On May 23, 2012, Jakub Jelinek <ja...@redhat.com> wrote:
> On Wed, May 23, 2012 at 06:27:21AM -0300, Alexandre Oliva wrote:
>> + for (loc = var->var_part[0].loc_chain; loc; loc = loc->next)
>> + if (GET_CODE (loc->loc) == MEM
>> + && !nonoverlapping_memrefs_p (loc->loc, mloc, false))
> Isn't nonoverlapping_memrefs_p predicate too conservative?
> cselib.c uses canon_true_dependence to decide what should be invalidated.
Yeah, I guess that should do. I've finally managed to analyze the
effects of using canon_true_dependence on debug info, and it does seem
to produce reasonable results:
before after
= entry value count =
33005 35700 i686/cc1plus
99 116 i686/libgcc_s.so
216 239 i686/libstdc++.so
99902 104390 amd64/cc1plus
308 319 amd64/libgcc_s.so
8819 8864 amd64/libstdc++.so
= call site value count =
519877 514591 i686/cc1plus
406 403 i686/libgcc_s.so
10284 10121 i686/libstdc++.so
518401 518220 amd64/cc1plus
341 341 amd64/libgcc_s.so
11309 11261 amd64/libstdc++.so
loc info coverage (before | after)
i686/cc1plus:
cov% samples cumul cov% samples cumul
0.0 155345/28% 155345/28% | 0.0 155561/29% 155561/29%
0..5 6606/1% 161951/30% | 0..5 7969/1% 163530/30%
6..10 5984/1% 167935/31% | 6..10 6336/1% 169866/31%
11..15 4823/0% 172758/32% | 11..15 5117/0% 174983/32%
16..20 6262/1% 179020/33% | 16..20 6677/1% 181660/33%
21..25 5259/0% 184279/34% | 21..25 5688/1% 187348/34%
26..30 5149/0% 189428/35% | 26..30 5409/1% 192757/35%
31..35 4547/0% 193975/36% | 31..35 4868/0% 197625/36%
36..40 7204/1% 201179/37% | 36..40 7524/1% 205149/38%
41..45 8343/1% 209522/39% | 41..45 8656/1% 213805/39%
46..50 8744/1% 218266/40% | 46..50 9252/1% 223057/41%
51..55 5806/1% 224072/41% | 51..55 6023/1% 229080/42%
56..60 6834/1% 230906/43% | 56..60 7072/1% 236152/44%
61..65 5391/1% 236297/44% | 61..65 5554/1% 241706/45%
66..70 9269/1% 245566/45% | 66..70 9327/1% 251033/46%
71..75 6249/1% 251815/46% | 71..75 6309/1% 257342/47%
76..80 8871/1% 260686/48% | 76..80 8905/1% 266247/49%
81..85 8775/1% 269461/50% | 81..85 8786/1% 275033/51%
86..90 13323/2% 282784/52% | 86..90 13286/2% 288319/53%
91..95 21279/3% 304063/56% | 91..95 20947/3% 309266/57%
96..99 21323/3% 325386/60% | 96..99 20247/3% 329513/61%
100 211312/39% 536698/100% | 100 206704/38% 536217/100%
i686/libgcc_s.so:
cov% samples cumul cov% samples cumul
0.0 511/21% 511/21% | 0.0 512/21% 512/21%
0..5 44/1% 555/23% | 0..5 67/2% 579/24%
6..10 45/1% 600/25% | 6..10 41/1% 620/26%
11..15 35/1% 635/26% | 11..15 37/1% 657/27%
16..20 28/1% 663/27% | 16..20 29/1% 686/29%
21..25 32/1% 695/29% | 21..25 32/1% 718/30%
26..30 40/1% 735/31% | 26..30 41/1% 759/32%
31..35 32/1% 767/32% | 31..35 34/1% 793/33%
36..40 29/1% 796/33% | 36..40 33/1% 826/34%
41..45 42/1% 838/35% | 41..45 44/1% 870/36%
46..50 47/1% 885/37% | 46..50 56/2% 926/39%
51..55 33/1% 918/38% | 51..55 35/1% 961/40%
56..60 45/1% 963/40% | 56..60 48/2% 1009/42%
61..65 44/1% 1007/42% | 61..65 43/1% 1052/44%
66..70 64/2% 1071/45% | 66..70 68/2% 1120/47%
71..75 45/1% 1116/47% | 71..75 45/1% 1165/49%
76..80 67/2% 1183/49% | 76..80 69/2% 1234/52%
81..85 76/3% 1259/53% | 81..85 76/3% 1310/55%
86..90 131/5% 1390/58% | 86..90 119/5% 1429/60%
91..95 83/3% 1473/62% | 91..95 81/3% 1510/63%
96..99 54/2% 1527/64% | 96..99 49/2% 1559/66%
100 842/35% 2369/100% | 100 802/33% 2361/100%
i686/libstdc++.so
cov% samples cumul cov% samples cumul
0.0 12708/37% 12708/37% | 0.0 12737/37% 12737/37%
0..5 125/0% 12833/38% | 0..5 263/0% 13000/38%
6..10 167/0% 13000/38% | 6..10 201/0% 13201/39%
11..15 125/0% 13125/39% | 11..15 157/0% 13358/39%
16..20 197/0% 13322/39% | 16..20 216/0% 13574/40%
21..25 169/0% 13491/40% | 21..25 194/0% 13768/40%
26..30 120/0% 13611/40% | 26..30 155/0% 13923/41%
31..35 179/0% 13790/41% | 31..35 188/0% 14111/41%
36..40 238/0% 14028/41% | 36..40 257/0% 14368/42%
41..45 226/0% 14254/42% | 41..45 266/0% 14634/43%
46..50 258/0% 14512/43% | 46..50 270/0% 14904/44%
51..55 176/0% 14688/43% | 51..55 199/0% 15103/44%
56..60 349/1% 15037/44% | 56..60 362/1% 15465/46%
61..65 286/0% 15323/45% | 61..65 288/0% 15753/46%
66..70 259/0% 15582/46% | 66..70 260/0% 16013/47%
71..75 404/1% 15986/47% | 71..75 416/1% 16429/48%
76..80 413/1% 16399/48% | 76..80 403/1% 16832/50%
81..85 621/1% 17020/50% | 81..85 617/1% 17449/51%
86..90 788/2% 17808/52% | 86..90 733/2% 18182/54%
91..95 833/2% 18641/55% | 91..95 774/2% 18956/56%
96..99 537/1% 19178/57% | 96..99 495/1% 19451/57%
100 14426/42% 33604/100% | 100 14148/42% 33599/100%
amd64/cc1plus:
cov% samples cumul cov% samples cumul
0.0 160910/31% 160910/31% | 0.0 161076/31% 161076/31%
0..5 6266/1% 167176/32% | 0..5 6543/1% 167619/32%
6..10 5484/1% 172660/33% | 6..10 5615/1% 173234/33%
11..15 4874/0% 177534/34% | 11..15 4989/0% 178223/34%
16..20 5001/0% 182535/35% | 16..20 5108/0% 183331/35%
21..25 5383/1% 187918/36% | 21..25 5458/1% 188789/36%
26..30 4182/0% 192100/37% | 26..30 4286/0% 193075/37%
31..35 4731/0% 196831/38% | 31..35 4814/0% 197889/38%
36..40 6995/1% 203826/39% | 36..40 7068/1% 204957/40%
41..45 7749/1% 211575/41% | 41..45 7814/1% 212771/41%
46..50 8686/1% 220261/42% | 46..50 8788/1% 221559/43%
51..55 7650/1% 227911/44% | 51..55 7728/1% 229287/44%
56..60 6394/1% 234305/45% | 56..60 6457/1% 235744/46%
61..65 5629/1% 239934/46% | 61..65 5685/1% 241429/47%
66..70 7371/1% 247305/48% | 66..70 7448/1% 248877/48%
71..75 8137/1% 255442/49% | 71..75 8162/1% 257039/50%
76..80 19364/3% 274806/53% | 76..80 19363/3% 276402/54%
81..85 12056/2% 286862/55% | 81..85 12024/2% 288426/56%
86..90 15509/3% 302371/58% | 86..90 15431/3% 303857/59%
91..95 17138/3% 319509/62% | 91..95 16897/3% 320754/62%
96..99 17654/3% 337163/65% | 96..99 17034/3% 337788/66%
100 175723/34% 512886/100% | 100 173852/33% 511640/100%
i686/libgcc_s.so:
cov% samples cumul cov% samples cumul
0.0 450/23% 450/23% 0.0 450/23% 450/23%
0..5 46/2% 496/26% | 0..5 47/2% 497/26%
6..10 29/1% 525/27% | 6..10 30/1% 527/27%
11..15 33/1% 558/29% | 11..15 34/1% 561/29%
16..20 32/1% 590/31% | 16..20 33/1% 594/31%
21..25 31/1% 621/32% | 21..25 31/1% 625/32%
26..30 20/1% 641/33% | 26..30 20/1% 645/34%
31..35 24/1% 665/34% | 31..35 24/1% 669/35%
36..40 39/2% 704/37% | 36..40 41/2% 710/37%
41..45 53/2% 757/39% | 41..45 52/2% 762/40%
46..50 25/1% 782/41% | 46..50 25/1% 787/41%
51..55 32/1% 814/42% | 51..55 32/1% 819/43%
56..60 40/2% 854/44% | 56..60 40/2% 859/45%
61..65 42/2% 896/47% | 61..65 43/2% 902/47%
66..70 55/2% 951/50% | 66..70 54/2% 956/50%
71..75 69/3% 1020/53% | 71..75 69/3% 1025/54%
76..80 41/2% 1061/55% | 76..80 43/2% 1068/56%
81..85 33/1% 1094/57% | 81..85 32/1% 1100/57%
86..90 74/3% 1168/61% | 86..90 73/3% 1173/61%
91..95 57/2% 1225/64% | 91..95 56/2% 1229/64%
96..99 45/2% 1270/66% | 96..99 44/2% 1273/67%
100 632/33% 1902/100% | 100 624/32% 1897/100%
amd64/libstdc++.so
cov% samples cumul cov% samples cumul
0.0 10565/36% 10565/36% | 0.0 10594/36% 10594/36%
0..5 121/0% 10686/36% | 0..5 141/0% 10735/36%
6..10 158/0% 10844/37% | 6..10 187/0% 10922/37%
11..15 164/0% 11008/37% | 11..15 186/0% 11108/37%
16..20 234/0% 11242/38% | 16..20 237/0% 11345/38%
21..25 236/0% 11478/39% | 21..25 239/0% 11584/39%
26..30 206/0% 11684/39% | 26..30 212/0% 11796/40%
31..35 273/0% 11957/40% | 31..35 286/0% 12082/41%
36..40 375/1% 12332/42% | 36..40 376/1% 12458/42%
41..45 286/0% 12618/43% | 41..45 285/0% 12743/43%
46..50 422/1% 13040/44% | 46..50 419/1% 13162/44%
51..55 196/0% 13236/45% | 51..55 193/0% 13355/45%
56..60 292/0% 13528/46% | 56..60 303/1% 13658/46%
61..65 429/1% 13957/47% | 61..65 431/1% 14089/48%
66..70 365/1% 14322/48% | 66..70 373/1% 14462/49%
71..75 375/1% 14697/50% | 71..75 378/1% 14840/50%
76..80 652/2% 15349/52% | 76..80 650/2% 15490/52%
81..85 817/2% 16166/55% | 81..85 798/2% 16288/55%
86..90 787/2% 16953/57% | 86..90 780/2% 17068/58%
91..95 1090/3% 18043/61% | 91..95 1076/3% 18144/61%
96..99 570/1% 18613/63% | 96..99 562/1% 18706/63%
100 10683/36% 29296/100% | 100 10565/36% 29271/100%
This patch was regstrapped along with the patch for PR47624 (ping
<http://gcc.gnu.org/ml/gcc-patches/2012-04/msg01320.html>) on
x86_64-linux-gnu and i686-linux-gnu. Ok to install?
for gcc/ChangeLog
from Alexandre Oliva <aol...@redhat.com>
PR debug/49888
* var-tracking.c: Include alias.h.
(overlapping_mems): New struct.
(drop_overlapping_mem_locs): New.
(clobber_overlapping_mems): New.
(var_mem_delete_and_set, var_mem_delete): Call it.
(val_bind): Likewise, but only if modified.
(compute_bb_dataflow, emit_notes_in_bb): Call it on MEMs.
* Makefile.in (var-tracking.o): Depend in $(ALIAS_H).
for gcc/testsuite/ChangeLog
from Alexandre Oliva <aol...@redhat.com>
PR debug/49888
* gcc.dg/guality/pr49888.c: New.
Index: gcc/var-tracking.c
===================================================================
--- gcc/var-tracking.c.orig 2012-06-05 03:03:47.154714459 -0300
+++ gcc/var-tracking.c 2012-06-05 12:50:57.724756717 -0300
@@ -115,6 +115,7 @@
#include "pointer-set.h"
#include "recog.h"
#include "tm_p.h"
+#include "alias.h"
/* var-tracking.c assumes that tree code with the same value as VALUE rtx code
has no chance to appear in REG_EXPR/MEM_EXPRs and isn't a decl.
@@ -1954,6 +1955,111 @@ var_regno_delete (dataflow_set *set, int
*reg = NULL;
}
+/* Hold parameters for the hashtab traversal function
+ drop_overlapping_mem_locs, see below. */
+
+struct overlapping_mems
+{
+ dataflow_set *set;
+ rtx loc, addr;
+};
+
+/* Remove all MEMs that overlap with COMS->LOC from the location list
+ of a hash table entry for a value. COMS->ADDR must be a
+ canonicalized form of COMS->LOC's address, and COMS->LOC must be
+ canonicalized itself. */
+
+static int
+drop_overlapping_mem_locs (void **slot, void *data)
+{
+ struct overlapping_mems *coms = (struct overlapping_mems *)data;
+ dataflow_set *set = coms->set;
+ rtx mloc = coms->loc, addr = coms->addr;
+ variable var = (variable) *slot;
+
+ if (var->onepart == ONEPART_VALUE)
+ {
+ location_chain loc, *locp;
+ bool changed = false;
+ rtx cur_loc;
+
+ gcc_assert (var->n_var_parts == 1);
+
+ if (shared_var_p (var, set->vars))
+ {
+ for (loc = var->var_part[0].loc_chain; loc; loc = loc->next)
+ if (GET_CODE (loc->loc) == MEM
+ && canon_true_dependence (mloc, GET_MODE (mloc), addr,
+ loc->loc, NULL))
+ break;
+
+ if (!loc)
+ return 1;
+
+ slot = unshare_variable (set, slot, var, VAR_INIT_STATUS_UNKNOWN);
+ var = (variable)*slot;
+ gcc_assert (var->n_var_parts == 1);
+ }
+
+ if (VAR_LOC_1PAUX (var))
+ cur_loc = VAR_LOC_FROM (var);
+ else
+ cur_loc = var->var_part[0].cur_loc;
+
+ for (locp = &var->var_part[0].loc_chain, loc = *locp;
+ loc; loc = *locp)
+ {
+ if (GET_CODE (loc->loc) != MEM
+ || !canon_true_dependence (mloc, GET_MODE (mloc), addr,
+ loc->loc, NULL))
+ {
+ locp = &loc->next;
+ continue;
+ }
+
+ *locp = loc->next;
+ /* If we have deleted the location which was last emitted
+ we have to emit new location so add the variable to set
+ of changed variables. */
+ if (cur_loc == loc->loc)
+ {
+ changed = true;
+ var->var_part[0].cur_loc = NULL;
+ if (VAR_LOC_1PAUX (var))
+ VAR_LOC_FROM (var) = NULL;
+ }
+ pool_free (loc_chain_pool, loc);
+ }
+
+ if (!var->var_part[0].loc_chain)
+ {
+ var->n_var_parts--;
+ changed = true;
+ }
+ if (changed)
+ variable_was_changed (var, set);
+ }
+
+ return 1;
+}
+
+/* Remove from SET all VALUE bindings to MEMs that overlap with LOC. */
+
+static void
+clobber_overlapping_mems (dataflow_set *set, rtx loc)
+{
+ struct overlapping_mems coms;
+
+ coms.set = set;
+ coms.loc = canon_rtx (loc);
+ coms.addr = canon_rtx (get_addr (XEXP (loc, 0)));
+
+ set->traversed_vars = set->vars;
+ htab_traverse (shared_hash_htab (set->vars),
+ drop_overlapping_mem_locs, &coms);
+ set->traversed_vars = NULL;
+}
+
/* Set the location of DV, OFFSET as the MEM LOC. */
static void
@@ -1996,6 +2102,7 @@ var_mem_delete_and_set (dataflow_set *se
tree decl = MEM_EXPR (loc);
HOST_WIDE_INT offset = INT_MEM_OFFSET (loc);
+ clobber_overlapping_mems (set, loc);
decl = var_debug_decl (decl);
if (initialized == VAR_INIT_STATUS_UNKNOWN)
@@ -2016,6 +2123,7 @@ var_mem_delete (dataflow_set *set, rtx l
tree decl = MEM_EXPR (loc);
HOST_WIDE_INT offset = INT_MEM_OFFSET (loc);
+ clobber_overlapping_mems (set, loc);
decl = var_debug_decl (decl);
if (clobber)
clobber_variable_part (set, NULL, dv_from_decl (decl), offset, NULL);
@@ -2059,6 +2167,9 @@ val_bind (dataflow_set *set, rtx val, rt
{
struct elt_loc_list *l = CSELIB_VAL_PTR (val)->locs;
+ if (modified)
+ clobber_overlapping_mems (set, loc);
+
if (l && GET_CODE (l->loc) == VALUE)
l = canonical_cselib_val (CSELIB_VAL_PTR (l->loc))->locs;
@@ -6371,6 +6482,8 @@ compute_bb_dataflow (basic_block bb)
}
else if (REG_P (uloc))
var_regno_delete (out, REGNO (uloc));
+ else if (MEM_P (uloc))
+ clobber_overlapping_mems (out, uloc);
val_store (out, val, dstv, insn, true);
}
@@ -8870,6 +8983,8 @@ emit_notes_in_bb (basic_block bb, datafl
}
else if (REG_P (uloc))
var_regno_delete (set, REGNO (uloc));
+ else if (MEM_P (uloc))
+ clobber_overlapping_mems (set, uloc);
val_store (set, val, dstv, insn, true);
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in.orig 2012-06-05 03:02:32.904609594 -0300
+++ gcc/Makefile.in 2012-06-05 12:54:21.000000000 -0300
@@ -3130,8 +3130,8 @@ var-tracking.o : var-tracking.c $(CONFIG
$(RTL_H) $(TREE_H) hard-reg-set.h insn-config.h reload.h $(FLAGS_H) \
$(BASIC_BLOCK_H) bitmap.h alloc-pool.h $(FIBHEAP_H) $(HASHTAB_H) \
$(REGS_H) $(EXPR_H) $(TIMEVAR_H) $(TREE_PASS_H) $(TREE_FLOW_H) \
- cselib.h $(TARGET_H) $(DIAGNOSTIC_CORE_H) $(PARAMS_H) $(DIAGNOSTIC_H) pointer-set.h \
- $(RECOG_H) $(TM_P_H) $(TREE_PRETTY_PRINT_H)
+ cselib.h $(TARGET_H) $(DIAGNOSTIC_CORE_H) $(PARAMS_H) $(DIAGNOSTIC_H) \
+ pointer-set.h $(RECOG_H) $(TM_P_H) $(TREE_PRETTY_PRINT_H) $(ALIAS_H)
profile.o : profile.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
$(TREE_H) $(FLAGS_H) $(REGS_H) $(EXPR_H) $(FUNCTION_H) $(BASIC_BLOCK_H) \
$(DIAGNOSTIC_CORE_H) $(COVERAGE_H) $(TREE_FLOW_H) value-prof.h cfghooks.h \
Index: gcc/testsuite/gcc.dg/guality/pr49888.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gcc/testsuite/gcc.dg/guality/pr49888.c 2012-06-05 12:50:57.878744571 -0300
@@ -0,0 +1,25 @@
+/* PR debug/49888 */
+/* { dg-do run } */
+/* { dg-options "-g" } */
+
+static int v;
+
+static void __attribute__((noinline, noclone))
+f (int *p)
+{
+ int c = *p;
+ v = c;
+ *p = 1; /* { dg-final { gdb-test 12 "c" "0" } } */
+ /* c may very well be optimized out at this point, so we test !c,
+ which will evaluate to the expected value. We just want to make
+ sure it doesn't remain bound to *p as it did before, in which
+ case !c would evaluate to 0. */
+ v = 0; /* { dg-final { gdb-test 17 "!c" "1" } } */
+}
+int
+main ()
+{
+ int a = 0;
+ f (&a);
+ return 0;
+}
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer
