| Message ID | ZcKZz7PBdlnJxzOM@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | range-op: Fix up ABSU_EXPR handling [PR113756] | expand |
LGTM. Up to the release managers. Thanks for tracking this down. Aldy On Tue, Feb 6, 2024 at 9:43 PM Jakub Jelinek <jakub@redhat.com> wrote: > > Hi! > > ABSU_EXPR unary expr is special because it has a signed integer > argument and unsigned integer result (of the same precision). > > The following testcase is miscompiled since ABSU_EXPR handling has > been added to range-op because it uses widest_int::from with the > result sign (i.e. UNSIGNED) rather than the operand sign (i.e. SIGNED), > so e.g. for the 32-bit int argument mask ends up 0xffffffc1 or something > similar and even when it has most significant bit in the precision set, > in widest_int (tree-ssa-ccp.cc really should stop using widest_int, but > that is I think stage1 task) it doesn't appear to be negative and so > bit_value_unop ABSU_EXPR doesn't set the resulting mask/value from > oring of the argument and its negation. > > Fixed thusly, not doing that for GIMPLE_BINARY_RHS because I don't know > about a binary op that would need something similar. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2024-02-06 Jakub Jelinek <jakub@redhat.com> > > PR tree-optimization/113756 > * range-op.cc (update_known_bitmask): For GIMPLE_UNARY_RHS, > use TYPE_SIGN (lh.type ()) instead of sign for widest_int::from > of lh_bits value and mask. > > * gcc.dg/pr113756.c: New test. > > --- gcc/range-op.cc.jj 2024-01-03 11:51:28.199777434 +0100 > +++ gcc/range-op.cc 2024-02-06 16:51:55.549127825 +0100 > @@ -435,8 +435,10 @@ update_known_bitmask (irange &r, tree_co > bit_value_unop (code, sign, prec, &widest_value, &widest_mask, > TYPE_SIGN (lh.type ()), > TYPE_PRECISION (lh.type ()), > - widest_int::from (lh_bits.value (), sign), > - widest_int::from (lh_bits.mask (), sign)); > + widest_int::from (lh_bits.value (), > + TYPE_SIGN (lh.type ())), > + widest_int::from (lh_bits.mask (), > + TYPE_SIGN (lh.type ()))); > break; > case GIMPLE_BINARY_RHS: > bit_value_binop (code, sign, prec, &widest_value, &widest_mask, > --- gcc/testsuite/gcc.dg/pr113756.c.jj 2024-02-06 17:00:52.835679796 +0100 > +++ gcc/testsuite/gcc.dg/pr113756.c 2024-02-06 17:00:31.159980326 +0100 > @@ -0,0 +1,36 @@ > +/* PR tree-optimization/113756 */ > +/* { dg-do run { target int32plus } } */ > +/* { dg-options "-O2" } */ > + > +int d, e, i, k, l = -8; > +signed char h, j; > + > +int > +bar (int n, int o, int p3) > +{ > + int a = o - p3, b = n - p3, c = a + b, f = -b, g = c < 0 ? -c : c; > + return a <= f && a <= g ? o : p3; > +} > + > +void > +foo (int *n, unsigned short o) > +{ > + unsigned p = 8896; > + for (; e >= 0; e--) > + p = 5377; > + for (; h <= 0; h++) > + for (; j <= 0; j++) > + { > + *n = 1611581749; > + i = bar (34, p - 5294, *n - 1611581687); > + k = i + p + 65535 + o + *n - 1611718251; > + if (k != 0) > + __builtin_abort (); > + } > +} > + > +int > +main () > +{ > + foo (&l, l); > +} > > Jakub >
--- gcc/range-op.cc.jj 2024-01-03 11:51:28.199777434 +0100 +++ gcc/range-op.cc 2024-02-06 16:51:55.549127825 +0100 @@ -435,8 +435,10 @@ update_known_bitmask (irange &r, tree_co bit_value_unop (code, sign, prec, &widest_value, &widest_mask, TYPE_SIGN (lh.type ()), TYPE_PRECISION (lh.type ()), - widest_int::from (lh_bits.value (), sign), - widest_int::from (lh_bits.mask (), sign)); + widest_int::from (lh_bits.value (), + TYPE_SIGN (lh.type ())), + widest_int::from (lh_bits.mask (), + TYPE_SIGN (lh.type ()))); break; case GIMPLE_BINARY_RHS: bit_value_binop (code, sign, prec, &widest_value, &widest_mask, --- gcc/testsuite/gcc.dg/pr113756.c.jj 2024-02-06 17:00:52.835679796 +0100 +++ gcc/testsuite/gcc.dg/pr113756.c 2024-02-06 17:00:31.159980326 +0100 @@ -0,0 +1,36 @@ +/* PR tree-optimization/113756 */ +/* { dg-do run { target int32plus } } */ +/* { dg-options "-O2" } */ + +int d, e, i, k, l = -8; +signed char h, j; + +int +bar (int n, int o, int p3) +{ + int a = o - p3, b = n - p3, c = a + b, f = -b, g = c < 0 ? -c : c; + return a <= f && a <= g ? o : p3; +} + +void +foo (int *n, unsigned short o) +{ + unsigned p = 8896; + for (; e >= 0; e--) + p = 5377; + for (; h <= 0; h++) + for (; j <= 0; j++) + { + *n = 1611581749; + i = bar (34, p - 5294, *n - 1611581687); + k = i + p + 65535 + o + *n - 1611718251; + if (k != 0) + __builtin_abort (); + } +} + +int +main () +{ + foo (&l, l); +}