SPIRV-Cross/shaders-msl-no-opt/asm/frag/switch-block-case-fallthrough.asm.frag
Hans-Kristian Arntzen c365cc1b43 Deal with OpPhi and case fallthrough.
This is quite complex since we cannot flush Phi inside the case labels,
we have to do it outside by emitting a lot of manual branches ourselves.

This should be extremely rare, but we need to handle this case.
2019-06-21 13:38:23 +02:00

81 lines
2.9 KiB
JavaScript

; SPIR-V
; Version: 1.0
; Generator: Khronos Glslang Reference Front End; 7
; Bound: 29
; Schema: 0
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %main "main" %vIndex %FragColor
OpExecutionMode %main OriginUpperLeft
OpSource GLSL 450
OpName %main "main"
OpName %vIndex "vIndex"
OpName %FragColor "FragColor"
OpName %i "i"
OpName %j "j"
OpDecorate %vIndex Flat
OpDecorate %vIndex Location 0
OpDecorate %FragColor Location 0
%void = OpTypeVoid
%3 = OpTypeFunction %void
%int = OpTypeInt 32 1
%bool = OpTypeBool
%int_0 = OpConstant %int 0
%int_1 = OpConstant %int 1
%int_2 = OpConstant %int 2
%int_3 = OpConstant %int 3
%_ptr_Input_int = OpTypePointer Input %int
%vIndex = OpVariable %_ptr_Input_int Input
%float = OpTypeFloat 32
%v4float = OpTypeVector %float 4
%_ptr_Output_v4float = OpTypePointer Output %v4float
%FragColor = OpVariable %_ptr_Output_v4float Output
%_ptr_Function_int = OpTypePointer Function %int
%main = OpFunction %void None %3
%header = OpLabel
%i = OpVariable %_ptr_Function_int Function %int_0
%j = OpVariable %_ptr_Function_int Function
%9 = OpLoad %int %vIndex
OpSelectionMerge %switch_merge None
OpSwitch %9 %default_case 100 %default_case 0 %case_0 1 %case_1 11 %case_1 2 %case_2 3 %case_3 4 %case_4 5 %case_5
%case_0 = OpLabel
OpBranch %default_case
%default_case = OpLabel
%default_case_phi = OpPhi %int %int_2 %header %int_3 %case_0
; Test what happens when a case block dominates access to a variable.
OpStore %j %default_case_phi
OpBranch %case_1
%case_1 = OpLabel
; Test phi nodes between case labels.
%case_1_phi = OpPhi %int %int_0 %default_case %int_1 %header
OpStore %j %case_1_phi
OpBranch %case_2
%case_2 = OpLabel
OpBranch %switch_merge
%case_3 = OpLabel
; Conditionally branch to another case block. This is really dumb, but it is apparently legal.
%case_3_cond = OpSGreaterThan %bool %9 %int_3
OpBranchConditional %case_3_cond %case_4 %switch_merge
%case_4 = OpLabel
; When emitted from case 3, we should *not* see fallthrough behavior.
OpBranch %case_5
%case_5 = OpLabel
OpStore %i %int_0
OpBranch %switch_merge
%switch_merge = OpLabel
%26 = OpLoad %int %i
%27 = OpConvertSToF %float %26
%28 = OpCompositeConstruct %v4float %27 %27 %27 %27
OpStore %FragColor %28
OpReturn
OpFunctionEnd