dawn-cmake/test/tint/builtins/gen/firstTrailingBit/110f2c.wgsl.expected.hlsl
Ben Clayton df3630c194 builtins: Add firstTrailingBit
Currently polyfilled for all backends.
HLSL should be able to map this to 'firstbitlow', 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/1003

Bug: tint:1367
Bug: tint:1449
Change-Id: I8125b32687196678906e5a9d056b4f2efd885073
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/81502
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
2022-02-23 14:32:14 +00:00

46 lines
1.3 KiB
HLSL

uint4 tint_first_trailing_bit(uint4 v) {
uint4 x = uint4(v);
const uint4 b16 = (bool4((x & uint4((65535u).xxxx))) ? uint4((0u).xxxx) : uint4((16u).xxxx));
x = (x >> b16);
const uint4 b8 = (bool4((x & uint4((255u).xxxx))) ? uint4((0u).xxxx) : uint4((8u).xxxx));
x = (x >> b8);
const uint4 b4 = (bool4((x & uint4((15u).xxxx))) ? uint4((0u).xxxx) : uint4((4u).xxxx));
x = (x >> b4);
const uint4 b2 = (bool4((x & uint4((3u).xxxx))) ? uint4((0u).xxxx) : uint4((2u).xxxx));
x = (x >> b2);
const uint4 b1 = (bool4((x & uint4((1u).xxxx))) ? uint4((0u).xxxx) : uint4((1u).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 firstTrailingBit_110f2c() {
uint4 res = tint_first_trailing_bit(uint4(0u, 0u, 0u, 0u));
}
struct tint_symbol {
float4 value : SV_Position;
};
float4 vertex_main_inner() {
firstTrailingBit_110f2c();
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() {
firstTrailingBit_110f2c();
return;
}
[numthreads(1, 1, 1)]
void compute_main() {
firstTrailingBit_110f2c();
return;
}