Message ID | 20180620141758.GG7166@tucnak |
---|---|
State | New |
Headers | show |
Series | Fix vrp_meet (PR tree-optimization/86231) | expand |
On Wed, 20 Jun 2018, Jakub Jelinek wrote: > Hi! > > On the second following testcase, we call vrp_meet on [1B, 2B] and ~[0B, 1B] > and instead of computing the right ~[0B, 0B], we compute invalid ~[0B, -1B]. > > Similarly, on the first testcase, vrp_meet on [4, 8] and ~[2, 6] computes > ~[2, 1] which is invalid and is canonicalized into VARYING, while we want > ~[2, 3]. > > The problem is a thinko, for the new minimum we need to subtract 1 from the > vr0's minimum, but we overwrite it before that with the vr1's minimum and so > always compute ~[vr1min, vr1min-1]. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk/8.2? OK. Looks also broken on older branches so please adjust the PR to make sure we consider backporting. Thanks, Richard. > 2018-06-20 Jakub Jelinek <jakub@redhat.com> > > PR tree-optimization/86231 > * tree-vrp.c (union_ranges): For ( [ ) ] or ( )[ ] range and > anti-range don't overwrite *vr0min before using it to compute *vr0max. > > * gcc.dg/tree-ssa/vrp119.c: New test. > * gcc.c-torture/execute/pr86231.c: New test. > > --- gcc/tree-vrp.c.jj 2018-05-31 20:53:31.200438223 +0200 > +++ gcc/tree-vrp.c 2018-06-20 09:36:55.536561840 +0200 > @@ -5922,9 +5922,9 @@ union_ranges (enum value_range_type *vr0 > if (TREE_CODE (*vr0min) == INTEGER_CST) > { > *vr0type = vr1type; > - *vr0min = vr1min; > *vr0max = int_const_binop (MINUS_EXPR, *vr0min, > build_int_cst (TREE_TYPE (*vr0min), 1)); > + *vr0min = vr1min; > } > else > goto give_up; > --- gcc/testsuite/gcc.dg/tree-ssa/vrp119.c.jj 2018-06-20 09:31:06.984238418 +0200 > +++ gcc/testsuite/gcc.dg/tree-ssa/vrp119.c 2018-06-20 09:33:07.526350273 +0200 > @@ -0,0 +1,20 @@ > +/* PR tree-optimization/86231 */ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-vrp1" } */ > +/* { dg-final { scan-tree-dump-not "link_error" "vrp1" } } */ > + > +int bar (int); > +void link_error (void); > + > +int > +foo (int x, int y, int z) > +{ > + if (x < 4 || x > 8) __builtin_unreachable (); > + if (y >= 2 && y <= 6) __builtin_unreachable (); > + /* x is [4, 8], y is ~[2, 6], resulting range of e should be ~[2, 3]. */ > + int e = (z ? x : y); > + bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (e)))))))))))); > + if (e == 2 || e == 3) > + link_error (); > + return e; > +} > --- gcc/testsuite/gcc.c-torture/execute/pr86231.c.jj 2018-06-20 09:19:46.797601458 +0200 > +++ gcc/testsuite/gcc.c-torture/execute/pr86231.c 2018-06-20 09:30:44.437217496 +0200 > @@ -0,0 +1,30 @@ > +/* PR tree-optimization/86231 */ > + > +#define ONE ((void *) 1) > +#define TWO ((void *) 2) > + > +__attribute__((noipa)) int > +foo (void *p, int x) > +{ > + if (p == ONE) return 0; > + if (!p) > + p = x ? TWO : ONE; > + return p == ONE ? 0 : 1; > +} > + > +int v[8]; > + > +int > +main () > +{ > + if (foo ((void *) 0, 0) != 0 > + || foo ((void *) 0, 1) != 1 > + || foo (ONE, 0) != 0 > + || foo (ONE, 1) != 0 > + || foo (TWO, 0) != 1 > + || foo (TWO, 1) != 1 > + || foo (&v[7], 0) != 1 > + || foo (&v[7], 1) != 1) > + __builtin_abort (); > + return 0; > +} > > Jakub > >
--- gcc/tree-vrp.c.jj 2018-05-31 20:53:31.200438223 +0200 +++ gcc/tree-vrp.c 2018-06-20 09:36:55.536561840 +0200 @@ -5922,9 +5922,9 @@ union_ranges (enum value_range_type *vr0 if (TREE_CODE (*vr0min) == INTEGER_CST) { *vr0type = vr1type; - *vr0min = vr1min; *vr0max = int_const_binop (MINUS_EXPR, *vr0min, build_int_cst (TREE_TYPE (*vr0min), 1)); + *vr0min = vr1min; } else goto give_up; --- gcc/testsuite/gcc.dg/tree-ssa/vrp119.c.jj 2018-06-20 09:31:06.984238418 +0200 +++ gcc/testsuite/gcc.dg/tree-ssa/vrp119.c 2018-06-20 09:33:07.526350273 +0200 @@ -0,0 +1,20 @@ +/* PR tree-optimization/86231 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-vrp1" } */ +/* { dg-final { scan-tree-dump-not "link_error" "vrp1" } } */ + +int bar (int); +void link_error (void); + +int +foo (int x, int y, int z) +{ + if (x < 4 || x > 8) __builtin_unreachable (); + if (y >= 2 && y <= 6) __builtin_unreachable (); + /* x is [4, 8], y is ~[2, 6], resulting range of e should be ~[2, 3]. */ + int e = (z ? x : y); + bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (bar (e)))))))))))); + if (e == 2 || e == 3) + link_error (); + return e; +} --- gcc/testsuite/gcc.c-torture/execute/pr86231.c.jj 2018-06-20 09:19:46.797601458 +0200 +++ gcc/testsuite/gcc.c-torture/execute/pr86231.c 2018-06-20 09:30:44.437217496 +0200 @@ -0,0 +1,30 @@ +/* PR tree-optimization/86231 */ + +#define ONE ((void *) 1) +#define TWO ((void *) 2) + +__attribute__((noipa)) int +foo (void *p, int x) +{ + if (p == ONE) return 0; + if (!p) + p = x ? TWO : ONE; + return p == ONE ? 0 : 1; +} + +int v[8]; + +int +main () +{ + if (foo ((void *) 0, 0) != 0 + || foo ((void *) 0, 1) != 1 + || foo (ONE, 0) != 0 + || foo (ONE, 1) != 0 + || foo (TWO, 0) != 1 + || foo (TWO, 1) != 1 + || foo (&v[7], 0) != 1 + || foo (&v[7], 1) != 1) + __builtin_abort (); + return 0; +}