------- Comment #3 from jakub at gcc dot gnu dot org 2010-01-26 12:14 -------
Note the http://gcc.gnu.org/ml/gcc-patches/2010-01/msg01282.html doesn't
bootstrap on the redhat/gcc-4_4-branch on ppc, while it bootstraps on the trunk
on x86_64-linux and i686-linux and on the branch on those arches too.
I will try to bootstrap trunk with that patch on ppc soon to see.
Anyway, the bootstrap problem can be simplified to:
typedef struct { char **b; int c[]; } T;
int a;
extern int d[], e;
extern char f[30];
static void
foo (unsigned *x, unsigned *y, int z)
{
int i;
for (i = 0; i < z; i++)
x[i] = y[i / 2];
}
void
bar (T *y)
{
unsigned x[4];
foo (x, (unsigned *) d, e);
__builtin_memcpy (y->b [y->c[0]], f, a);
}
at -O2 -g -m64 this doesn't assemble, as .debug_loc contains:
.LLST3:
.8byte .LVL1-.Ltext0 # Location list begin address (*.LLST3)
.8byte .LVL7-.Ltext0 # Location list end address (*.LLST3)
.2byte 0x1 # Location expression size
.byte 0x59 # DW_OP_reg9
.8byte .LVL7-.Ltext0 # Location list begin address (*.LLST3)
.8byte .LVL9-1-.Ltext0 # Location list end address (*.LLST3)
.2byte 0xc # Location expression size
.byte 0x72 # DW_OP_breg2
.byte 0x0 # sleb128 0
.byte 0x3 # DW_OP_addr
.8byte ....@toc
.byte 0x22 # DW_OP_plus
.8byte 0x0 # Location list terminator begin (*.LLST3)
.8byte 0x0 # Location list terminator end (*.LLST3)
and @toc isn't allowed in .8byte.
There is:
(insn 41 43 40 2 random.i:18 (set (reg/f:DI 9 9 [orig:148 d.0 ] [148])
(mem/u/c:DI (plus:DI (reg:DI 2 2)
(const:DI (unspec:DI [
(symbol_ref/u:DI ("*.LC2") [flags 0x2])
] 49))) [7 S8 A8])) 350 {*movdi_internal64}
(expr_list:REG_DEAD (reg:DI 2 2)
(expr_list:REG_EQUIV (symbol_ref:DI ("d") [flags 0xc0] <var_decl
0x7fdb7e28de60 d>)
(nil))))
...
(debug_insn 47 46 48 2 random.i:18 (var_location:DI y (reg/f:DI 9 9 [orig:148
d.0 ] [148])) -1 (nil))
before var-tracking and apparently var-tracking doesn't consider that
REG_EQUIV, which leads to:
(note 142 75 89 5 (var_location y (expr_list:REG_DEP_TRUE (mem/u/c:DI (plus:DI
(reg:DI 2 2)
(const:DI (unspec:DI [
(symbol_ref/u:DI ("*.LC2") [flags 0x2])
] 49))) [7 S8 A8])
(const_int 0 [0x0]))) NOTE_INSN_VAR_LOCATION)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42861
