tree 45653f897e8c647acfe30d317d5813c0cdcd4c64
parent 232e3c08c9eb9aba822510bae57f920351b1eb40
author Branislav Rankov <branislav.rankov@arm.com> 1588254427 +0100
committer Szabolcs Nagy <szabolcs.nagy@arm.com> 1588254617 +0100

string: ARMv8.5 MTE: Add MTE compatible version of strcmp.

Reading outside the range of the string is only allowed within 16 byte
aligned granules when MTE is enabled.

This implementation is based on string/aarch64/strcmp.S

Change the case when strings are are misaligned, align the pointers
down, and ignore bytes before the start of the string. Carry the part
that is not compared to the next comparison.

Testing done:
optimized-routines/string/test/strcmp.c on big and little endian.
Booted nanodroid with MTE enabled.
bionic string tests with MTE enabled.

Benchmarks results:
Run both bionic benchmarks and glibc benchmarks on Pixel4. Cores A76 and A55.