x86: Optimize memchr() for x86-64
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- v1 Latest2 patches 7 repliesIn review
Patches in v1 No applies recorded yet
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/2 | x86/lib: Optimize memchr()arch/ arch/ arch/ | +82 | 6 replies | |
| 2/2 | x86/um: Use x86_64-optimized memchrarch/ | +1 | 0 replies |
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Cover letter [PATCH 0/2] x86: Optimize memchr() for x86-64
*** BLURB HERE ***
These patch series add an optimized "memchr()" for x86-64 and USER-MODE LINUX (UML).
There exists an assemebly implementation for x86-32. However, for x86-64, there isn't any optimized version. We implement word-wise comparison so that 8 characters can be compared at the same time on x86-64 CPU. The optimized “memchr()” is nearly 4x faster than the orginal implementation for long strings.
We test the optimized “memchr()” in UML and also recompile the 5.18 Kernel with the optimized “memchr()”. They run correctly.
In this patch we add a new file "string_64.c", which only contains "memchr()". We can add more optimized string functions in it in the future.
Yu-Jen Chang (2):
x86/lib: Optimize memchr()
x86/um: Use x86_64-optimized memchr
arch/x86/include/asm/string_64.h | 3 ++ arch/x86/lib/Makefile | 1 + arch/x86/lib/string_64.c | 78 ++++++++++++++++++++++++++++++++ arch/x86/um/Makefile | 2 +- 4 files changed, 83 insertions(+), 1 deletion(-) create mode 100644 arch/x86/lib/string_64.c
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2.25.1