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8169693136
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
int2 tint_first_leading_bit(int2 v) {
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uint2 x = ((v < int2((0).xx)) ? uint2(~(v)) : uint2(v));
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const uint2 b16 = (bool2((x & uint2((4294901760u).xx))) ? uint2((16u).xx) : uint2((0u).xx));
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x = (x >> b16);
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const uint2 b8 = (bool2((x & uint2((65280u).xx))) ? uint2((8u).xx) : uint2((0u).xx));
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x = (x >> b8);
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const uint2 b4 = (bool2((x & uint2((240u).xx))) ? uint2((4u).xx) : uint2((0u).xx));
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x = (x >> b4);
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const uint2 b2 = (bool2((x & uint2((12u).xx))) ? uint2((2u).xx) : uint2((0u).xx));
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x = (x >> b2);
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const uint2 b1 = (bool2((x & uint2((2u).xx))) ? uint2((1u).xx) : uint2((0u).xx));
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const uint2 is_zero = ((x == uint2((0u).xx)) ? uint2((4294967295u).xx) : uint2((0u).xx));
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return int2((((((b16 | b8) | b4) | b2) | b1) | is_zero));
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}
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void firstLeadingBit_a622c2() {
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int2 res = tint_first_leading_bit(int2(0, 0));
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}
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struct tint_symbol {
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float4 value : SV_Position;
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};
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float4 vertex_main_inner() {
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firstLeadingBit_a622c2();
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return float4(0.0f, 0.0f, 0.0f, 0.0f);
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}
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tint_symbol vertex_main() {
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const float4 inner_result = vertex_main_inner();
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tint_symbol wrapper_result = (tint_symbol)0;
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wrapper_result.value = inner_result;
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return wrapper_result;
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}
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void fragment_main() {
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firstLeadingBit_a622c2();
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return;
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}
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[numthreads(1, 1, 1)]
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void compute_main() {
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firstLeadingBit_a622c2();
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return;
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}
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