dawn-cmake/test/tint/builtins/gen/firstLeadingBit/f0779d.wgsl.expected.hlsl
Ben Clayton 8169693136 builtins: Add firstLeadingBit
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>
2022-02-23 18:20:30 +00:00

46 lines
1.0 KiB
HLSL

uint tint_first_leading_bit(uint v) {
uint x = v;
const uint b16 = (bool((x & 4294901760u)) ? 16u : 0u);
x = (x >> b16);
const uint b8 = (bool((x & 65280u)) ? 8u : 0u);
x = (x >> b8);
const uint b4 = (bool((x & 240u)) ? 4u : 0u);
x = (x >> b4);
const uint b2 = (bool((x & 12u)) ? 2u : 0u);
x = (x >> b2);
const uint b1 = (bool((x & 2u)) ? 1u : 0u);
const uint is_zero = ((x == 0u) ? 4294967295u : 0u);
return uint((((((b16 | b8) | b4) | b2) | b1) | is_zero));
}
void firstLeadingBit_f0779d() {
uint res = tint_first_leading_bit(1u);
}
struct tint_symbol {
float4 value : SV_Position;
};
float4 vertex_main_inner() {
firstLeadingBit_f0779d();
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_f0779d();
return;
}
[numthreads(1, 1, 1)]
void compute_main() {
firstLeadingBit_f0779d();
return;
}