On Tue, Apr 26, 2011 at 10:30 PM, Lee Moore <mo...@imperas.com> wrote:
> Hi All,
>
> This is based upon gcc version 4.5.3 (20110221 pre-release)
> Any help appreciated
>
> This shows a bug in the Linaro gcc compiler with the Arm NEON vset_lane
> intrinsic
> Note in the objdump that the vmov.8 instruction that places the
> value in the vector for the non-q version uses 1 where it should use
> 2 and 3:
>
> 18: ee410bb0 vmov.8 d17[1], r0
> 1c: ee420bb0 vmov.8 d18[1], r0
> 20: ee400b90 vmov.8 d16[0], r0
> 3c: ee440bb0 vmov.8 d20[1], r0
>
> For the q version the vmov.8 instructions are correct:
> 40: ee420bf0 vmov.8 d18[3], r0
> 54: ee420bd0 vmov.8 d18[2], r0
> 64: ee400b90 vmov.8 d16[0], r0
> 70: ee420bb0 vmov.8 d18[1], r0
>
> /* Source code */
> #include <arm_neon.h>
> static uint8x8_t vec[5]
> static uint8x16_t qvec[5];
> void set(uint8_t value)
> {
> vec[1] = vset_lane_u8(value, vec[0], 3);
> vec[2] = vset_lane_u8(value, vec[0], 2);
> vec[3] = vset_lane_u8(value, vec[0], 1);
> vec[4] = vset_lane_u8(value, vec[0], 0);
> qvec[1] = vsetq_lane_u8(value, qvec[0], 3);
> qvec[2] = vsetq_lane_u8(value, qvec[0], 2);
> qvec[3] = vsetq_lane_u8(value, qvec[0], 1);
> qvec[4] = vsetq_lane_u8(value, qvec[0], 0);
> }
Hi Lee. Thanks for the bug report. Sorry for the delay in replying
but we've been busy with the summit and this slipped through.
I've logged Launchpad bug #784375 with your test case. The good news
is that it's already been fixed in Linaro GCC 4.5/4.6 2011.05 which is
due out on Thursday.
-- Michael
_______________________________________________
linaro-toolchain mailing list
linaro-toolchain@lists.linaro.org
http://lists.linaro.org/mailman/listinfo/linaro-toolchain
