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authorAnton Youdkevitch <anton.youdkevitch@bell-sw.com>2019-05-03 11:01:34 -0700
committerSteve Ellcey <sellcey@caviumnetworks.com>2019-05-03 11:01:34 -0700
commit32e902a94e24fc5a00168d0df3301098704c61fb (patch)
tree88bd3588b0e08141855220a21467f230366b42db /ChangeLog
parentac3da35de5cf113edfd514c2fc8ccbaed4536aaf (diff)
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aarch64: thunderx2 memmove performance improvements
The performance improvement is about 20%-30% for
larger cases and about 1%-5% for smaller cases.

Used SIMD load/store instead of GPR for large
overlapping forward moves.

Reused existing memcpy implementation for smaller
or overlapping backward moves.

Fixed the existing memcpy implementation to allow it
to deal with the overlapping case.

Simplified loop tails in the memcpy implementation -
use branchless overlapping sequence of fixed length
load/stores instead of branching depending on the
size.

A cleanup/optimization converting str's to stp's.

Added __memmove_thunderx2 to the list of the
available implementations.
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+2019-05-03  Anton Youdkevitch  <anton.youdkevitch@bell-sw.com>
+
+	* sysdeps/aarch64/multiarch/ifunc-impl-list.c: Added
+	__memmove_thunderx2 to the list of implementations
+	* sysdeps/aarch64/multiarch/memmove.c: Likewise
+	* sysdeps/aarch64/multiarch/memcpy_thunderx2.S:
+	(__memmove_thunderx2): Rewritten using SIMD ld/st
+	(__memcpy_thunderx2): Fixed handling overlapping cases.
+	Used ldp/stp instead of ldr/str if possible. Made loops
+	tails branchless.
+
 2019-05-03  Florian Weimer  <fweimer@redhat.com>
 
 	* misc/tst-tsearch.c (walk_tree): Add more error checking.