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[Bug target/40470] unable to find a register to spill in class ‘SSE_FIRST_REG’
- From: "hjl dot tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 17 Jun 2009 20:34:30 -0000
- Subject: [Bug target/40470] unable to find a register to spill in class ‘SSE_FIRST_REG’
- References: <bug-40470-682@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from hjl dot tools at gmail dot com 2009-06-17 20:34 -------
(In reply to comment #4)
> Another testcase:
>
> [hjl@gnu-6 gcc]$ cat /tmp/pr40470-3.c
> #include <nmmintrin.h>
> __m128i load (char *);
> char *
> foo (char *p1, char *p2,
> int bmsk, __m128i mask1, __m128i mask2)
> {
> int len = 0;
> __m128i frag1, frag2;
> int cmp_s;
> if( !p2[0]) return p1;
> if( !p1[0] ) return NULL;
> frag2 = load (p2);
> frag1 = load (p1);
> frag2 = _mm_blendv_epi8(frag2, mask2, mask1);
> frag1 = _mm_blendv_epi8(frag1, mask1, mask2);
> cmp_s = _mm_cmpistrs(frag2, frag1, 0x0c);
> if( cmp_s )
> __asm("bsfl %[bmsk], %[len]" : [len] "=r" (len) : [bmsk] "r" (bmsk) );
> return p1 + len;
> }
> [hjl@gnu-6 gcc]$ ./xgcc -B./ -O2 -msse4 /tmp/pr40470-3.c -S
> -fno-asynchronous-unwind-tables
> /tmp/pr40470-3.c: In function ?foo?:
> /tmp/pr40470-3.c:20:1: error: unable to find a register to spill in class
> ?SSE_FIRST_REG?
> /tmp/pr40470-3.c:20:1: error: this is the insn:
> (insn 30 87 32 4 ./include/smmintrin.h:62 (set (reg:V16QI 25 xmm4 [82])
> (unspec:V16QI [
> (subreg:V16QI (reg/v:V2DI 25 xmm4 [orig:60 frag2 ] [60]) 0)
> (reg:V16QI 22 xmm1 [orig:64 D.8164 ] [64])
> (reg:V16QI 23 xmm2 [orig:63 D.8165 ] [63])
> ] 134)) 1791 {*sse4_1_pblendvb} (expr_list:REG_DEAD (reg/v:V2DI 25
> xmm4 [orig:60 frag2 ] [60])
> (nil)))
> /tmp/pr40470-3.c:20:1: internal compiler error: in spill_failure, at
> reload1.c:2094
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <http://gcc.gnu.org/bugs.html> for instructions.
> [hjl@gnu-6 gcc]$
Even with my patch, GCSE removes xmm0 in those patterns and
makes it harder for IRA/reload to handle.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40470