diff options
Diffstat (limited to 'lib/intprops.h')
| -rw-r--r-- | lib/intprops.h | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/lib/intprops.h b/lib/intprops.h index a84bd6af531..293204ab43a 100644 --- a/lib/intprops.h +++ b/lib/intprops.h @@ -27,6 +27,10 @@ E should not have side effects. */ #define _GL_INT_CONVERT(e, v) ((e) - (e) + (v)) +/* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see + <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00406.html>. */ +#define _GL_INT_NEGATE_CONVERT(e, v) ((e) - (e) - (v)) + /* The extra casts in the following macros work around compiler bugs, e.g., in Cray C 5.0.3.0. */ @@ -50,7 +54,7 @@ /* Return 1 if the integer expression E, after integer promotion, has a signed type. E should not have side effects. */ -#define _GL_INT_SIGNED(e) (_GL_INT_CONVERT (e, -1) < 0) +#define _GL_INT_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) /* Minimum and maximum values for integer types and expressions. These @@ -79,7 +83,7 @@ #define _GL_INT_MAXIMUM(e) \ (_GL_INT_SIGNED (e) \ ? _GL_SIGNED_INT_MAXIMUM (e) \ - : _GL_INT_CONVERT (e, -1)) + : _GL_INT_NEGATE_CONVERT (e, 1)) #define _GL_SIGNED_INT_MAXIMUM(e) \ (((_GL_INT_CONVERT (e, 1) << (sizeof ((e) + 0) * CHAR_BIT - 2)) - 1) * 2 + 1) @@ -179,16 +183,21 @@ : 0 < (a)) /* Return 1 if A * B would overflow in [MIN,MAX] arithmetic. - See above for restrictions. */ + See above for restrictions. Avoid && and || as they tickle + bugs in Sun C 5.11 2010/08/13 and other compilers; see + <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00401.html>. */ #define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \ ((b) < 0 \ ? ((a) < 0 \ ? (a) < (max) / (b) \ - : (b) < -1 && (min) / (b) < (a)) \ - : (0 < (b) \ - && ((a) < 0 \ - ? (a) < (min) / (b) \ - : (max) / (b) < (a)))) + : (b) == -1 \ + ? 0 \ + : (min) / (b) < (a)) \ + : (b) == 0 \ + ? 0 \ + : ((a) < 0 \ + ? (a) < (min) / (b) \ + : (max) / (b) < (a))) /* Return 1 if A / B would overflow in [MIN,MAX] arithmetic. See above for restrictions. Do not check for division by zero. */ @@ -234,11 +243,11 @@ (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \ || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)) #define _GL_DIVIDE_OVERFLOW(a, b, min, max) \ - ((min) < 0 ? (b) == _GL_INT_CONVERT (min, -1) && (a) < - (max) \ + ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ : (a) < 0 ? (b) <= (a) + (b) - 1 \ : (b) < 0 && (a) + (b) <= (a)) #define _GL_REMAINDER_OVERFLOW(a, b, min, max) \ - ((min) < 0 ? (b) == _GL_INT_CONVERT (min, -1) && (a) < - (max) \ + ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b) \ : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max)) @@ -302,13 +311,10 @@ /* Return 1 if the expression A <op> B would overflow, where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test, assuming MIN and MAX are the minimum and maximum for the result type. - - This macro assumes that A | B is a valid integer if both A and B are, - which is true of all known practical hosts. If this is a problem - for you, please let us know how to fix it for your host. */ + Arguments should be free of side effects. */ #define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \ op_result_overflow (a, b, \ - _GL_INT_MINIMUM ((a) | (b)), \ - _GL_INT_MAXIMUM ((a) | (b))) + _GL_INT_MINIMUM ((b) - (b) + (a)), \ + _GL_INT_MAXIMUM ((b) - (b) + (a))) #endif /* _GL_INTPROPS_H */ |