[DirectX] Set Shader Flag DisableOptimizations

bharadwajy · bharadwajy · commit 216c451521ea · 2025-02-11T17:30:03.000-05:00
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.
diff --git 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
diff --git 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;
 }
@@ -212,20 +230,24 @@ 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;
 
 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
