diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/vrp48.c | 20 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 16 |
4 files changed, 45 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 51d848d..f8ee864 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2009-04-24 Richard Guenther <rguenther@suse.de> + + * tree-vrp.c (extract_range_from_binary_expr): Handle overflow + from unsigned additions. + 2009-04-24 Joseph Myers <joseph@codesourcery.com> * c-typeck.c (set_init_index): Allow array designators that are diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 083a7e3..e5b8fff 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2009-04-24 Richard Guenther <rguenther@suse.de> + + * gcc.dg/tree-ssa/vrp48.c: New testcase. + 2009-04-24 Joseph Myers <joseph@codesourcery.com> * gcc.dg/array-const-1.c, gcc.dg/array-const-2.c, diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp48.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp48.c new file mode 100644 index 0000000..a8cf8db --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp48.c @@ -0,0 +1,20 @@ +extern void link_failure (void); + +static int __attribute__ ((noinline)) foo (int x) +{ + if (x >= 1) + if (x <= 10) + { + if (x < 1 || x > 10) + link_failure (); + x = x + 1; + } + return x; +} + +int main (void) +{ + int i = foo (0); + return 0; +} + diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index e3d14b2..8464ffd 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -2248,6 +2248,22 @@ extract_range_from_binary_expr (value_range_t *vr, the same end of each range. */ min = vrp_int_const_binop (code, vr0.min, vr1.min); max = vrp_int_const_binop (code, vr0.max, vr1.max); + + /* If both additions overflowed the range kind is still correct. + This happens regularly with subtracting something in unsigned + arithmetic. + ??? See PR30318 for all the cases we do not handle. */ + if (code == PLUS_EXPR + && (TREE_OVERFLOW (min) && !is_overflow_infinity (min)) + && (TREE_OVERFLOW (max) && !is_overflow_infinity (max))) + { + min = build_int_cst_wide (TREE_TYPE (min), + TREE_INT_CST_LOW (min), + TREE_INT_CST_HIGH (min)); + max = build_int_cst_wide (TREE_TYPE (max), + TREE_INT_CST_LOW (max), + TREE_INT_CST_HIGH (max)); + } } else if (code == MULT_EXPR || code == TRUNC_DIV_EXPR |