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From e6b2e8c99b9295953acd13658d44591561252337 Mon Sep 17 00:00:00 2001
From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 30 May 2011 11:17:35 +0000
Subject: [PATCH] 2011-05-30 Richard Guenther <rguenther@suse.de>
PR tree-optimization/49218
* tree-vrp.c (adjust_range_with_scev): Properly check whether
overflow occured.
* gcc.c-torture/execute/pr49218.c: New testcase.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@174430 138bc75d-0d04-0410-961f-82ee72b054a4
index 2f50595..be083fc 100644
new file mode 100644
index 0000000..2fb18dd
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr49218.c
@@ -0,0 +1,20 @@
+#ifdef __SIZEOF_INT128__
+typedef __int128 L;
+#else
+typedef long long L;
+#endif
+float f;
+
+int
+main ()
+{
+ L i = f;
+ if (i <= 10)
+ do
+ {
+ ++i;
+ asm ("");
+ }
+ while (i != 11);
+ return 0;
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 6914a08..299a948 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -3422,11 +3422,17 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop,
loop->nb_iterations_upper_bound,
double_int_one),
unsigned_p, &overflow);
- tem = double_int_to_tree (TREE_TYPE (init), dtmp);
/* If the multiplication overflowed we can't do a meaningful
- adjustment. */
- if (!overflow && double_int_equal_p (dtmp, tree_to_double_int (tem)))
- {
+ adjustment. Likewise if the result doesn't fit in the type
+ of the induction variable. For a signed type we have to
+ check whether the result has the expected signedness which
+ is that of the step as nb_iterations_upper_bound is unsigned. */
+ if (!overflow
+ && double_int_fits_to_tree_p (TREE_TYPE (init), dtmp)
+ && (unsigned_p
+ || ((dtmp.high ^ TREE_INT_CST_HIGH (step)) >= 0)))
+ {
+ tem = double_int_to_tree (TREE_TYPE (init), dtmp);
extract_range_from_binary_expr (&maxvr, PLUS_EXPR,
TREE_TYPE (init), init, tem);
/* Likewise if the addition did. */
--
1.7.0.4
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