this
+      // transform can invalidate `inbounds`.
       VectorPtr = new VPReverseVectorPointerRecipe(
           Ptr, &Plan.getVF(), getLoadStoreType(I),
-          GEP && GEP->isInBounds() ? GEPNoWrapFlags::inBounds()
-                                   : GEPNoWrapFlags::none(),
+          GEPNoWrapFlags::none(),
           I->getDebugLoc());
     else
       VectorPtr = new VPVectorPointerRecipe(Ptr, getLoadStoreType(I),
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index f97cae215ec087..cda90d70e5c8da 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -1986,10 +1986,10 @@ void VPReverseVectorPointerRecipe::execute(VPTransformState &State) {
   // LastLane = 1 - RunTimeVF
   Value *LastLane = Builder.CreateSub(ConstantInt::get(IndexTy, 1), RunTimeVF);
   Value *Ptr = State.get(getOperand(0), VPLane(0));
-  // N.B. we deliberately do not use getGEPNoWrapFlags here, because this
-  // transform can invalidate `inbounds`.
-  Value *ResultPtr = Builder.CreateGEP(IndexedTy, Ptr, NumElt, "");
-  ResultPtr = Builder.CreateGEP(IndexedTy, ResultPtr, LastLane, "");
+  Value *ResultPtr =
+      Builder.CreateGEP(IndexedTy, Ptr, NumElt, "", getGEPNoWrapFlags());
+  ResultPtr = Builder.CreateGEP(IndexedTy, ResultPtr, LastLane, "",
+                                getGEPNoWrapFlags());
 
   State.set(this, ResultPtr, /*IsScalar*/ true);
 }