diff options
| author | Matt Turner <[email protected]> | 2016-01-07 16:16:35 -0800 |
|---|---|---|
| committer | Matt Turner <[email protected]> | 2016-01-13 11:22:40 -0800 |
| commit | 74cff779eb5217fe2b791f2a23405096901f45fd (patch) | |
| tree | 7ec2648c95a5ea3aaf12c8184cab1a2bc3a671b6 /src | |
| parent | a5fcff6628c641d01954d0af4aee0e723a570cad (diff) | |
nir: Change bfm's semantics to match Intel/AMD/SM5.
Intel/AMD's hardware instructions do not handle arguments of 32.
Constant evaluation should not produce a result different from the
hardware instruction.
The s/1ull/1u/ change is intentional: previously we wanted defined
behavior for the "1 << 32" case, but we're making this case undefined so
we can make it 1u and save ourselves a 64-bit operation.
Reviewed-by: Ian Romanick <[email protected]>
Diffstat (limited to 'src')
| -rw-r--r-- | src/glsl/nir/nir_opcodes.py | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/glsl/nir/nir_opcodes.py b/src/glsl/nir/nir_opcodes.py index d7ba0b62375..1c65def691a 100644 --- a/src/glsl/nir/nir_opcodes.py +++ b/src/glsl/nir/nir_opcodes.py @@ -511,12 +511,15 @@ binop("fpow", tfloat, "", "powf(src0, src1)") binop_horiz("pack_half_2x16_split", 1, tuint, 1, tfloat, 1, tfloat, "pack_half_1x16(src0.x) | (pack_half_1x16(src1.x) << 16)") +# bfm implements the behavior of the first operation of the SM5 "bfi" assembly +# and that of the "bfi1" i965 instruction. That is, it has undefined behavior +# if either of its arguments are 32. binop_convert("bfm", tuint, tint, "", """ int bits = src0, offset = src1; -if (offset < 0 || bits < 0 || offset + bits > 32) - dst = 0; /* undefined per the spec */ +if (offset < 0 || bits < 0 || offset > 31 || bits > 31 || offset + bits > 32) + dst = 0; /* undefined */ else - dst = ((1ull << bits) - 1) << offset; + dst = ((1u << bits) - 1) << offset; """) opcode("ldexp", 0, tfloat, [0, 0], [tfloat, tint], "", """ |