tree-ssa-operands.c (add_virtual_operand): Consistently prune accesses.

2007-11-20  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-operands.c (add_virtual_operand): Consistently prune
	accesses.

	* gcc.c-torture/execute/20071120-1.c: New testcase.

From-SVN: r130315

gcc/ChangeLog

@@ -1,3 +1,8 @@
+2007-11-20  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-operands.c (add_virtual_operand): Consistently prune
+	accesses.
+
 2007-11-20  Thiemo Seufer  <ths@mips.com>
 
 	* config/mips/mips.c (mips_file_start): Add support for

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2007-11-20  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.c-torture/execute/20071120-1.c: New testcase.
+
 2007-11-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/34146

gcc/testsuite/gcc.c-torture/execute/20071120-1.c

@@ -0,0 +1,81 @@
+extern void abort (void);
+
+void __attribute__((noinline,noreturn))
+vec_assert_fail (void)
+{
+    abort ();
+}
+
+struct ggc_root_tab {
+    void *base;
+};
+
+typedef struct deferred_access_check {} VEC_deferred_access_check_gc;
+
+typedef struct deferred_access {
+    VEC_deferred_access_check_gc* deferred_access_checks;
+    int deferring_access_checks_kind;
+} deferred_access;
+
+typedef struct VEC_deferred_access_base {
+    unsigned num;
+    deferred_access vec[1];
+} VEC_deferred_access_base;
+
+static __inline__ deferred_access *
+VEC_deferred_access_base_last (VEC_deferred_access_base *vec_)
+{
+    (void)((vec_ && vec_->num) ? 0 : (vec_assert_fail (), 0));
+    return &vec_->vec[vec_->num - 1];
+}
+
+static __inline__  void
+VEC_deferred_access_base_pop (VEC_deferred_access_base *vec_)
+{
+    (void)((vec_->num) ? 0 : (vec_assert_fail (), 0));
+    --vec_->num;
+}
+
+void __attribute__((noinline))
+perform_access_checks (VEC_deferred_access_check_gc* p)
+{
+    abort ();
+}
+
+typedef struct VEC_deferred_access_gc {
+    VEC_deferred_access_base base;
+} VEC_deferred_access_gc;
+
+static VEC_deferred_access_gc *deferred_access_stack;
+static unsigned deferred_access_no_check;
+
+const struct ggc_root_tab gt_pch_rs_gt_cp_semantics_h[] = {
+    {
+	&deferred_access_no_check
+    }
+};
+
+void __attribute__((noinline)) pop_to_parent_deferring_access_checks (void)
+{
+    if (deferred_access_no_check)
+	deferred_access_no_check--;
+    else
+    {
+        VEC_deferred_access_check_gc *checks;
+        deferred_access *ptr;
+	checks = (VEC_deferred_access_base_last(deferred_access_stack ? &deferred_access_stack->base : 0))->deferred_access_checks;
+        VEC_deferred_access_base_pop(deferred_access_stack ? &deferred_access_stack->base : 0);
+        ptr = VEC_deferred_access_base_last(deferred_access_stack ? &deferred_access_stack->base : 0);
+        if (ptr->deferring_access_checks_kind == 0)
+	    perform_access_checks (checks);
+    }
+}
+
+int main()
+{
+    deferred_access_stack = __builtin_malloc (sizeof(VEC_deferred_access_gc) + sizeof(deferred_access) * 8);
+    deferred_access_stack->base.num = 2;
+    deferred_access_stack->base.vec[0].deferring_access_checks_kind = 1;
+    pop_to_parent_deferring_access_checks ();
+    return 0;
+}

gcc/tree-ssa-operands.c

@@ -1531,7 +1531,6 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
 		 unspecified [0, -1], we cannot prune it.  Otherwise try doing
 		 so using access_can_touch_variable.  */
 	      if (full_ref
-		  && !(offset == 0 && size == -1)
 		  && !access_can_touch_variable (full_ref, al, offset, size))
 		continue;