> Boostrap / regtest on strict-alignment platforms welcome.
Bootstrap/regtest on SPARC/Solaris is OK, modulo:
XPASS: gcc.dg/memmove-4.c scan-tree-dump-not optimized "memmove"
FAIL: gcc.dg/strlenopt-8.c scan-tree-dump-times strlen "strlen \\\\(" 0
FAIL: gcc.dg/strlenopt-8.c scan-tree-dump-times strlen "memcpy \\\\(" 4
for both 32-bit and 64-bit.
> Unless I hear some positives I'll let the patch sit here as I
> don't really care too much about those pesky targets (and
> targets can choose to opt-in by providing movmisalign optabs
> anyway so they don't go the store/extract_bit_field path).
The patch is a step forward but it doesn't fully solve the problem:
#include <stdint.h>
#include <string.h>
uint32_t foo_noalign(const uint32_t *s) {
uint32_t v;
memcpy(&v, s, sizeof(v));
return v;
}
uint32_t foo(const uint32_t *s) {
uint32_t v;
memcpy(&v, __builtin_assume_aligned(s, 4), sizeof(v));
return v;
}
As discussed in the audit trail, the compiler ought to generate again the same
code on strict-alignment targets in both cases, as Clang apparently and as GCC
itself during most of its existence (until GCC 4.5 to be precise).
--
Eric Botcazou
