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Merge from gnulib

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This incorporates:
2017-04-14 intprops: try to avoid tickling similar bugs
2017-04-14 intprops: port to Oracle Studio 12.3 x86
* doc/misc/texinfo.tex, lib/intprops.h: Copy from gnulib.
This commit is contained in:
Paul Eggert 2017-04-15 22:22:49 -07:00 • committed by Paul Eggert
parent 23d3eeb798
commit 0ef7f64407
2 changed files with 32 additions and 19 deletions
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45
lib/intprops.h
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@ -389,10 +389,10 @@ verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH);
(_Generic \
(*(r), \
signed char: \
_GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
_GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
signed char, SCHAR_MIN, SCHAR_MAX), \
short int: \
_GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
_GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
short int, SHRT_MIN, SHRT_MAX), \
int: \
_GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
@ -406,10 +406,10 @@ verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH);
#else
# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
(sizeof *(r) == sizeof (signed char) \
? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
signed char, SCHAR_MIN, SCHAR_MAX) \
: sizeof *(r) == sizeof (short int) \
? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
short int, SHRT_MIN, SHRT_MAX) \
: sizeof *(r) == sizeof (int) \
? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
@ -431,9 +431,8 @@ verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH);
/* Store the low-order bits of A <op> B into *R, where the operation
is given by OP. Use the unsigned type UT for calculation to avoid
overflow problems. *R's type is T, with extremal values TMIN and
TMAX. T must be a signed integer type. Return 1 if the result
overflows. */
overflow problems. *R's type is T, with extrema TMIN and TMAX.
T must be a signed integer type. Return 1 if the result overflows. */
#define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \
(sizeof ((a) op (b)) < sizeof (t) \
? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \
@ -442,17 +441,27 @@ verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH);
((overflow (a, b) \
|| (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \
|| (tmax) < ((a) op (b))) \
? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 1) \
: (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 0))
? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 1) \
: (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 0))
/* Return A <op> B, where the operation is given by OP. Use the
unsigned type UT for calculation to avoid overflow problems.
Convert the result to type T without overflow by subtracting TMIN
from large values before converting, and adding it afterwards.
Compilers can optimize all the operations except OP. */
#define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t, tmin, tmax) \
(((ut) (a) op (ut) (b)) <= (tmax) \
? (t) ((ut) (a) op (ut) (b)) \
: ((t) (((ut) (a) op (ut) (b)) - (tmin)) + (tmin)))
/* Return the low-order bits of A <op> B, where the operation is given
by OP. Use the unsigned type UT for calculation to avoid undefined
behavior on signed integer overflow, and convert the result to type T.
UT is at least as wide as T and is no narrower than unsigned int,
T is two's complement, and there is no padding or trap representations.
Assume that converting UT to T yields the low-order bits, as is
done in all known two's-complement C compilers. E.g., see:
https://gcc.gnu.org/onlinedocs/gcc/Integers-implementation.html
According to the C standard, converting UT to T yields an
implementation-defined result or signal for values outside T's
range. However, code that works around this theoretical problem
runs afoul of a compiler bug in Oracle Studio 12.3 x86. See:
http://lists.gnu.org/archive/html/bug-gnulib/2017-04/msg00049.html
As the compiler bug is real, don't try to work around the
theoretical problem. */
#define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t) \
((t) ((ut) (a) op (ut) (b)))
#endif /* _GL_INTPROPS_H */