------- Comment #5 from siarhei dot siamashka at gmail dot com 2010-03-14
12:23 -------
Do you want to force data into specific neon registers because of the
restriction on the neon registers which can be used as scalar operand for
multiplication?
It works for me.
/**************************/
#include <stdint.h>
#include <arm_neon.h>
void f(int16_t *ptr)
{
register int16x4_t mul_consts asm ("d0");
int16x4_t data;
int32x4_t tmp;
mul_consts = vset_lane_s16(0x1234, mul_consts, 0);
asm volatile (
"vld1.16 {%P1}, [%2]\n"
"vmull.s16 %q0, %P1, %P3[0]\n"
"vshrn.s32 %P1, %q0, #15\n"
"vst1.16 {%P1}, [%2]\n"
: "=&w" (tmp), "=&w" (data)
: "r" (ptr), "w" (mul_consts)
: "memory"
);
}
/**************************/
While not forcing 'mul_consts' variable into 'd0' register fails as expected:
/tmp/ccvzAXVb.s: Assembler messages:
/tmp/ccvzAXVb.s:27: Error: scalar out of range for multiply instruction --
`vmull.s16 q9,d17,d16[0]'
So I don't see any problem here. Tested with gcc 4.3.4 and 4.4.3
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41538
