diff options
| author | Aldy Hernandez <aldyh@redhat.com> | 2022-10-02 10:46:47 +0200 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@redhat.com> | 2022-10-03 13:06:25 +0200 |
| commit | c0129d6b2a5f2b3cfedd213d48c95581f75312aa (patch) | |
| tree | 513c7d1239f83a03e4dd455241b37ff567992693 /gcc | |
| parent | 7f6f1f521fc12d4dbbdd0766d8fb7121d1e5ea8d (diff) | |
| download | gcc-c0129d6b2a5f2b3cfedd213d48c95581f75312aa.zip gcc-c0129d6b2a5f2b3cfedd213d48c95581f75312aa.tar.gz gcc-c0129d6b2a5f2b3cfedd213d48c95581f75312aa.tar.bz2 | |
Do not pessimize range in set_nonzero_bits.
Currently if we have a range of [0,0] and we set the nonzero bits to
1, the current code pessimizes the range to [0,1] because it assumes
the range is [1,1] plus the possibility of 0. This fixes the
oversight.
gcc/ChangeLog:
* value-range.cc (irange::set_nonzero_bits): Do not pessimize range.
(range_tests_nonzero_bits): New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/value-range.cc | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/gcc/value-range.cc b/gcc/value-range.cc index e1066f4..6e19657 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -2934,6 +2934,14 @@ irange::set_nonzero_bits (const wide_int_ref &bits) // range immediately. if (wi::popcount (bits) == 1) { + // Make sure we don't pessimize the range. + tree tbits = wide_int_to_tree (type (), bits); + if (!contains_p (tbits)) + { + set_nonzero_bits (tbits); + return; + } + bool has_zero = contains_p (build_zero_cst (type ())); set (type (), bits, bits); if (has_zero) @@ -3628,6 +3636,11 @@ range_tests_nonzero_bits () r1.set_nonzero_bits (0xff); r0.union_ (r1); ASSERT_TRUE (r0.varying_p ()); + + // Test that setting a nonzero bit of 1 does not pessimize the range. + r0.set_zero (integer_type_node); + r0.set_nonzero_bits (1); + ASSERT_TRUE (r0.zero_p ()); } // Build an frange from string endpoints. |