From f06a4faf8a2b4d046eb40e94b47948cc47d79902 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 31 Dec 2014 11:47:41 -0500 Subject: powerpc: Optimized st{r,p}ncpy for POWER8/PPC64 This patch adds an optimized POWER8 st{r,p}ncpy using unaligned accesses. It shows 10%-80% improvement over the optimized POWER7 one that uses only aligned accesses, specially on unaligned inputs. The algorithm first read and check 16 bytes (if inputs do not cross a 4K page size). The it realign source to 16-bytes and issue a 16 bytes read and compare loop to speedup null byte checks for large strings. Also, different from POWER7 optimization, the null pad is done inline in the implementation using possible unaligned accesses, instead of realying on a memset call. Special case is added for page cross reads. --- NEWS | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'NEWS') diff --git a/NEWS b/NEWS index e020918..08b3daa 100644 --- a/NEWS +++ b/NEWS @@ -19,7 +19,8 @@ Version 2.21 17744, 17745, 17746, 17747, 17748, 17775, 17777, 17780, 17781, 17782, 17791, 17793, 17796, 17797, 17803, 17806, 17834 -* Optimized strcpy and stpcpy implementations for powerpc64/powerpc64le. +* Optimized strcpy, stpcpy, strncpy, stpncpy implementations for + powerpc64/powerpc64le. * Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64 and powerpc64le. This may improve lock scaling of existing programs on -- cgit v1.1