It folds -C*ABS<n> to ABS<-C*n>. Anyone else thinks this function needs
to go? :/
Bootstrapped & tested on x86_64-unknown-linux-gnu, applied to mainline.
Richard.
2007-11-17 Richard Guenther <
rguenther@...>
PR middle-end/34130
* fold-const.c (extract_muldiv_1): Do not move negative
constants inside ABS_EXPR.
* gcc.c-torture/execute/pr34130.c: New testcase.
Index: fold-const.c
===================================================================
*** fold-const.c (revision 130238)
--- fold-const.c (working copy)
*************** extract_muldiv_1 (tree t, tree c, enum t
*** 6095,6100 ****
--- 6095,6103 ----
}
break;
}
+ /* If the constant is negative, we cannot simplify this. */
+ if (tree_int_cst_sgn (c) == -1)
+ break;
/* FALLTHROUGH */
case NEGATE_EXPR:
if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
Index: testsuite/gcc.c-torture/execute/pr34130.c
===================================================================
*** testsuite/gcc.c-torture/execute/pr34130.c (revision 0)
--- testsuite/gcc.c-torture/execute/pr34130.c (revision 0)
***************
*** 0 ****
--- 1,12 ----
+ extern void abort (void);
+ int foo (int i)
+ {
+ return -2 * __builtin_abs(i - 2);
+ }
+ int main()
+ {
+ if (foo(1) != -2
+ || foo(3) != -2)
+ abort ();
+ return 0;
+ }
