77702f1704
When we determine that a function only contains a single return
statement and it is at the top level (i.e. not inside any scopes),
there is no need to create a temporary variable and store the
result expression into a variable. Instead, we can directly replace
the function-call expression with the return-statement's expression.
Unlike my previous solution, this does not require variable
declarations to be rewritten. The no-scopes limitation makes it
slightly less effective in theory, but in practice we still get
almost all of the benefit. The no-scope limitation bites us on
structures like
@if (true) {
return x;
} else {
return y;
}
Which will optimize away the if, but leave the scope:
{
return x;
}
However, this is not a big deal; the biggest wins are single-line
helper functions like `guarded_divide` and `unpremul` which retain
the full benefit.
Change-Id: I7fbb725e65db021b9795c04c816819669815578f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/345167
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
77 lines
2.5 KiB
JavaScript
77 lines
2.5 KiB
JavaScript
OpCapability Shader
|
|
%1 = OpExtInstImport "GLSL.std.450"
|
|
OpMemoryModel Logical GLSL450
|
|
OpEntryPoint Fragment %main "main" %sk_FragColor %sk_Clockwise %src %dst
|
|
OpExecutionMode %main OriginUpperLeft
|
|
OpName %sk_FragColor "sk_FragColor"
|
|
OpName %sk_Clockwise "sk_Clockwise"
|
|
OpName %src "src"
|
|
OpName %dst "dst"
|
|
OpName %main "main"
|
|
OpName %_1_result "_1_result"
|
|
OpDecorate %sk_FragColor RelaxedPrecision
|
|
OpDecorate %sk_FragColor Location 0
|
|
OpDecorate %sk_FragColor Index 0
|
|
OpDecorate %sk_Clockwise RelaxedPrecision
|
|
OpDecorate %sk_Clockwise BuiltIn FrontFacing
|
|
OpDecorate %src RelaxedPrecision
|
|
OpDecorate %dst RelaxedPrecision
|
|
OpDecorate %18 RelaxedPrecision
|
|
OpDecorate %20 RelaxedPrecision
|
|
OpDecorate %22 RelaxedPrecision
|
|
OpDecorate %23 RelaxedPrecision
|
|
OpDecorate %25 RelaxedPrecision
|
|
OpDecorate %27 RelaxedPrecision
|
|
OpDecorate %30 RelaxedPrecision
|
|
OpDecorate %32 RelaxedPrecision
|
|
OpDecorate %33 RelaxedPrecision
|
|
OpDecorate %36 RelaxedPrecision
|
|
OpDecorate %38 RelaxedPrecision
|
|
OpDecorate %40 RelaxedPrecision
|
|
OpDecorate %41 RelaxedPrecision
|
|
%float = OpTypeFloat 32
|
|
%v4float = OpTypeVector %float 4
|
|
%_ptr_Output_v4float = OpTypePointer Output %v4float
|
|
%sk_FragColor = OpVariable %_ptr_Output_v4float Output
|
|
%bool = OpTypeBool
|
|
%_ptr_Input_bool = OpTypePointer Input %bool
|
|
%sk_Clockwise = OpVariable %_ptr_Input_bool Input
|
|
%_ptr_Input_v4float = OpTypePointer Input %v4float
|
|
%src = OpVariable %_ptr_Input_v4float Input
|
|
%dst = OpVariable %_ptr_Input_v4float Input
|
|
%void = OpTypeVoid
|
|
%14 = OpTypeFunction %void
|
|
%_ptr_Function_v4float = OpTypePointer Function %v4float
|
|
%float_1 = OpConstant %float 1
|
|
%v3float = OpTypeVector %float 3
|
|
%main = OpFunction %void None %14
|
|
%15 = OpLabel
|
|
%_1_result = OpVariable %_ptr_Function_v4float Function
|
|
%18 = OpLoad %v4float %src
|
|
%20 = OpLoad %v4float %src
|
|
%21 = OpCompositeExtract %float %20 3
|
|
%22 = OpFSub %float %float_1 %21
|
|
%23 = OpLoad %v4float %dst
|
|
%24 = OpVectorTimesScalar %v4float %23 %22
|
|
%25 = OpFAdd %v4float %18 %24
|
|
OpStore %_1_result %25
|
|
%27 = OpLoad %v4float %_1_result
|
|
%28 = OpVectorShuffle %v3float %27 %27 0 1 2
|
|
%30 = OpLoad %v4float %dst
|
|
%31 = OpCompositeExtract %float %30 3
|
|
%32 = OpFSub %float %float_1 %31
|
|
%33 = OpLoad %v4float %src
|
|
%34 = OpVectorShuffle %v3float %33 %33 0 1 2
|
|
%35 = OpVectorTimesScalar %v3float %34 %32
|
|
%36 = OpLoad %v4float %dst
|
|
%37 = OpVectorShuffle %v3float %36 %36 0 1 2
|
|
%38 = OpFAdd %v3float %35 %37
|
|
%26 = OpExtInst %v3float %1 FMax %28 %38
|
|
%39 = OpLoad %v4float %_1_result
|
|
%40 = OpVectorShuffle %v4float %39 %26 4 5 6 3
|
|
OpStore %_1_result %40
|
|
%41 = OpLoad %v4float %_1_result
|
|
OpStore %sk_FragColor %41
|
|
OpReturn
|
|
OpFunctionEnd
|