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| author | Arjun Shankar <arjun@redhat.com> | 2022-06-21 12:12:11 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-06-21 12:13:52 +0200 |
| commit | ab981aab92cbc71918fbaadcf6fa64bdb2b69be7 (patch) | |
| tree | f655a675752e9fd0e7a2c0b6f3d07fff26dcd8be /libgo | |
| parent | a0c30fe3b888f20215f3e040d21b62b603804ca9 (diff) | |
| download | gcc-ab981aab92cbc71918fbaadcf6fa64bdb2b69be7.zip gcc-ab981aab92cbc71918fbaadcf6fa64bdb2b69be7.tar.gz gcc-ab981aab92cbc71918fbaadcf6fa64bdb2b69be7.tar.bz2 | |
match.pd: Remove "+ 0x80000000" in int comparisons [PR94899]
Expressions of the form "X + CST < Y + CST" where:
* CST is an unsigned integer constant with only the MSB set, and
* X and Y's types have integer conversion ranks <= CST's
can be simplified to "(signed) X < (signed) Y".
This is because, assuming a 32-bit signed numbers,
(unsigned) INT_MIN + 0x80000000 is 0, and
(unsigned) INT_MAX + 0x80000000 is UINT_MAX.
i.e. the result increases monotonically with signed input.
This means:
((signed) X < (signed) Y) iff (X + 0x80000000 < Y + 0x80000000)
gcc/
PR tree-optimization/94899
* match.pd (X + C < Y + C -> (signed) X < (signed) Y, if C is
0x80000000): New simplification.
gcc/testsuite/
* gcc.dg/pr94899.c: New test.
Diffstat (limited to 'libgo')
0 files changed, 0 insertions, 0 deletions