Hi!
To avoid -fcompare-debug failures, we promote_debug_loc VALUEs looked
up from DEBUG_INSNs when they are looked from some other insns.
Unfortunately, the scheduler after cselib_lookup_from_insn from
DEBUG_INSN calls cselib_subst_to_values, which may e.g. cselib_lookup_mem
(with create=0). As that is with cselib_current_insn == NULL,
promote_debug_loc considers it being a non-DEBUG_INSN lookup and promotes
it to non-debug, which on the testcase in the PR (too large and too hard
to further reduce) results in different n_useless_values and
remove_useless_values being triggered at different times between
-g and -g0 compilations.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
tested on the testcase with ia64-linux cross. Ok for trunk?
2012-02-13 Jakub Jelinek <ja...@redhat.com>
PR bootstrap/52172
* cselib.h (cselib_subst_to_values_from_insn): New prototype.
* cselib.c (cselib_subst_to_values_from_insn): New function.
* sched-deps.c (add_insn_mem_dependence,
sched_analyze_1, sched_analyze_2): Use it.
--- gcc/cselib.h.jj 2012-01-01 19:54:46.000000000 +0100
+++ gcc/cselib.h 2012-02-13 21:29:21.792483236 +0100
@@ -88,6 +88,7 @@ extern rtx cselib_expand_value_rtx_cb (r
extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int,
cselib_expand_callback, void *);
extern rtx cselib_subst_to_values (rtx, enum machine_mode);
+extern rtx cselib_subst_to_values_from_insn (rtx, enum machine_mode, rtx);
extern void cselib_invalidate_rtx (rtx);
extern void cselib_reset_table (unsigned int);
--- gcc/cselib.c.jj 2012-02-13 18:15:17.000000000 +0100
+++ gcc/cselib.c 2012-02-13 21:33:37.019088486 +0100
@@ -1905,6 +1905,19 @@ cselib_subst_to_values (rtx x, enum mach
return copy;
}
+/* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
+
+rtx
+cselib_subst_to_values_from_insn (rtx x, enum machine_mode memmode, rtx insn)
+{
+ rtx ret;
+ gcc_assert (!cselib_current_insn);
+ cselib_current_insn = insn;
+ ret = cselib_subst_to_values (x, memmode);
+ cselib_current_insn = NULL;
+ return ret;
+}
+
/* Look up the rtl expression X in our tables and return the value it
has. If CREATE is zero, we return NULL if we don't know the value.
Otherwise, we create a new one if possible, using mode MODE if X
--- gcc/sched-deps.c.jj 2012-01-26 09:22:21.000000000 +0100
+++ gcc/sched-deps.c 2012-02-13 21:30:40.235054596 +0100
@@ -1728,7 +1728,8 @@ add_insn_mem_dependence (struct deps_des
if (sched_deps_info->use_cselib)
{
mem = shallow_copy_rtx (mem);
- XEXP (mem, 0) = cselib_subst_to_values (XEXP (mem, 0), GET_MODE (mem));
+ XEXP (mem, 0) = cselib_subst_to_values_from_insn (XEXP (mem, 0),
+ GET_MODE (mem), insn);
}
link = alloc_EXPR_LIST (VOIDmode, canon_rtx (mem), *mem_list);
*mem_list = link;
@@ -2449,7 +2450,9 @@ sched_analyze_1 (struct deps_desc *deps,
t = shallow_copy_rtx (dest);
cselib_lookup_from_insn (XEXP (t, 0), address_mode, 1,
GET_MODE (t), insn);
- XEXP (t, 0) = cselib_subst_to_values (XEXP (t, 0), GET_MODE (t));
+ XEXP (t, 0)
+ = cselib_subst_to_values_from_insn (XEXP (t, 0), GET_MODE (t),
+ insn);
}
t = canon_rtx (t);
@@ -2609,7 +2612,9 @@ sched_analyze_2 (struct deps_desc *deps,
t = shallow_copy_rtx (t);
cselib_lookup_from_insn (XEXP (t, 0), address_mode, 1,
GET_MODE (t), insn);
- XEXP (t, 0) = cselib_subst_to_values (XEXP (t, 0), GET_MODE (t));
+ XEXP (t, 0)
+ = cselib_subst_to_values_from_insn (XEXP (t, 0), GET_MODE (t),
+ insn);
}
if (!DEBUG_INSN_P (insn))
Jakub
