diff options
| author | Ian Romanick <[email protected]> | 2019-04-30 08:00:32 -0700 |
|---|---|---|
| committer | Ian Romanick <[email protected]> | 2019-05-01 09:07:47 -0700 |
| commit | 85e6865ff62390c632909a07a46deab54c742963 (patch) | |
| tree | 40d1b6ebcaacde5a6b7424fcd445fe9c47119104 /src/compiler | |
| parent | 70da00ffd65e56c8c8cc6ecfcec462fb52ee5102 (diff) | |
nir: Saturating integer arithmetic is not associative
In 8-bits,
iadd_sat(iadd_sat(0x7f, 0x7f), -1) =
iadd_sat(0x7f, -1) =
0x7e
but,
iadd_sat(0x7f, iadd_sat(0x7f, -1)) =
iadd_sat(0x7f, 0x7e) =
0x7f
Fixes: 272e927d0e9 ("nir/spirv: initial handling of OpenCL.std extension opcodes")
Reviewed-by: Karol Herbst <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
Diffstat (limited to 'src/compiler')
| -rw-r--r-- | src/compiler/nir/nir_opcodes.py | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py index d35d820aa5b..246d3d40381 100644 --- a/src/compiler/nir/nir_opcodes.py +++ b/src/compiler/nir/nir_opcodes.py @@ -482,7 +482,7 @@ def binop_reduce(name, output_size, output_type, src_type, prereduce_expr, binop("fadd", tfloat, commutative + associative, "src0 + src1") binop("iadd", tint, commutative + associative, "src0 + src1") -binop("iadd_sat", tint, commutative + associative, """ +binop("iadd_sat", tint, commutative, """ src1 > 0 ? (src0 + src1 < src0 ? (1ull << (bit_size - 1)) - 1 : src0 + src1) : (src0 < src0 + src1 ? (1ull << (bit_size - 1)) : src0 + src1) |