This fixes PR50729, so much for not implementing it by using
value-ranges ... opens up the door for more bugs ;)
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2011-10-17 Richard Guenther <rguent...@suse.de>
PR tree-optimization/50729
* tree-vrp.c (extract_range_from_unary_expr_1): Remove
redundant test.
(simplify_conversion_using_ranges): Properly test the
intermediate result.
* gcc.dg/torture/pr50729.c: New testcase.
Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c (revision 180077)
--- gcc/tree-vrp.c (working copy)
*************** extract_range_from_unary_expr_1 (value_r
*** 2913,2927 ****
determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
if (POINTER_TYPE_P (type))
{
! if (CONVERT_EXPR_CODE_P (code))
! {
! if (range_is_nonnull (&vr0))
! set_value_range_to_nonnull (vr, type);
! else if (range_is_null (&vr0))
! set_value_range_to_null (vr, type);
! else
! set_value_range_to_varying (vr);
! }
else
set_value_range_to_varying (vr);
return;
--- 2913,2922 ----
determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
if (POINTER_TYPE_P (type))
{
! if (range_is_nonnull (&vr0))
! set_value_range_to_nonnull (vr, type);
! else if (range_is_null (&vr0))
! set_value_range_to_null (vr, type);
else
set_value_range_to_varying (vr);
return;
*************** simplify_conversion_using_ranges (gimple
*** 7288,7297 ****
TYPE_UNSIGNED (TREE_TYPE (middleop)));
middlemax = double_int_ext (innermax, TYPE_PRECISION (TREE_TYPE (middleop)),
TYPE_UNSIGNED (TREE_TYPE (middleop)));
! /* If the middle values do not represent a proper range fail. */
! if (double_int_cmp (middlemin, middlemax,
! TYPE_UNSIGNED (TREE_TYPE (middleop))) > 0)
return false;
if (!double_int_equal_p (double_int_ext (middlemin,
TYPE_PRECISION (finaltype),
TYPE_UNSIGNED (finaltype)),
--- 7283,7299 ----
TYPE_UNSIGNED (TREE_TYPE (middleop)));
middlemax = double_int_ext (innermax, TYPE_PRECISION (TREE_TYPE (middleop)),
TYPE_UNSIGNED (TREE_TYPE (middleop)));
! /* If the middle values are not equal to the original values fail.
! But only if the inner cast truncates (thus we ignore differences
! in extension to handle the case going from a range to an anti-range
! and back). */
! if ((TYPE_PRECISION (TREE_TYPE (innerop))
! > TYPE_PRECISION (TREE_TYPE (middleop)))
! && (!double_int_equal_p (innermin, middlemin)
! || !double_int_equal_p (innermax, middlemax)))
return false;
+ /* Require that the final conversion applied to both the original
+ and the intermediate range produces the same result. */
if (!double_int_equal_p (double_int_ext (middlemin,
TYPE_PRECISION (finaltype),
TYPE_UNSIGNED (finaltype)),
Index: gcc/testsuite/gcc.dg/torture/pr50729.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr50729.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr50729.c (revision 0)
***************
*** 0 ****
--- 1,20 ----
+ /* { dg-do run } */
+ /* { dg-require-effective-target int32plus } */
+
+ extern void abort (void);
+ unsigned short __attribute__((noinline))
+ foo (int i)
+ {
+ if (i >= 0
+ && i <= 0x400000)
+ return (unsigned short)(signed char)i;
+ return i;
+ }
+ int main()
+ {
+ int i;
+ for (i = 0; i < 0xffff; ++i)
+ if (foo(i) != (unsigned short)(signed char) i)
+ abort ();
+ return 0;
+ }
