differences are in the noise (+-3 vars at most in any single 10% coverage range).
Ok for trunk?
2010-10-27 Jakub Jelinek <jakub@redhat.com>
PR debug/46171
* df-problems.c (struct dead_debug_use, struct dead_debug): Move
earlier.
(df_set_unused_notes_for_mw, df_create_unused_note): Add DEBUG
argument, call dead_debug_reset when adding REG_UNUSED note.
(dead_debug_reset): New function.
(df_note_bb_compute): Adjust df_set_unused_notes_for_mw and
df_create_unused_note callers.
* gcc.dg/pr46171.c: New test.
@@ -2838,6 +2838,26 @@ df_whole_mw_reg_unused_p (struct df_mw_h
return true;
}
+
+/* Node of a linked list of uses of dead REGs in debug insns. */
+struct dead_debug_use
+{
+ df_ref use;
+ struct dead_debug_use *next;
+};
+
+/* Linked list of the above, with a bitmap of the REGs in the
+ list. */
+struct dead_debug
+{
+ struct dead_debug_use *head;
+ bitmap used;
+ bitmap to_rescan;
+};
+
+static void dead_debug_reset (struct dead_debug *, unsigned int);
+
+
/* Set the REG_UNUSED notes for the multiword hardreg defs in INSN
based on the bits in LIVE. Do not generate notes for registers in
artificial uses. DO_NOT_GEN is updated so that REG_DEAD notes are
@@ -2848,7 +2868,8 @@ df_whole_mw_reg_unused_p (struct df_mw_h
static void
df_set_unused_notes_for_mw (rtx insn, struct df_mw_hardreg *mws,
bitmap live, bitmap do_not_gen,
- bitmap artificial_uses)
+ bitmap artificial_uses,
+ struct dead_debug *debug)
{
unsigned int r;
@@ -2862,6 +2883,7 @@ df_set_unused_notes_for_mw (rtx insn, st
{
unsigned int regno = mws->start_regno;
df_set_note (REG_UNUSED, insn, mws->mw_reg);
+ dead_debug_reset (debug, regno);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 1: ", insn, REG_NOTES (insn));
@@ -2876,6 +2898,7 @@ df_set_unused_notes_for_mw (rtx insn, st
&& !bitmap_bit_p (artificial_uses, r))
{
df_set_note (REG_UNUSED, insn, regno_reg_rtx[r]);
+ dead_debug_reset (debug, r);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 2: ", insn, REG_NOTES (insn));
#endif
@@ -2981,7 +3007,8 @@ df_set_dead_notes_for_mw (rtx insn, stru
static void
df_create_unused_note (rtx insn, df_ref def,
- bitmap live, bitmap artificial_uses)
+ bitmap live, bitmap artificial_uses,
+ struct dead_debug *debug)
{
unsigned int dregno = DF_REF_REGNO (def);
@@ -3001,6 +3028,7 @@ df_create_unused_note (rtx insn, df_ref
rtx reg = (DF_REF_LOC (def))
? *DF_REF_REAL_LOC (def): DF_REF_REG (def);
df_set_note (REG_UNUSED, insn, reg);
+ dead_debug_reset (debug, dregno);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 3: ", insn, REG_NOTES (insn));
#endif
@@ -3009,21 +3037,6 @@ df_create_unused_note (rtx insn, df_ref
return;
}
-/* Node of a linked list of uses of dead REGs in debug insns. */
-struct dead_debug_use
-{
- df_ref use;
- struct dead_debug_use *next;
-};
-
-/* Linked list of the above, with a bitmap of the REGs in the
- list. */
-struct dead_debug
-{
- struct dead_debug_use *head;
- bitmap used;
- bitmap to_rescan;
-};
/* Initialize DEBUG to an empty list, and clear USED, if given. */
static inline void
@@ -3077,6 +3090,34 @@ dead_debug_finish (struct dead_debug *de
}
}
+/* Reset DEBUG_INSNs with pending uses of DREGNO. */
+static void
+dead_debug_reset (struct dead_debug *debug, unsigned int dregno)
+{
+ struct dead_debug_use **tailp = &debug->head;
+ struct dead_debug_use *cur;
+ rtx insn;
+
+ if (!debug->used || !bitmap_clear_bit (debug->used, dregno))
+ return;
+
+ while ((cur = *tailp))
+ {
+ if (DF_REF_REGNO (cur->use) == dregno)
+ {
+ *tailp = cur->next;
+ insn = DF_REF_INSN (cur->use);
+ INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
+ if (debug->to_rescan == NULL)
+ debug->to_rescan = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (debug->to_rescan, INSN_UID (insn));
+ XDELETE (cur);
+ }
+ else
+ tailp = &(*tailp)->next;
+ }
+}
+
/* Add USE to DEBUG. It must be a dead reference to UREGNO in a debug
insn. Create a bitmap for DEBUG as needed. */
static inline void
@@ -3259,7 +3299,7 @@ df_note_bb_compute (unsigned int bb_inde
&& !df_ignore_stack_reg (mws->start_regno))
df_set_unused_notes_for_mw (insn,
mws, live, do_not_gen,
- artificial_uses);
+ artificial_uses, &debug);
mws_rec++;
}
@@ -3272,7 +3312,7 @@ df_note_bb_compute (unsigned int bb_inde
if (!DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER))
{
df_create_unused_note (insn,
- def, live, artificial_uses);
+ def, live, artificial_uses, &debug);
bitmap_set_bit (do_not_gen, dregno);
}
@@ -3290,7 +3330,7 @@ df_note_bb_compute (unsigned int bb_inde
if (DF_MWS_REG_DEF_P (mws))
df_set_unused_notes_for_mw (insn,
mws, live, do_not_gen,
- artificial_uses);
+ artificial_uses, &debug);
mws_rec++;
}
@@ -3299,7 +3339,7 @@ df_note_bb_compute (unsigned int bb_inde
df_ref def = *def_rec;
unsigned int dregno = DF_REF_REGNO (def);
df_create_unused_note (insn,
- def, live, artificial_uses);
+ def, live, artificial_uses, &debug);
if (!DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER))
bitmap_set_bit (do_not_gen, dregno);
@@ -0,0 +1,13 @@
+/* PR debug/46171 */
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-dce -g" } */
+
+double bard ();
+float barf (float);
+
+void
+foo (float f)
+{
+ f = barf (f);
+ double d = bard ();
+}
Hi! We have RTL like: (insn 6 3 7 2 (set (reg:SF 21 xmm0) (reg/v:SF 61 [ f ])) pr46171.c:7 110 {*movsf_internal} (nil)) (call_insn 7 6 17 2 (set (reg:SF 21 xmm0) (call (mem:QI (symbol_ref:DI ("barf") [flags 0x41] <function_decl 0x7ffff16d1000 barf>) [0 S1 A8]) (const_int 0 [0]))) pr46171.c:7 883 {*call_value_0_rex64} (nil) (expr_list:REG_DEP_TRUE (use (reg:SF 21 xmm0)) (nil))) (debug_insn 17 7 9 2 (var_location:SF D#2 (reg:SF 21 xmm0)) -1 (nil)) (debug_insn 9 17 10 2 (var_location:SF f (debug_expr:SF D#2)) pr46171.c:7 -1 (nil)) (insn 10 9 11 2 (set (reg:QI 0 ax) (const_int 0 [0])) pr46171.c:8 66 {*movqi_internal} (nil)) (call_insn 11 10 16 2 (set (reg:DF 21 xmm0) (call (mem:QI (symbol_ref:DI ("bard") [flags 0x41] <function_decl 0x7ffff16b2f00 bard>) [0 S1 A8]) (const_int 0 [0]))) pr46171.c:8 883 {*call_value_0_rex64} (expr_list:REG_UNUSED (reg:DF 21 xmm0) <--- (nil)) (expr_list:REG_DEP_TRUE (use (reg:QI 0 ax)) (nil))) (debug_insn 16 11 13 2 (var_location:DF D#1 (reg:DF 21 xmm0)) -1 (nil)) (debug_insn 13 16 0 2 (var_location:DF d (debug_expr:DF D#1)) pr46171.c:8 -1 (nil)) DF wants to add REG_UNUSED note, as xmm0 is never used afterwards and thus should be live just on a single insn. We don't do anything with the queued dead_debug references though, and up mixing DFmode xmm0 with SFmode xmm0 and ICE on trying to do a SFmode SUBREG from DFmode DEBUG_EXPR. Fixed by making sure we reset things when we are creating REG_UNUSED notes. Bootstrapped/regtested on x86_64-linux and i686-linux, dwarflint --check=locstats Jakub