gnu.cfg: Add __builtin_ctz - #8721
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__builtin_ctzl, and __builtin_ctzll trailing zero count functions.
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Thanks for your contribution. Can those functions be |
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I don't see __builtin_ctz at that link. I instead found it here: https://gcc.gnu.org/onlinedocs/gcc/Bit-Operation-Builtins.html, which has several other similar functions that could be added as well. I also found a file in gcc that gives the ctz builtin ATTR_CONST_NOTHROW_LEAF_LIST so it is pure/const as expected of a bit fiddling function. I will look into making a more general PR for all these builtins. |
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Sep 10, 2026
I implemented all of the functions described at [https://gcc.gnu.org/onlinedocs/gcc/Built-in-Functions.html](https://gcc.gnu.org/onlinedocs/gcc/Built-in-Functions.html) except for the ones that have a variable return type based on the arguments. This PR should be a superset of the changes proposed in #8721. I didn't write any tests because I am not sure what the standard practice is. Should I try to have a test for each <function> tag? I have some tests, but I figured I would ask first.
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Reference: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html