]> git.ipfire.org Git - thirdparty/gcc.git/commit
match.pd: Guard 2 simplifications on integral TYPE_OVERFLOW_UNDEFINED [PR114090]
authorJakub Jelinek <jakub@redhat.com>
Mon, 26 Feb 2024 09:08:45 +0000 (10:08 +0100)
committerJakub Jelinek <jakub@redhat.com>
Mon, 26 Feb 2024 09:09:21 +0000 (10:09 +0100)
commit24aa051af7c59f37ec45aea754b48b97d210ea6d
tree0fb4c9002b4ab93d7a90f068d7ffcbcccd113cd6
parentf9d2a95be5680e04f53141c2675798b06d23f409
match.pd: Guard 2 simplifications on integral TYPE_OVERFLOW_UNDEFINED [PR114090]

These 2 patterns are incorrect on floating point, or for -fwrapv, or
for -ftrapv, or the first one for unsigned types (the second one is
mathematically correct, but we ought to just fold that to 0 instead).

So, the following patch properly guards this.

I think we don't need && !TYPE_OVERFLOW_SANITIZED (type) because
in both simplifications there would be UB before and after on
signed integer minimum.

2024-02-26  Jakub Jelinek  <jakub@redhat.com>

PR tree-optimization/114090
* match.pd ((x >= 0 ? x : 0) + (x <= 0 ? -x : 0) -> abs x):
Restrict pattern to ANY_INTEGRAL_TYPE_P and TYPE_OVERFLOW_UNDEFINED
types.
((x <= 0 ? -x : 0) -> max(-x, 0)): Likewise.

* gcc.dg/pr114090.c: New test.
gcc/match.pd
gcc/testsuite/gcc.dg/pr114090.c [new file with mode: 0644]