#!amber # Copyright 2019 Google LLC # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # A test for a bug found by GraphicsFuzz. # Short description: A fragment shader with return before writing wrong color # The test passes because the shader always writes color red. # Main writes red and returns. Code after writing red is never executed. # Optimized using spirv-opt with the following arguments: # '--private-to-local' # '--eliminate-local-multi-store' # '--redundancy-elimination' # '--eliminate-dead-code-aggressive' # '--simplify-instructions' # '--eliminate-dead-branches' # '--merge-blocks' # '--reduce-load-size' # '--combine-access-chains' # '--combine-access-chains' # '--eliminate-dead-branches' # '--ccp' # '--redundancy-elimination' # '--simplify-instructions' # '--vector-dce' # '--ccp' # '--private-to-local' # '--eliminate-dead-inserts' # spirv-opt commit hash: ad7f2c5c4c7f51360e9e079109a9217aa5ba5cc0 SHADER vertex variant_vertex_shader PASSTHROUGH # variant_fragment_shader is derived from the following GLSL: # #version 310 es # precision highp float; # # precision highp int; # # struct _GLF_struct_0 # { # int msb9; # }; # # layout(location = 0) out vec4 _GLF_color; # # void main() # { # _GLF_struct_0 _GLF_struct_replacement_0; # # do # { # for (int j = 0; 1 < findLSB(1024); 1) # { # _GLF_color = vec4(1.0, 0.0, 0.0, 1.0); // Write color red # return; // We always return here. The code below is never executed. # } # } while (_GLF_struct_replacement_0.msb9 > 1); # _GLF_color = vec4(1.0, 1.0, _GLF_struct_replacement_0.msb9, 1.0); # } SHADER fragment variant_fragment_shader SPIRV-ASM TARGET_ENV spv1.0 ; SPIR-V ; Version: 1.0 ; Generator: Khronos Glslang Reference Front End; 7 ; Bound: 43 ; Schema: 0 OpCapability Shader %1 = OpExtInstImport "GLSL.std.450" OpMemoryModel Logical GLSL450 OpEntryPoint Fragment %4 "main" %27 OpExecutionMode %4 OriginUpperLeft OpSource ESSL 310 OpName %4 "main" OpName %27 "_GLF_color" OpName %32 "_GLF_struct_0" OpMemberName %32 0 "msb9" OpName %34 "_GLF_struct_replacement_0" OpDecorate %21 RelaxedPrecision OpDecorate %27 Location 0 %2 = OpTypeVoid %3 = OpTypeFunction %2 %10 = OpTypeInt 32 1 %11 = OpTypePointer Function %10 %13 = OpConstant %10 0 %19 = OpConstant %10 1 %20 = OpConstant %10 1024 %22 = OpTypeBool %24 = OpTypeFloat 32 %25 = OpTypeVector %24 4 %26 = OpTypePointer Output %25 %27 = OpVariable %26 Output %28 = OpConstant %24 1 %29 = OpConstant %24 0 %30 = OpConstantComposite %25 %28 %29 %29 %28 %32 = OpTypeStruct %10 %33 = OpTypePointer Function %32 %4 = OpFunction %2 None %3 %5 = OpLabel %34 = OpVariable %33 Function OpBranch %6 %6 = OpLabel OpLoopMerge %8 %16 None OpBranch %14 %14 = OpLabel %21 = OpExtInst %10 %1 FindILsb %20 %23 = OpSLessThan %22 %19 %21 OpLoopMerge %42 %17 None OpBranchConditional %23 %15 %42 %15 = OpLabel OpStore %27 %30 OpReturn %17 = OpLabel OpBranch %14 %42 = OpLabel OpBranch %16 %16 = OpLabel %35 = OpAccessChain %11 %34 %13 %36 = OpLoad %10 %35 %37 = OpSGreaterThan %22 %36 %19 OpBranchConditional %37 %6 %8 %8 = OpLabel %39 = OpLoad %10 %35 %40 = OpConvertSToF %24 %39 %41 = OpCompositeConstruct %25 %28 %28 %40 %28 OpStore %27 %41 OpReturn OpFunctionEnd END # uniforms for variant BUFFER variant_framebuffer FORMAT B8G8R8A8_UNORM PIPELINE graphics variant_pipeline ATTACH variant_vertex_shader ATTACH variant_fragment_shader FRAMEBUFFER_SIZE 256 256 BIND BUFFER variant_framebuffer AS color LOCATION 0 END CLEAR_COLOR variant_pipeline 0 0 0 255 CLEAR variant_pipeline RUN variant_pipeline DRAW_RECT POS 0 0 SIZE 256 256 EXPECT variant_framebuffer IDX 0 0 SIZE 256 256 EQ_RGBA 255 0 0 255