dawn-cmake/test/tint/builtins/gen/firstLeadingBit/a622c2.wgsl.expected.msl
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

49 lines
1.3 KiB
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#include <metal_stdlib>
using namespace metal;
int2 tint_first_leading_bit(int2 v) {
uint2 x = select(uint2(v), uint2(~(v)), (v < int2(0)));
uint2 const b16 = select(uint2(0u), uint2(16u), bool2((x & uint2(4294901760u))));
x = (x >> b16);
uint2 const b8 = select(uint2(0u), uint2(8u), bool2((x & uint2(65280u))));
x = (x >> b8);
uint2 const b4 = select(uint2(0u), uint2(4u), bool2((x & uint2(240u))));
x = (x >> b4);
uint2 const b2 = select(uint2(0u), uint2(2u), bool2((x & uint2(12u))));
x = (x >> b2);
uint2 const b1 = select(uint2(0u), uint2(1u), bool2((x & uint2(2u))));
uint2 const is_zero = select(uint2(0u), uint2(4294967295u), (x == uint2(0u)));
return int2((((((b16 | b8) | b4) | b2) | b1) | is_zero));
}
void firstLeadingBit_a622c2() {
int2 res = tint_first_leading_bit(int2());
}
struct tint_symbol {
float4 value [[position]];
};
float4 vertex_main_inner() {
firstLeadingBit_a622c2();
return float4();
}
vertex tint_symbol vertex_main() {
float4 const inner_result = vertex_main_inner();
tint_symbol wrapper_result = {};
wrapper_result.value = inner_result;
return wrapper_result;
}
fragment void fragment_main() {
firstLeadingBit_a622c2();
return;
}
kernel void compute_main() {
firstLeadingBit_a622c2();
return;
}