| Message ID | 20100812143504.GP702@tyan-ft48-01.lab.bos.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Aug 12, 2010 at 4:35 PM, Jakub Jelinek <jakub@redhat.com> wrote: > Hi! > > The range folding code in fold-const.c expects ranges to have always > low <= high (with NULL being -inf resp. +inf), and for PLUS_EXPR/MINUS_EXPR > the code normalizes, but not so for NEGATE_EXPR. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux. > Ok for trunk/4.5/4.4? Ok. Thanks, Richard. > 2010-08-12 Jakub Jelinek <jakub@redhat.com> > > PR middle-end/45262 > * fold-const.c (make_range) <case NEGATE_EXPR>: Punt if > -a overflows. Normalize the range. > > * gcc.c-torture/execute/pr45262.c: New test. > > --- gcc/fold-const.c.jj 2010-07-09 13:44:24.000000000 +0200 > +++ gcc/fold-const.c 2010-08-12 13:44:42.000000000 +0200 > @@ -3985,9 +3985,9 @@ make_range (tree exp, int *pin_p, tree * > n_high = range_binop (MINUS_EXPR, exp_type, > build_int_cst (exp_type, 0), > 0, low, 0); > - low = n_low, high = n_high; > - exp = arg0; > - continue; > + if (n_high != 0 && TREE_OVERFLOW (n_high)) > + break; > + goto normalize; > > case BIT_NOT_EXPR: > /* ~ X -> -X - 1 */ > @@ -4021,6 +4021,7 @@ make_range (tree exp, int *pin_p, tree * > if (TYPE_OVERFLOW_UNDEFINED (arg0_type)) > *strict_overflow_p = true; > > + normalize: > /* Check for an unsigned range which has wrapped around the maximum > value thus making n_high < n_low, and normalize it. */ > if (n_low && n_high && tree_int_cst_lt (n_high, n_low)) > --- gcc/testsuite/gcc.c-torture/execute/pr45262.c.jj 2010-08-12 13:51:49.000000000 +0200 > +++ gcc/testsuite/gcc.c-torture/execute/pr45262.c 2010-08-12 13:51:21.000000000 +0200 > @@ -0,0 +1,33 @@ > +/* PR middle-end/45262 */ > + > +extern void abort (void); > + > +int > +foo (unsigned int x) > +{ > + return ((int) x < 0) || ((int) (-x) < 0); > +} > + > +int > +bar (unsigned int x) > +{ > + return x >> 31 || (-x) >> 31; > +} > + > +int > +main (void) > +{ > + if (foo (1) != 1) > + abort (); > + if (foo (0) != 0) > + abort (); > + if (foo (-1) != 1) > + abort (); > + if (bar (1) != 1) > + abort (); > + if (bar (0) != 0) > + abort (); > + if (bar (-1) != 1) > + abort (); > + return 0; > +} > > Jakub >
--- gcc/fold-const.c.jj 2010-07-09 13:44:24.000000000 +0200 +++ gcc/fold-const.c 2010-08-12 13:44:42.000000000 +0200 @@ -3985,9 +3985,9 @@ make_range (tree exp, int *pin_p, tree * n_high = range_binop (MINUS_EXPR, exp_type, build_int_cst (exp_type, 0), 0, low, 0); - low = n_low, high = n_high; - exp = arg0; - continue; + if (n_high != 0 && TREE_OVERFLOW (n_high)) + break; + goto normalize; case BIT_NOT_EXPR: /* ~ X -> -X - 1 */ @@ -4021,6 +4021,7 @@ make_range (tree exp, int *pin_p, tree * if (TYPE_OVERFLOW_UNDEFINED (arg0_type)) *strict_overflow_p = true; + normalize: /* Check for an unsigned range which has wrapped around the maximum value thus making n_high < n_low, and normalize it. */ if (n_low && n_high && tree_int_cst_lt (n_high, n_low)) --- gcc/testsuite/gcc.c-torture/execute/pr45262.c.jj 2010-08-12 13:51:49.000000000 +0200 +++ gcc/testsuite/gcc.c-torture/execute/pr45262.c 2010-08-12 13:51:21.000000000 +0200 @@ -0,0 +1,33 @@ +/* PR middle-end/45262 */ + +extern void abort (void); + +int +foo (unsigned int x) +{ + return ((int) x < 0) || ((int) (-x) < 0); +} + +int +bar (unsigned int x) +{ + return x >> 31 || (-x) >> 31; +} + +int +main (void) +{ + if (foo (1) != 1) + abort (); + if (foo (0) != 0) + abort (); + if (foo (-1) != 1) + abort (); + if (bar (1) != 1) + abort (); + if (bar (0) != 0) + abort (); + if (bar (-1) != 1) + abort (); + return 0; +}