[DirectX] Set Shader Flag DisableOptimizations #126813

bharadwajy · 2025-02-11T22:34:29Z

Set the shader flag DisableOptimizations based on optnone attribute of shader entry functions.
Add DXIL Metadata Analysis pass as pre-requisite for Shader Flags pass to obtain entry function information collected therein.
Named module metadata dx.disable_optimizations is intended to indicate disabling optimizations (-O0) via commandline flag. However, its intent is fulfilled via an optnone attribute of shader entry functions via a recent change - b92bab3 - and thus not needed. Delete generation of named metadata and corresponding test file disable_opt.ll.
Add tests to verify correctness of setting shader flag.

Set the shader flag DisableOptimizations based on the optnone attribute of shader entry functions. Add DXIL Metadata Analysis pass as pre-requisite for Shader Flags pass to obtain entry function information collected therein. Delete generation of named metadata dx.disable_optimization that it is intended to indicate commandline flag specifying disable opt. However, its intent is fulfilled using optnone attribute of shader entry functions and not needed. Delete corresponding test file disable_opt.ll Named module metadata `dx.disable_optimizations` is intended to indicate disabling optimizations (`-O0`) via commandline flag. However, its intent is fulfilled via an `optnone` attribute of shader entry functions via a recent change and thus not needed. Delete generation of named metadata and corresponding test file `disable_opt.ll`. Add tests to verify correctness of setting shader flag.

llvmbot · 2025-02-11T22:35:00Z

@llvm/pr-subscribers-clang-codegen
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-backend-directx

Author: S. Bharadwaj Yadavalli (bharadwajy)

Changes

Set the shader flag DisableOptimizations based on optnone attribute of shader entry functions.
Add DXIL Metadata Analysis pass as pre-requisite for Shader Flags pass to obtain entry function information collected therein.
Named module metadata dx.disable_optimizations is intended to indicate disabling optimizations (-O0) via commandline flag. However, its intent is fulfilled via an optnone attribute of shader entry functions via a recent change - b92bab3 - and thus not needed. Delete generation of named metadata and corresponding test file disable_opt.ll.
Add tests to verify correctness of setting shader flag.

Closes #112263

Full diff: https://github.com/llvm/llvm-project/pull/126813.diff

8 Files Affected:

(modified) clang/lib/CodeGen/CGHLSLRuntime.cpp (-6)
(removed) clang/test/CodeGenHLSL/disable_opt.hlsl (-12)
(modified) llvm/lib/Target/DirectX/DXILShaderFlags.cpp (+25-3)
(modified) llvm/lib/Target/DirectX/DXILShaderFlags.h (+3-1)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll (+43)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll (+53)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll (+30)
(modified) llvm/test/CodeGen/DirectX/llc-pipeline.ll (+1-1)

diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 6cccd353cff96..03ddc87d8d3df 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -54,10 +54,6 @@ void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
   auto *DXILValMD = M.getOrInsertNamedMetadata(DXILValKey);
   DXILValMD->addOperand(Val);
 }
-void addDisableOptimizations(llvm::Module &M) {
-  StringRef Key = "dx.disable_optimizations";
-  M.addModuleFlag(llvm::Module::ModFlagBehavior::Override, Key, 1);
-}
 // cbuffer will be translated into global variable in special address space.
 // If translate into C,
 // cbuffer A {
@@ -171,8 +167,6 @@ void CGHLSLRuntime::finishCodeGen() {
     addDxilValVersion(TargetOpts.DxilValidatorVersion, M);
 
   generateGlobalCtorDtorCalls();
-  if (CGM.getCodeGenOpts().OptimizationLevel == 0)
-    addDisableOptimizations(M);
 
   const DataLayout &DL = M.getDataLayout();
 
diff --git a/clang/test/CodeGenHLSL/disable_opt.hlsl b/clang/test/CodeGenHLSL/disable_opt.hlsl
deleted file mode 100644
index bfffe76cfa9de..0000000000000
--- a/clang/test/CodeGenHLSL/disable_opt.hlsl
+++ /dev/null
@@ -1,12 +0,0 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -O0 -emit-llvm -xhlsl -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -O3 -emit-llvm -xhlsl -o - %s | FileCheck %s --check-prefix=OPT
-
-// CHECK:!"dx.disable_optimizations", i32 1}
-
-// OPT-NOT:"dx.disable_optimizations"
-
-float bar(float a, float b);
-
-float foo(float a, float b) {
-  return bar(a, b);
-}
diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
index 6a15bac153d85..bb502d8f189f6 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
@@ -17,6 +17,8 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/DXILResource.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -96,7 +98,8 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
 }
 
 /// Construct ModuleShaderFlags for module Module M
-void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM) {
+void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM,
+                                   const ModuleMetadataInfo &MMDI) {
   CallGraph CG(M);
 
   // Compute Shader Flags Mask for all functions using post-order visit of SCC
@@ -142,6 +145,20 @@ void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM) {
       // Merge SCCSF with that of F
       FunctionFlags[F].merge(SCCSF);
   }
+
+  // Set DisableOptimizations flag based on the presence of OptimizeNone
+  // attribute of entry functions.
+  if (MMDI.EntryPropertyVec.size() > 0) {
+    CombinedSFMask.DisableOptimizations =
+        MMDI.EntryPropertyVec[0].Entry->hasFnAttribute(
+            llvm::Attribute::OptimizeNone);
+    // Ensure all entry functions have the same optimization attribute
+    for (auto EF : MMDI.EntryPropertyVec)
+      if (CombinedSFMask.DisableOptimizations !=
+          EF.Entry->hasFnAttribute(llvm::Attribute::OptimizeNone))
+        EF.Entry->getContext().diagnose(DiagnosticInfoUnsupported(
+            *(EF.Entry), "Inconsistent optnone attribute "));
+  }
 }
 
 void ComputedShaderFlags::print(raw_ostream &OS) const {
@@ -180,9 +197,10 @@ AnalysisKey ShaderFlagsAnalysis::Key;
 ModuleShaderFlags ShaderFlagsAnalysis::run(Module &M,
                                            ModuleAnalysisManager &AM) {
   DXILResourceTypeMap &DRTM = AM.getResult<DXILResourceTypeAnalysis>(M);
+  const ModuleMetadataInfo MMDI = AM.getResult<DXILMetadataAnalysis>(M);
 
   ModuleShaderFlags MSFI;
-  MSFI.initialize(M, DRTM);
+  MSFI.initialize(M, DRTM, MMDI);
 
   return MSFI;
 }
@@ -212,14 +230,17 @@ PreservedAnalyses ShaderFlagsAnalysisPrinter::run(Module &M,
 bool ShaderFlagsAnalysisWrapper::runOnModule(Module &M) {
   DXILResourceTypeMap &DRTM =
       getAnalysis<DXILResourceTypeWrapperPass>().getResourceTypeMap();
+  const ModuleMetadataInfo MMDI =
+      getAnalysis<DXILMetadataAnalysisWrapperPass>().getModuleMetadata();
 
-  MSFI.initialize(M, DRTM);
+  MSFI.initialize(M, DRTM, MMDI);
   return false;
 }
 
 void ShaderFlagsAnalysisWrapper::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequiredTransitive<DXILResourceTypeWrapperPass>();
+  AU.addRequired<DXILMetadataAnalysisWrapperPass>();
 }
 
 char ShaderFlagsAnalysisWrapper::ID = 0;
@@ -227,5 +248,6 @@ char ShaderFlagsAnalysisWrapper::ID = 0;
 INITIALIZE_PASS_BEGIN(ShaderFlagsAnalysisWrapper, "dx-shader-flag-analysis",
                       "DXIL Shader Flag Analysis", true, true)
 INITIALIZE_PASS_DEPENDENCY(DXILResourceTypeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(DXILMetadataAnalysisWrapperPass)
 INITIALIZE_PASS_END(ShaderFlagsAnalysisWrapper, "dx-shader-flag-analysis",
                     "DXIL Shader Flag Analysis", true, true)
diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.h b/llvm/lib/Target/DirectX/DXILShaderFlags.h
index e6c6d56402c1a..abf7cc86259ed 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.h
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.h
@@ -14,6 +14,7 @@
 #ifndef LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 #define LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 
+#include "llvm/Analysis/DXILMetadataAnalysis.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
@@ -83,7 +84,8 @@ struct ComputedShaderFlags {
 };
 
 struct ModuleShaderFlags {
-  void initialize(Module &, DXILResourceTypeMap &DRTM);
+  void initialize(Module &, DXILResourceTypeMap &DRTM,
+                  const ModuleMetadataInfo &MMDI);
   const ComputedShaderFlags &getFunctionFlags(const Function *) const;
   const ComputedShaderFlags &getCombinedFlags() const { return CombinedSFMask; }
 
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
new file mode 100644
index 0000000000000..4c5c77fabbb9d
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
@@ -0,0 +1,43 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+
+; CHECK: ; Combined Shader Flags for Module
+; CHECK-NEXT: ; Shader Flags Value: 0x00000001
+
+; CHECK: ; Note: extra DXIL module flags:
+; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+
+; CHECK: ; Shader Flags for Module Functions
+; CHECK: ; Function main : 0x00000000
+; The test source in this file generated from the following command:
+; clang -cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -emit-llvm -O0 -o - <<EOF
+; [numthreads(1,1,1)]
+; [shader("compute")]
+; void main() {}
+; EOF
+
+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.0-pc-shadermodel6.0-compute"
+
+; Function Attrs: convergent noinline norecurse optnone
+define void @main() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: alwaysinline convergent mustprogress norecurse nounwind
+define noundef i32 @_Z3foov() #1 {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { alwaysinline convergent mustprogress norecurse nounwind "approx-func-fp-math"="true" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0}
+!dx.valver = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
new file mode 100644
index 0000000000000..5ad11a2f07881
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
@@ -0,0 +1,53 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+
+; CHECK: ; Combined Shader Flags for Module
+; CHECK-NEXT: ; Shader Flags Value: 0x00000001
+
+; CHECK: ; Note: extra DXIL module flags:
+; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+
+; CHECK: ; Shader Flags for Module Functions
+; CHECK: ; Function main : 0x00000000
+; The test source in this file generated from the following command:
+; clang -cc1 -triple dxil-pc-shadermodel6.3-library -x hlsl -emit-llvm -O0 -o - <<EOF
+
+; [numthreads(1,1,1)]
+; [shader("compute")]
+; void main() {}
+
+; int foo() {return 0;}
+; EOF
+
+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.3-pc-shadermodel6.3-library"
+
+; Function Attrs: convergent mustprogress noinline norecurse nounwind optnone
+define internal void @_Z4mainv() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: convergent noinline norecurse optnone
+define void @main() #1 {
+entry:
+  call void @_Z4mainv()
+  ret void
+}
+
+; Function Attrs: convergent mustprogress noinline norecurse nounwind optnone
+define noundef i32 @_Z3foov() #0 {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { convergent mustprogress noinline norecurse nounwind optnone "approx-func-fp-math"="true" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0}
+!dx.valver = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll
new file mode 100644
index 0000000000000..74d5fd093ded6
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll
@@ -0,0 +1,30 @@
+; RUN: not opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+target triple = "dxilv1.3-pc-shadermodel6.3-library"
+
+; All entry functions of a library shader need to either have optnone
+; or not have the attribute
+; CHECK: error:
+; CHECK-SAME: in function entry_two
+; CHECK-SAME:  Inconsistent optnone attribute
+; Function Attrs: convergent noinline norecurse optnone
+define void @entry_one() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: convergent noinline norecurse
+define void @entry_two() #1 {
+entry:
+  ret void
+}
+
+attributes #0 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { convergent noinline norecurse "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0, !1}
+!dx.valver = !{!2}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 4, !"dx.disable_optimizations", i32 1}
+!2 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/llc-pipeline.ll b/llvm/test/CodeGen/DirectX/llc-pipeline.ll
index b071557249414..03b2150bbc1dc 100644
--- a/llvm/test/CodeGen/DirectX/llc-pipeline.ll
+++ b/llvm/test/CodeGen/DirectX/llc-pipeline.ll
@@ -23,8 +23,8 @@
 ; CHECK-NEXT:     Scalarize vector operations
 ; CHECK-NEXT:   DXIL Resource Binding Analysis
 ; CHECK-NEXT:   DXIL resource Information
-; CHECK-NEXT:   DXIL Shader Flag Analysis
 ; CHECK-NEXT:   DXIL Module Metadata analysis
+; CHECK-NEXT:   DXIL Shader Flag Analysis
 ; CHECK-NEXT:   DXIL Translate Metadata
 ; CHECK-NEXT:   DXIL Op Lowering
 ; CHECK-NEXT:   DXIL Prepare Module

llvmbot · 2025-02-11T22:35:01Z

@llvm/pr-subscribers-hlsl

Author: S. Bharadwaj Yadavalli (bharadwajy)

Changes

Set the shader flag DisableOptimizations based on optnone attribute of shader entry functions.
Add DXIL Metadata Analysis pass as pre-requisite for Shader Flags pass to obtain entry function information collected therein.
Named module metadata dx.disable_optimizations is intended to indicate disabling optimizations (-O0) via commandline flag. However, its intent is fulfilled via an optnone attribute of shader entry functions via a recent change - b92bab3 - and thus not needed. Delete generation of named metadata and corresponding test file disable_opt.ll.
Add tests to verify correctness of setting shader flag.

Closes #112263

Full diff: https://github.com/llvm/llvm-project/pull/126813.diff

8 Files Affected:

(modified) clang/lib/CodeGen/CGHLSLRuntime.cpp (-6)
(removed) clang/test/CodeGenHLSL/disable_opt.hlsl (-12)
(modified) llvm/lib/Target/DirectX/DXILShaderFlags.cpp (+25-3)
(modified) llvm/lib/Target/DirectX/DXILShaderFlags.h (+3-1)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll (+43)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll (+53)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll (+30)
(modified) llvm/test/CodeGen/DirectX/llc-pipeline.ll (+1-1)

diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 6cccd353cff96..03ddc87d8d3df 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -54,10 +54,6 @@ void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
   auto *DXILValMD = M.getOrInsertNamedMetadata(DXILValKey);
   DXILValMD->addOperand(Val);
 }
-void addDisableOptimizations(llvm::Module &M) {
-  StringRef Key = "dx.disable_optimizations";
-  M.addModuleFlag(llvm::Module::ModFlagBehavior::Override, Key, 1);
-}
 // cbuffer will be translated into global variable in special address space.
 // If translate into C,
 // cbuffer A {
@@ -171,8 +167,6 @@ void CGHLSLRuntime::finishCodeGen() {
     addDxilValVersion(TargetOpts.DxilValidatorVersion, M);
 
   generateGlobalCtorDtorCalls();
-  if (CGM.getCodeGenOpts().OptimizationLevel == 0)
-    addDisableOptimizations(M);
 
   const DataLayout &DL = M.getDataLayout();
 
diff --git a/clang/test/CodeGenHLSL/disable_opt.hlsl b/clang/test/CodeGenHLSL/disable_opt.hlsl
deleted file mode 100644
index bfffe76cfa9de..0000000000000
--- a/clang/test/CodeGenHLSL/disable_opt.hlsl
+++ /dev/null
@@ -1,12 +0,0 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -O0 -emit-llvm -xhlsl -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -O3 -emit-llvm -xhlsl -o - %s | FileCheck %s --check-prefix=OPT
-
-// CHECK:!"dx.disable_optimizations", i32 1}
-
-// OPT-NOT:"dx.disable_optimizations"
-
-float bar(float a, float b);
-
-float foo(float a, float b) {
-  return bar(a, b);
-}
diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
index 6a15bac153d85..bb502d8f189f6 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
@@ -17,6 +17,8 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/DXILResource.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -96,7 +98,8 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
 }
 
 /// Construct ModuleShaderFlags for module Module M
-void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM) {
+void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM,
+                                   const ModuleMetadataInfo &MMDI) {
   CallGraph CG(M);
 
   // Compute Shader Flags Mask for all functions using post-order visit of SCC
@@ -142,6 +145,20 @@ void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM) {
       // Merge SCCSF with that of F
       FunctionFlags[F].merge(SCCSF);
   }
+
+  // Set DisableOptimizations flag based on the presence of OptimizeNone
+  // attribute of entry functions.
+  if (MMDI.EntryPropertyVec.size() > 0) {
+    CombinedSFMask.DisableOptimizations =
+        MMDI.EntryPropertyVec[0].Entry->hasFnAttribute(
+            llvm::Attribute::OptimizeNone);
+    // Ensure all entry functions have the same optimization attribute
+    for (auto EF : MMDI.EntryPropertyVec)
+      if (CombinedSFMask.DisableOptimizations !=
+          EF.Entry->hasFnAttribute(llvm::Attribute::OptimizeNone))
+        EF.Entry->getContext().diagnose(DiagnosticInfoUnsupported(
+            *(EF.Entry), "Inconsistent optnone attribute "));
+  }
 }
 
 void ComputedShaderFlags::print(raw_ostream &OS) const {
@@ -180,9 +197,10 @@ AnalysisKey ShaderFlagsAnalysis::Key;
 ModuleShaderFlags ShaderFlagsAnalysis::run(Module &M,
                                            ModuleAnalysisManager &AM) {
   DXILResourceTypeMap &DRTM = AM.getResult<DXILResourceTypeAnalysis>(M);
+  const ModuleMetadataInfo MMDI = AM.getResult<DXILMetadataAnalysis>(M);
 
   ModuleShaderFlags MSFI;
-  MSFI.initialize(M, DRTM);
+  MSFI.initialize(M, DRTM, MMDI);
 
   return MSFI;
 }
@@ -212,14 +230,17 @@ PreservedAnalyses ShaderFlagsAnalysisPrinter::run(Module &M,
 bool ShaderFlagsAnalysisWrapper::runOnModule(Module &M) {
   DXILResourceTypeMap &DRTM =
       getAnalysis<DXILResourceTypeWrapperPass>().getResourceTypeMap();
+  const ModuleMetadataInfo MMDI =
+      getAnalysis<DXILMetadataAnalysisWrapperPass>().getModuleMetadata();
 
-  MSFI.initialize(M, DRTM);
+  MSFI.initialize(M, DRTM, MMDI);
   return false;
 }
 
 void ShaderFlagsAnalysisWrapper::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequiredTransitive<DXILResourceTypeWrapperPass>();
+  AU.addRequired<DXILMetadataAnalysisWrapperPass>();
 }
 
 char ShaderFlagsAnalysisWrapper::ID = 0;
@@ -227,5 +248,6 @@ char ShaderFlagsAnalysisWrapper::ID = 0;
 INITIALIZE_PASS_BEGIN(ShaderFlagsAnalysisWrapper, "dx-shader-flag-analysis",
                       "DXIL Shader Flag Analysis", true, true)
 INITIALIZE_PASS_DEPENDENCY(DXILResourceTypeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(DXILMetadataAnalysisWrapperPass)
 INITIALIZE_PASS_END(ShaderFlagsAnalysisWrapper, "dx-shader-flag-analysis",
                     "DXIL Shader Flag Analysis", true, true)
diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.h b/llvm/lib/Target/DirectX/DXILShaderFlags.h
index e6c6d56402c1a..abf7cc86259ed 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.h
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.h
@@ -14,6 +14,7 @@
 #ifndef LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 #define LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 
+#include "llvm/Analysis/DXILMetadataAnalysis.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
@@ -83,7 +84,8 @@ struct ComputedShaderFlags {
 };
 
 struct ModuleShaderFlags {
-  void initialize(Module &, DXILResourceTypeMap &DRTM);
+  void initialize(Module &, DXILResourceTypeMap &DRTM,
+                  const ModuleMetadataInfo &MMDI);
   const ComputedShaderFlags &getFunctionFlags(const Function *) const;
   const ComputedShaderFlags &getCombinedFlags() const { return CombinedSFMask; }
 
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
new file mode 100644
index 0000000000000..4c5c77fabbb9d
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
@@ -0,0 +1,43 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+
+; CHECK: ; Combined Shader Flags for Module
+; CHECK-NEXT: ; Shader Flags Value: 0x00000001
+
+; CHECK: ; Note: extra DXIL module flags:
+; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+
+; CHECK: ; Shader Flags for Module Functions
+; CHECK: ; Function main : 0x00000000
+; The test source in this file generated from the following command:
+; clang -cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -emit-llvm -O0 -o - <<EOF
+; [numthreads(1,1,1)]
+; [shader("compute")]
+; void main() {}
+; EOF
+
+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.0-pc-shadermodel6.0-compute"
+
+; Function Attrs: convergent noinline norecurse optnone
+define void @main() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: alwaysinline convergent mustprogress norecurse nounwind
+define noundef i32 @_Z3foov() #1 {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { alwaysinline convergent mustprogress norecurse nounwind "approx-func-fp-math"="true" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0}
+!dx.valver = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
new file mode 100644
index 0000000000000..5ad11a2f07881
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
@@ -0,0 +1,53 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+
+; CHECK: ; Combined Shader Flags for Module
+; CHECK-NEXT: ; Shader Flags Value: 0x00000001
+
+; CHECK: ; Note: extra DXIL module flags:
+; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+
+; CHECK: ; Shader Flags for Module Functions
+; CHECK: ; Function main : 0x00000000
+; The test source in this file generated from the following command:
+; clang -cc1 -triple dxil-pc-shadermodel6.3-library -x hlsl -emit-llvm -O0 -o - <<EOF
+
+; [numthreads(1,1,1)]
+; [shader("compute")]
+; void main() {}
+
+; int foo() {return 0;}
+; EOF
+
+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.3-pc-shadermodel6.3-library"
+
+; Function Attrs: convergent mustprogress noinline norecurse nounwind optnone
+define internal void @_Z4mainv() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: convergent noinline norecurse optnone
+define void @main() #1 {
+entry:
+  call void @_Z4mainv()
+  ret void
+}
+
+; Function Attrs: convergent mustprogress noinline norecurse nounwind optnone
+define noundef i32 @_Z3foov() #0 {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { convergent mustprogress noinline norecurse nounwind optnone "approx-func-fp-math"="true" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0}
+!dx.valver = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll
new file mode 100644
index 0000000000000..74d5fd093ded6
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/lib-entry-attr-error.ll
@@ -0,0 +1,30 @@
+; RUN: not opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+
+target triple = "dxilv1.3-pc-shadermodel6.3-library"
+
+; All entry functions of a library shader need to either have optnone
+; or not have the attribute
+; CHECK: error:
+; CHECK-SAME: in function entry_two
+; CHECK-SAME:  Inconsistent optnone attribute
+; Function Attrs: convergent noinline norecurse optnone
+define void @entry_one() #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: convergent noinline norecurse
+define void @entry_two() #1 {
+entry:
+  ret void
+}
+
+attributes #0 = { convergent noinline norecurse optnone "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { convergent noinline norecurse "approx-func-fp-math"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.module.flags = !{!0, !1}
+!dx.valver = !{!2}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 4, !"dx.disable_optimizations", i32 1}
+!2 = !{i32 1, i32 8}
diff --git a/llvm/test/CodeGen/DirectX/llc-pipeline.ll b/llvm/test/CodeGen/DirectX/llc-pipeline.ll
index b071557249414..03b2150bbc1dc 100644
--- a/llvm/test/CodeGen/DirectX/llc-pipeline.ll
+++ b/llvm/test/CodeGen/DirectX/llc-pipeline.ll
@@ -23,8 +23,8 @@
 ; CHECK-NEXT:     Scalarize vector operations
 ; CHECK-NEXT:   DXIL Resource Binding Analysis
 ; CHECK-NEXT:   DXIL resource Information
-; CHECK-NEXT:   DXIL Shader Flag Analysis
 ; CHECK-NEXT:   DXIL Module Metadata analysis
+; CHECK-NEXT:   DXIL Shader Flag Analysis
 ; CHECK-NEXT:   DXIL Translate Metadata
 ; CHECK-NEXT:   DXIL Op Lowering
 ; CHECK-NEXT:   DXIL Prepare Module

farzonl · 2025-02-12T15:31:01Z

llvm/lib/Target/DirectX/DXILShaderFlags.cpp

  return false;
 }

 void ShaderFlagsAnalysisWrapper::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.setPreservesAll();
  AU.addRequiredTransitive<DXILResourceTypeWrapperPass>();
+  AU.addRequired<DXILMetadataAnalysisWrapperPass>();


This change causes DXIL Module Metadata analysis pass to run before DXIL Shader Flag Analysis because it is now needed MMDI.EntryPropertyVec[0].Entry->hasFnAttribute( llvm::Attribute::OptimizeNone); to initialize ModuleShaderFlags.

I think before we never intended to fetch fn attributes since you were using dx.disable_optimizations.
Does that make optnone a one off here or are there other attributes that could use this pattern?

This change causes DXIL Module Metadata analysis pass to run before DXIL Shader Flag Analysis because it is now needed MMDI.EntryPropertyVec[0].Entry->hasFnAttribute( llvm::Attribute::OptimizeNone); to initialize ModuleShaderFlags.

I think before we never intended to fetch fn attributes since you were using dx.disable_optimizations.

Yes, that was the proposed mechanism in PR #123136. This PR supersedes that following the feedback there.

Does that make optnone a one off here or are there other attributes that could use this pattern?

The list of entry function information collected by Metadata Analysis pass is leveraged in this pass to look at optnone of each of the entry functions. Similarly it can be leveraged by other passes that require access to entry function information - for example, a pass that would want to query for entry function declaration withHLSLWaveSizeAttr.

Entry functions can be collected during the call graph traversal in this pass to query for optnone attribute. I just chose to leverage the same info that would be built in Metadata Analysis pass.

bogner · 2025-02-12T18:16:18Z

llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll

+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.0-pc-shadermodel6.0-compute"


Best to remove these when they aren't relevant to the test at hand.

bogner · 2025-02-12T18:16:59Z

llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll

+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxilv1.3-pc-shadermodel6.3-library"


bogner · 2025-02-12T18:17:39Z

llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll

+!llvm.module.flags = !{!0}
+!dx.valver = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 8}


We shouldn't need the module.flags and valver metadata for these tests

bogner · 2025-02-12T18:20:37Z

llvm/lib/Target/DirectX/DXILShaderFlags.cpp

+        MMDI.EntryPropertyVec[0].Entry->hasFnAttribute(
+            llvm::Attribute::OptimizeNone);
+    // Ensure all entry functions have the same optimization attribute
+    for (auto EF : MMDI.EntryPropertyVec)


Should be const auto & or const EntryProperties & rather than forcing copies here. Also what is "EF" an abbreviation of? It doesn't seem to have anything to do with what this variable represents. I'd probably call this "Props" or something like that.

- Set the shader flag `DisableOptimizations` based on `optnone` attribute of shader entry functions. - Add DXIL Metadata Analysis pass as pre-requisite for Shader Flags pass to obtain entry function information collected therein. - Named module metadata `dx.disable_optimizations` is intended to indicate disabling optimizations (`-O0`) via commandline flag. However, its intent is fulfilled by `optnone` attribute of shader entry functions as implemented in a recent change, and thus not needed. Delete generation of named metadata and corresponding test file `disable_opt.ll`. - Add tests to verify correctness of setting shader flag. Closes llvm#112263

bharadwajy requested review from bogner and llvm-beanz February 11, 2025 22:34

llvmbot added clang Clang issues not falling into any other category clang:codegen IR generation bugs: mangling, exceptions, etc. backend:DirectX HLSL HLSL Language Support labels Feb 11, 2025

farzonl reviewed Feb 12, 2025

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farzonl approved these changes Feb 12, 2025

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bogner approved these changes Feb 12, 2025

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Address PR feedback

11cbfe1

bharadwajy merged commit f2650c5 into llvm:main Feb 12, 2025
7 of 9 checks passed

bogner mentioned this pull request Feb 13, 2025

[DirectX] Set Shader Flag DisableOptimizations. #123136

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damyanp moved this to Closed in HLSL Support Apr 25, 2025

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