For the following HLSL code:
SamplerState gSS :register(s2, space0);
Texture2D gTex :register(t0, space0);
cbuffer MyCBuffer :register(b0, space2)
{
float2 scale;
float3 size;
};
float4 GetTexture2DLod(Texture2D tex, SamplerState samplerState, float2 uv, float lod)
{
return tex.SampleLevel(samplerState, uv.xy, lod);
}
float4 PS_BlurFilter_Box1() : SV_Target
{
float4 color = 0.0f;
float i = 0.0f;
for (i = -size.x; i <= size.x; i++)
color += GetTexture2DLod(gTex, gSS, i * scale, 0.f);
return color;
}DXC/Spiregg generates the following raw SPIR-V:
OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target
OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft
OpName %bb_entry "bb.entry"
OpName %for_check "for.check"
OpName %for_body "for.body"
OpName %for_continue "for.continue"
OpName %for_merge "for.merge"
OpName %bb_entry_0 "bb.entry"
OpName %type_sampler "type.sampler"
OpName %gSS "gSS"
OpName %type_2d_image "type.2d.image"
OpName %gTex "gTex"
OpName %type_MyCBuffer "type.MyCBuffer"
OpMemberName %type_MyCBuffer 0 "scale"
OpMemberName %type_MyCBuffer 1 "size"
OpName %var_MyCBuffer "var.MyCBuffer"
OpName %src_PS_BlurFilter_Box1 "src.PS_BlurFilter_Box1"
OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1"
OpName %out_var_SV_Target "out.var.SV_Target"
OpName %color "color"
OpName %i "i"
OpName %param_var_tex "param.var.tex"
OpName %param_var_samplerState "param.var.samplerState"
OpName %param_var_uv "param.var.uv"
OpName %param_var_lod "param.var.lod"
OpName %GetTexture2DLod "GetTexture2DLod"
OpName %tex "tex"
OpName %samplerState "samplerState"
OpName %uv "uv"
OpName %lod "lod"
OpName %type_sampled_image "type.sampled.image"
OpMemberDecorate %type_MyCBuffer 0 Offset 0
OpMemberDecorate %type_MyCBuffer 1 Offset 16
OpDecorate %type_MyCBuffer Block
OpDecorate %out_var_SV_Target Location 0
OpDecorate %gSS DescriptorSet 0
OpDecorate %gSS Binding 2
OpDecorate %gTex DescriptorSet 0
OpDecorate %gTex Binding 0
OpDecorate %var_MyCBuffer DescriptorSet 2
OpDecorate %var_MyCBuffer Binding 0
%int = OpTypeInt 32 1
%type_sampler = OpTypeSampler
%_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler
%float = OpTypeFloat 32
%type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown
%_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image
%v2float = OpTypeVector %float 2
%v3float = OpTypeVector %float 3
%type_MyCBuffer = OpTypeStruct %v2float %v3float
%_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer
%void = OpTypeVoid
%15 = OpTypeFunction %void
%v4float = OpTypeVector %float 4
%_ptr_Output_v4float = OpTypePointer Output %v4float
%22 = OpTypeFunction %v4float
%_ptr_Function_v4float = OpTypePointer Function %v4float
%_ptr_Function_float = OpTypePointer Function %float
%_ptr_Uniform_v3float = OpTypePointer Uniform %v3float
%_ptr_Uniform_float = OpTypePointer Uniform %float
%bool = OpTypeBool
%_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image
%_ptr_Function_type_sampler = OpTypePointer Function %type_sampler
%_ptr_Function_v2float = OpTypePointer Function %v2float
%_ptr_Uniform_v2float = OpTypePointer Uniform %v2float
%71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float
%type_sampled_image = OpTypeSampledImage %type_2d_image
%float_0 = OpConstant %float 0
%27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0
%int_1 = OpConstant %int 1
%int_0 = OpConstant %int 0
%float_1 = OpConstant %float 1
%gSS = OpVariable %_ptr_UniformConstant_type_sampler UniformConstant
%gTex = OpVariable %_ptr_UniformConstant_type_2d_image UniformConstant
%var_MyCBuffer = OpVariable %_ptr_Uniform_type_MyCBuffer Uniform
%out_var_SV_Target = OpVariable %_ptr_Output_v4float Output
%PS_BlurFilter_Box1 = OpFunction %void None %15
%17 = OpLabel
%19 = OpFunctionCall %v4float %src_PS_BlurFilter_Box1
OpStore %out_var_SV_Target %19
OpReturn
OpFunctionEnd
%src_PS_BlurFilter_Box1 = OpFunction %v4float None %22
%bb_entry = OpLabel
%color = OpVariable %_ptr_Function_v4float Function
%i = OpVariable %_ptr_Function_float Function
%param_var_tex = OpVariable %_ptr_Function_type_2d_image Function
%param_var_samplerState = OpVariable %_ptr_Function_type_sampler Function
%param_var_uv = OpVariable %_ptr_Function_v2float Function
%param_var_lod = OpVariable %_ptr_Function_float Function
OpStore %color %27
OpStore %i %float_0
%37 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1
%40 = OpAccessChain %_ptr_Uniform_float %37 %int_0
%41 = OpLoad %float %40
%42 = OpFNegate %float %41
OpStore %i %42
OpBranch %for_check
%for_check = OpLabel
%44 = OpLoad %float %i
%45 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1
%46 = OpAccessChain %_ptr_Uniform_float %45 %int_0
%47 = OpLoad %float %46
%48 = OpFOrdLessThanEqual %bool %44 %47
OpLoopMerge %for_merge %for_continue None
OpBranchConditional %48 %for_body %for_merge
%for_body = OpLabel
%51 = OpLoad %type_2d_image %gTex
OpStore %param_var_tex %51
%54 = OpLoad %type_sampler %gSS
OpStore %param_var_samplerState %54
%58 = OpAccessChain %_ptr_Uniform_v2float %var_MyCBuffer %int_0
%59 = OpLoad %v2float %58
%60 = OpLoad %float %i
%61 = OpVectorTimesScalar %v2float %59 %60
OpStore %param_var_uv %61
OpStore %param_var_lod %float_0
%64 = OpFunctionCall %v4float %GetTexture2DLod %param_var_tex %param_var_samplerState %param_var_uv %param_var_lod
%65 = OpLoad %v4float %color
%66 = OpFAdd %v4float %65 %64
OpStore %color %66
OpBranch %for_continue
%for_continue = OpLabel
%67 = OpLoad %float %i
%69 = OpFAdd %float %67 %float_1
OpStore %i %69
OpBranch %for_check
%for_merge = OpLabel
%70 = OpLoad %v4float %color
OpReturnValue %70
OpFunctionEnd
%GetTexture2DLod = OpFunction %v4float None %71
%tex = OpFunctionParameter %_ptr_Function_type_2d_image
%samplerState = OpFunctionParameter %_ptr_Function_type_sampler
%uv = OpFunctionParameter %_ptr_Function_v2float
%lod = OpFunctionParameter %_ptr_Function_float
%bb_entry_0 = OpLabel
%77 = OpLoad %type_2d_image %tex
%78 = OpLoad %type_sampler %samplerState
%79 = OpLoad %v2float %uv
%80 = OpLoad %float %lod
%81 = OpSampledImage %type_sampled_image %77 %78
%83 = OpImageSampleExplicitLod %v4float %81 %79 Lod %80
OpReturnValue %83
OpFunctionEndLegalization passes (RegisterLegalizationPasses()) turns it into
OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target
OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft
OpName %type_sampler "type.sampler"
OpName %gSS "gSS"
OpName %type_2d_image "type.2d.image"
OpName %gTex "gTex"
OpName %type_MyCBuffer "type.MyCBuffer"
OpMemberName %type_MyCBuffer 0 "scale"
OpMemberName %type_MyCBuffer 1 "size"
OpName %var_MyCBuffer "var.MyCBuffer"
OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1"
OpName %out_var_SV_Target "out.var.SV_Target"
OpName %type_sampled_image "type.sampled.image"
OpMemberDecorate %type_MyCBuffer 0 Offset 0
OpMemberDecorate %type_MyCBuffer 1 Offset 16
OpDecorate %type_MyCBuffer Block
OpDecorate %out_var_SV_Target Location 0
OpDecorate %gSS DescriptorSet 0
OpDecorate %gSS Binding 2
OpDecorate %gTex DescriptorSet 0
OpDecorate %gTex Binding 0
OpDecorate %var_MyCBuffer DescriptorSet 2
OpDecorate %var_MyCBuffer Binding 0
%int = OpTypeInt 32 1
%type_sampler = OpTypeSampler
%_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler
%float = OpTypeFloat 32
%type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown
%_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image
%v2float = OpTypeVector %float 2
%v3float = OpTypeVector %float 3
%type_MyCBuffer = OpTypeStruct %v2float %v3float
%_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer
%void = OpTypeVoid
%15 = OpTypeFunction %void
%v4float = OpTypeVector %float 4
%_ptr_Output_v4float = OpTypePointer Output %v4float
%22 = OpTypeFunction %v4float
%_ptr_Function_v4float = OpTypePointer Function %v4float
%_ptr_Function_float = OpTypePointer Function %float
%_ptr_Uniform_v3float = OpTypePointer Uniform %v3float
%_ptr_Uniform_float = OpTypePointer Uniform %float
%bool = OpTypeBool
%_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image
%_ptr_Function_type_sampler = OpTypePointer Function %type_sampler
%_ptr_Function_v2float = OpTypePointer Function %v2float
%_ptr_Uniform_v2float = OpTypePointer Uniform %v2float
%71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float
%type_sampled_image = OpTypeSampledImage %type_2d_image
%float_0 = OpConstant %float 0
%27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0
%int_1 = OpConstant %int 1
%int_0 = OpConstant %int 0
%float_1 = OpConstant %float 1
%gSS = OpVariable %_ptr_UniformConstant_type_sampler UniformConstant
%gTex = OpVariable %_ptr_UniformConstant_type_2d_image UniformConstant
%var_MyCBuffer = OpVariable %_ptr_Uniform_type_MyCBuffer Uniform
%out_var_SV_Target = OpVariable %_ptr_Output_v4float Output
%PS_BlurFilter_Box1 = OpFunction %void None %15
%17 = OpLabel
%91 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1
%92 = OpAccessChain %_ptr_Uniform_float %91 %int_0
%93 = OpLoad %float %92
%94 = OpFNegate %float %93
OpBranch %95
%95 = OpLabel
%123 = OpPhi %v4float %27 %17 %112 %102
%124 = OpPhi %float %94 %17 %114 %102
%97 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1
%98 = OpAccessChain %_ptr_Uniform_float %97 %int_0
%99 = OpLoad %float %98
%100 = OpFOrdLessThanEqual %bool %124 %99
OpLoopMerge %101 %102 None
OpBranchConditional %100 %103 %101
%103 = OpLabel
%104 = OpLoad %type_2d_image %gTex
%105 = OpLoad %type_sampler %gSS
%106 = OpAccessChain %_ptr_Uniform_v2float %var_MyCBuffer %int_0
%107 = OpLoad %v2float %106
%109 = OpVectorTimesScalar %v2float %107 %124
%121 = OpSampledImage %type_sampled_image %104 %105
%122 = OpImageSampleExplicitLod %v4float %121 %109 Lod %float_0
%112 = OpFAdd %v4float %123 %122
OpBranch %102
%102 = OpLabel
%114 = OpFAdd %float %124 %float_1
OpBranch %95
%101 = OpLabel
OpStore %out_var_SV_Target %123
OpReturn
OpFunctionEndWhich seems correct. But optimization passes (RegisterPerformancePasses()) turns it into
OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target
OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft
OpName %type_sampler "type.sampler"
OpName %type_2d_image "type.2d.image"
OpName %type_MyCBuffer "type.MyCBuffer"
OpMemberName %type_MyCBuffer 0 "scale"
OpMemberName %type_MyCBuffer 1 "size"
OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1"
OpName %out_var_SV_Target "out.var.SV_Target"
OpName %type_sampled_image "type.sampled.image"
OpMemberDecorate %type_MyCBuffer 0 Offset 0
OpMemberDecorate %type_MyCBuffer 1 Offset 16
OpDecorate %type_MyCBuffer Block
OpDecorate %out_var_SV_Target Location 0
%int = OpTypeInt 32 1
%type_sampler = OpTypeSampler
%_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler
%float = OpTypeFloat 32
%type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown
%_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image
%v2float = OpTypeVector %float 2
%v3float = OpTypeVector %float 3
%type_MyCBuffer = OpTypeStruct %v2float %v3float
%_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer
%void = OpTypeVoid
%15 = OpTypeFunction %void
%v4float = OpTypeVector %float 4
%_ptr_Output_v4float = OpTypePointer Output %v4float
%22 = OpTypeFunction %v4float
%_ptr_Function_v4float = OpTypePointer Function %v4float
%_ptr_Function_float = OpTypePointer Function %float
%_ptr_Uniform_v3float = OpTypePointer Uniform %v3float
%_ptr_Uniform_float = OpTypePointer Uniform %float
%bool = OpTypeBool
%_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image
%_ptr_Function_type_sampler = OpTypePointer Function %type_sampler
%_ptr_Function_v2float = OpTypePointer Function %v2float
%_ptr_Uniform_v2float = OpTypePointer Uniform %v2float
%71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float
%type_sampled_image = OpTypeSampledImage %type_2d_image
%float_0 = OpConstant %float 0
%27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0
%int_1 = OpConstant %int 1
%int_0 = OpConstant %int 0
%float_1 = OpConstant %float 1
%out_var_SV_Target = OpVariable %_ptr_Output_v4float Output
%PS_BlurFilter_Box1 = OpFunction %void None %15
%17 = OpLabel
OpStore %out_var_SV_Target %27
OpReturn
OpFunctionEndThe for loop is completely gone.
Originally reported in microsoft/DirectXShaderCompiler#958.
Likely related to #1143, but I'm not certain.
Using the correct top of the tree: 702852b
For the following HLSL code:
DXC/Spiregg generates the following raw SPIR-V:
OpCapability Shader OpMemoryModel Logical GLSL450 OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft OpName %bb_entry "bb.entry" OpName %for_check "for.check" OpName %for_body "for.body" OpName %for_continue "for.continue" OpName %for_merge "for.merge" OpName %bb_entry_0 "bb.entry" OpName %type_sampler "type.sampler" OpName %gSS "gSS" OpName %type_2d_image "type.2d.image" OpName %gTex "gTex" OpName %type_MyCBuffer "type.MyCBuffer" OpMemberName %type_MyCBuffer 0 "scale" OpMemberName %type_MyCBuffer 1 "size" OpName %var_MyCBuffer "var.MyCBuffer" OpName %src_PS_BlurFilter_Box1 "src.PS_BlurFilter_Box1" OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" OpName %out_var_SV_Target "out.var.SV_Target" OpName %color "color" OpName %i "i" OpName %param_var_tex "param.var.tex" OpName %param_var_samplerState "param.var.samplerState" OpName %param_var_uv "param.var.uv" OpName %param_var_lod "param.var.lod" OpName %GetTexture2DLod "GetTexture2DLod" OpName %tex "tex" OpName %samplerState "samplerState" OpName %uv "uv" OpName %lod "lod" OpName %type_sampled_image "type.sampled.image" OpMemberDecorate %type_MyCBuffer 0 Offset 0 OpMemberDecorate %type_MyCBuffer 1 Offset 16 OpDecorate %type_MyCBuffer Block OpDecorate %out_var_SV_Target Location 0 OpDecorate %gSS DescriptorSet 0 OpDecorate %gSS Binding 2 OpDecorate %gTex DescriptorSet 0 OpDecorate %gTex Binding 0 OpDecorate %var_MyCBuffer DescriptorSet 2 OpDecorate %var_MyCBuffer Binding 0 %int = OpTypeInt 32 1 %type_sampler = OpTypeSampler %_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler %float = OpTypeFloat 32 %type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown %_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image %v2float = OpTypeVector %float 2 %v3float = OpTypeVector %float 3 %type_MyCBuffer = OpTypeStruct %v2float %v3float %_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer %void = OpTypeVoid %15 = OpTypeFunction %void %v4float = OpTypeVector %float 4 %_ptr_Output_v4float = OpTypePointer Output %v4float %22 = OpTypeFunction %v4float %_ptr_Function_v4float = OpTypePointer Function %v4float %_ptr_Function_float = OpTypePointer Function %float %_ptr_Uniform_v3float = OpTypePointer Uniform %v3float %_ptr_Uniform_float = OpTypePointer Uniform %float %bool = OpTypeBool %_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image %_ptr_Function_type_sampler = OpTypePointer Function %type_sampler %_ptr_Function_v2float = OpTypePointer Function %v2float %_ptr_Uniform_v2float = OpTypePointer Uniform %v2float %71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float %type_sampled_image = OpTypeSampledImage %type_2d_image %float_0 = OpConstant %float 0 %27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0 %int_1 = OpConstant %int 1 %int_0 = OpConstant %int 0 %float_1 = OpConstant %float 1 %gSS = OpVariable %_ptr_UniformConstant_type_sampler UniformConstant %gTex = OpVariable %_ptr_UniformConstant_type_2d_image UniformConstant %var_MyCBuffer = OpVariable %_ptr_Uniform_type_MyCBuffer Uniform %out_var_SV_Target = OpVariable %_ptr_Output_v4float Output %PS_BlurFilter_Box1 = OpFunction %void None %15 %17 = OpLabel %19 = OpFunctionCall %v4float %src_PS_BlurFilter_Box1 OpStore %out_var_SV_Target %19 OpReturn OpFunctionEnd %src_PS_BlurFilter_Box1 = OpFunction %v4float None %22 %bb_entry = OpLabel %color = OpVariable %_ptr_Function_v4float Function %i = OpVariable %_ptr_Function_float Function %param_var_tex = OpVariable %_ptr_Function_type_2d_image Function %param_var_samplerState = OpVariable %_ptr_Function_type_sampler Function %param_var_uv = OpVariable %_ptr_Function_v2float Function %param_var_lod = OpVariable %_ptr_Function_float Function OpStore %color %27 OpStore %i %float_0 %37 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1 %40 = OpAccessChain %_ptr_Uniform_float %37 %int_0 %41 = OpLoad %float %40 %42 = OpFNegate %float %41 OpStore %i %42 OpBranch %for_check %for_check = OpLabel %44 = OpLoad %float %i %45 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1 %46 = OpAccessChain %_ptr_Uniform_float %45 %int_0 %47 = OpLoad %float %46 %48 = OpFOrdLessThanEqual %bool %44 %47 OpLoopMerge %for_merge %for_continue None OpBranchConditional %48 %for_body %for_merge %for_body = OpLabel %51 = OpLoad %type_2d_image %gTex OpStore %param_var_tex %51 %54 = OpLoad %type_sampler %gSS OpStore %param_var_samplerState %54 %58 = OpAccessChain %_ptr_Uniform_v2float %var_MyCBuffer %int_0 %59 = OpLoad %v2float %58 %60 = OpLoad %float %i %61 = OpVectorTimesScalar %v2float %59 %60 OpStore %param_var_uv %61 OpStore %param_var_lod %float_0 %64 = OpFunctionCall %v4float %GetTexture2DLod %param_var_tex %param_var_samplerState %param_var_uv %param_var_lod %65 = OpLoad %v4float %color %66 = OpFAdd %v4float %65 %64 OpStore %color %66 OpBranch %for_continue %for_continue = OpLabel %67 = OpLoad %float %i %69 = OpFAdd %float %67 %float_1 OpStore %i %69 OpBranch %for_check %for_merge = OpLabel %70 = OpLoad %v4float %color OpReturnValue %70 OpFunctionEnd %GetTexture2DLod = OpFunction %v4float None %71 %tex = OpFunctionParameter %_ptr_Function_type_2d_image %samplerState = OpFunctionParameter %_ptr_Function_type_sampler %uv = OpFunctionParameter %_ptr_Function_v2float %lod = OpFunctionParameter %_ptr_Function_float %bb_entry_0 = OpLabel %77 = OpLoad %type_2d_image %tex %78 = OpLoad %type_sampler %samplerState %79 = OpLoad %v2float %uv %80 = OpLoad %float %lod %81 = OpSampledImage %type_sampled_image %77 %78 %83 = OpImageSampleExplicitLod %v4float %81 %79 Lod %80 OpReturnValue %83 OpFunctionEndLegalization passes (
RegisterLegalizationPasses()) turns it intoOpCapability Shader OpMemoryModel Logical GLSL450 OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft OpName %type_sampler "type.sampler" OpName %gSS "gSS" OpName %type_2d_image "type.2d.image" OpName %gTex "gTex" OpName %type_MyCBuffer "type.MyCBuffer" OpMemberName %type_MyCBuffer 0 "scale" OpMemberName %type_MyCBuffer 1 "size" OpName %var_MyCBuffer "var.MyCBuffer" OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" OpName %out_var_SV_Target "out.var.SV_Target" OpName %type_sampled_image "type.sampled.image" OpMemberDecorate %type_MyCBuffer 0 Offset 0 OpMemberDecorate %type_MyCBuffer 1 Offset 16 OpDecorate %type_MyCBuffer Block OpDecorate %out_var_SV_Target Location 0 OpDecorate %gSS DescriptorSet 0 OpDecorate %gSS Binding 2 OpDecorate %gTex DescriptorSet 0 OpDecorate %gTex Binding 0 OpDecorate %var_MyCBuffer DescriptorSet 2 OpDecorate %var_MyCBuffer Binding 0 %int = OpTypeInt 32 1 %type_sampler = OpTypeSampler %_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler %float = OpTypeFloat 32 %type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown %_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image %v2float = OpTypeVector %float 2 %v3float = OpTypeVector %float 3 %type_MyCBuffer = OpTypeStruct %v2float %v3float %_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer %void = OpTypeVoid %15 = OpTypeFunction %void %v4float = OpTypeVector %float 4 %_ptr_Output_v4float = OpTypePointer Output %v4float %22 = OpTypeFunction %v4float %_ptr_Function_v4float = OpTypePointer Function %v4float %_ptr_Function_float = OpTypePointer Function %float %_ptr_Uniform_v3float = OpTypePointer Uniform %v3float %_ptr_Uniform_float = OpTypePointer Uniform %float %bool = OpTypeBool %_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image %_ptr_Function_type_sampler = OpTypePointer Function %type_sampler %_ptr_Function_v2float = OpTypePointer Function %v2float %_ptr_Uniform_v2float = OpTypePointer Uniform %v2float %71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float %type_sampled_image = OpTypeSampledImage %type_2d_image %float_0 = OpConstant %float 0 %27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0 %int_1 = OpConstant %int 1 %int_0 = OpConstant %int 0 %float_1 = OpConstant %float 1 %gSS = OpVariable %_ptr_UniformConstant_type_sampler UniformConstant %gTex = OpVariable %_ptr_UniformConstant_type_2d_image UniformConstant %var_MyCBuffer = OpVariable %_ptr_Uniform_type_MyCBuffer Uniform %out_var_SV_Target = OpVariable %_ptr_Output_v4float Output %PS_BlurFilter_Box1 = OpFunction %void None %15 %17 = OpLabel %91 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1 %92 = OpAccessChain %_ptr_Uniform_float %91 %int_0 %93 = OpLoad %float %92 %94 = OpFNegate %float %93 OpBranch %95 %95 = OpLabel %123 = OpPhi %v4float %27 %17 %112 %102 %124 = OpPhi %float %94 %17 %114 %102 %97 = OpAccessChain %_ptr_Uniform_v3float %var_MyCBuffer %int_1 %98 = OpAccessChain %_ptr_Uniform_float %97 %int_0 %99 = OpLoad %float %98 %100 = OpFOrdLessThanEqual %bool %124 %99 OpLoopMerge %101 %102 None OpBranchConditional %100 %103 %101 %103 = OpLabel %104 = OpLoad %type_2d_image %gTex %105 = OpLoad %type_sampler %gSS %106 = OpAccessChain %_ptr_Uniform_v2float %var_MyCBuffer %int_0 %107 = OpLoad %v2float %106 %109 = OpVectorTimesScalar %v2float %107 %124 %121 = OpSampledImage %type_sampled_image %104 %105 %122 = OpImageSampleExplicitLod %v4float %121 %109 Lod %float_0 %112 = OpFAdd %v4float %123 %122 OpBranch %102 %102 = OpLabel %114 = OpFAdd %float %124 %float_1 OpBranch %95 %101 = OpLabel OpStore %out_var_SV_Target %123 OpReturn OpFunctionEndWhich seems correct. But optimization passes (
RegisterPerformancePasses()) turns it intoOpCapability Shader OpMemoryModel Logical GLSL450 OpEntryPoint Fragment %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" %out_var_SV_Target OpExecutionMode %PS_BlurFilter_Box1 OriginUpperLeft OpName %type_sampler "type.sampler" OpName %type_2d_image "type.2d.image" OpName %type_MyCBuffer "type.MyCBuffer" OpMemberName %type_MyCBuffer 0 "scale" OpMemberName %type_MyCBuffer 1 "size" OpName %PS_BlurFilter_Box1 "PS_BlurFilter_Box1" OpName %out_var_SV_Target "out.var.SV_Target" OpName %type_sampled_image "type.sampled.image" OpMemberDecorate %type_MyCBuffer 0 Offset 0 OpMemberDecorate %type_MyCBuffer 1 Offset 16 OpDecorate %type_MyCBuffer Block OpDecorate %out_var_SV_Target Location 0 %int = OpTypeInt 32 1 %type_sampler = OpTypeSampler %_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler %float = OpTypeFloat 32 %type_2d_image = OpTypeImage %float 2D 0 0 0 1 Unknown %_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image %v2float = OpTypeVector %float 2 %v3float = OpTypeVector %float 3 %type_MyCBuffer = OpTypeStruct %v2float %v3float %_ptr_Uniform_type_MyCBuffer = OpTypePointer Uniform %type_MyCBuffer %void = OpTypeVoid %15 = OpTypeFunction %void %v4float = OpTypeVector %float 4 %_ptr_Output_v4float = OpTypePointer Output %v4float %22 = OpTypeFunction %v4float %_ptr_Function_v4float = OpTypePointer Function %v4float %_ptr_Function_float = OpTypePointer Function %float %_ptr_Uniform_v3float = OpTypePointer Uniform %v3float %_ptr_Uniform_float = OpTypePointer Uniform %float %bool = OpTypeBool %_ptr_Function_type_2d_image = OpTypePointer Function %type_2d_image %_ptr_Function_type_sampler = OpTypePointer Function %type_sampler %_ptr_Function_v2float = OpTypePointer Function %v2float %_ptr_Uniform_v2float = OpTypePointer Uniform %v2float %71 = OpTypeFunction %v4float %_ptr_Function_type_2d_image %_ptr_Function_type_sampler %_ptr_Function_v2float %_ptr_Function_float %type_sampled_image = OpTypeSampledImage %type_2d_image %float_0 = OpConstant %float 0 %27 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0 %int_1 = OpConstant %int 1 %int_0 = OpConstant %int 0 %float_1 = OpConstant %float 1 %out_var_SV_Target = OpVariable %_ptr_Output_v4float Output %PS_BlurFilter_Box1 = OpFunction %void None %15 %17 = OpLabel OpStore %out_var_SV_Target %27 OpReturn OpFunctionEndThe for loop is completely gone.
Originally reported in microsoft/DirectXShaderCompiler#958.
Likely related to #1143, but I'm not certain.
Using the correct top of the tree: 702852b