[llvm] [DirectX] [NFC] Revise descriptions of DXIL module flags (PR #133543)

Fri Mar 28 16:41:41 PDT 2025

llvmbot wrote:




@llvm/pr-subscribers-llvm-binary-utilities

Author: Deric C. (Icohedron)

<details>
<summary>Changes</summary>

This PR revises the descriptions of DXIL module flags.

Descriptions such as `D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION` are referring to Global Flags in DXBC.
DXBC is not a supported backend target, so references to DXBC should not be present.

There is also confusion with regards to the description of the `LowPrecisionPresent` DXIL module flag, which currently reads `D3D11_1_SB_GLOBAL_FLAG_ENABLE_MINIMUM_PRECISION` and implies the use of minimum-precision to handle 16-bit types.
However this is not true, because both the flags `LowPrecisionPresent` and `UseNativeLowPrecision` can simultaneously be set in the same DXIL module, and minimum precision mode is mutually exclusive with native low precision.
This PR revises the description of the `LowPrecisionPresent` flag to accurately describe what it represents.

---
Full diff: https://github.com/llvm/llvm-project/pull/133543.diff


5 Files Affected:

- (modified) llvm/include/llvm/BinaryFormat/DXContainerConstants.def (+8-8) 
- (modified) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll (+1-1) 
- (modified) llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll (+1-1) 
- (modified) llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll (+1-1) 
- (modified) llvm/test/CodeGen/DirectX/ShaderFlags/raw-and-structured-buffers.ll (+1-1) 


``````````diff

diff --git a/llvm/include/llvm/BinaryFormat/DXContainerConstants.def b/llvm/include/llvm/BinaryFormat/DXContainerConstants.def
index 6d44ea14df444..8bf7048df1b56 100644
--- a/llvm/include/llvm/BinaryFormat/DXContainerConstants.def
+++ b/llvm/include/llvm/BinaryFormat/DXContainerConstants.def
@@ -17,7 +17,7 @@ CONTAINER_PART(PSG1)
 // SHADER_FEATURE_FLAG(bit offset for the shader info flag, bit offset for DXIL module flag, name, description.
 
 SHADER_FEATURE_FLAG(0,   2, Doubles, "Double-precision floating point")
-SHADER_FEATURE_FLAG(1,  17, ComputeShadersPlusRawAndStructuredBuffers, "Raw and Structured buffers")
+SHADER_FEATURE_FLAG(1,  17, ComputeShadersPlusRawAndStructuredBuffers, "CS4 raw and structured buffers")
 SHADER_FEATURE_FLAG(2,  16, UAVsAtEveryStage, "UAVs at every shader stage")
 SHADER_FEATURE_FLAG(3,  15, Max64UAVs, "64 UAV slots")
 SHADER_FEATURE_FLAG(4,  -1, MinimumPrecision, "Minimum-precision data types")
@@ -76,13 +76,13 @@ ROOT_ELEMENT_FLAG(11, SamplerHeapDirectlyIndexed)
 #ifdef DXIL_MODULE_FLAG
 
 // Only save DXIL module flags which not map to feature flags here.
-DXIL_MODULE_FLAG( 0,  DisableOptimizations,   "D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION")
-DXIL_MODULE_FLAG( 1,  DisableMathRefactoring, "D3D10_SB_GLOBAL_FLAG_REFACTORING_ALLOWED")
-DXIL_MODULE_FLAG( 3,  ForceEarlyDepthStencil, "D3D11_SB_GLOBAL_FLAG_FORCE_EARLY_DEPTH_STENCIL")
-DXIL_MODULE_FLAG( 4,  EnableRawAndStructuredBuffers, "Raw and Structured buffers")
-DXIL_MODULE_FLAG( 5,  LowPrecisionPresent, "D3D11_1_SB_GLOBAL_FLAG_ENABLE_MINIMUM_PRECISION")
-DXIL_MODULE_FLAG( 8,  AllResourcesBound, "D3D12_SB_GLOBAL_FLAG_ALL_RESOURCES_BOUND")
-DXIL_MODULE_FLAG(23,  UseNativeLowPrecision, "Native 16bit types enabled")
+DXIL_MODULE_FLAG( 0,  DisableOptimizations,   "Disable shader optimizations")
+DXIL_MODULE_FLAG( 1,  DisableMathRefactoring, "Disable math refactoring")
+DXIL_MODULE_FLAG( 3,  ForceEarlyDepthStencil, "Force early depth-stencil test")
+DXIL_MODULE_FLAG( 4,  EnableRawAndStructuredBuffers, "Raw and structured buffers")
+DXIL_MODULE_FLAG( 5,  LowPrecisionPresent, "Low-precision data types")
+DXIL_MODULE_FLAG( 8,  AllResourcesBound, "All resources bound")
+DXIL_MODULE_FLAG(23,  UseNativeLowPrecision, "Native 16-bit types enabled")
 DXIL_MODULE_FLAG(33,  ResMayNotAlias, "Any UAV may not alias any other UAV")
 
 #undef DXIL_MODULE_FLAG
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
index 421c8b67350c2..8bf242fdbec67 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-cs.ll
@@ -5,7 +5,7 @@
 ; CHECK-NEXT: ; Shader Flags Value: 0x00000001
 
 ; CHECK: ; Note: extra DXIL module flags:
-; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+; CHECK-NEXT: ;       Disable shader optimizations
 
 ; CHECK: ; Shader Flags for Module Functions
 ; CHECK: ; Function main : 0x00000000
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
index 240bd314cd1b2..3bf582cc2e255 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/disable-opt-lib.ll
@@ -5,7 +5,7 @@
 ; CHECK-NEXT: ; Shader Flags Value: 0x00000001
 
 ; CHECK: ; Note: extra DXIL module flags:
-; CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_SKIP_OPTIMIZATION
+; CHECK-NEXT: ;       Disable shader optimizations
 
 ; CHECK: ; Shader Flags for Module Functions
 ; CHECK: ; Function main : 0x00000000
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll
index fd25a165bfe8d..73f1d5d2456af 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll
@@ -8,7 +8,7 @@ target triple = "dxil-pc-shadermodel6.7-library"
 ;CHECK-NEXT: ;
 ;CHECK-NEXT: ; Note: shader requires additional functionality:
 ;CHECK-NEXT: ; Note: extra DXIL module flags:
-;CHECK-NEXT: ;       D3D11_1_SB_GLOBAL_FLAG_ENABLE_MINIMUM_PRECISION
+;CHECK-NEXT: ;       Low-precision data types
 ;CHECK-NEXT: ;
 ;CHECK-NEXT: ; Shader Flags for Module Functions
 
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/raw-and-structured-buffers.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/raw-and-structured-buffers.ll
index 9cb83c4e992ba..03112b60c8811 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/raw-and-structured-buffers.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/raw-and-structured-buffers.ll
@@ -9,7 +9,7 @@ target triple = "dxil-pc-shadermodel6.7-library"
 ; CHECK-NEXT: Shader Flags Value: 0x00000010
 
 ; CHECK: Note: shader requires additional functionality:
-; CHECK:       Raw and Structured buffers
+; CHECK:       Raw and structured buffers
 
 ; CHECK: Function rawbuf : 0x00000010
 define float @rawbuf() "hlsl.export" {

``````````

</details>


https://github.com/llvm/llvm-project/pull/133543
