This reverts the group_case_labels_stmt part of r8-546-gca4d2851687875.
This is placed in the wrong location to remove the case statements that go
directly to __builtin_unreachable. In fact the removal of the case statements
make us lose optimizations in some cases (Wuninitialized-pr107919-1.C for one).
Also this fixes PR 125290 by no longer leaving around a switch which just
has a default case.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/125290
gcc/ChangeLog:
* tree-cfg.cc (group_case_labels_stmt): Remove code that was
added to remove `cases` that goto blocks of unreachable.
* tree-ssa-forwprop.cc (optimize_unreachable): Remove the
comment about switch cases being handled.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wuninitialized-pr107919-1.C: Remove xfail.
* gcc.dg/analyzer/taint-assert.c: Update for the non-removal
of block containing unreachable.
* gcc.dg/torture/pr125290-1.c: New test.
Signed-off-by: Andrew Pinski <[email protected]>
---
.../g++.dg/warn/Wuninitialized-pr107919-1.C | 2 +-
gcc/testsuite/gcc.dg/analyzer/taint-assert.c | 4 +-
gcc/testsuite/gcc.dg/torture/pr125290-1.c | 40 +++++++++++++++
gcc/tree-cfg.cc | 51 +------------------
gcc/tree-ssa-forwprop.cc | 3 +-
5 files changed, 46 insertions(+), 54 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr125290-1.c
diff --git a/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
b/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
index 049fa4d307a..b3ed4628bdd 100644
--- a/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
+++ b/gcc/testsuite/g++.dg/warn/Wuninitialized-pr107919-1.C
@@ -14,4 +14,4 @@ void do_something(void* storage)
std::swap(event, swappedValue);
}
-// { dg-bogus "may be used uninitialized" "" { xfail *-*-* } 0 }
+// { dg-bogus "may be used uninitialized" "" 0 }
diff --git a/gcc/testsuite/gcc.dg/analyzer/taint-assert.c
b/gcc/testsuite/gcc.dg/analyzer/taint-assert.c
index a858e996a80..e46cbe95801 100644
--- a/gcc/testsuite/gcc.dg/analyzer/taint-assert.c
+++ b/gcc/testsuite/gcc.dg/analyzer/taint-assert.c
@@ -322,8 +322,8 @@ test_switch_bogus_case_unreachable (int n)
case 2:
return -1;
case 42:
- /* This case gets optimized away before we see it. */
- __builtin_unreachable ();
+ /* The wording is rather inaccurate here. */
+ __builtin_unreachable (); /* { dg-warning "use of attacked-controlled
value in condition for assertion" } */
}
}
diff --git a/gcc/testsuite/gcc.dg/torture/pr125290-1.c
b/gcc/testsuite/gcc.dg/torture/pr125290-1.c
new file mode 100644
index 00000000000..6183cbd2681
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr125290-1.c
@@ -0,0 +1,40 @@
+/* PR tree-optimization/125290 */
+/* { dg-do compile } */
+
+int g21;
+int g31, f14f16_c12;
+void f14f16()
+{
+ short v7;
+ long v9;
+ long v13;
+ if (g31)
+ {
+ g21 = 0;
+ switch (v7)
+ {
+ case 4:
+ case 66: break;
+ default: __builtin_unreachable();
+ }
+ }
+ else
+ {
+ lbl_bf2:
+ v9 = g21;
+ }
+ v13 = v9;
+ switch (v13)
+ {
+ case 55:
+ case 2: goto lbl_sw12;
+ default:
+ if (f14f16_c12)
+ goto lbl_bf2;
+ else
+ return;
+ }
+lbl_sw12:
+ __builtin_unreachable();
+}
+
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index b2968c412ed..5f751e15d9d 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -1712,7 +1712,6 @@ group_case_labels_stmt (gswitch *stmt)
int old_size = gimple_switch_num_labels (stmt);
int i, next_index, new_size;
basic_block default_bb = NULL;
- hash_set<tree> *removed_labels = NULL;
default_bb = gimple_switch_default_bb (cfun, stmt);
@@ -1728,12 +1727,9 @@ group_case_labels_stmt (gswitch *stmt)
gcc_assert (base_case);
base_bb = label_to_block (cfun, CASE_LABEL (base_case));
- /* Discard cases that have the same destination as the default case or
- whose destination blocks have already been removed as unreachable. */
+ /* Discard cases that have the same destination as the default case. */
if (base_bb == NULL
- || base_bb == default_bb
- || (removed_labels
- && removed_labels->contains (CASE_LABEL (base_case))))
+ || base_bb == default_bb)
{
i++;
continue;
@@ -1756,8 +1752,6 @@ group_case_labels_stmt (gswitch *stmt)
/* Merge the cases if they jump to the same place,
and their ranges are consecutive. */
if (merge_bb == base_bb
- && (removed_labels == NULL
- || !removed_labels->contains (CASE_LABEL (merge_case)))
&& wi::to_wide (CASE_LOW (merge_case)) == bhp1)
{
base_high
@@ -1770,46 +1764,6 @@ group_case_labels_stmt (gswitch *stmt)
break;
}
- /* Discard cases that have an unreachable destination block. */
- if (EDGE_COUNT (base_bb->succs) == 0
- && gimple_seq_unreachable_p (bb_seq (base_bb))
- /* Don't optimize this if __builtin_unreachable () is the
- implicitly added one by the C++ FE too early, before
- -Wreturn-type can be diagnosed. We'll optimize it later
- during switchconv pass or any other cfg cleanup. */
- && (gimple_in_ssa_p (cfun)
- || (LOCATION_LOCUS (gimple_location (last_nondebug_stmt
(base_bb)))
- != BUILTINS_LOCATION)))
- {
- edge base_edge = find_edge (gimple_bb (stmt), base_bb);
- if (base_edge != NULL)
- {
- for (gimple_stmt_iterator gsi = gsi_start_bb (base_bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
- if (glabel *stmt = dyn_cast <glabel *> (gsi_stmt (gsi)))
- {
- if (FORCED_LABEL (gimple_label_label (stmt))
- || DECL_NONLOCAL (gimple_label_label (stmt)))
- {
- /* Forced/non-local labels aren't going to be removed,
- but they will be moved to some neighbouring basic
- block. If some later case label refers to one of
- those labels, we should throw that case away rather
- than keeping it around and referring to some random
- other basic block without an edge to it. */
- if (removed_labels == NULL)
- removed_labels = new hash_set<tree>;
- removed_labels->add (gimple_label_label (stmt));
- }
- }
- else
- break;
- remove_edge_and_dominated_blocks (base_edge);
- }
- i = next_index;
- continue;
- }
-
if (new_size < i)
gimple_switch_set_label (stmt, new_size,
gimple_switch_label (stmt, i));
@@ -1822,7 +1776,6 @@ group_case_labels_stmt (gswitch *stmt)
if (new_size < old_size)
gimple_switch_set_num_labels (stmt, new_size);
- delete removed_labels;
return new_size < old_size;
}
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 0d76f85e2ac..a45ca961ec8 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -5262,8 +5262,7 @@ optimize_unreachable (basic_block bb)
}
else
{
- /* Todo: handle other cases. Note that unreachable switch case
- statements have already been removed. */
+ /* Todo: handle other cases. e.g. switch. */
continue;
}
--
2.43.0
