Adhemerval Zanella 367c31b5d6 string: Improve generic strncmp ...

It follows the strategy:

   - Align the first input to word boundary using byte operations.

   - If second input is also word aligned, read a word per time, check
     for  null (using has_zero), and check final words using byte
     operation.

   - If second input is not word aligned, loop by aligning the source,
     and merge the result of two reads.  Similar to aligned case, check
     for null with has_zero, and check final words using byte operation.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64-linux-gnu,
and powerpc-linux-gnu by removing the arch-specific assembly
implementation and disabling multi-arch (it covers both LE and BE
for 64 and 32 bits).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

2023-02-06 16:19:35 -03:00

3.9 KiB

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