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>
25 lines
912 B
Metal
25 lines
912 B
Metal
#include <metal_stdlib>
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#include <simd/simd.h>
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using namespace metal;
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struct Inputs {
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float4 src;
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float4 dst;
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};
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struct Outputs {
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float4 sk_FragColor [[color(0)]];
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};
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float _blend_overlay_component(float2 s, float2 d) {
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return 2.0 * d.x <= d.y ? (2.0 * s.x) * d.x : s.y * d.y - (2.0 * (d.y - d.x)) * (s.y - s.x);
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}
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fragment Outputs fragmentMain(Inputs _in [[stage_in]], bool _frontFacing [[front_facing]], float4 _fragCoord [[position]]) {
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Outputs _outputStruct;
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thread Outputs* _out = &_outputStruct;
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float4 _1_result = float4(_blend_overlay_component(_in.src.xw, _in.dst.xw), _blend_overlay_component(_in.src.yw, _in.dst.yw), _blend_overlay_component(_in.src.zw, _in.dst.zw), _in.src.w + (1.0 - _in.src.w) * _in.dst.w);
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_1_result.xyz = _1_result.xyz + _in.dst.xyz * (1.0 - _in.src.w) + _in.src.xyz * (1.0 - _in.dst.w);
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_out->sk_FragColor = _1_result;
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return *_out;
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}
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