http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60598
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-03-20
CC| |jakub at gcc dot gnu.org,
| |krebbel at gcc dot gnu.org,
| |rth at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Slightly more reduced testcase for -march=z196 -mtune=zEC12 -m64 -O2 -fpic:
struct S { unsigned a, b[32]; };
void
foo (struct S *x, struct S *y)
{
unsigned a = y->a, i;
if (x == y)
for (i = 0; i < a - 1 - i; i++)
{
unsigned t = x->b[i];
x->b[i] = x->b[a - 1 - i];
x->b[a - 1 - i] = t;
}
else
{
x->a = a;
for (i = 0; i < a; i++)
x->b[i] = y->b[a - 1 - i];
}
}
Regressed with r208165, seems that the function is shrink-wrapped and the *.ce3
pass incorrectly moves a frame related insn across a conditional jump to a code
label right before the frame related insn, where the conditional jump falls
through into a simple_return. Having the register save ahead of such
conditional jump means the *.dwarf2 pass sees a path where we reach with saved,
but not restored, register the simple_return and die.
(jump_insn 48 39 156 3 (parallel [
(set (pc)
(if_then_else (ne (reg/v:SI 1 %r1 [orig:87 a ] [87])
(const_int 1 [0x1]))
(label_ref:DI 164)
(pc)))
(set (reg:SI 1 %r1 [orig:89 D.1427 ] [89])
(plus:SI (reg/v:SI 1 %r1 [orig:87 a ] [87])
(const_int -1 [0xffffffffffffffff])))
(clobber (scratch:SI))
(clobber (reg:CC 33 %cc))
]) pr60598.c:8 619 {doloop_si64}
(expr_list:REG_UNUSED (reg:CC 33 %cc)
(int_list:REG_BR_PROB 9697 (nil)))
-> 164)
(code_label 156 48 151 5 14 "" [1 uses])
(note 151 156 166 5 [bb 5] NOTE_INSN_BASIC_BLOCK)
(jump_insn 166 151 153 5 (simple_return) -1
(nil)
-> simple_return)
(barrier 153 166 164)
(code_label 164 153 163 6 15 "" [1 uses])
(note 163 164 147 6 [bb 6] NOTE_INSN_BASIC_BLOCK)
(insn/f 147 163 148 6 (set (reg:DI 16 %f0)
(reg:DI 11 %r11)) pr60598.c:5 -1
(expr_list:REG_DEAD (reg:DI 11 %r11)
(nil)))
(note 148 147 126 6 NOTE_INSN_PROLOGUE_END)
is what we have in the *.peephole2 dump, and the *.ce3 pass moves insn 147 and
148 right before insn 48.
