Not clear to me, (2U i) should be zero if the shift count is masked.
2U 31 is undefined behavior on those targets.
Precisely not, or else we are not talking about the same notion of masking.
--
Eric Botcazou
Eric Botcazou writes:
Not clear to me, (2U i) should be zero if the shift count is masked.
2U 31 is undefined behavior on those targets.
Precisely not, or else we are not talking about the same notion of masking.
I believe Jakub is referring to the following in the C standard:
On Sat, Apr 26, 2014 at 03:30:25PM +0200, Eric Botcazou wrote:
Not clear to me, (2U i) should be zero if the shift count is masked.
2U 31 is undefined behavior on those targets.
Precisely not, or else we are not talking about the same notion of masking.
Eh, C99, 6.5.7/3:
If the value
I believe Jakub is referring to the following in the C standard:
Bitwise shift operators
...
Semantics
... If the value of the right operand ... is greater than or equal to the
width of the promoted left operand, the behavior is undefined.
So on 16-bit int systems you can't portably
So, if you have int16 target, where unsigned int is 16-bit and UINT_MAX
65535, then shift count must be = 0 and 16, therefore, 2U 31 is
undefined behavior.
Well, if the shift count is masked by the target, if will be masked according
to the width of the register and the result will
This is a regression present on all active branches. The first pattern added
by http://gcc.gnu.org/ml/gcc-patches/2011-10/msg00060.html is wrong since, as
counter-intuitive as it may seem, sll also does a full 64-bit shift.
Tested on SPARC/Solaris, applied on all active branches.
2014-04-25
On Fri, Apr 25, 2014 at 12:47:32PM +0200, Eric Botcazou wrote:
/* PR target/60941 */
/* Reported by Martin Husemann mar...@netbsd.org */
extern void abort (void);
static void __attribute__((noinline))
set (unsigned long *l)
{
*l = 31;
}
int main (void)
{
unsigned long l;
I'm afraid the testcase will fail on int16 targets, so perhaps
you should guard the body of main other than return 0; with
#if __INT_MAX__ = 2147483647ULL
or
#if __SIZEOF_INT__ = 4
or similar (or require int32plus target, but gcc.c-torture/execute/
is not a good place for that and *.x files
On Fri, Apr 25, 2014 at 01:24:13PM +0200, Eric Botcazou wrote:
I'm afraid the testcase will fail on int16 targets, so perhaps
you should guard the body of main other than return 0; with
#if __INT_MAX__ = 2147483647ULL
or
#if __SIZEOF_INT__ = 4
or similar (or require int32plus target,
