This fixes PR49218 - we have to be careful to catch all overflow cases
when forcing a signed/unsigned double-int to a tree.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk
and branch.
Richard.
2011-05-30 Richard Guenther <rguent...@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.
Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c (revision 174427)
--- gcc/tree-vrp.c (working copy)
*************** adjust_range_with_scev (value_range_t *v
*** 3423,3433 ****
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)))
{
extract_range_from_binary_expr (&maxvr, PLUS_EXPR,
TREE_TYPE (init), init, tem);
/* Likewise if the addition did. */
--- 3423,3439 ----
loop->nb_iterations_upper_bound,
double_int_one),
unsigned_p, &overflow);
/* If the multiplication overflowed we can't do a meaningful
! 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. */
Index: gcc/testsuite/gcc.c-torture/execute/pr49218.c
===================================================================
*** gcc/testsuite/gcc.c-torture/execute/pr49218.c (revision 0)
--- gcc/testsuite/gcc.c-torture/execute/pr49218.c (revision 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;
+ }
