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* [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2
@ 2014-10-28 2:25 spf_zju at 126 dot com
2014-10-28 11:34 ` [Bug c/63663] " spf_zju at 126 dot com
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: spf_zju at 126 dot com @ 2014-10-28 2:25 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63663
Bug ID: 63663
Summary: [NEON] wrong value when computing the leading zero
of int16x4_t type at O2
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: spf_zju at 126 dot com
the 1.c code is :
#include <arm_neon.h>
#include <stdio.h>
int main()
{
int16x4_t vector_int16x4;
int16x4_t vector_res_int16x4;
vector_int16x4 = vdup_n_s16(0);
vector_res_int16x4 = vclz_s16(vector_int16x4);
return vector_res_int16x4[0];
}
compiled with :armeb-linux-gnueabi-gcc -S -O2 -mfloat-abi=softfp -mfpu=neon
1.c
the assembly:
main:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
@ link register save eliminated.
mov r0, #32
bx lr
the main should return #16,not #32.
this bug appears in the trunk snapshot 20141026.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c/63663] [NEON] wrong value when computing the leading zero of int16x4_t type at O2
2014-10-28 2:25 [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2 spf_zju at 126 dot com
@ 2014-10-28 11:34 ` spf_zju at 126 dot com
2014-10-28 12:51 ` [Bug target/63663] " ramana at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: spf_zju at 126 dot com @ 2014-10-28 11:34 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63663
--- Comment #1 from wind <spf_zju at 126 dot com> ---
I find this issue is related to the definition of a MACRO.
/* The arm5 clz instruction returns 32. */
#define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) ((VALUE) = 32, 1).
I am confused that in the armv7 NEON, the mode is HI ,it is also equal 32. Is
it right ? anyone can give me some explanation .
I should post a patch to fix this bug soon.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/63663] [NEON] wrong value when computing the leading zero of int16x4_t type at O2
2014-10-28 2:25 [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2 spf_zju at 126 dot com
2014-10-28 11:34 ` [Bug c/63663] " spf_zju at 126 dot com
@ 2014-10-28 12:51 ` ramana at gcc dot gnu.org
2014-11-26 11:00 ` rearnsha at gcc dot gnu.org
2014-11-26 11:46 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ramana at gcc dot gnu.org @ 2014-10-28 12:51 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63663
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target|armeb-linux-gnueabi |armeb-linux-gnueabi,
| |arm-none-linux-gnueabihf
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-10-28
CC| |michael.collison at linaro dot org
| |, ramana at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #2 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
Patch being discussed here.
https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00731.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/63663] [NEON] wrong value when computing the leading zero of int16x4_t type at O2
2014-10-28 2:25 [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2 spf_zju at 126 dot com
2014-10-28 11:34 ` [Bug c/63663] " spf_zju at 126 dot com
2014-10-28 12:51 ` [Bug target/63663] " ramana at gcc dot gnu.org
@ 2014-11-26 11:00 ` rearnsha at gcc dot gnu.org
2014-11-26 11:46 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: rearnsha at gcc dot gnu.org @ 2014-11-26 11:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63663
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #3 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
Fixed with:
https://gcc.gnu.org/ml/gcc-patches/2014-10/msg02311.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/63663] [NEON] wrong value when computing the leading zero of int16x4_t type at O2
2014-10-28 2:25 [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2 spf_zju at 126 dot com
` (2 preceding siblings ...)
2014-11-26 11:00 ` rearnsha at gcc dot gnu.org
@ 2014-11-26 11:46 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: rearnsha at gcc dot gnu.org @ 2014-11-26 11:46 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63663
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |5.0
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-11-26 11:46 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2014-10-28 2:25 [Bug c/63663] New: [NEON] wrong value when computing the leading zero of int16x4_t type at O2 spf_zju at 126 dot com
2014-10-28 11:34 ` [Bug c/63663] " spf_zju at 126 dot com
2014-10-28 12:51 ` [Bug target/63663] " ramana at gcc dot gnu.org
2014-11-26 11:00 ` rearnsha at gcc dot gnu.org
2014-11-26 11:46 ` rearnsha at gcc dot gnu.org
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