diff options
| author | Richard Sandiford <richard.sandiford@arm.com> | 2018-07-25 08:41:35 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2018-07-25 08:41:35 +0000 |
| commit | e8dce850a7ffcffff4690f62f85e0ed4ede4d82a (patch) | |
| tree | 9f721d74a8a88c9af1612dc3c67cdb9f9aa32b6b /libgfortran/io/async.c | |
| parent | de6c8d7f72822c579ff07382d74ecb5c142a49b2 (diff) | |
| download | gcc-e8dce850a7ffcffff4690f62f85e0ed4ede4d82a.zip gcc-e8dce850a7ffcffff4690f62f85e0ed4ede4d82a.tar.gz gcc-e8dce850a7ffcffff4690f62f85e0ed4ede4d82a.tar.bz2 | |
Fix ceil_log2(0) (PR 86644)
This PR shows a pathological case in which we try SLP vectorisation on
dead code. We record that 0 bits of the result are enough to satisfy
all users (which is true), and that led to precision being 0 in:
static unsigned int
vect_element_precision (unsigned int precision)
{
precision = 1 << ceil_log2 (precision);
return MAX (precision, BITS_PER_UNIT);
}
ceil_log2 (0) returned 64 rather than 0, leading to 1 << 64, which is UB.
2018-07-25 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* hwint.c (ceil_log2): Fix comment. Return 0 for 0.
From-SVN: r262961
Diffstat (limited to 'libgfortran/io/async.c')
0 files changed, 0 insertions, 0 deletions