On Sat, Jan 9, 2016 at 12:37 AM, Jeff Law <l...@redhat.com> wrote: > On 12/23/2015 02:39 AM, Uros Bizjak wrote: >> >> Hello! >> >> There is a logic error in Honza's patch "Transparent alias suport part >> 10" [1]. The part in memrefs_conflict_p should be changed to: >> >> - /* If decls are different or we know by offsets that there is no >> overlap, >> - we win. */ >> - if (!cmp || !offset_overlap_p (c, xsize, ysize)) >> + /* If decls are different and we know by offsets that >> + there is no overlap, we win. */ >> + if (!cmp && !offset_overlap_p (c, xsize, ysize)) >> return 0; >> - /* Decls may or may not be different and offsets overlap....*/ >> + /* Decls are different and offsets overlap....*/ >> >> Even if decls are different, their offsets shouldn't overlap! >> Addresses with alignment ANDs depend on increased xsize and ysize, so >> no wonder gcc fails to bootstrap on alpha. >> >> In addition to this, the check for SYMBOL_REFs in base_alias_check >> should be moved after checks for addresses. >> >> The patch also adds some simplification. If >> symtab_address::equal_address_to returns -1 for "unknown" (as is >> otherwise customary throughout the sources), we can simplify >> compare_base_decls a bit. >> >> 2015-12-23 Uros Bizjak <ubiz...@gmail.com> >> >> PR middle-end/68999 >> * symtab.c (symtab_node::equal_address_to): Return -1 instead of 2 >> if we can't determine address equivalence. >> * alias.c (compare_base_decl): Update for changed return value of >> symtab_node::equal_address_to. >> (memrefs_conflict_p): Return 0 when decls are different >> and offsets don't overlap. >> (base_alias_check): Move check for addresses with alignment ANDs >> before the call for compare_base_decls. > > So with the symtab and part of the alias bits in, I assume you're going to > post the remainder of the fix separately, right?
Yes, the patch is already posted at [1]. [1] https://gcc.gnu.org/ml/gcc-patches/2016-01/msg00436.html Uros.
