mirror of
https://github.com/encounter/dawn-cmake.git
synced 2025-07-06 05:06:07 +00:00
Currently polyfilled for all backends. HLSL should be able to map this to 'firstbithigh', but there might need to be some special case handling for 0 (undocumented behavior). For now just polyfill. CTS tests: https://github.com/gpuweb/cts/pull/1004 Bug: tint:1367 Bug: tint:1449 Change-Id: I9c9a08ea93d1c4a602e0ab763e95e2eea336fb0d Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/81503 Reviewed-by: David Neto <dneto@google.com> Kokoro: Kokoro <noreply+kokoro@google.com> Commit-Queue: Ben Clayton <bclayton@google.com>
46 lines
1.3 KiB
HLSL
46 lines
1.3 KiB
HLSL
uint4 tint_first_leading_bit(uint4 v) {
|
|
uint4 x = v;
|
|
const uint4 b16 = (bool4((x & uint4((4294901760u).xxxx))) ? uint4((16u).xxxx) : uint4((0u).xxxx));
|
|
x = (x >> b16);
|
|
const uint4 b8 = (bool4((x & uint4((65280u).xxxx))) ? uint4((8u).xxxx) : uint4((0u).xxxx));
|
|
x = (x >> b8);
|
|
const uint4 b4 = (bool4((x & uint4((240u).xxxx))) ? uint4((4u).xxxx) : uint4((0u).xxxx));
|
|
x = (x >> b4);
|
|
const uint4 b2 = (bool4((x & uint4((12u).xxxx))) ? uint4((2u).xxxx) : uint4((0u).xxxx));
|
|
x = (x >> b2);
|
|
const uint4 b1 = (bool4((x & uint4((2u).xxxx))) ? uint4((1u).xxxx) : uint4((0u).xxxx));
|
|
const uint4 is_zero = ((x == uint4((0u).xxxx)) ? uint4((4294967295u).xxxx) : uint4((0u).xxxx));
|
|
return uint4((((((b16 | b8) | b4) | b2) | b1) | is_zero));
|
|
}
|
|
|
|
void firstLeadingBit_000ff3() {
|
|
uint4 res = tint_first_leading_bit(uint4(0u, 0u, 0u, 0u));
|
|
}
|
|
|
|
struct tint_symbol {
|
|
float4 value : SV_Position;
|
|
};
|
|
|
|
float4 vertex_main_inner() {
|
|
firstLeadingBit_000ff3();
|
|
return float4(0.0f, 0.0f, 0.0f, 0.0f);
|
|
}
|
|
|
|
tint_symbol vertex_main() {
|
|
const float4 inner_result = vertex_main_inner();
|
|
tint_symbol wrapper_result = (tint_symbol)0;
|
|
wrapper_result.value = inner_result;
|
|
return wrapper_result;
|
|
}
|
|
|
|
void fragment_main() {
|
|
firstLeadingBit_000ff3();
|
|
return;
|
|
}
|
|
|
|
[numthreads(1, 1, 1)]
|
|
void compute_main() {
|
|
firstLeadingBit_000ff3();
|
|
return;
|
|
}
|