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* [Bug tree-optimization/55590] New: SRA still produces unnecessarily unaligned memory accesses @ 2012-12-04 10:35 jamborm at gcc dot gnu.org 2012-12-05 15:18 ` [Bug tree-optimization/55590] " jamborm at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2012-12-04 10:35 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55590 Bug #: 55590 Summary: SRA still produces unnecessarily unaligned memory accesses Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: jamborm@gcc.gnu.org ReportedBy: jamborm@gcc.gnu.org SRA can still produce unaligned memory accesses which should be aligned when it's basing its new scalar access on a MEM_REF buried below COMPONENT_REFs or ARRAY_REFs. Testcase 1: /* { dg-do compile } */ /* { dg-options "-O2 -mavx" } */ #include <immintrin.h> struct S { __m128 a, b; }; struct T { int a; struct S s; }; void foo (struct T *p, __m128 v) { struct S s; s = p->s; s.b = _mm_add_ps(s.b, v); p->s = s; } /* { dg-final { scan-assembler-not "vmovups" } } */ on x86_64 compiles to vmovups 32(%rdi), %xmm1 vaddps %xmm0, %xmm1, %xmm0 vmovups %xmm0, 32(%rdi) even though it should really be vaddps 32(%rdi), %xmm0, %xmm0 vmovaps %xmm0, 32(%rdi) ret Testcase 2 (which describes why this should be fixed differently from the recent IPA-SRA patch because of the variable array index): /* { dg-do compile } */ /* { dg-options "-O2 -mavx" } */ #include <immintrin.h> struct S { __m128 a, b; }; struct T { int a; struct S s[8]; }; void foo (struct T *p, int i, __m128 v) { struct S s; s = p->s[i]; s.b = _mm_add_ps(s.b, v); p->s[i] = s; } /* { dg-final { scan-assembler-not "vmovups" } } */ Compiles to movslq %esi, %rsi salq $5, %rsi leaq 16(%rdi,%rsi), %rax vmovups 16(%rax), %xmm1 vaddps %xmm0, %xmm1, %xmm0 vmovups %xmm0, 16(%rax) ret when it should produce movslq %esi, %rsi salq $5, %rsi leaq 16(%rdi,%rsi), %rax vaddps 16(%rax), %xmm0, %xmm0 vmovaps %xmm0, 16(%rax) ret I'm testing a patch. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/55590] SRA still produces unnecessarily unaligned memory accesses 2012-12-04 10:35 [Bug tree-optimization/55590] New: SRA still produces unnecessarily unaligned memory accesses jamborm at gcc dot gnu.org @ 2012-12-05 15:18 ` jamborm at gcc dot gnu.org 2012-12-07 12:51 ` jamborm at gcc dot gnu.org 2012-12-07 13:08 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2012-12-05 15:18 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55590 Martin Jambor <jamborm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- URL| |http://gcc.gnu.org/ml/gcc-p | |atches/2012-12/msg00237.htm | |l --- Comment #1 from Martin Jambor <jamborm at gcc dot gnu.org> 2012-12-05 15:17:29 UTC --- I have submitted the patch to the mailing list: http://gcc.gnu.org/ml/gcc-patches/2012-12/msg00237.html ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/55590] SRA still produces unnecessarily unaligned memory accesses 2012-12-04 10:35 [Bug tree-optimization/55590] New: SRA still produces unnecessarily unaligned memory accesses jamborm at gcc dot gnu.org 2012-12-05 15:18 ` [Bug tree-optimization/55590] " jamborm at gcc dot gnu.org @ 2012-12-07 12:51 ` jamborm at gcc dot gnu.org 2012-12-07 13:08 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2012-12-07 12:51 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55590 --- Comment #2 from Martin Jambor <jamborm at gcc dot gnu.org> 2012-12-07 12:50:46 UTC --- Author: jamborm Date: Fri Dec 7 12:50:43 2012 New Revision: 194300 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194300 Log: 2012-12-07 Martin Jambor <mjambor@suse.cz> PR tree-optimization/55590 * tree-sra.c (build_ref_for_offset): Use get_object_alignment_1 to get base alignment. * testsuite/gcc.target/i386/pr55590-1.c: New test. * testsuite/gcc.target/i386/pr55590-2.c: Likewise. Added: trunk/gcc/testsuite/gcc.target/i386/pr55590-1.c trunk/gcc/testsuite/gcc.target/i386/pr55590-2.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-sra.c ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/55590] SRA still produces unnecessarily unaligned memory accesses 2012-12-04 10:35 [Bug tree-optimization/55590] New: SRA still produces unnecessarily unaligned memory accesses jamborm at gcc dot gnu.org 2012-12-05 15:18 ` [Bug tree-optimization/55590] " jamborm at gcc dot gnu.org 2012-12-07 12:51 ` jamborm at gcc dot gnu.org @ 2012-12-07 13:08 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2012-12-07 13:08 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55590 Martin Jambor <jamborm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |FIXED --- Comment #3 from Martin Jambor <jamborm at gcc dot gnu.org> 2012-12-07 13:07:56 UTC --- Fixed. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-12-07 13:08 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-12-04 10:35 [Bug tree-optimization/55590] New: SRA still produces unnecessarily unaligned memory accesses jamborm at gcc dot gnu.org 2012-12-05 15:18 ` [Bug tree-optimization/55590] " jamborm at gcc dot gnu.org 2012-12-07 12:51 ` jamborm at gcc dot gnu.org 2012-12-07 13:08 ` jamborm at gcc dot gnu.org
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