> > > > > > I see. But then the slow_unaligned_access implementation should use > > > non_strict_align as default somehow as SLOW_UNALIGNED_ACCESS is > > > defaulted to STRICT_ALIGN. > > > > > > Given that SLOW_UNALIGNED_ACCESS has different values for different > > > modes it would also make sense to be more specific for the testcase in > > > question, like word_mode_slow_unaligned_access to tell this only applies > > > to > > > word_mode? > > > > Ah, that's fair enough. I've updated the patch and the new changelog is: > > Did you attach the old patch? I don't see strict_aling being tested in > the word_mode_np_slow_unalign test. >
Sorry! I misunderstood your previous email. I've added the check accordingly. But this also raises a question, some targets have defined SLOW_UNALIGNED_ACCESS in a way that uses only internal state to determine the value where STRICT_ALIGNMENT is essentially ignored. e.g. PowerPC and riscv. The code generation *might* change for them but the tests won't run. I see now way to make the test accurate (as in, runs in all cases where the codegen changed) unless I expose SLOW_UNALIGNED_ACCESS as a define so I can test for it. Would this be the way to go? Thanks, Tamar > Richard. > > > > > gcc/ > > 2017-11-15 Tamar Christina <tamar.christ...@arm.com> > > > > * expr.c (copy_blkmode_to_reg): Fix bitsize for targets > > with fast unaligned access. > > * doc/sourcebuild.texi (word_mode_no_slow_unalign): New. > > > > gcc/testsuite/ > > 2017-11-15 Tamar Christina <tamar.christ...@arm.com> > > > > * gcc.dg/struct-simple.c: New. > > * lib/target-supports.exp > > (check_effective_target_word_mode_no_slow_unalign): New. > > > > Ok for trunk? > > > > Thanks, > > Tamar > > > > > > > > Thanks, > > > Richard. > > > > > > > Thanks, > > > > Tamar > > > > > > > > > > Otherwise the expr.c change looks ok. > > > > > > > > > > Thanks, > > > > > Richard. > > > > > > > > > > > Thanks, > > > > > > Tamar > > > > > > > > > > > > > > > > > > gcc/ > > > > > > 2017-11-14 Tamar Christina <tamar.christ...@arm.com> > > > > > > > > > > > > * expr.c (copy_blkmode_to_reg): Fix bitsize for targets > > > > > > with fast unaligned access. > > > > > > * doc/sourcebuild.texi (no_slow_unalign): New. > > > > > > > > > > > > gcc/testsuite/ > > > > > > 2017-11-14 Tamar Christina <tamar.christ...@arm.com> > > > > > > > > > > > > * gcc.dg/struct-simple.c: New. > > > > > > * lib/target-supports.exp > > > > > > (check_effective_target_no_slow_unalign): New. > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Richard Biener <rguent...@suse.de> > > > > > SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham > > > > > Norton, HRB 21284 (AG Nuernberg) > > > > > > > > > > > > > > -- > > > Richard Biener <rguent...@suse.de> > > > SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, > > > HRB 21284 (AG Nuernberg) > > > > -- > Richard Biener <rguent...@suse.de> > SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB > 21284 (AG Nuernberg) --
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi index 1646d0a99911aa7b2e66762e5907fbb0454ed00d..3b200964462a82ebbe68bbe798cc91ed27337034 100644 --- a/gcc/doc/sourcebuild.texi +++ b/gcc/doc/sourcebuild.texi @@ -2178,8 +2178,12 @@ Target supports @code{wchar_t} that is compatible with @code{char32_t}. @item comdat_group Target uses comdat groups. + +@item word_mode_no_slow_unalign +Target does not have slow unaligned access when doing word size accesses. @end table + @subsubsection Local to tests in @code{gcc.target/i386} @table @code diff --git a/gcc/expr.c b/gcc/expr.c index 2f8432d92ccac17c0a548faf4a16eff0656cef1b..afcea8fef58155d0a899991c10cd485ba8af888d 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -2769,7 +2769,9 @@ copy_blkmode_to_reg (machine_mode mode, tree src) n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; dst_words = XALLOCAVEC (rtx, n_regs); - bitsize = MIN (TYPE_ALIGN (TREE_TYPE (src)), BITS_PER_WORD); + bitsize = BITS_PER_WORD; + if (targetm.slow_unaligned_access (word_mode, TYPE_ALIGN (TREE_TYPE (src)))) + bitsize = MIN (TYPE_ALIGN (TREE_TYPE (src)), BITS_PER_WORD); /* Copy the structure BITSIZE bits at a time. */ for (bitpos = 0, xbitpos = padding_correction; diff --git a/gcc/testsuite/gcc.dg/struct-simple.c b/gcc/testsuite/gcc.dg/struct-simple.c new file mode 100644 index 0000000000000000000000000000000000000000..17b956022e4efb37044c7a74cc8baa9fb779221a --- /dev/null +++ b/gcc/testsuite/gcc.dg/struct-simple.c @@ -0,0 +1,52 @@ +/* { dg-do-run } */ +/* { dg-require-effective-target word_mode_no_slow_unalign } */ +/* { dg-additional-options "-fdump-rtl-final" } */ + +/* Copyright 1996, 1999, 2007 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. + + Please email any bugs, comments, and/or additions to this file to: + bug-...@prep.ai.mit.edu */ + +#include <stdio.h> + +struct struct3 { char a, b, c; }; +struct struct3 foo3 = { 'A', 'B', 'C'}, L3; + +struct struct3 fun3() +{ + return foo3; +} + +#ifdef PROTOTYPES +void Fun3(struct struct3 foo3) +#else +void Fun3(foo3) + struct struct3 foo3; +#endif +{ + L3 = foo3; +} + +int main() +{ + struct struct3 x = fun3(); + + printf("a:%c, b:%c, c:%c\n", x.a, x.b, x.c); +} + +/* { dg-final { scan-rtl-dump-not {zero_extract:.+\[\s*foo3\s*\]} "final" } } */ + diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index b6f9e51c4817cf8235c8e33b14e2763308eb482a..e1bd9da20b671eb19ad5a96e3463a516d01ceb83 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -6037,6 +6037,32 @@ proc check_effective_target_unaligned_stack { } { return $et_unaligned_stack_saved } +# Return 1 if the target plus current options does not have +# slow unaligned access when using word size accesses. +# +# This won't change for different subtargets so cache the result. + +proc check_effective_target_word_mode_no_slow_unalign { } { + global et_word_mode_no_slow_unalign_saved + global et_index + + if [info exists et_word_mode_no_slow_unalign_saved($et_index)] { + verbose "check_effective_target_word_mode_no_slow_unalign: \ + using cached result" 2 + } else { + set et_word_mode_no_slow_unalign_saved($et_index) 0 + if { ([istarget x86_64-*-*] + || [istarget aarch64*-*-*]) + && [is-effective-target non_strict_align] + } { + set et_word_mode_no_slow_unalign_saved($et_index) 1 + } + } + verbose "check_effective_target_word_mode_no_slow_unalign:\ + returning $et_word_mode_no_slow_unalign_saved($et_index)" 2 + return $et_word_mode_no_slow_unalign_saved($et_index) +} + # Return 1 if the target plus current options does not support a vector # alignment mechanism, 0 otherwise. #