diff options
| author | Kristian H. Kristensen <[email protected]> | 2019-04-18 11:23:13 -0700 |
|---|---|---|
| committer | Kristian H. Kristensen <[email protected]> | 2019-04-19 16:17:37 +0000 |
| commit | 41593f3c3711cd61156d91ad12bb8aabf91a9556 (patch) | |
| tree | a7b933c52c94996ec40e794693f7c62adba46440 /src/compiler/nir | |
| parent | 15605cc9d481dccc8f4dff0e6471600809d56980 (diff) | |
nir_opcodes.py: Saturate to expression that doesn't overflow
Compiler warns about overflow when assigning UINT64_MAX to something
smaller than a uin64_t:
src/compiler/nir/nir_constant_expressions.c:16909:50: warning: implicit conversion from 'unsigned long long' to 'uint1_t' (aka 'unsigned char') changes value from 18446744073709551615 to 255 [-Wconstant-conversion]
uint1_t dst = (src0 + src1) < src0 ? UINT64_MAX : (src0 + src1);
~~~ ^~~~~~~~~~
Shift UINT64_MAX down to the appropriate maximum value for the type
being assigned to.
Signed-off-by: Kristian H. Kristensen <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
Diffstat (limited to 'src/compiler/nir')
| -rw-r--r-- | src/compiler/nir/nir_constant_expressions.py | 2 | ||||
| -rw-r--r-- | src/compiler/nir/nir_opcodes.py | 2 |
2 files changed, 3 insertions, 1 deletions
diff --git a/src/compiler/nir/nir_constant_expressions.py b/src/compiler/nir/nir_constant_expressions.py index 0f89e90d7b7..f26fd0a3ea2 100644 --- a/src/compiler/nir/nir_constant_expressions.py +++ b/src/compiler/nir/nir_constant_expressions.py @@ -66,6 +66,8 @@ template = """\ #include "util/bigmath.h" #include "nir_constant_expressions.h" +#define MAX_UINT_FOR_SIZE(bits) (UINT64_MAX >> (64 - (bits))) + /** * Evaluate one component of packSnorm4x8. */ diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py index 0f56dd9596c..d35d820aa5b 100644 --- a/src/compiler/nir/nir_opcodes.py +++ b/src/compiler/nir/nir_opcodes.py @@ -488,7 +488,7 @@ binop("iadd_sat", tint, commutative + associative, """ (src0 < src0 + src1 ? (1ull << (bit_size - 1)) : src0 + src1) """) binop("uadd_sat", tuint, commutative, - "(src0 + src1) < src0 ? UINT64_MAX : (src0 + src1)") + "(src0 + src1) < src0 ? MAX_UINT_FOR_SIZE(sizeof(src0) * 8) : (src0 + src1)") binop("isub_sat", tint, "", """ src1 < 0 ? (src0 - src1 < src0 ? (1ull << (bit_size - 1)) - 1 : src0 - src1) : |