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| author | Andrew Pinski <apinski@marvell.com> | 2023-09-17 11:20:36 -0700 |
|---|---|---|
| committer | Andrew Pinski <apinski@marvell.com> | 2023-09-18 13:45:35 -0700 |
| commit | 7ea501d3ea698e1c845fb61e3487f4cd949e6253 (patch) | |
| tree | 5abc352ce405662ffebe81270253815ffb8a889c | |
| parent | 951d3c191d01440ad54415f683437770b0c957e4 (diff) | |
| download | gcc-7ea501d3ea698e1c845fb61e3487f4cd949e6253.zip gcc-7ea501d3ea698e1c845fb61e3487f4cd949e6253.tar.gz gcc-7ea501d3ea698e1c845fb61e3487f4cd949e6253.tar.bz2 | |
MATCH: Make zero_one_valued_p non-recursive fully
So it turns out VN can't handle any kind of recursion for match. In this
case we have `b = a & -1` and we try to match a as being zero_one_valued_p
and VN returns b as being the value and we just go into an infinite loop at
this point.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Note genmatch should warn (or error out) if this gets detected so I filed PR 111446
which I will be looking into next week or the week after so we don't run into
this issue again.
PR tree-optimization/111442
gcc/ChangeLog:
* match.pd (zero_one_valued_p): Have the bit_and match not be
recursive.
gcc/testsuite/ChangeLog:
* gcc.c-torture/compile/pr111442-1.c: New test.
| -rw-r--r-- | gcc/match.pd | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr111442-1.c | 13 |
2 files changed, 17 insertions, 1 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index a405c9f..bef513a 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -2183,8 +2183,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* (a&1) is always [0,1] too. This is useful again when the range is not known. */ +/* Note this can't be recursive due to VN handling of equivalents, + VN and would cause an infinite recursion. */ (match zero_one_valued_p - (bit_and:c@0 @1 zero_one_valued_p)) + (bit_and:c@0 @1 integer_onep) + (if (INTEGRAL_TYPE_P (type)))) /* A conversion from an zero_one_valued_p is still a [0,1]. This is useful when the range of a variable is not known */ diff --git a/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c new file mode 100644 index 0000000..5814ee9 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c @@ -0,0 +1,13 @@ + +int *a, b; +int main() { + int d = 1, e; + if (d) + e = a ? 0 % 0 : 0; + if (d) + a = &d; + d = -1; + b = d & e; + b = 2 * e ^ 1; + return 0; +} |