SPIRV-Cross/shaders-no-opt/asm/frag/relaxed-precision-inheritance-rules-hoisted-temporaries.asm.frag
Hans-Kristian Arntzen 7a6c2da9aa GLSL: Handle more proper semantics for RelaxedPrecision.
GLSL and RelaxedPrecision are quite different in what they affect.
RelaxedPrecision affects operations, while this is merely implied in
GLSL based on inputs.

This leads to situations where we have to promote mediump inputs to
highp, and the simplest approach is to force highp temporaries for
inputs which are consumed in a highp context. For completeness, we also
demote RelaxedPrecision inputs to mediump variables.

PHI is handled by copying the PHI into a temporary.

We have to be very careful with hoisted temporaries, since the child
temporary will not be analyzed up-front. We inherit the hoisted-ness
state and emit the hoisted child temporary as necessary. When faking the
temporaries with OpCopyObject, we make sure to block any variable
hoisting.

Hoisting children of PHI variables is fine, since PHIs are not hoisted with
the same framework as other temporaries.
2022-05-02 15:11:24 +02:00

98 lines
3.7 KiB
JavaScript

; SPIR-V
; Version: 1.0
; Generator: Khronos Glslang Reference Front End; 10
; Bound: 52
; Schema: 0
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %main "main" %vColor %FragColor
OpExecutionMode %main OriginUpperLeft
OpSource ESSL 310
OpName %main "main"
OpName %a "a"
OpName %vColor "vColor"
OpName %b "b"
OpName %i "i"
OpName %FragColor "FragColor"
OpDecorate %a RelaxedPrecision
OpDecorate %vColor RelaxedPrecision
OpDecorate %vColor Location 0
OpDecorate %16 RelaxedPrecision
OpDecorate %20 RelaxedPrecision
OpDecorate %FragColor RelaxedPrecision
OpDecorate %FragColor Location 0
OpDecorate %37 RelaxedPrecision
OpDecorate %38 RelaxedPrecision
OpDecorate %39 RelaxedPrecision
OpDecorate %43 RelaxedPrecision
OpDecorate %44 RelaxedPrecision
OpDecorate %45 RelaxedPrecision
OpDecorate %49 RelaxedPrecision
%void = OpTypeVoid
%3 = OpTypeFunction %void
%float = OpTypeFloat 32
%_ptr_Function_float = OpTypePointer Function %float
%v4float = OpTypeVector %float 4
%_ptr_Input_v4float = OpTypePointer Input %v4float
%vColor = OpVariable %_ptr_Input_v4float Input
%uint = OpTypeInt 32 0
%uint_0 = OpConstant %uint 0
%_ptr_Input_float = OpTypePointer Input %float
%uint_1 = OpConstant %uint 1
%int = OpTypeInt 32 1
%_ptr_Function_int = OpTypePointer Function %int
%int_0 = OpConstant %int 0
%int_4 = OpConstant %int 4
%bool = OpTypeBool
%_ptr_Output_v4float = OpTypePointer Output %v4float
%FragColor = OpVariable %_ptr_Output_v4float Output
%float_1 = OpConstant %float 1
%int_1 = OpConstant %int 1
%main = OpFunction %void None %3
%5 = OpLabel
%a = OpVariable %_ptr_Function_float Function
%b = OpVariable %_ptr_Function_float Function
%i = OpVariable %_ptr_Function_int Function
%15 = OpAccessChain %_ptr_Input_float %vColor %uint_0
%16 = OpLoad %float %15
OpStore %a %16
%19 = OpAccessChain %_ptr_Input_float %vColor %uint_1
%20 = OpLoad %float %19
OpStore %b %20
OpStore %i %int_0
OpBranch %25
%25 = OpLabel
OpLoopMerge %27 %28 None
OpBranch %29
%29 = OpLabel
%30 = OpLoad %int %i
%33 = OpSLessThan %bool %30 %int_4
OpBranchConditional %33 %26 %27
%26 = OpLabel
%37 = OpLoad %v4float %FragColor
%38 = OpCompositeConstruct %v4float %float_1 %float_1 %float_1 %float_1
%39 = OpFAdd %v4float %37 %38
OpStore %FragColor %39
OpBranch %28
%28 = OpLabel
%40 = OpLoad %int %i
%42 = OpIAdd %int %40 %int_1
OpStore %i %42
%43 = OpLoad %float %a
%44 = OpLoad %float %a
%45 = OpFMul %float %43 %44
%force_tmp = OpFMul %float %45 %44
%46 = OpLoad %float %b
%47 = OpFAdd %float %46 %force_tmp
OpStore %b %47
OpBranch %25
%27 = OpLabel
%48 = OpLoad %float %b
%49 = OpLoad %v4float %FragColor
%50 = OpCompositeConstruct %v4float %48 %48 %48 %48
%51 = OpFAdd %v4float %49 %50
OpStore %FragColor %51
OpReturn
OpFunctionEnd