On 25 September 2014 08:39, Thomas Preud'homme <thomas.preudho...@arm.com> wrote: >> From: Christophe Lyon [mailto:christophe.l...@linaro.org] >> Sent: Thursday, September 25, 2014 4:28 AM > >> >> Hi Thomas, > > Hi Christophe, > >> >> Although I could notice the improvement: >> Pass disappears [PASS => ]: >> gcc.dg/optimize-bswapsi-1.c scan-tree-dump-times bswap "32 bit >> bswap >> implementation found at" 3 >> New pass [ => PASS]: >> gcc.dg/optimize-bswapsi-1.c scan-tree-dump-times bswap "32 bit >> bswap >> implementation found at" 4 >> >> for arm-*, armeb-* and aarch64-* targets, there is no change for >> aarch64_be: is this expected? > > No, but neither is this: > > @@ -1905,11 +1913,10 @@ find_bswap_or_nop_1 (gimple stmt, struct > symbolic_number *n, int limit) > > /* Sign extension: result is dependent on the value. */ > old_type_size = TYPE_PRECISION (n->type) / BITS_PER_UNIT; > - if (!TYPE_UNSIGNED (n->type) > - && type_size > old_type_size > - && n->n & ((uint64_t) 0xff << ((old_type_size - 1) > - * BITS_PER_MARKER))) > - return NULL; > + if (!TYPE_UNSIGNED (n->type) && type_size > old_type_size > + && HEAD_MARKER (n->n, old_type_size)) > + for (i = 0; i < type_size - old_type_size; i++) > + n->n |= MARKER_BYTE_UNKNOWN << (type_size - 1 - i); > > if (type_size < 64 / BITS_PER_MARKER) > { > > type_size - 1 - I gives a number of marker bytes to shift. I forgot to > multiply by the number of bits in a marker. Can you do the change locally and > tell me if the test now succeed for aarch64_be? >
While attempting to try this, I noticed that more precisely the test is currently UNSUPPORTED on aarch64_be, which is because check_effective_target_bswap only accepts istarget aarch64-*-*. I didn't try yet to change it into istarget aarch64*-*-*. > Best regards, > > Thomas > > > >
