[llvm] [Reland] Adjust bit cast instruction filter for DXIL Prepare pass (PR #143783)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 11 13:58:44 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-directx
Author: Joshua Batista (bob80905)
<details>
<summary>Changes</summary>
Relands https://github.com/llvm/llvm-project/pull/142678 after a revert was needed due to unforeseen bugs.
---
Full diff: https://github.com/llvm/llvm-project/pull/143783.diff
3 Files Affected:
- (modified) llvm/lib/Target/DirectX/DXILPrepare.cpp (+42-2)
- (modified) llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll (+23-35)
- (added) llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll (+53)
``````````diff
diff --git a/llvm/lib/Target/DirectX/DXILPrepare.cpp b/llvm/lib/Target/DirectX/DXILPrepare.cpp
index e0068787f5e5a..cb58f4833631d 100644
--- a/llvm/lib/Target/DirectX/DXILPrepare.cpp
+++ b/llvm/lib/Target/DirectX/DXILPrepare.cpp
@@ -148,9 +148,49 @@ 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;
+ }
+
+ Type *ValTy = Operand->getType();
+ // Also omit the bitcast for matching global array types
+ if (auto *GlobalVar = dyn_cast<GlobalVariable>(Operand))
+ 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;
+ }
+
+ // finally, drill down GEP instructions until we get the array
+ // that is being accessed, and compare element types
+ 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 = 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;
+ }
+ }
+
// 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/llc-vector-load-scalarize.ll b/llvm/test/CodeGen/DirectX/llc-vector-load-scalarize.ll
index 7e5a92e1311f8..30ee555ca2dda 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 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]]
+; 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
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..1f33700e014c7
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/noop_bitcast_global_array_type.ll
@@ -0,0 +1,53 @@
+; 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
+
+; 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-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-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-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-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
+
+ 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
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/143783
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