On Wed, 2 Nov 2016, Jakub Jelinek wrote:
> On Wed, Nov 02, 2016 at 10:34:15AM +0100, Richard Biener wrote:
> > Ok, just looking at regex.c (I happen to have regex.i around) shows
> > the first hit as
> >
> > #2 0x00000000008d9914 in true_dependence_1 (mem=0x7ffff61ef360,
> > mem_mode=DImode, mem_addr=0x7ffff6220cf0, x=0x7ffff6605060,
> > x_addr=0x7ffff662ffd8, mem_canonicalized=true)
> > at /space/rguenther/src/svn/trunk/gcc/alias.c:2928
> > 2928 if (nonoverlapping_memrefs_p (mem, x, false))
> > (gdb) p debug_tree (expry)
> > <function_decl 0x7ffff6941f00 __builtin_malloc
> > type <function_type 0x7ffff68b0dc8
> >
> > 2928 if (nonoverlapping_memrefs_p (mem, x, false))
> > (gdb) p debug_rtx (mem)
> > (mem/f/c:DI (plus:DI (reg/f:DI 7 sp)
> > (const_int 200 [0xc8])) [5 p+0 S8 A64])
> > $4 = void
> > (gdb) p debug_rtx (x)
> > (mem:QI (symbol_ref:DI ("malloc") [flags 0x41] <function_decl
> > 0x7ffff6943000 malloc>) [0 __builtin_malloc S1 A8])
> > $5 = void
> >
> > called from DSE check_mem_read_rtx. I believe that's a bogus query.
>
> I guess I should also log debug_rtx (DECL_RTL (expr{x,y})) in those cases
> then and perhaps also if we ever return non-zero in those cases.
Yeah, plus if a followup test would have disambiguated things (the
dispatch to the tree oracle for example).
> > (I see only a single hit on regex.c, your log seems to have multiple
> > ones...)
>
> That was statistics gathered across x86_64-linux and i686-linux simultaneous
> bootstraps + regtests (and most likely I've mistyped the first value
> from (int) BITS_PER_WORD to (int) BITS_PER_UNIT :( ). So regex.c is built
> there many times (3 times each bootstrap at least).
Ah, ok. At least 12 times for x86_64 with multilibs (we build PIC and
non-PIC variants IIRC).
Richard.
