On Tue, 14 Nov 2017, Tamar Christina wrote: > Hi All, > > This patch allows larger bitsizes to be used as copy size > when the target does not have SLOW_UNALIGNED_ACCESS. > > fun3: > adrp x2, .LANCHOR0 > add x2, x2, :lo12:.LANCHOR0 > mov x0, 0 > sub sp, sp, #16 > ldrh w1, [x2, 16] > ldrb w2, [x2, 18] > add sp, sp, 16 > bfi x0, x1, 0, 8 > ubfx x1, x1, 8, 8 > bfi x0, x1, 8, 8 > bfi x0, x2, 16, 8 > ret > > is turned into > > fun3: > adrp x0, .LANCHOR0 > add x0, x0, :lo12:.LANCHOR0 > sub sp, sp, #16 > ldrh w1, [x0, 16] > ldrb w0, [x0, 18] > strh w1, [sp, 8] > strb w0, [sp, 10] > ldr w0, [sp, 8] > add sp, sp, 16 > ret > > which avoids the bfi's for a simple 3 byte struct copy. > > Regression tested on aarch64-none-linux-gnu and x86_64-pc-linux-gnu and no > regressions. > > This patch is just splitting off from the previous combined patch with > AArch64 and adding > a testcase. > > I assume Jeff's ACK from > https://gcc.gnu.org/ml/gcc-patches/2017-08/msg01523.html is still > valid as the code did not change.
Given your no_slow_unalign isn't mode specific can't you use the existing non_strict_align? 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)
