[llvm] [Reland] Adjust bit cast instruction filter for DXIL Prepare pass (PR #143783)

Joshua Batista via llvm-commits llvm-commits at lists.llvm.org
Mon Jun 16 10:34:34 PDT 2025


https://github.com/bob80905 updated https://github.com/llvm/llvm-project/pull/143783

>From e850ff32f584ab7c9d14aa8c05ad0dbe4cc9f934 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Tue, 3 Jun 2025 15:03:02 -0700
Subject: [PATCH 1/9] first attempt

---
 llvm/lib/Target/DirectX/DXILPrepare.cpp       | 37 +++++++++++++++++-
 .../DirectX/noop_bitcast_global_array_type.ll | 39 +++++++++++++++++++
 2 files changed, 74 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll

diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index e0068787f5e5a..54e4499830ff0 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -148,9 +148,42 @@ class DXILPrepareModule : public ModulePass {
                                      Type *Ty) {
     // Omit bitcasts if the incoming value matches the instruction type.
     auto It = PointerTypes.find(Operand);
-    if (It != PointerTypes.end())
-      if (cast<TypedPointerType>(It->second)->getElementType() == Ty)
+    if (It != PointerTypes.end()) {
+      auto OpTy = cast<TypedPointerType>(It->second)->getElementType();
+      if (OpTy == Ty)
         return nullptr;
+    }
+
+    // Also omit the bitcast for matching global array types
+    if (auto *GlobalVar = llvm::dyn_cast<llvm::GlobalVariable>(Operand)) {
+      llvm::Type *ValTy = GlobalVar->getValueType();
+
+      if (auto *ArrTy = llvm::dyn_cast<llvm::ArrayType>(ValTy)) {
+        llvm::Type *ElTy = ArrTy->getElementType();
+        if (ElTy == Ty)
+          return nullptr;
+      }
+    }
+
+    // finally, drill down GEP instructions until we get the array
+    // that is being accessed, and compare element types
+    if (auto *GEPInstr = llvm::dyn_cast<llvm::ConstantExpr>(Operand)) {
+      while (GEPInstr->getOpcode() == llvm::Instruction::GetElementPtr) {
+        llvm::Value *OpArg = GEPInstr->getOperand(0);
+
+        if (auto *GlobalVar = llvm::dyn_cast<llvm::GlobalVariable>(OpArg)) {
+          llvm::Constant *initializer = GlobalVar->getInitializer();
+
+          llvm::Type *ValTy = GlobalVar->getValueType();
+          if (auto *ArrTy = llvm::dyn_cast<llvm::ArrayType>(ValTy)) {
+            llvm::Type *ElTy = ArrTy->getElementType();
+            if (ElTy == Ty)
+              return nullptr;
+          }
+        }
+      }
+    }
+
     // Insert bitcasts where we are removing the instruction.
     Builder.SetInsertPoint(&Inst);
     // This code only gets hit in opaque-pointer mode, so the type of the
diff --git a/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
new file mode 100644
index 0000000000000..4cca76efcf461
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
@@ -0,0 +1,39 @@
+; RUN: opt -S --dxil-prepare %s | FileCheck %s
+
+; Test that global arrays do not get a bitcast instruction
+; after the dxil-prepare pass.
+
+target triple = "dxilv1.2-unknown-shadermodel6.2-compute"
+
+ at inputTile.1dim = local_unnamed_addr addrspace(3) global [3 x float] zeroinitializer, align 2
+
+define float @testload() local_unnamed_addr {
+  ; NOTE: this would be "bitcast ptr addrspace(3)..." before the change that introduced this test,
+  ; after the dxil-prepare pass is run
+  ; CHECK: load float, ptr addrspace(3) @inputTile.1dim, align 2
+  %v = load float, ptr addrspace(3) @inputTile.1dim, align 2  
+  
+  ret float %v
+}
+
+define void @teststore() local_unnamed_addr {  
+  ; CHECK: store float 2.000000e+00, ptr addrspace(3) @inputTile.1dim, align 2
+  store float 2.000000e+00, ptr addrspace(3) @inputTile.1dim, align 2  
+  
+  ret void
+}
+
+define float @testGEPConst() local_unnamed_addr {  
+  ; CHECK: load float, ptr addrspace(3) getelementptr (float, ptr addrspace(3) @inputTile.1dim, i32 1), align 4
+  %v = load float, ptr addrspace(3) getelementptr (float, ptr addrspace(3) @inputTile.1dim, i32 1), align 4
+  
+  ret float %v
+}
+
+define float @testGEPNonConst(i32 %i) local_unnamed_addr {  
+  ; CHECK: getelementptr float, ptr addrspace(3) @inputTile.1dim, i32 %i
+  %gep = getelementptr float, ptr addrspace(3) @inputTile.1dim, i32 %i
+  %v = load float, ptr addrspace(3) %gep
+  
+  ret float %v
+}

>From 0c5b90283b1bd2682a443bd7e11ffcba50379944 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Tue, 3 Jun 2025 16:24:48 -0700
Subject: [PATCH 2/9] fix while loop

---
 llvm/lib/Target/DirectX/DXILPrepare.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index 54e4499830ff0..8bd5e40100de0 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -167,13 +167,17 @@ class DXILPrepareModule : public ModulePass {
 
     // finally, drill down GEP instructions until we get the array
     // that is being accessed, and compare element types
-    if (auto *GEPInstr = llvm::dyn_cast<llvm::ConstantExpr>(Operand)) {
+    if (llvm::ConstantExpr *GEPInstr =
+            llvm::dyn_cast<llvm::ConstantExpr>(Operand)) {
       while (GEPInstr->getOpcode() == llvm::Instruction::GetElementPtr) {
         llvm::Value *OpArg = GEPInstr->getOperand(0);
+        if (llvm::ConstantExpr *NewGEPInstr =
+                llvm::dyn_cast<llvm::ConstantExpr>(OpArg)) {
+          GEPInstr = NewGEPInstr;
+          continue;
+        }
 
         if (auto *GlobalVar = llvm::dyn_cast<llvm::GlobalVariable>(OpArg)) {
-          llvm::Constant *initializer = GlobalVar->getInitializer();
-
           llvm::Type *ValTy = GlobalVar->getValueType();
           if (auto *ArrTy = llvm::dyn_cast<llvm::ArrayType>(ValTy)) {
             llvm::Type *ElTy = ArrTy->getElementType();
@@ -181,6 +185,7 @@ class DXILPrepareModule : public ModulePass {
               return nullptr;
           }
         }
+        break;
       }
     }
 

>From 38feb9411aa586aa2009c0fa98c4e27d6d0bc77b Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Tue, 3 Jun 2025 17:05:46 -0700
Subject: [PATCH 3/9] add check label and check next

---
 .../DirectX/noop_bitcast_global_array_type.ll        | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
index 4cca76efcf461..396643b06609a 100644
--- a/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
+++ b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
@@ -7,31 +7,35 @@ target triple = "dxilv1.2-unknown-shadermodel6.2-compute"
 
 @inputTile.1dim = local_unnamed_addr addrspace(3) global [3 x float] zeroinitializer, align 2
 
+; CHECK-LABEL: testload
 define float @testload() local_unnamed_addr {
   ; NOTE: this would be "bitcast ptr addrspace(3)..." before the change that introduced this test,
   ; after the dxil-prepare pass is run
-  ; CHECK: load float, ptr addrspace(3) @inputTile.1dim, align 2
+  ; CHECK-NEXT: load float, ptr addrspace(3) @inputTile.1dim, align 2
   %v = load float, ptr addrspace(3) @inputTile.1dim, align 2  
   
   ret float %v
 }
 
+; CHECK-LABEL: teststore
 define void @teststore() local_unnamed_addr {  
-  ; CHECK: store float 2.000000e+00, ptr addrspace(3) @inputTile.1dim, align 2
+  ; CHECK-next: store float 2.000000e+00, ptr addrspace(3) @inputTile.1dim, align 2
   store float 2.000000e+00, ptr addrspace(3) @inputTile.1dim, align 2  
   
   ret void
 }
 
+; CHECK-LABEL: testGEPConst
 define float @testGEPConst() local_unnamed_addr {  
-  ; CHECK: load float, ptr addrspace(3) getelementptr (float, ptr addrspace(3) @inputTile.1dim, i32 1), align 4
+  ; CHECK-NEXT: load float, ptr addrspace(3) getelementptr (float, ptr addrspace(3) @inputTile.1dim, i32 1), align 4
   %v = load float, ptr addrspace(3) getelementptr (float, ptr addrspace(3) @inputTile.1dim, i32 1), align 4
   
   ret float %v
 }
 
+; CHECK-LABEL: testGEPNonConst
 define float @testGEPNonConst(i32 %i) local_unnamed_addr {  
-  ; CHECK: getelementptr float, ptr addrspace(3) @inputTile.1dim, i32 %i
+  ; CHECK-NEXT: getelementptr float, ptr addrspace(3) @inputTile.1dim, i32 %i
   %gep = getelementptr float, ptr addrspace(3) @inputTile.1dim, i32 %i
   %v = load float, ptr addrspace(3) %gep
   

>From 248b1edf7d2f7dab0caddcc94a4d749744bad106 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Wed, 4 Jun 2025 11:31:28 -0700
Subject: [PATCH 4/9] update test

---
 .../DirectX/llc-vector-load-scalarize.ll      | 58 ++++++++-----------
 1 file changed, 23 insertions(+), 35 deletions(-)

diff --git a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
index 7e5a92e1311f8..e5aa4ff1e1db9 100644
--- a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
+++ b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
@@ -60,19 +60,15 @@ define <4 x i32> @load_array_vec_test() #0 {
 define <4 x i32> @load_vec_test() #0 {
 ; CHECK-LABEL: define <4 x i32> @load_vec_test(
 ; CHECK-SAME: ) #[[ATTR0]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = bitcast ptr addrspace(3) @vecData.scalarized to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) [[TMP1]], align 4
-; CHECK-NEXT:    [[TMP3:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 1) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) [[TMP3]], align 4
-; CHECK-NEXT:    [[TMP5:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 2) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP6:%.*]] = load i32, ptr addrspace(3) [[TMP5]], align 4
-; CHECK-NEXT:    [[TMP7:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 3) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP8:%.*]] = load i32, ptr addrspace(3) [[TMP7]], align 4
-; CHECK-NEXT:    [[DOTUPTO0:%.*]] = insertelement <4 x i32> poison, i32 [[TMP2]], i32 0
-; CHECK-NEXT:    [[DOTUPTO1:%.*]] = insertelement <4 x i32> [[DOTUPTO0]], i32 [[TMP4]], i32 1
-; CHECK-NEXT:    [[DOTUPTO2:%.*]] = insertelement <4 x i32> [[DOTUPTO1]], i32 [[TMP6]], i32 2
-; CHECK-NEXT:    [[TMP9:%.*]] = insertelement <4 x i32> [[DOTUPTO2]], i32 [[TMP8]], i32 3
-; CHECK-NEXT:    ret <4 x i32> [[TMP9]]
+; CHECK-NEXT:    [[TMP1:%.*]] = load i32, ptr addrspace(3) @vecData.scalarized, align 4
+; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 1), align 4
+; CHECK-NEXT:    [[TMP3:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 2), align 4
+; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @vecData.scalarized, i32 3), align 4
+; CHECK-NEXT:    [[DOTUPTO0:%.*]] = insertelement <4 x i32> poison, i32 [[TMP1]], i32 0
+; CHECK-NEXT:    [[DOTUPTO1:%.*]] = insertelement <4 x i32> [[DOTUPTO0]], i32 [[TMP2]], i32 1
+; CHECK-NEXT:    [[DOTUPTO2:%.*]] = insertelement <4 x i32> [[DOTUPTO1]], i32 [[TMP3]], i32 2
+; CHECK-NEXT:    [[TMP5:%.*]] = insertelement <4 x i32> [[DOTUPTO2]], i32 [[TMP4]], i32 3
+; CHECK-NEXT:    ret <4 x i32> [[TMP5]]
 ;
   %1 = load <4 x i32>, <4 x i32> addrspace(3)* @"vecData", align 4
   ret <4 x i32> %1
@@ -107,31 +103,23 @@ define <4 x i32> @load_static_array_of_vec_test(i32 %index) #0 {
 define <4 x i32> @multid_load_test() #0 {
 ; CHECK-LABEL: define <4 x i32> @multid_load_test(
 ; CHECK-SAME: ) #[[ATTR0]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = bitcast ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) [[TMP1]], align 4
-; CHECK-NEXT:    [[TMP3:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) [[TMP3]], align 4
-; CHECK-NEXT:    [[TMP5:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 2) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP6:%.*]] = load i32, ptr addrspace(3) [[TMP5]], align 4
-; CHECK-NEXT:    [[TMP7:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 3) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP8:%.*]] = load i32, ptr addrspace(3) [[TMP7]], align 4
-; CHECK-NEXT:    [[TMP11:%.*]] = bitcast ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1) to ptr addrspace(3)
-; CHECK-NEXT:    [[TMP12:%.*]] = load i32, ptr addrspace(3) [[TMP11]], align 4
-; CHECK-NEXT:    [[DOTI12:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 1) to ptr addrspace(3)
-; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) [[DOTI12]], align 4
-; CHECK-NEXT:    [[DOTI24:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 2) to ptr addrspace(3)
-; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) [[DOTI24]], align 4
-; CHECK-NEXT:    [[DOTI36:%.*]] = bitcast ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 3) to ptr addrspace(3)
-; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) [[DOTI36]], align 4
-; CHECK-NEXT:    [[DOTI08:%.*]] = add i32 [[TMP2]], [[TMP12]]
-; CHECK-NEXT:    [[DOTI19:%.*]] = add i32 [[TMP4]], [[DOTI13]]
-; CHECK-NEXT:    [[DOTI210:%.*]] = add i32 [[TMP6]], [[DOTI25]]
-; CHECK-NEXT:    [[DOTI311:%.*]] = add i32 [[TMP8]], [[DOTI37]]
+; CHECK-NEXT:    [[TMP1:%.*]] = load i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, align 4
+; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
+; CHECK-NEXT:    [[TMP3:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 2), align 4
+; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 3), align 4
+; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
+; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 1), align 4
+; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 2), align 4
+; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 3), align 4
+; CHECK-NEXT:    [[DOTI08:%.*]] = add i32 [[TMP1]], [[TMP5]]
+; CHECK-NEXT:    [[DOTI19:%.*]] = add i32 [[TMP2]], [[DOTI13]]
+; CHECK-NEXT:    [[DOTI210:%.*]] = add i32 [[TMP3]], [[DOTI25]]
+; CHECK-NEXT:    [[DOTI311:%.*]] = add i32 [[TMP4]], [[DOTI37]]
 ; CHECK-NEXT:    [[DOTUPTO015:%.*]] = insertelement <4 x i32> poison, i32 [[DOTI08]], i32 0
 ; CHECK-NEXT:    [[DOTUPTO116:%.*]] = insertelement <4 x i32> [[DOTUPTO015]], i32 [[DOTI19]], i32 1
 ; CHECK-NEXT:    [[DOTUPTO217:%.*]] = insertelement <4 x i32> [[DOTUPTO116]], i32 [[DOTI210]], i32 2
-; CHECK-NEXT:    [[TMP16:%.*]] = insertelement <4 x i32> [[DOTUPTO217]], i32 [[DOTI311]], i32 3
-; CHECK-NEXT:    ret <4 x i32> [[TMP16]]
+; CHECK-NEXT:    [[TMP6:%.*]] = insertelement <4 x i32> [[DOTUPTO217]], i32 [[DOTI311]], i32 3
+; CHECK-NEXT:    ret <4 x i32> [[TMP6]]
 ;
   %1 = load <4 x i32>, <4 x i32> addrspace(3)* getelementptr inbounds ([3 x [3 x <4 x i32>]], [3 x [3 x <4 x i32>]] addrspace(3)* @"groushared2dArrayofVectors", i32 0, i32 0, i32 0), align 4
   %2 = load <4 x i32>, <4 x i32> addrspace(3)* getelementptr inbounds ([3 x [3 x <4 x i32>]], [3 x [3 x <4 x i32>]] addrspace(3)* @"groushared2dArrayofVectors", i32 0, i32 1, i32 1), align 4

>From 681fe9aeb1c3f696794ee083376c13a1d2faded8 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Wed, 4 Jun 2025 12:51:34 -0700
Subject: [PATCH 5/9] force pointer type deduction

---
 llvm/lib/Target/DirectX/DXILPrepare.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index 8bd5e40100de0..ec50aa149ceb5 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -149,7 +149,7 @@ class DXILPrepareModule : public ModulePass {
     // Omit bitcasts if the incoming value matches the instruction type.
     auto It = PointerTypes.find(Operand);
     if (It != PointerTypes.end()) {
-      auto OpTy = cast<TypedPointerType>(It->second)->getElementType();
+      auto *OpTy = cast<TypedPointerType>(It->second)->getElementType();
       if (OpTy == Ty)
         return nullptr;
     }

>From 1554fca27842c6d94ad22dff2b36e2e962fe6f11 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Wed, 4 Jun 2025 17:13:55 -0700
Subject: [PATCH 6/9] remove llvm:: namespace, and add alloca case

---
 llvm/lib/Target/DirectX/DXILPrepare.cpp | 31 ++++++++++++++-----------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index ec50aa149ceb5..6a7ae9e704264 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -155,32 +155,35 @@ class DXILPrepareModule : public ModulePass {
     }
 
     // Also omit the bitcast for matching global array types
-    if (auto *GlobalVar = llvm::dyn_cast<llvm::GlobalVariable>(Operand)) {
-      llvm::Type *ValTy = GlobalVar->getValueType();
+    if (auto *GlobalVar = dyn_cast<GlobalVariable>(Operand)) {
+      Type *ValTy = GlobalVar->getValueType();
 
-      if (auto *ArrTy = llvm::dyn_cast<llvm::ArrayType>(ValTy)) {
-        llvm::Type *ElTy = ArrTy->getElementType();
+      if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
+        Type *ElTy = ArrTy->getElementType();
         if (ElTy == Ty)
           return nullptr;
       }
     }
 
+    // Also omit the bitcast for alloca instructions
+    if (auto *AI = dyn_cast<AllocaInst>(Operand)) {
+      return nullptr;
+    }
+
     // finally, drill down GEP instructions until we get the array
     // that is being accessed, and compare element types
-    if (llvm::ConstantExpr *GEPInstr =
-            llvm::dyn_cast<llvm::ConstantExpr>(Operand)) {
-      while (GEPInstr->getOpcode() == llvm::Instruction::GetElementPtr) {
-        llvm::Value *OpArg = GEPInstr->getOperand(0);
-        if (llvm::ConstantExpr *NewGEPInstr =
-                llvm::dyn_cast<llvm::ConstantExpr>(OpArg)) {
+    if (ConstantExpr *GEPInstr = dyn_cast<ConstantExpr>(Operand)) {
+      while (GEPInstr->getOpcode() == Instruction::GetElementPtr) {
+        Value *OpArg = GEPInstr->getOperand(0);
+        if (ConstantExpr *NewGEPInstr = dyn_cast<ConstantExpr>(OpArg)) {
           GEPInstr = NewGEPInstr;
           continue;
         }
 
-        if (auto *GlobalVar = llvm::dyn_cast<llvm::GlobalVariable>(OpArg)) {
-          llvm::Type *ValTy = GlobalVar->getValueType();
-          if (auto *ArrTy = llvm::dyn_cast<llvm::ArrayType>(ValTy)) {
-            llvm::Type *ElTy = ArrTy->getElementType();
+        if (auto *GlobalVar = dyn_cast<GlobalVariable>(OpArg)) {
+          Type *ValTy = GlobalVar->getValueType();
+          if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
+            Type *ElTy = ArrTy->getElementType();
             if (ElTy == Ty)
               return nullptr;
           }

>From a84a7c27bb2dc991d444aa0560119a13ea148060 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Wed, 4 Jun 2025 18:51:24 -0700
Subject: [PATCH 7/9] adjust alloca logic and test

---
 llvm/lib/Target/DirectX/DXILPrepare.cpp       | 35 +++++++++----------
 .../DirectX/noop_bitcast_global_array_type.ll | 10 ++++++
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index 6a7ae9e704264..cb58f4833631d 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -154,20 +154,18 @@ class DXILPrepareModule : public ModulePass {
         return nullptr;
     }
 
+    Type *ValTy = Operand->getType();
     // Also omit the bitcast for matching global array types
-    if (auto *GlobalVar = dyn_cast<GlobalVariable>(Operand)) {
-      Type *ValTy = GlobalVar->getValueType();
+    if (auto *GlobalVar = dyn_cast<GlobalVariable>(Operand))
+      ValTy = GlobalVar->getValueType();
 
-      if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
-        Type *ElTy = ArrTy->getElementType();
-        if (ElTy == Ty)
-          return nullptr;
-      }
-    }
+    if (auto *AI = dyn_cast<AllocaInst>(Operand))
+      ValTy = AI->getAllocatedType();
 
-    // Also omit the bitcast for alloca instructions
-    if (auto *AI = dyn_cast<AllocaInst>(Operand)) {
-      return nullptr;
+    if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
+      Type *ElTy = ArrTy->getElementType();
+      if (ElTy == Ty)
+        return nullptr;
     }
 
     // finally, drill down GEP instructions until we get the array
@@ -180,13 +178,14 @@ class DXILPrepareModule : public ModulePass {
           continue;
         }
 
-        if (auto *GlobalVar = dyn_cast<GlobalVariable>(OpArg)) {
-          Type *ValTy = GlobalVar->getValueType();
-          if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
-            Type *ElTy = ArrTy->getElementType();
-            if (ElTy == Ty)
-              return nullptr;
-          }
+        if (auto *GlobalVar = dyn_cast<GlobalVariable>(OpArg))
+          ValTy = GlobalVar->getValueType();
+        if (auto *AI = dyn_cast<AllocaInst>(Operand))
+          ValTy = AI->getAllocatedType();
+        if (auto *ArrTy = dyn_cast<ArrayType>(ValTy)) {
+          Type *ElTy = ArrTy->getElementType();
+          if (ElTy == Ty)
+            return nullptr;
         }
         break;
       }
diff --git a/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
index 396643b06609a..1f33700e014c7 100644
--- a/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
+++ b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
@@ -41,3 +41,13 @@ define float @testGEPNonConst(i32 %i) local_unnamed_addr {
   
   ret float %v
 }
+
+; CHECK-LABEL: testAlloca
+define float @testAlloca(i32 %i) local_unnamed_addr {  
+  ; CHECK-NEXT: alloca [3 x float], align 4
+  %arr = alloca [3 x float], align 4
+  ; CHECK-NEXT: getelementptr [3 x float], ptr %arr, i32 1
+  %gep = getelementptr [3 x float], ptr %arr, i32 1
+  %v = load float, ptr %gep
+  ret float %v
+}

>From 02252fdeb4038744c27b932337a4c138a9305ad7 Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Thu, 5 Jun 2025 12:13:25 -0700
Subject: [PATCH 8/9] fix args

---
 llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
index e5aa4ff1e1db9..30ee555ca2dda 100644
--- a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
+++ b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
@@ -107,10 +107,10 @@ define <4 x i32> @multid_load_test() #0 {
 ; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
 ; CHECK-NEXT:    [[TMP3:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 2), align 4
 ; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 3), align 4
-; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
-; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 1), align 4
-; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 2), align 4
-; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 3), align 4
+; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), align 4
+; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 1), align 4
+; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 2), align 4
+; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 3), align 4
 ; CHECK-NEXT:    [[DOTI08:%.*]] = add i32 [[TMP1]], [[TMP5]]
 ; CHECK-NEXT:    [[DOTI19:%.*]] = add i32 [[TMP2]], [[DOTI13]]
 ; CHECK-NEXT:    [[DOTI210:%.*]] = add i32 [[TMP3]], [[DOTI25]]

>From b2a389acbcaf4e5d94f90acd49365a72329233df Mon Sep 17 00:00:00 2001
From: Joshua Batista <jbatista at microsoft.com>
Date: Wed, 11 Jun 2025 17:43:47 -0700
Subject: [PATCH 9/9] remove second arg

---
 llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
index 30ee555ca2dda..e5aa4ff1e1db9 100644
--- a/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
+++ b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
@@ -107,10 +107,10 @@ define <4 x i32> @multid_load_test() #0 {
 ; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
 ; CHECK-NEXT:    [[TMP3:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 2), align 4
 ; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 3), align 4
-; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), align 4
-; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 1), align 4
-; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 2), align 4
-; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 0, i32 1), i32 3), align 4
+; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), align 4
+; CHECK-NEXT:    [[DOTI13:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 1), align 4
+; CHECK-NEXT:    [[DOTI25:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 2), align 4
+; CHECK-NEXT:    [[DOTI37:%.*]] = load i32, ptr addrspace(3) getelementptr (i32, ptr addrspace(3) getelementptr inbounds ([36 x i32], ptr addrspace(3) @groushared2dArrayofVectors.scalarized.1dim, i32 1), i32 3), align 4
 ; CHECK-NEXT:    [[DOTI08:%.*]] = add i32 [[TMP1]], [[TMP5]]
 ; CHECK-NEXT:    [[DOTI19:%.*]] = add i32 [[TMP2]], [[DOTI13]]
 ; CHECK-NEXT:    [[DOTI210:%.*]] = add i32 [[TMP3]], [[DOTI25]]



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