dbm/Makefile.in
author Steve Snyder <swsnyder@snydernet.net>
Thu, 01 Oct 2009 14:19:41 -0400
changeset 33346 8a43f01f1d6478ad072c1f4a41fb633f8a5e3a32
parent 23987 44d8c5d92a441697092e7712194cacbc8ee97c9d
child 123604 54d17ee1b6be1aa6463d87189a3e91c358fde96b
permissions -rw-r--r--
Bug 512865. qcms: Improve SSE2 performance, add SSE support. r=jrmuizel This patch greatly improves the performance of QCMS transformations on x86 & x86_64 systems. Some notes: 0. On 32-bit x86 systems it does runtime selection between non-SIMD, SSE, and SSE2 code paths. 1. On x86_64 systems the SSE2 code path is always taken. The non-SIMD and SSE code paths are left intact, but contemporary versions of the GCC and MSVC compilers will see that they cannot be reached and optimize them away. 2. The execution of the SSE2 code path is reduced by 67%, relative to the original Intel/Microsoft formatted ASM code. The relative performance is seen on a Pentium4 (Northwood) 2.4GHz CPU with DDR1 RAM. 3. The SSE code path provides a 80% reduction in execution time, relative to the non-SIMD code path. The relative performance is seen on a Pentium3 (Coppermine) 1.26GHz CPU with SDRAM. 4. The code has been split out into separate files so that it can be built with different cflags (-msse, and -msse2) when using gcc. 5. Try to land again, this time with __attribute__((__force_align_arg_pointer__)) to avoid crashes on linux.