8c3d5b4b6c
More aggressively prune unreachable code as follows.
When no control flow edges reach a merge block or continue target:
- delete their contents so that:
- a merge block becomes OpLabel, then OpUnreachable
- a continue target becomes OpLabel, then an OpBranch back to the
loop header
- any basic block which is dominated by such a merge block or continue
target is removed as well.
- decorations targeting the removed instructions are removed.
Enables the SPIR-V builder post-processing step the GLSLANG_WEB case.
47 lines
1.5 KiB
JavaScript
47 lines
1.5 KiB
JavaScript
#version 450
|
|
|
|
#extension GL_EXT_control_flow_attributes : enable
|
|
|
|
bool cond;
|
|
|
|
void f0() {
|
|
[[loop]] for (;;) { }
|
|
}
|
|
|
|
void f1() {
|
|
[[dont_unroll]] while(true) { }
|
|
}
|
|
|
|
void main()
|
|
{
|
|
[[unroll]] for (int i = 0; i < 8; ++i) { }
|
|
f0();
|
|
[[dependency_infinite]] do { } while(true);
|
|
[[dependency_length(1+3)]] for (int i = 0; i < 8; ++i) { }
|
|
[[flatten]] if (cond) { } else { }
|
|
[[branch]] if (cond) cond = false;
|
|
[[dont_flatten]] switch(3) { } // dropped
|
|
[[dont_flatten]] switch(3) { case 3: break; }
|
|
|
|
// warnings on all these
|
|
[[unroll(2)]] for (int i = 0; i < 8; ++i) { }
|
|
[[dont_unroll(-2)]] while(true) { }
|
|
[[dependency_infinite(3)]] do { } while(true);
|
|
[[dependency_length]] for (int i = 0; i < 8; ++i) { }
|
|
[[flatten(3)]] if (cond) { } else { }
|
|
[[branch(5.2)]] if (cond) cond = false;
|
|
[[dont_flatten(3 + 7)]] switch(3) { case 3: break; }
|
|
|
|
// other valid uses
|
|
[[ unroll, dont_unroll, dependency_length(2) ]] while(cond) { }
|
|
[ [ dont_flatten , branch ] ] switch(3) { case 3: break; }
|
|
[
|
|
// attribute
|
|
[
|
|
// here
|
|
flatten
|
|
]
|
|
] if (cond) { } else { }
|
|
[[ dependency_length(2), dependency_infinite ]] while(cond) { }
|
|
}
|