skia2/tests/sksl/inliner/InlinerHonorsGLSLOutParamSemantics.glsl


out vec4 sk_FragColor;
uniform vec4 colorGreen;
uniform vec4 colorRed;
bool out_params_are_distinct_bhh(out float x, out float y) {
    x = 1.0;
    y = 2.0;
    return x == 1.0 && y == 2.0;
}
vec4 main() {
    float x = 0.0;
    return out_params_are_distinct_bhh(x, x) ? colorGreen : colorRed;
}
Add test to demonstrate out-param semantics violation. GLSL ES2 documentation on out parameters: "Evaluation of an out parameter results in an l-value that is used to copy out a value when the function returns." The inliner does not do any alias checking when inlining an `out` param. That is, passing the same variable to two separate `out` parameters would not generate two distinct lvalues in the inlined code; it reuses the same variable for each out-params in the inlined code. (Amusingly, our CFG can fully optimize away this test code so it just returns "red".) Change-Id: Ib781d2cfdac54f01b6abe159af0c84ff24ff6976 Bug: skia:11326 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370256 Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Auto-Submit: John Stiles <johnstiles@google.com> 2021-02-13 16:25:51 +00:00
			`out vec4 sk_FragColor;`
			`uniform vec4 colorGreen;`
			`uniform vec4 colorRed;`
Mangle function names in GLSL. This will be implemented in Metal and SPIR-V in followup CLs. Change-Id: I397b4db40b15dd54cf1d8a17f414c3fe184b48d2 Bug: skia:10851 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387638 Auto-Submit: John Stiles <johnstiles@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Reviewed-by: Brian Osman <brianosman@google.com> 2021-03-22 15:43:11 +00:00			`bool out_params_are_distinct_bhh(out float x, out float y) {`
Disallow inlining a function with out-parameters. It is difficult to do this both efficiently and correctly while honoring GLSL semantics (which require the lvalues to be kept distinct, even when they point to the same variable). We could make it work by making copies of every out parameter in each direction (going in for inouts, and coming out for outs and inouts). However, this could be self-defeating if it makes it harder for the driver to track variable lifetimes. Simply opting out of inlining these functions entirely seems like the best tradeoff; let the driver optimize them if it can, and we can enjoy reduced complexity in the SkSL inliner. Change-Id: I62f7b4550cc181cfe789e4f2ff4e408ba1baf9cb Bug: skia:11326 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370257 Reviewed-by: Brian Osman <brianosman@google.com> Reviewed-by: Ethan Nicholas <ethannicholas@google.com> Commit-Queue: John Stiles <johnstiles@google.com> 2021-03-17 17:20:10 +00:00			`x = 1.0;`
			`y = 2.0;`
			`return x == 1.0 && y == 2.0;`
			`}`
Add test to demonstrate out-param semantics violation. GLSL ES2 documentation on out parameters: "Evaluation of an out parameter results in an l-value that is used to copy out a value when the function returns." The inliner does not do any alias checking when inlining an `out` param. That is, passing the same variable to two separate `out` parameters would not generate two distinct lvalues in the inlined code; it reuses the same variable for each out-params in the inlined code. (Amusingly, our CFG can fully optimize away this test code so it just returns "red".) Change-Id: Ib781d2cfdac54f01b6abe159af0c84ff24ff6976 Bug: skia:11326 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370256 Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Auto-Submit: John Stiles <johnstiles@google.com> 2021-02-13 16:25:51 +00:00			`vec4 main() {`
Performance experiment: disable control-flow analysis. This CL will be used to test for potential performance regressions (or improvements) that we might cause by disabling this optimization pass. It will be reverted in ~1 day. Change-Id: I26b7687c341eb6d81231406381c39869cfccf6d6 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381259 Auto-Submit: John Stiles <johnstiles@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Reviewed-by: Ethan Nicholas <ethannicholas@google.com> Reviewed-by: Brian Osman <brianosman@google.com> 2021-03-08 18:29:15 +00:00			`float x = 0.0;`
Mangle function names in GLSL. This will be implemented in Metal and SPIR-V in followup CLs. Change-Id: I397b4db40b15dd54cf1d8a17f414c3fe184b48d2 Bug: skia:10851 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387638 Auto-Submit: John Stiles <johnstiles@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Reviewed-by: Brian Osman <brianosman@google.com> 2021-03-22 15:43:11 +00:00			`return out_params_are_distinct_bhh(x, x) ? colorGreen : colorRed;`
Add test to demonstrate out-param semantics violation. GLSL ES2 documentation on out parameters: "Evaluation of an out parameter results in an l-value that is used to copy out a value when the function returns." The inliner does not do any alias checking when inlining an `out` param. That is, passing the same variable to two separate `out` parameters would not generate two distinct lvalues in the inlined code; it reuses the same variable for each out-params in the inlined code. (Amusingly, our CFG can fully optimize away this test code so it just returns "red".) Change-Id: Ib781d2cfdac54f01b6abe159af0c84ff24ff6976 Bug: skia:11326 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370256 Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Auto-Submit: John Stiles <johnstiles@google.com> 2021-02-13 16:25:51 +00:00			`}`