#!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: Shader with matrix multiplication in loop

# The test passes because 'm1' is the identity matrix, so that 'm2' is also the identity matrix, meaning that 'v' gets set to '(1.0, 0.0)'.  As a result, the colour that is written is guaranteed to be red

# Optimized using spirv-opt with the following arguments:
# '--simplify-instructions'
# '--combine-access-chains'
# '--eliminate-dead-branches'
# '--merge-return'
# '--combine-access-chains'
# '--eliminate-dead-code-aggressive'
# '--reduce-load-size'
# '--eliminate-local-single-block'
# '--private-to-local'
# '--inline-entry-points-exhaustive'
# '--copy-propagate-arrays'
# '--eliminate-local-multi-store'
# '--scalar-replacement=100'
# '--eliminate-dead-branches'
# '--eliminate-local-single-store'
# spirv-opt commit hash: f1e5cd73f658abcc23ee96d78f2dc27c4b7028c1


SHADER vertex variant_vertex_shader PASSTHROUGH

# variant_fragment_shader is derived from the following GLSL:
# #version 310 es
# precision highp float;
#
# precision highp int;
#
# layout(location = 0) out vec4 _GLF_color;
#
# void main(void)
# {
#  vec2 v;
#  mat2 m1 = mat2(1.0, 0.0, 0.0, 1.0);
#  for(
#      int i = 0;
#      i < 1;
#      i++
#  )
#   {
#    do
#     {
#      mat2 m2;
#      m2 = m1 * m1;
#      v = m2 * vec2(1.0, 0.0);
#     }
#    while(false);
#   }
#   _GLF_color = vec4(v, 0.0, 1.0);
# }
SHADER fragment variant_fragment_shader SPIRV-ASM TARGET_ENV spv1.0
; SPIR-V
; Version: 1.0
; Generator: Khronos Glslang Reference Front End; 8
; Bound: 56
; Schema: 0
               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %4 "main" %46
               OpExecutionMode %4 OriginUpperLeft
               OpSource ESSL 310
               OpName %4 "main"
               OpName %10 "m1"
               OpName %18 "i"
               OpName %33 "m2"
               OpName %38 "v"
               OpName %46 "_GLF_color"
               OpDecorate %46 Location 0
          %2 = OpTypeVoid
          %3 = OpTypeFunction %2
          %6 = OpTypeFloat 32
          %7 = OpTypeVector %6 2
          %8 = OpTypeMatrix %7 2
          %9 = OpTypePointer Function %8
         %11 = OpConstant %6 1
         %12 = OpConstant %6 0
         %13 = OpConstantComposite %7 %11 %12
         %14 = OpConstantComposite %7 %12 %11
         %15 = OpConstantComposite %8 %13 %14
         %16 = OpTypeInt 32 1
         %17 = OpTypePointer Function %16
         %19 = OpConstant %16 0
         %26 = OpConstant %16 1
         %27 = OpTypeBool
         %37 = OpTypePointer Function %7
         %41 = OpConstantFalse %27
         %44 = OpTypeVector %6 4
         %45 = OpTypePointer Output %44
         %46 = OpVariable %45 Output
         %53 = OpUndef %7
          %4 = OpFunction %2 None %3
          %5 = OpLabel
         %10 = OpVariable %9 Function
         %18 = OpVariable %17 Function
         %33 = OpVariable %9 Function
         %38 = OpVariable %37 Function
               OpStore %10 %15
               OpStore %18 %19
               OpBranch %20
         %20 = OpLabel
         %55 = OpPhi %8 %15 %5 %55 %23
         %52 = OpPhi %7 %53 %5 %40 %23
         %51 = OpPhi %16 %19 %5 %43 %23
               OpLoopMerge %22 %23 None
               OpBranch %24
         %24 = OpLabel
         %28 = OpSLessThan %27 %51 %26
               OpBranchConditional %28 %21 %22
         %21 = OpLabel
               OpBranch %29
         %29 = OpLabel
               OpLoopMerge %31 %32 None
               OpBranch %30
         %30 = OpLabel
         %36 = OpMatrixTimesMatrix %8 %55 %55
               OpStore %33 %36
         %40 = OpMatrixTimesVector %7 %36 %13
               OpStore %38 %40
               OpBranch %32
         %32 = OpLabel
               OpBranchConditional %41 %29 %31
         %31 = OpLabel
               OpBranch %23
         %23 = OpLabel
         %43 = OpIAdd %16 %51 %26
               OpStore %18 %43
               OpBranch %20
         %22 = OpLabel
         %48 = OpCompositeExtract %6 %52 0
         %49 = OpCompositeExtract %6 %52 1
         %50 = OpCompositeConstruct %44 %48 %49 %12 %11
               OpStore %46 %50
               OpReturn
               OpFunctionEnd
END


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