Hi!
On powerpc64-linux the ext-elim-1.c testcase started failing,
becuase we have there an insn with a sign (or was it zero?) extension
in a parallel with setting flags. Via note_stores it happily accepts
the insn as an candidate, but later on assumes the sign extension
must be right in the insn pattern by passing PATTERN of the insn
as set_pat on which we do XEXP (SET_SRC (set_pat), 0).
The following patch fixes it by passing curr_cand->expr (i.e. the
sign/zero extending set we've found earlier) as set_pat, and
additionally just uses single_set instead of note_stores to find the
candidates - we don't try to understand what the other sets in
the pattern do and e.g. removing an insn that has an unneeded
extension but also sets flags or something similar based on it
and something actually uses them would result in wrong-code.
Bootstrapped/regtested on x86_64-linux and i686-linux, tested on
powerpc64-linux on the testcase. Ok for trunk?
2012-01-25 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/51978
* ree.c (make_defs_and_copies_lists): Change set_pat type
to const_rtx.
(combine_reaching_defs): Likewise.
(struct re_info): Remove.
(add_removable_extension): Remove x and data arguments,
add insn, insn_list and def_map. Use the arguments directly
instead of using struct re_info.
(find_removable_extensions): Don't call add_removable_extension
through note_stores, instead just call it with single_set
result if non-NULL.
(find_and_remove_re): Pass curr_cand->expr instead of
PATTERN (curr_cand->insn) as set_pat argument to
combine_reaching_defs.
--- gcc/ree.c.jj 2012-01-23 18:23:55.000000000 +0100
+++ gcc/ree.c 2012-01-24 23:47:15.539731021 +0100
@@ -523,7 +523,7 @@ typedef struct ext_state
success. */
static bool
-make_defs_and_copies_lists (rtx extend_insn, rtx set_pat,
+make_defs_and_copies_lists (rtx extend_insn, const_rtx set_pat,
ext_state *state)
{
rtx src_reg = XEXP (SET_SRC (set_pat), 0);
@@ -651,7 +651,7 @@ merge_def_and_ext (ext_cand *cand, rtx d
and false upon failure. */
static bool
-combine_reaching_defs (ext_cand *cand, rtx set_pat, ext_state *state)
+combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state)
{
rtx def_insn;
bool merge_successful = true;
@@ -742,27 +742,13 @@ combine_reaching_defs (ext_cand *cand, r
return false;
}
-/* This structure holds information while walking the RTL stream. */
-
-struct re_info
-{
- /* The current insn. */
- rtx insn;
-
- /* The list of candidates. */
- VEC (ext_cand, heap) *insn_list;
-
- /* The map of definition instructions to candidates. */
- ext_cand **def_map;
-};
-
-/* Add an extension pattern that could be eliminated. This is called via
- note_stores from find_removable_extensions. */
+/* Add an extension pattern that could be eliminated. */
static void
-add_removable_extension (rtx x ATTRIBUTE_UNUSED, const_rtx expr, void *data)
+add_removable_extension (const_rtx expr, rtx insn,
+ VEC (ext_cand, heap) **insn_list,
+ ext_cand **def_map)
{
- struct re_info *rei = (struct re_info *)data;
enum rtx_code code;
enum machine_mode mode;
rtx src, dest;
@@ -785,13 +771,13 @@ add_removable_extension (rtx x ATTRIBUTE
ext_cand *cand;
/* First, make sure we can get all the reaching definitions. */
- defs = get_defs (rei->insn, XEXP (src, 0), NULL);
+ defs = get_defs (insn, XEXP (src, 0), NULL);
if (!defs)
{
if (dump_file)
{
fprintf (dump_file, "Cannot eliminate extension:\n");
- print_rtl_single (dump_file, rei->insn);
+ print_rtl_single (dump_file, insn);
fprintf (dump_file, " because of missing definition(s)\n");
}
return;
@@ -800,13 +786,13 @@ add_removable_extension (rtx x ATTRIBUTE
/* Second, make sure the reaching definitions don't feed another and
different extension. FIXME: this obviously can be improved. */
for (def = defs; def; def = def->next)
- if ((cand = rei->def_map[INSN_UID(DF_REF_INSN (def->ref))])
+ if ((cand = def_map[INSN_UID(DF_REF_INSN (def->ref))])
&& (cand->code != code || cand->mode != mode))
{
if (dump_file)
{
fprintf (dump_file, "Cannot eliminate extension:\n");
- print_rtl_single (dump_file, rei->insn);
+ print_rtl_single (dump_file, insn);
fprintf (dump_file, " because of other extension\n");
}
return;
@@ -814,14 +800,14 @@ add_removable_extension (rtx x ATTRIBUTE
/* Then add the candidate to the list and insert the reaching definitions
into the definition map. */
- cand = VEC_safe_push (ext_cand, heap, rei->insn_list, NULL);
+ cand = VEC_safe_push (ext_cand, heap, *insn_list, NULL);
cand->expr = expr;
cand->code = code;
cand->mode = mode;
- cand->insn = rei->insn;
+ cand->insn = insn;
for (def = defs; def; def = def->next)
- rei->def_map[INSN_UID(DF_REF_INSN (def->ref))] = cand;
+ def_map[INSN_UID(DF_REF_INSN (def->ref))] = cand;
}
}
@@ -831,12 +817,10 @@ add_removable_extension (rtx x ATTRIBUTE
static VEC (ext_cand, heap)*
find_removable_extensions (void)
{
- struct re_info rei;
+ VEC (ext_cand, heap) *insn_list = NULL;
basic_block bb;
- rtx insn;
-
- rei.insn_list = VEC_alloc (ext_cand, heap, 8);
- rei.def_map = XCNEWVEC (ext_cand *, max_insn_uid);
+ rtx insn, set;
+ ext_cand **def_map = XCNEWVEC (ext_cand *, max_insn_uid);
FOR_EACH_BB (bb)
FOR_BB_INSNS (bb, insn)
@@ -844,13 +828,15 @@ find_removable_extensions (void)
if (!NONDEBUG_INSN_P (insn))
continue;
- rei.insn = insn;
- note_stores (PATTERN (insn), add_removable_extension, &rei);
+ set = single_set (insn);
+ if (set == NULL_RTX)
+ continue;
+ add_removable_extension (set, insn, &insn_list, def_map);
}
- XDELETEVEC (rei.def_map);
+ XDELETEVEC (def_map);
- return rei.insn_list;
+ return insn_list;
}
/* This is the main function that checks the insn stream for redundant
@@ -895,7 +881,7 @@ find_and_remove_re (void)
print_rtl_single (dump_file, curr_cand->insn);
}
- if (combine_reaching_defs (curr_cand, PATTERN (curr_cand->insn), &state))
+ if (combine_reaching_defs (curr_cand, curr_cand->expr, &state))
{
if (dump_file)
fprintf (dump_file, "Eliminated the extension.\n");
Jakub
