simd/jsimd_arm_neon.S


Log

Author Commit Date CI Message
DRC bd49803f 2016-02-19T08:53:33 Use consistent/modern code formatting for pointers The convention used by libjpeg: type * variable; is not very common anymore, because it looks too much like multiplication. Some (particularly C++ programmers) prefer to tuck the pointer symbol against the type: type* variable; to emphasize that a pointer to a type is effectively a new type. However, this can also be confusing, since defining multiple variables on the same line would not work properly: type* variable1, variable2; /* Only variable1 is actually a pointer. */ This commit reformats the entirety of the libjpeg-turbo code base so that it uses the same code formatting convention for pointers that the TurboJPEG API code uses: type *variable1, *variable2; This seems to be the most common convention among C programmers, and it is the convention used by other codec libraries, such as libpng and libtiff.
DRC 15aaa7f7 2016-02-07T17:39:33 ARM SIMD: Comment tweaks
DRC cf888486 2016-02-02T23:17:06 Use consistent formatting in ARM NEON SIMD code There aren't really any best practices to follow here. I tried as best as I could to adopt a standard that would ease any future maintenance burdens. The basic tenets of that standard are: * Assembly instructions always start on Column 5, and operands always start on Column 21, except: - The instruction and operand can be indented (usually by 2 spaces) to indicate a separate instruction stream. - If the instruction is within an enclosing .if block in a macro, it should always be indented relative to the .if block. * Comments are placed with an eye toward readability. There are always at least 2 spaces between the end of a line of code and the associated in-line comment. Where it made sense, I tried to line up the comments in blocks, and some were shifted right to avoid overlap with neighboring instruction lines. Not an exact science. * Assembler directives and macros use 2-space indenting rules. .if blocks are indented relative to the macro, and code within the .if blocks is indented relative to the .if directive. * No extraneous spaces between operands. Lining up the operands vertically did not really improve readability-- personally, I think it made it worse, since my eye would tend to lose its place in the uniform columns of characters. Also, code with a lot of vertical alignment is really hard to maintain, since changing one line could necessitate changing a bunch of other lines to avoid spoiling the alignment. * No extraneous spaces in #defines or other directives. In general, the only extraneous spaces (other than indenting spaces) are between: - Instructions and operands - Operands and in-line comments This standard should be more or less in keeping with other formatting standards used within the project.
DRC 499c470b 2016-01-13T03:13:20 ARM32 NEON SIMD implementation of Huffman encoding Full-color compression speedups relative to libjpeg-turbo 1.4.2: 800 MHz ARM Cortex-A9, iOS, 32-bit: 26-44% (avg. 32%) Refer to #42 and #47 for discussion. This commit also removes the unnecessary if (simd_support & JSIMD_ARM_NEON) statements from the jsimd* algorithm functions. Since the jsimd_can*() functions check for the existence of NEON, the corresponding algorithm functions will never be called if NEON isn't available. Removing those if statements improved performance across the board by a couple of percent. Based on: https://github.com/mayeut/libjpeg-turbo/commit/fc023c880ce1d6c908fb78ccc25f5d5fd910ccc5
DRC 1e32fe31 2015-10-14T17:32:39 Replace INT32 with a new internal datatype (JLONG) These days, INT32 is a commonly-defined datatype in system headers. We cannot eliminate the definition of that datatype from jmorecfg.h, since the INT32 typedef has technically been part of the libjpeg API since version 5 (1994.) However, using INT32 internally is risky, because the inclusion of a particular header (Xmd.h, for instance) could change the definition of INT32 from long to int on 64-bit platforms and thus change the internal behavior of libjpeg-turbo in unexpected ways (for instance, failing to correctly set __INT32_IS_ACTUALLY_LONG to match the INT32 typedef-- perhaps as a result of including the wrong version of jpeglib.h-- could cause libjpeg-turbo to produce incorrect results.) The library has always been built in environments in which INT32 is effectively long (on Windows, long is always 32-bit, so effectively it's the same as int), so it makes sense to turn INT32 into an explicitly long datatype. This ensures that libjpeg-turbo will always behave consistently, regardless of the headers included at compile time. Addresses a concern expressed in #26.
DRC a6efae14 2014-08-25T15:26:09 Reformat code per Siarhei's original patch (to clearly indicate that the offset instructions are completely independent) and add Siarhei as an individual author (he no longer works for Nokia.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1388 632fc199-4ca6-4c93-a231-07263d6284db
DRC d729f4da 2014-08-23T15:47:51 ARM NEON SIMD support for YCC-to-RGB565 conversion, and optimizations to the existing YCC-to-RGB conversion code: ----- https://github.com/ssvb/libjpeg-turbo/commit/aee36252be20054afce371a92406fc66ba6627b5.patch From aee36252be20054afce371a92406fc66ba6627b5 Mon Sep 17 00:00:00 2001 From: Siarhei Siamashka <siarhei.siamashka@gmail.com> Date: Wed, 13 Aug 2014 03:50:22 +0300 Subject: [PATCH] ARM: Faster NEON yuv->rgb conversion for Krait and Cortex-A15 The older code was developed and tested only on ARM Cortex-A8 and ARM Cortex-A9. Tuning it for newer ARM processors can introduce some speed-up (up to 20%). The performance of the inner loop (conversion of 8 pixels) improves from ~27 cycles down to ~22 cycles on Qualcomm Krait 300, and from ~20 cycles down to ~18 cycles on ARM Cortex-A15. The performance remains exactly the same on ARM Cortex-A7 (~58 cycles), ARM Cortex-A8 (~25 cycles) and ARM Cortex-A9 (~30 cycles) processors. Also use larger indentation in the source code for separating two independent instruction streams. ----- https://github.com/ssvb/libjpeg-turbo/commit/a5efdbf22ce9c1acd4b14a353cec863c2c57557e.patch From a5efdbf22ce9c1acd4b14a353cec863c2c57557e Mon Sep 17 00:00:00 2001 From: Siarhei Siamashka <siarhei.siamashka@gmail.com> Date: Wed, 13 Aug 2014 07:23:09 +0300 Subject: [PATCH] ARM: NEON optimized yuv->rgb565 conversion The performance of the inner loop (conversion of 8 pixels): * ARM Cortex-A7: ~55 cycles * ARM Cortex-A8: ~28 cycles * ARM Cortex-A9: ~32 cycles * ARM Cortex-A15: ~20 cycles * Qualcomm Krait: ~24 cycles Based on the Linaro rgb565 patch from https://sourceforge.net/p/libjpeg-turbo/patches/24/ but implements better instructions scheduling. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1385 632fc199-4ca6-4c93-a231-07263d6284db
DRC 2e2ce5a1 2014-08-22T11:31:46 .func/.endfunc are only necessary when generating STABS debug info, which basically went out of style with parachute pants and Rick Astley. At any rate, none of the platforms for which we're building the ARM code use it (DWARF is the common format these days), and the .func/.endfunc directives cause the clang integrated assembler to fail (http://llvm.org/bugs/show_bug.cgi?id=20424). git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1375 632fc199-4ca6-4c93-a231-07263d6284db
DRC 3e00f03a 2014-02-05T07:40:00 Formatting tweaks git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@1107 632fc199-4ca6-4c93-a231-07263d6284db
DRC 316617fa 2012-06-13T05:17:03 Accelerated 4:2:2 upsampling routine for ARM (improves performance ~20-30% when decompressing 4:2:2 JPEGs using fancy upsampling) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.2.x@837 632fc199-4ca6-4c93-a231-07263d6284db
DRC b071f01c 2011-09-06T18:58:22 Update Nokia contact info git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@694 632fc199-4ca6-4c93-a231-07263d6284db
DRC ad6955d4 2011-09-06T18:57:53 Improve performance of IFAST iDCT by changing the order of transpose and descale steps git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@693 632fc199-4ca6-4c93-a231-07263d6284db
DRC 5129e396 2011-09-06T18:55:45 Make ARM ISLOW iDCT faster on typical cases, and eliminate the possibility of 16-bit overflows when handling arbitrary coefficients. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@692 632fc199-4ca6-4c93-a231-07263d6284db
DRC 98a44fe0 2011-08-24T23:27:44 Improve the performance of YCbCr to RGB conversion on ARM git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@691 632fc199-4ca6-4c93-a231-07263d6284db
DRC ce4e3e86 2011-08-22T13:48:01 NEON-accelerated slow integer inverse DCT git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@690 632fc199-4ca6-4c93-a231-07263d6284db
DRC 82bd5219 2011-08-17T21:00:59 NEON-accelerated quantization git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@689 632fc199-4ca6-4c93-a231-07263d6284db
DRC 4b024a62 2011-08-15T08:36:51 Improve performance of ARM NEON IFAST iDCT git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@686 632fc199-4ca6-4c93-a231-07263d6284db
DRC 7a9376c1 2011-08-12T19:27:20 ARM NEON-accelerated RGB-to-YCbCr conversion git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@682 632fc199-4ca6-4c93-a231-07263d6284db
DRC b740054f 2011-08-10T23:31:13 Support for accelerated forward DCT using ARM NEON instructions git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@678 632fc199-4ca6-4c93-a231-07263d6284db
DRC 8c60d22f 2011-06-17T21:12:58 NEON-optimized 2x2 and 4x4 scaled iDCTs git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@662 632fc199-4ca6-4c93-a231-07263d6284db
DRC 4346f91f 2011-06-14T22:16:50 iOS ARM support git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@659 632fc199-4ca6-4c93-a231-07263d6284db
DRC 321e0686 2011-05-03T08:47:43 ARM NEON support git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@607 632fc199-4ca6-4c93-a231-07263d6284db