author Steve Snyder <>
Thu, 01 Oct 2009 14:19:41 -0400
changeset 33346 8a43f01f1d6478ad072c1f4a41fb633f8a5e3a32
parent 1 9b2a99adc05e53cd4010de512f50118594756650
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.

Please be apprised of the following Legal Notices:

A) The U.S. District Court for the Eastern District of Virginia has
ruled that the Netscape Navigator code does not infringe Wang's U.S.
Patent No. 4,751,669 ("the '669 Patent") because: 1) HTML is not
Videotex as defined by the '669 patent; 2) web servers are not central
suppliers; and 3) Navigator does not "connect," as defined by the '669
Patent, to web servers on the Internet. Wang may appeal this decision to
the Federal Circuit. Wang contended that its Patent disclosing a
"Videotex" system, is infringed by the following functionality in the
Netscape Navigator code: 1) the animated logo and status line indicators
--See Claims 1,8 and 9; 2) the "File Save As" function --See Claims
23-27; 3) Bookmarks and Rename Bookmarks in the Properties window --See
Claims 20-22; 4) storing HTML, GIF, and JPEG files and adding filename
extensions --See Claim 38

B) Intermind owns pending U.S. patent applications on communications
systems which employ metadata ("channel objects") to define a control
structure for information transfer. The Netscape code does not infringe
as released; however, modifications which utilize channel objects as
described by Intermind should be considered carefully. The following is
a statement from Intermind: "Intermind's claims fundamentally involve
the use of a control structure to automate communications. ...The
essence of Intermind's top claim is that two devices sender and receiver
have persistent storage, communicate over a network, and exchange a
control structure including metadata which describes: 1) what
information is to be updated, 2) when to update this information, and 3)
how to transfer the updated information. In addition, at least the
receiving device must be able to process the metadata in order to
perform the update determination and transfer. Any digital
communications system which incorporates all of these elements will be
covered by Intermind's patents." See

C) Stac, Inc., and its licensing agent Hi/fn, own several patents which
disclose data compression methods implementing an LZS compression
algorithm, including U.S. Patent Nos. 4,701,745 and 5,016, 009 ("the
Stac Patents"). The Netscape Communicator code does not perform
compression. If you modify the Netscape source code to perform
compression, please take notice of the Stac Patents.

D) Netscape Communications Corporation ("Netscape") does not guarantee
that any source code or executable code available from the
domain is Year 2000 compliant.