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| author | Aldy Hernandez <aldyh@redhat.com> | 2021-05-12 15:22:15 -0400 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@redhat.com> | 2021-05-12 16:46:58 -0400 |
| commit | d902a1b57606536982a1001670f998de685eaf7c (patch) | |
| tree | 70f23a7edb0c0a6825af6613deed94734620d2e0 | |
| parent | 8982a5354d2697eeb12a77d49b6730db90053618 (diff) | |
| download | gcc-d902a1b57606536982a1001670f998de685eaf7c.zip gcc-d902a1b57606536982a1001670f998de685eaf7c.tar.gz gcc-d902a1b57606536982a1001670f998de685eaf7c.tar.bz2 | |
Skip out on processing __builtin_clz when varying.
The previous changes to irange::constant_p return TRUE for
VARYING, since VARYING has numerical end points like any other
constant range. The problem is that some users of constant_p
depended on constant_p excluding the full domain. The
range handler for __builtin_clz, that is shared between ranger
and vr_values, is one such user.
This patch excludes varying_p(), to match the original behavior
for clz.
gcc/ChangeLog:
PR c/100521
* gimple-range.cc (range_of_builtin_call): Skip out on
processing __builtin_clz when varying.
| -rw-r--r-- | gcc/gimple-range.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr100521.c | 8 |
2 files changed, 9 insertions, 1 deletions
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc index e94bb35..5b288d8 100644 --- a/gcc/gimple-range.cc +++ b/gcc/gimple-range.cc @@ -737,7 +737,7 @@ range_of_builtin_call (range_query &query, irange &r, gcall *call) query.range_of_expr (r, arg, call); // From clz of minimum we can compute result maximum. - if (r.constant_p ()) + if (r.constant_p () && !r.varying_p ()) { int newmaxi = prec - 1 - wi::floor_log2 (r.lower_bound ()); // Argument is unsigned, so do nothing if it is [0, ...] range. diff --git a/gcc/testsuite/gcc.dg/pr100521.c b/gcc/testsuite/gcc.dg/pr100521.c new file mode 100644 index 0000000..fd9f0db --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr100521.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +int +__builtin_clz (int a) +{ + return __builtin_clz(a); +} |