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[PATCH] Fix ipa-pure-const can_throw propagation
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jan Hubicka <hubicka at ucw dot cz>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 12 Nov 2014 23:36:00 +0100
- Subject: [PATCH] Fix ipa-pure-const can_throw propagation
- Authentication-results: sourceware.org; auth=none
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
The following testcase is miscompiled starting with 4.6.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
For 4.9/4.8, I'd prefer to use a one-liner instead:
- for (ie = node->indirect_calls; ie; ie = ie->next_callee)
+ for (ie = w->indirect_calls; ie; ie = ie->next_callee)
2014-11-12 Jakub Jelinek <jakub@redhat.com>
PR ipa/63838
* ipa-pure-const.c (propagate_nothrow): Walk w->indirect_calls
chain instead of node->indirect_calls. Put !can_throw into
conditions of all the loops.
* g++.dg/ipa/pr63838.C: New test.
--- gcc/ipa-pure-const.c.jj 2014-11-11 00:06:11.000000000 +0100
+++ gcc/ipa-pure-const.c 2014-11-12 18:32:56.351139726 +0100
@@ -1448,7 +1448,7 @@ propagate_nothrow (void)
/* Find the worst state for any node in the cycle. */
w = node;
- while (w)
+ while (w && !can_throw)
{
struct cgraph_edge *e, *ie;
funct_state w_l = get_function_state (w);
@@ -1457,10 +1457,7 @@ propagate_nothrow (void)
|| w->get_availability () == AVAIL_INTERPOSABLE)
can_throw = true;
- if (can_throw)
- break;
-
- for (e = w->callees; e; e = e->next_callee)
+ for (e = w->callees; e && !can_throw; e = e->next_callee)
{
enum availability avail;
struct cgraph_node *y = e->callee->function_symbol (&avail);
@@ -1469,8 +1466,6 @@ propagate_nothrow (void)
{
funct_state y_l = get_function_state (y);
- if (can_throw)
- break;
if (y_l->can_throw && !TREE_NOTHROW (w->decl)
&& e->can_throw_external)
can_throw = true;
@@ -1478,12 +1473,9 @@ propagate_nothrow (void)
else if (e->can_throw_external && !TREE_NOTHROW (y->decl))
can_throw = true;
}
- for (ie = node->indirect_calls; ie; ie = ie->next_callee)
+ for (ie = w->indirect_calls; ie && !can_throw; ie = ie->next_callee)
if (ie->can_throw_external)
- {
- can_throw = true;
- break;
- }
+ can_throw = true;
w_info = (struct ipa_dfs_info *) w->aux;
w = w_info->next_cycle;
}
@@ -1794,5 +1786,3 @@ make_pass_warn_function_noreturn (gcc::c
{
return new pass_warn_function_noreturn (ctxt);
}
-
-
--- gcc/testsuite/g++.dg/ipa/pr63838.C.jj 2014-11-12 19:48:50.403403040 +0100
+++ gcc/testsuite/g++.dg/ipa/pr63838.C 2014-11-12 19:48:59.650247907 +0100
@@ -0,0 +1,56 @@
+// PR ipa/63838
+// { dg-do run }
+// { dg-options "-O2 -fdump-ipa-pure-const" }
+// { dg-final { scan-ipa-dump-not "Function found to be nothrow: void foo" "pure-const" } }
+// { dg-final { scan-ipa-dump-not "Function found to be nothrow: void bar" "pure-const" } }
+// { dg-final { cleanup-ipa-dump "pure-const" } }
+
+__attribute__((noinline, noclone)) static void bar (int);
+volatile int v;
+void (*fn) ();
+struct S { S () { v++; } ~S () { v++; } };
+
+__attribute__((noinline, noclone)) static void
+foo (int x)
+{
+ v++;
+ if (x == 5)
+ bar (x);
+}
+
+__attribute__((noinline, noclone)) static void
+bar (int x)
+{
+ v++;
+ if (x == 6)
+ foo (x);
+ else if (x == 5)
+ fn ();
+}
+
+__attribute__((noinline, noclone)) int
+baz (int x)
+{
+ S s;
+ foo (x);
+}
+
+void
+throw0 ()
+{
+ throw 0;
+}
+
+int
+main ()
+{
+ fn = throw0;
+ asm volatile ("" : : : "memory");
+ try
+ {
+ baz (5);
+ }
+ catch (int)
+ {
+ }
+}
Jakub