diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c133aac33657170e8609fa44d0f6d0cca3f18b0d..8065b245164239ddf0d70d48ab4f6a021b4ef25a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2010-01-03 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/42438
+ * tree-ssa-pre.c (struct bb_bitmap_sets): Add
+ contains_may_not_return_call flag.
+ (BB_MAY_NOTRETURN): New.
+ (valid_in_sets): Trapping nary operations are not valid
+ in blocks that may not return.
+ (insert_into_preds_of_block): Remove check for trapping
+ expressions.
+ (compute_avail): Compute also BB_MAY_NOTRETURN.
+
2010-01-03 Gerald Pfeifer <gerald@pfeifer.com>
* doc/invoke.texi: Add 2010 to copyright years.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d1580faf8930bfb1ea5ecbdad17d41059a8c9bdb..609589ca072ddd2cedb8f8c757d76551237067c0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-01-03 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/42438
+ * gcc.dg/tree-ssa/ssa-pre-27.c: New testcase.
+
2010-01-02 Richard Guenther <rguenther@suse.de>
PR testsuite/41651
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-27.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-27.c
new file mode 100644
index 0000000000000000000000000000000000000000..1d60a30132076262bf4d0d923938bd114eb9d740
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-27.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-pre" } */
+
+int foo (int i, int j, int b)
+{
+ int res = 0;
+ if (b)
+ res = i/j;
+ /* We should insert the possibly trapping i/j. */
+ res += i/j;
+ return res;
+}
+
+extern void bar (void);
+int foo2 (int i, int j, int b)
+{
+ int res = 0;
+ if (b)
+ res = i/j;
+ /* But we fail so here because of the possibly not returning
+ call in the same basic-block. */
+ res += i/j;
+ bar ();
+ return res;
+}
+
+/* { dg-final { scan-tree-dump-times "# prephitmp" 1 "pre" } } */
+/* { dg-final { scan-tree-dump-times "# prephitmp" 2 "pre" { xfail *-*-* } } } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 52e973fadb6835184efa490972da89904be7c8fe..7d9b9bf32d0bb31130f3cb31a0fcde3483e73bfa 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -382,11 +382,14 @@ typedef struct bb_bitmap_sets
bitmap expr_dies;
/* True if we have visited this block during ANTIC calculation. */
- unsigned int visited:1;
+ unsigned int visited : 1;
/* True we have deferred processing this block during ANTIC
calculation until its successor is processed. */
unsigned int deferred : 1;
+
+ /* True when the block contains a call that might not return. */
+ unsigned int contains_may_not_return_call : 1;
} *bb_value_sets_t;
#define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
@@ -399,6 +402,7 @@ typedef struct bb_bitmap_sets
#define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
#define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
#define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
+#define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
/* Basic block list in postorder. */
@@ -2032,6 +2036,13 @@ valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr,
return false;
}
}
+ /* If the NARY may trap make sure the block does not contain
+ a possible exit point.
+ ??? This is overly conservative if we translate AVAIL_OUT
+ as the available expression might be after the exit point. */
+ if (BB_MAY_NOTRETURN (block)
+ && vn_nary_may_trap (nary))
+ return false;
return true;
}
break;
@@ -2469,6 +2480,7 @@ compute_antic (void)
BB_VISITED (block) = 0;
BB_DEFERRED (block) = 0;
+
/* While we are here, give empty ANTIC_IN sets to each block. */
ANTIC_IN (block) = bitmap_set_new ();
PA_IN (block) = bitmap_set_new ();
@@ -3187,16 +3199,6 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
}
}
- /* Make sure we are not inserting trapping expressions. */
- FOR_EACH_EDGE (pred, ei, block->preds)
- {
- bprime = pred->src;
- eprime = avail[bprime->index];
- if (eprime->kind == NARY
- && vn_nary_may_trap (PRE_EXPR_NARY (eprime)))
- return false;
- }
-
/* Make the necessary insertions. */
FOR_EACH_EDGE (pred, ei, block->preds)
{
@@ -3804,6 +3806,8 @@ compute_avail (void)
for (gsi = gsi_start_phis (block); !gsi_end_p (gsi); gsi_next (&gsi))
make_values_for_phi (gsi_stmt (gsi), block);
+ BB_MAY_NOTRETURN (block) = 0;
+
/* Now compute value numbers and populate value sets with all
the expressions computed in BLOCK. */
for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi))
@@ -3814,6 +3818,23 @@ compute_avail (void)
stmt = gsi_stmt (gsi);
gimple_set_uid (stmt, stmt_uid++);
+ /* Cache whether the basic-block has any non-visible side-effect
+ or control flow.
+ If this isn't a call or it is the last stmt in the
+ basic-block then the CFG represents things correctly. */
+ if (is_gimple_call (stmt)
+ && !stmt_ends_bb_p (stmt))
+ {
+ /* Non-looping const functions always return normally.
+ Otherwise the call might not return or have side-effects
+ that forbids hoisting possibly trapping expressions
+ before it. */
+ int flags = gimple_call_flags (stmt);
+ if (!(flags & ECF_CONST)
+ || (flags & ECF_LOOPING_CONST_OR_PURE))
+ BB_MAY_NOTRETURN (block) = 1;
+ }
+
FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
{
pre_expr e = get_or_alloc_expr_for_name (op);