This patch fixes a common case where one line is distributed to 3 BBs,
but only 1 discriminator is assigned.
Bootstrapped and passed gcc regression test.
OK for trunk?
Thanks,
Dehao
gcc/ChangeLog:
* tree-cfg.c (locus_descrim_hasher::hash): Only hash lineno.
(locus_descrim_hasher::equal): Likewise.
(next_discriminator_for_locus): Likewise.
(assign_discriminator): Add return value.
(make_edges): Assign more discriminator if necessary.
(make_cond_expr_edges): Likewise.
(make_goto_expr_edges): Likewise.
gcc/testsuite/ChangeLog:
* gcc.dg/debug/dwarf2/discriminator.c: New Test.
Index: gcc/testsuite/gcc.dg/debug/dwarf2/discriminator.c
===================================================================
--- gcc/testsuite/gcc.dg/debug/dwarf2/discriminator.c (revision 0)
+++ gcc/testsuite/gcc.dg/debug/dwarf2/discriminator.c (revision 0)
@@ -0,0 +1,16 @@
+/* { dg-do compile { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-options "-O0 -gdwarf-2" } */
+/* { dg-final { scan-assembler "loc \[0-9] 9 \[0-9]( is_stmt \[0-9])?\n" } } */
+/* { dg-final { scan-assembler "loc \[0-9] 9 \[0-9]( is_stmt \[0-9])?
discriminator 2\n" } } */
+/* { dg-final { scan-assembler "loc \[0-9] 9 \[0-9]( is_stmt \[0-9])?
discriminator 1\n" } } */
+
+int foo(int n) {
+ int i, ret = 0;
+ for (i = 0; i < n; i++) {
+ if (i % 10 == 1)
+ ret++;
+ else
+ ret--;
+ }
+ return ret;
+}
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c (revision 198891)
+++ gcc/tree-cfg.c (working copy)
@@ -105,7 +105,7 @@ struct locus_descrim_hasher : typed_free_remove <l
inline hashval_t
locus_descrim_hasher::hash (const value_type *item)
{
- return item->locus;
+ return LOCATION_LINE (item->locus);
}
/* Equality function for the locus-to-discriminator map. A and B
@@ -114,7 +114,7 @@ locus_descrim_hasher::hash (const value_type *item
inline bool
locus_descrim_hasher::equal (const value_type *a, const compare_type *b)
{
- return a->locus == b->locus;
+ return LOCATION_LINE (a->locus) == LOCATION_LINE (b->locus);
}
static hash_table <locus_descrim_hasher> discriminator_per_locus;
@@ -129,7 +129,7 @@ static void make_cond_expr_edges (basic_block);
static void make_gimple_switch_edges (basic_block);
static void make_goto_expr_edges (basic_block);
static void make_gimple_asm_edges (basic_block);
-static void assign_discriminator (location_t, basic_block);
+static bool assign_discriminator (location_t, basic_block);
static edge gimple_redirect_edge_and_branch (edge, basic_block);
static edge gimple_try_redirect_by_replacing_jump (edge, basic_block);
static unsigned int split_critical_edges (void);
@@ -693,7 +693,8 @@ make_edges (void)
{
make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
if (last)
- assign_discriminator (gimple_location (last), bb->next_bb);
+ if (assign_discriminator (gimple_location (last), bb->next_bb))
+ assign_discriminator (gimple_location (last), bb);
}
}
@@ -717,7 +718,8 @@ next_discriminator_for_locus (location_t locus)
item.locus = locus;
item.discriminator = 0;
- slot = discriminator_per_locus.find_slot_with_hash (&item, locus, INSERT);
+ slot = discriminator_per_locus.find_slot_with_hash (
+ &item, LOCATION_LINE (locus), INSERT);
gcc_assert (slot);
if (*slot == HTAB_EMPTY_ENTRY)
{
@@ -753,21 +755,29 @@ same_line_p (location_t locus1, location_t locus2)
}
/* Assign a unique discriminator value to block BB if it begins at the same
- LOCUS as its predecessor block. */
+ LOCUS as its pred/succ block. Return true if discriminator has already
+ been assigned for BB and needs to assign additional discriminator for
+ BB's predecessor. */
-static void
+static bool
assign_discriminator (location_t locus, basic_block bb)
{
gimple first_in_to_bb, last_in_to_bb;
- if (locus == 0 || bb->discriminator != 0)
- return;
+ if (locus == 0)
+ return false;
first_in_to_bb = first_non_label_stmt (bb);
last_in_to_bb = last_stmt (bb);
if ((first_in_to_bb && same_line_p (locus, gimple_location (first_in_to_bb)))
|| (last_in_to_bb && same_line_p (locus, gimple_location
(last_in_to_bb))))
- bb->discriminator = next_discriminator_for_locus (locus);
+ {
+ if (bb->discriminator != 0)
+ return true;
+ else
+ bb->discriminator = next_discriminator_for_locus (locus);
+ }
+ return false;
}
/* Create the edges for a GIMPLE_COND starting at block BB. */
@@ -796,12 +806,14 @@ make_cond_expr_edges (basic_block bb)
else_stmt = first_stmt (else_bb);
e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
- assign_discriminator (entry_locus, then_bb);
+ if (assign_discriminator (entry_locus, then_bb))
+ assign_discriminator (entry_locus, bb);
e->goto_locus = gimple_location (then_stmt);
e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
if (e)
{
- assign_discriminator (entry_locus, else_bb);
+ if (assign_discriminator (entry_locus, else_bb))
+ assign_discriminator (entry_locus, bb);
e->goto_locus = gimple_location (else_stmt);
}
@@ -1020,7 +1032,8 @@ make_goto_expr_edges (basic_block bb)
basic_block label_bb = label_to_block (dest);
edge e = make_edge (bb, label_bb, EDGE_FALLTHRU);
e->goto_locus = gimple_location (goto_t);
- assign_discriminator (e->goto_locus, label_bb);
+ if (assign_discriminator (e->goto_locus, label_bb))
+ assign_discriminator (e->goto_locus, bb);
gsi_remove (&last, true);
return;
}
