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| author | Aldy Hernandez <aldyh@redhat.com> | 2018-10-03 17:36:29 +0000 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@gcc.gnu.org> | 2018-10-03 17:36:29 +0000 |
| commit | 9b918e82027599898e5f2ff75342a51da06672a9 (patch) | |
| tree | 8bcd98852b04d4e16319dc8c385b377d9821b018 /gcc | |
| parent | 78125561e39be43dc140d5648abf402c4f7cf1c0 (diff) | |
| download | gcc-9b918e82027599898e5f2ff75342a51da06672a9.zip gcc-9b918e82027599898e5f2ff75342a51da06672a9.tar.gz gcc-9b918e82027599898e5f2ff75342a51da06672a9.tar.bz2 | |
re PR tree-optimization/87415 (wrong code at -O1 and above on x86_64-linux-gnu)
PR tree-optimization/87415
* tree-vrp.c (set_value_range_with_overflow): Special case one bit
precision fields.
From-SVN: r264817
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr87415.c | 20 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 9 |
3 files changed, 35 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index aa10aa0..30d7e77 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2018-10-03 Aldy Hernandez <aldyh@redhat.com> + + PR tree-optimization/87415 + * tree-vrp.c (set_value_range_with_overflow): Special case one bit + precision fields. + 2018-10-02 Jeff Law <law@redhat.com> * gimple-fold.c (get_range_strlen): Only set *nonstr when diff --git a/gcc/testsuite/gcc.dg/pr87415.c b/gcc/testsuite/gcc.dg/pr87415.c new file mode 100644 index 0000000..473384a --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr87415.c @@ -0,0 +1,20 @@ +/* { dg-do run } */ +/* { dg-options "-O2" } */ + +struct A +{ + int b:1; +}; + +int d; + +int main () +{ + struct A e = { 0 }; + if (!d) + e.b = -1; + if (!e.b) + __builtin_abort (); + + return 0; +} diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 005fc2f..cbc2ea2 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -1116,6 +1116,15 @@ set_value_range_with_overflow (value_range &vr, const unsigned int prec = TYPE_PRECISION (type); vr.type = VR_RANGE; vr.equiv = NULL; + + /* For one bit precision if max < min, then the swapped + range covers all values. */ + if (prec == 1 && wi::lt_p (wmax, wmin, sgn)) + { + set_value_range_to_varying (&vr); + return; + } + if (TYPE_OVERFLOW_WRAPS (type)) { /* If overflow wraps, truncate the values and adjust the |