re PR target/35659 (Miscompiled code with -O2 (but not with -O2 -funroll-loops) on ia64)

	PR target/35659
	* haifa-sched.c (sched_insn_is_legitimate_for_speculation_p): Move ...
	* sched-deps.c (sched_insn_is_legitimate_for_speculation_p): ... here.
	Don't allow predicated instructions for data speculation.
	* sched-int.h (sched_insn_is_legitimate_for_speculation_p): Move
	declaration.

From-SVN: r138759

4 files changed, 50 insertions, 27 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fb23834..7b50bdf 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,14 @@
 2008-08-06  Maxim Kuvyrkov  <maxim@codesourcery.com>
 
+	PR target/35659
+	* haifa-sched.c (sched_insn_is_legitimate_for_speculation_p): Move ...
+	* sched-deps.c (sched_insn_is_legitimate_for_speculation_p): ... here.
+	Don't allow predicated instructions for data speculation.
+	* sched-int.h (sched_insn_is_legitimate_for_speculation_p): Move
+	declaration.
+
+2008-08-06  Maxim Kuvyrkov  <maxim@codesourcery.com>
+
 	* haifa-sched.c (extend_global): Split to extend_global_data and
 	extend_region_data.  Update all uses.
 	(extend_all): Rename to extend_block_data.
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index db1d66f..76282bd 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -4019,32 +4019,6 @@ change_pattern (rtx insn, rtx new_pat)
   dfa_clear_single_insn_cache (insn);
 }
 
-/* Return true if INSN can potentially be speculated with type DS.  */
-bool
-sched_insn_is_legitimate_for_speculation_p (const_rtx insn, ds_t ds)
-{
-  if (HAS_INTERNAL_DEP (insn))
-    return false;
-
-  if (!NONJUMP_INSN_P (insn))
-    return false;
-
-  if (SCHED_GROUP_P (insn))
-    return false;
-
-  if (IS_SPECULATION_CHECK_P (insn))
-    return false;
-
-  if (side_effects_p (PATTERN (insn)))
-    return false;
-
-  if ((ds & BE_IN_SPEC)
-      && may_trap_p (PATTERN (insn)))
-    return false;
-
-  return true;
-}
-
 /* -1 - can't speculate,
    0 - for speculation with REQUEST mode it is OK to use
    current instruction pattern,
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index b8b3a44..bbd7a36 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -536,6 +536,46 @@ sched_insns_conditions_mutex_p (const_rtx insn1, const_rtx insn2)
 }
 
 
+/* Return true if INSN can potentially be speculated with type DS.  */
+bool
+sched_insn_is_legitimate_for_speculation_p (const_rtx insn, ds_t ds)
+{
+  if (HAS_INTERNAL_DEP (insn))
+    return false;
+
+  if (!NONJUMP_INSN_P (insn))
+    return false;
+
+  if (SCHED_GROUP_P (insn))
+    return false;
+
+  if (IS_SPECULATION_CHECK_P (insn))
+    return false;
+
+  if (side_effects_p (PATTERN (insn)))
+    return false;
+
+  if (ds & BE_IN_SPEC)
+    /* The following instructions, which depend on a speculatively scheduled
+       instruction, cannot be speculatively scheduled along.  */
+    {
+      if (may_trap_p (PATTERN (insn)))
+	/* If instruction might trap, it cannot be speculatively scheduled.
+	   For control speculation it's obvious why and for data speculation
+	   it's because the insn might get wrong input if speculation
+	   wasn't successful.  */
+	return false;
+
+      if ((ds & BE_IN_DATA)
+	  && sched_get_condition (insn) != NULL_RTX)
+	/* If this is a predicated instruction, then it cannot be
+	   speculatively scheduled.  See PR35659.  */
+	return false;
+    }
+
+  return true;
+}
+
 /* Initialize LIST_PTR to point to one of the lists present in TYPES_PTR,
    initialize RESOLVED_P_PTR with true if that list consists of resolved deps,
    and remove the type of returned [through LIST_PTR] list from TYPES_PTR.
diff --git a/gcc/sched-int.h b/gcc/sched-int.h
index f2e39bf..bfbb861 100644
--- a/gcc/sched-int.h
+++ b/gcc/sched-int.h
@@ -805,6 +805,7 @@ enum INSN_TRAP_CLASS
 
 /* Functions in sched-deps.c.  */
 extern bool sched_insns_conditions_mutex_p (const_rtx, const_rtx);
+extern bool sched_insn_is_legitimate_for_speculation_p (const_rtx, ds_t);
 extern void add_dependence (rtx, rtx, enum reg_note);
 extern void sched_analyze (struct deps *, rtx, rtx);
 extern bool deps_pools_are_empty_p (void);
@@ -838,7 +839,6 @@ extern void sched_finish (void);
 
 extern int try_ready (rtx);
 extern void * xrecalloc (void *, size_t, size_t, size_t);
-extern bool sched_insn_is_legitimate_for_speculation_p (const_rtx, ds_t);
 extern void unlink_bb_notes (basic_block, basic_block);
 extern void add_block (basic_block, basic_block);
 extern rtx bb_note (basic_block);