From 1098d3a5510e41a94ce96feaa087f608112ea01b Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 8 Sep 2009 11:25:47 +0200
Subject: [PATCH] re PR rtl-optimization/41239 (Scheduler reorders division by
zero before a call that might not return)
PR rtl-optimization/41239
* sched-int.h (struct deps): Add last_function_call_may_noreturn field.
* sched-rgn.c (deps_join): Join also last_function_call_may_noreturn
lists.
* sched-deps.c (sched_analyze_insn): Prevent moving trapping insns
across calls, as the calls might not always return normally.
(call_may_noreturn_p): New function.
(deps_analyze_insn): Update last_function_call_may_noreturn list.
(init_deps): Initialize it.
(remove_from_deps): Also remove calls from
last_function_call_may_noreturn list.
* gcc.c-torture/execute/pr41239.c: New test.
From-SVN: r151500
---
gcc/ChangeLog | 14 +++
gcc/sched-deps.c | 91 ++++++++++++++++++-
gcc/sched-int.h | 6 ++
gcc/sched-rgn.c | 5 +
gcc/testsuite/ChangeLog | 5 +
gcc/testsuite/gcc.c-torture/execute/pr41239.c | 67 ++++++++++++++
6 files changed, 186 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr41239.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 66c0c145fa6e..bb965df4b390 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2009-09-08 Jakub Jelinek <jakub@redhat.com>
+
+ PR rtl-optimization/41239
+ * sched-int.h (struct deps): Add last_function_call_may_noreturn field.
+ * sched-rgn.c (deps_join): Join also last_function_call_may_noreturn
+ lists.
+ * sched-deps.c (sched_analyze_insn): Prevent moving trapping insns
+ across calls, as the calls might not always return normally.
+ (call_may_noreturn_p): New function.
+ (deps_analyze_insn): Update last_function_call_may_noreturn list.
+ (init_deps): Initialize it.
+ (remove_from_deps): Also remove calls from
+ last_function_call_may_noreturn list.
+
2009-09-07 Bernd Schmidt <bernd.schmidt@analog.com>
* config/bfin/bfin.md (UNSPEC_VOLATILE_STALL): New constant.
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index e9dac316e9a9..cef383a1d0eb 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -2598,6 +2598,12 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn)
can_start_lhs_rhs_p = (NONJUMP_INSN_P (insn)
&& code == SET);
+ if (may_trap_p (x))
+ /* Avoid moving trapping instructions accross function calls that might
+ not always return. */
+ add_dependence_list (insn, deps->last_function_call_may_noreturn,
+ 1, REG_DEP_ANTI);
+
if (code == COND_EXEC)
{
sched_analyze_2 (deps, COND_EXEC_TEST (x), insn);
@@ -3114,6 +3120,73 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn)
}
}
+/* Return TRUE if INSN might not always return normally (e.g. call exit,
+ longjmp, loop forever, ...). */
+static bool
+call_may_noreturn_p (rtx insn)
+{
+ rtx call;
+
+ /* const or pure calls that aren't looping will always return. */
+ if (RTL_CONST_OR_PURE_CALL_P (insn)
+ && !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn))
+ return false;
+
+ call = PATTERN (insn);
+ if (GET_CODE (call) == PARALLEL)
+ call = XVECEXP (call, 0, 0);
+ if (GET_CODE (call) == SET)
+ call = SET_SRC (call);
+ if (GET_CODE (call) == CALL
+ && MEM_P (XEXP (call, 0))
+ && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF)
+ {
+ rtx symbol = XEXP (XEXP (call, 0), 0);
+ if (SYMBOL_REF_DECL (symbol)
+ && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL)
+ {
+ if (DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol))
+ == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)))
+ {
+ case BUILT_IN_BCMP:
+ case BUILT_IN_BCOPY:
+ case BUILT_IN_BZERO:
+ case BUILT_IN_INDEX:
+ case BUILT_IN_MEMCHR:
+ case BUILT_IN_MEMCMP:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMMOVE:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_MEMSET:
+ case BUILT_IN_RINDEX:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPNCPY:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRCHR:
+ case BUILT_IN_STRCMP:
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRCSPN:
+ case BUILT_IN_STRLEN:
+ case BUILT_IN_STRNCAT:
+ case BUILT_IN_STRNCMP:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_STRPBRK:
+ case BUILT_IN_STRRCHR:
+ case BUILT_IN_STRSPN:
+ case BUILT_IN_STRSTR:
+ /* Assume certain string/memory builtins always return. */
+ return false;
+ default:
+ break;
+ }
+ }
+ }
+
+ /* For all other calls assume that they might not always return. */
+ return true;
+}
+
/* Analyze INSN with DEPS as a context. */
void
deps_analyze_insn (struct deps *deps, rtx insn)
@@ -3212,7 +3285,16 @@ deps_analyze_insn (struct deps *deps, rtx insn)
/* Remember the last function call for limiting lifetimes. */
free_INSN_LIST_list (&deps->last_function_call);
deps->last_function_call = alloc_INSN_LIST (insn, NULL_RTX);
-
+
+ if (call_may_noreturn_p (insn))
+ {
+ /* Remember the last function call that might not always return
+ normally for limiting moves of trapping insns. */
+ free_INSN_LIST_list (&deps->last_function_call_may_noreturn);
+ deps->last_function_call_may_noreturn
+ = alloc_INSN_LIST (insn, NULL_RTX);
+ }
+
/* Before reload, begin a post-call group, so as to keep the
lifetimes of hard registers correct. */
if (! reload_completed)
@@ -3366,6 +3448,7 @@ init_deps (struct deps *deps)
deps->pending_flush_length = 0;
deps->last_pending_memory_flush = 0;
deps->last_function_call = 0;
+ deps->last_function_call_may_noreturn = 0;
deps->sched_before_next_call = 0;
deps->in_post_call_group_p = not_post_call;
deps->last_debug_insn = 0;
@@ -3446,7 +3529,11 @@ remove_from_deps (struct deps *deps, rtx insn)
}
if (CALL_P (insn))
- remove_from_dependence_list (insn, &deps->last_function_call);
+ {
+ remove_from_dependence_list (insn, &deps->last_function_call);
+ remove_from_dependence_list (insn,
+ &deps->last_function_call_may_noreturn);
+ }
remove_from_dependence_list (insn, &deps->sched_before_next_call);
}
diff --git a/gcc/sched-int.h b/gcc/sched-int.h
index de780e5e395c..4d60ece28c9d 100644
--- a/gcc/sched-int.h
+++ b/gcc/sched-int.h
@@ -502,6 +502,12 @@ struct deps
Used to prevent register lifetimes from expanding unnecessarily. */
rtx last_function_call;
+ /* A list of the last function calls that may not return normally
+ we have seen. We use a list to represent last function calls from
+ multiple predecessor blocks. Used to prevent moving trapping insns
+ across such calls. */
+ rtx last_function_call_may_noreturn;
+
/* A list of insns which use a pseudo register that does not already
cross a call. We create dependencies between each of those insn
and the next call insn, to ensure that they won't cross a call after
diff --git a/gcc/sched-rgn.c b/gcc/sched-rgn.c
index ff559adcda53..de2dd0acd1d3 100644
--- a/gcc/sched-rgn.c
+++ b/gcc/sched-rgn.c
@@ -2645,6 +2645,11 @@ deps_join (struct deps *succ_deps, struct deps *pred_deps)
= concat_INSN_LIST (pred_deps->last_function_call,
succ_deps->last_function_call);
+ /* last_function_call_may_noreturn is inherited by successor. */
+ succ_deps->last_function_call_may_noreturn
+ = concat_INSN_LIST (pred_deps->last_function_call_may_noreturn,
+ succ_deps->last_function_call_may_noreturn);
+
/* sched_before_next_call is inherited by successor. */
succ_deps->sched_before_next_call
= concat_INSN_LIST (pred_deps->sched_before_next_call,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1c00a6bdb7a2..026f8a95d587 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-09-07 Jakub Jelinek <jakub@redhat.com>
+
+ PR rtl-optimization/41239
+ * gcc.c-torture/execute/pr41239.c: New test.
+
2009-09-07 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/41192
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr41239.c b/gcc/testsuite/gcc.c-torture/execute/pr41239.c
new file mode 100644
index 000000000000..9966b867c3b4
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr41239.c
@@ -0,0 +1,67 @@
+/* PR rtl-optimization/41239 */
+
+struct S
+{
+ short nargs;
+ unsigned long arg[2];
+};
+
+extern void abort (void);
+extern void exit (int);
+extern char fn1 (int, const char *, int, const char *, const char *);
+extern void fn2 (int, ...);
+extern int fn3 (int);
+extern int fn4 (const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
+
+unsigned long
+test (struct S *x)
+{
+ signed int arg1 = x->arg[0];
+ long int arg2 = x->arg[1];
+
+ if (arg2 == 0)
+ (fn1 (20, "foo", 924, __func__, ((void *) 0))
+ ? (fn2 (fn3 (0x2040082), fn4 ("division by zero")))
+ : (void) 0);
+
+ return (long int) arg1 / arg2;
+}
+
+int
+main (void)
+{
+ struct S s = { 2, { 5, 0 } };
+ test (&s);
+ abort ();
+}
+
+__attribute__((noinline)) char
+fn1 (int x, const char *y, int z, const char *w, const char *v)
+{
+ asm volatile ("" : : "r" (w), "r" (v) : "memory");
+ asm volatile ("" : "+r" (x) : "r" (y), "r" (z) : "memory");
+ return x;
+}
+
+__attribute__((noinline)) int
+fn3 (int x)
+{
+ asm volatile ("" : "+r" (x) : : "memory");
+ return x;
+}
+
+__attribute__((noinline)) int
+fn4 (const char *x, ...)
+{
+ asm volatile ("" : "+r" (x) : : "memory");
+ return *x;
+}
+
+__attribute__((noinline)) void
+fn2 (int x, ...)
+{
+ asm volatile ("" : "+r" (x) : : "memory");
+ if (x)
+ /* Could be a longjmp or throw too. */
+ exit (0);
+}
--
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