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| author | Richard Biener <rguenther@suse.de> | 2012-10-22 13:26:48 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2012-10-22 13:26:48 +0000 |
| commit | 43b1bad65d0d1142c37a91dcf6cf2a035c541e4d (patch) | |
| tree | 514c75894fabfe05bd894b9b7d6abef68f48e6ac | |
| parent | e81bf2ce3b34a1fa0b83df792f5e8661dd1a61ca (diff) | |
| download | gcc-43b1bad65d0d1142c37a91dcf6cf2a035c541e4d.zip gcc-43b1bad65d0d1142c37a91dcf6cf2a035c541e4d.tar.gz gcc-43b1bad65d0d1142c37a91dcf6cf2a035c541e4d.tar.bz2 | |
re PR tree-optimization/55011 (GCC in an infinite loop at -O2 in VRP)
2012-10-22 Richard Biener <rguenther@suse.de>
PR tree-optimization/55011
* tree-vrp.c (update_value_range): For invalid lattice transitions
drop to VARYING.
* gcc.dg/torture/pr55011.c: New testcase.
From-SVN: r192689
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr55011.c | 22 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 15 |
4 files changed, 46 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d8db9c9..4de896b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2012-10-22 Richard Biener <rguenther@suse.de> + + PR tree-optimization/55011 + * tree-vrp.c (update_value_range): For invalid lattice transitions + drop to VARYING. + 2012-10-22 Julian Brown <julian@codesourcery.com> * config/arm/arm.h (CANNOT_CHANGE_MODE_CLASS): Avoid subreg'ing diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 39bc6d3..c994df9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2012-10-22 Richard Biener <rguenther@suse.de> + + PR tree-optimization/55011 + * gcc.dg/torture/pr55011.c: New testcase. + 2012-10-22 Greta Yorsh <Greta.Yorsh@arm.com> * gcc.target/arm/pr40457-1.c: Adjust expected output. diff --git a/gcc/testsuite/gcc.dg/torture/pr55011.c b/gcc/testsuite/gcc.dg/torture/pr55011.c new file mode 100644 index 0000000..67b2613 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr55011.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ + +char a; + +void f(void) +{ + char b = 2; + + for(;;) + { + unsigned short s = 1, *p = &s, *i; + + for(*i = 0; *i < 4; ++*i) + if(a | (*p /= (b += !!a)) <= 63739) + return; + + if(!s) + a = 0; + + for(;;); + } +} diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index de3eb2c..379914c 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -819,8 +819,19 @@ update_value_range (const_tree var, value_range_t *new_vr) || !vrp_bitmap_equal_p (old_vr->equiv, new_vr->equiv); if (is_new) - set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max, - new_vr->equiv); + { + /* Do not allow transitions up the lattice. The following + is slightly more awkward than just new_vr->type < old_vr->type + because VR_RANGE and VR_ANTI_RANGE need to be considered + the same. We may not have is_new when transitioning to + UNDEFINED or from VARYING. */ + if (new_vr->type == VR_UNDEFINED + || old_vr->type == VR_VARYING) + set_value_range_to_varying (old_vr); + else + set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max, + new_vr->equiv); + } BITMAP_FREE (new_vr->equiv); |