| Submitter | Jakub Jelinek |
|---|---|
| Date | Nov. 21, 2012, 8:38 p.m. |
| Message ID | <20121121203828.GI2315@tucnak.redhat.com> |
| Download | mbox | patch |
| Permalink | /patch/200855/ |
| State | New |
| Headers | show |
Comments
On Wed, Nov 21, 2012 at 9:38 PM, Jakub Jelinek <jakub@redhat.com> wrote: > Hi! > > If a type has 2 * HWI precision, sizem1 is maximum double_int (all ones) > and thus size = sizem1 + double_int_one overflows into 0. If either min0 > or min1 is also zero, we might wrongly canonicalize the range into a signed > one. Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, > ok for trunk? Ok. Thanks, Richard. > 2012-11-21 Jakub Jelinek <jakub@redhat.com> > > PR tree-optimization/54471 > * tree-vrp.c (extract_range_from_binary_expr_1): For MULT_EXPR, > don't canonicalize range if min2 is zero. > > * gcc.dg/tree-ssa/vrp86.c: New test. > * gcc.c-torture/execute/pr54471.c: New test. > > --- gcc/tree-vrp.c.jj 2012-11-21 16:00:05.000085079 +0100 > +++ gcc/tree-vrp.c 2012-11-21 18:24:58.385290035 +0100 > @@ -2653,7 +2653,7 @@ extract_range_from_binary_expr_1 (value_ > if (TYPE_UNSIGNED (expr_type)) > { > double_int min2 = size - min0; > - if (min2.cmp (max0, true) < 0) > + if (!min2.is_zero () && min2.cmp (max0, true) < 0) > { > min0 = -min2; > max0 -= size; > @@ -2661,7 +2661,7 @@ extract_range_from_binary_expr_1 (value_ > } > > min2 = size - min1; > - if (min2.cmp (max1, true) < 0) > + if (!min2.is_zero () && min2.cmp (max1, true) < 0) > { > min1 = -min2; > max1 -= size; > --- gcc/testsuite/gcc.dg/tree-ssa/vrp86.c.jj 2012-11-21 18:27:53.389280736 +0100 > +++ gcc/testsuite/gcc.dg/tree-ssa/vrp86.c 2012-11-21 18:27:47.000000000 +0100 > @@ -0,0 +1,28 @@ > +/* PR tree-optimization/54471 */ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-vrp1" } */ > + > +#ifdef __SIZEOF_INT128__ > +#define T __int128 > +#else > +#define T long long > +#endif > + > +void fn1call (void); > +void fn2call (void); > + > +void > +foo (unsigned T x) > +{ > + if (x > (unsigned T) -3) > + return; > + unsigned T y = 2 * x; > + if (y == 42) > + fn1call (); > + else > + fn2call (); > +} > + > +/* { dg-final { scan-tree-dump "fn1call" "vrp1"} } */ > +/* { dg-final { scan-tree-dump "fn2call" "vrp1"} } */ > +/* { dg-final { cleanup-tree-dump "vrp1" } } */ > --- gcc/testsuite/gcc.c-torture/execute/pr54471.c.jj 2012-11-21 18:24:58.386289954 +0100 > +++ gcc/testsuite/gcc.c-torture/execute/pr54471.c 2012-11-21 18:24:58.386289954 +0100 > @@ -0,0 +1,36 @@ > +/* PR tree-optimization/54471 */ > + > +#ifdef __SIZEOF_INT128__ > +#define T __int128 > +#else > +#define T long long > +#endif > + > +extern void abort (void); > + > +__attribute__ ((noinline)) > +unsigned T > +foo (T ixi, unsigned ctr) > +{ > + unsigned T irslt = 1; > + T ix = ixi; > + > + for (; ctr; ctr--) > + { > + irslt *= ix; > + ix *= ix; > + } > + > + if (irslt != 14348907) > + abort (); > + return irslt; > +} > + > +int > +main () > +{ > + unsigned T res; > + > + res = foo (3, 4); > + return 0; > +} > > Jakub
Patch
--- gcc/tree-vrp.c.jj 2012-11-21 16:00:05.000085079 +0100 +++ gcc/tree-vrp.c 2012-11-21 18:24:58.385290035 +0100 @@ -2653,7 +2653,7 @@ extract_range_from_binary_expr_1 (value_ if (TYPE_UNSIGNED (expr_type)) { double_int min2 = size - min0; - if (min2.cmp (max0, true) < 0) + if (!min2.is_zero () && min2.cmp (max0, true) < 0) { min0 = -min2; max0 -= size; @@ -2661,7 +2661,7 @@ extract_range_from_binary_expr_1 (value_ } min2 = size - min1; - if (min2.cmp (max1, true) < 0) + if (!min2.is_zero () && min2.cmp (max1, true) < 0) { min1 = -min2; max1 -= size; --- gcc/testsuite/gcc.dg/tree-ssa/vrp86.c.jj 2012-11-21 18:27:53.389280736 +0100 +++ gcc/testsuite/gcc.dg/tree-ssa/vrp86.c 2012-11-21 18:27:47.000000000 +0100 @@ -0,0 +1,28 @@ +/* PR tree-optimization/54471 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-vrp1" } */ + +#ifdef __SIZEOF_INT128__ +#define T __int128 +#else +#define T long long +#endif + +void fn1call (void); +void fn2call (void); + +void +foo (unsigned T x) +{ + if (x > (unsigned T) -3) + return; + unsigned T y = 2 * x; + if (y == 42) + fn1call (); + else + fn2call (); +} + +/* { dg-final { scan-tree-dump "fn1call" "vrp1"} } */ +/* { dg-final { scan-tree-dump "fn2call" "vrp1"} } */ +/* { dg-final { cleanup-tree-dump "vrp1" } } */ --- gcc/testsuite/gcc.c-torture/execute/pr54471.c.jj 2012-11-21 18:24:58.386289954 +0100 +++ gcc/testsuite/gcc.c-torture/execute/pr54471.c 2012-11-21 18:24:58.386289954 +0100 @@ -0,0 +1,36 @@ +/* PR tree-optimization/54471 */ + +#ifdef __SIZEOF_INT128__ +#define T __int128 +#else +#define T long long +#endif + +extern void abort (void); + +__attribute__ ((noinline)) +unsigned T +foo (T ixi, unsigned ctr) +{ + unsigned T irslt = 1; + T ix = ixi; + + for (; ctr; ctr--) + { + irslt *= ix; + ix *= ix; + } + + if (irslt != 14348907) + abort (); + return irslt; +} + +int +main () +{ + unsigned T res; + + res = foo (3, 4); + return 0; +}