Gcc Mtune

Using the GNU Compiler Collection (GCC): AArch64 Options

gcc.gnu.orgGCC uses nameto determine what kind of instructions it can emit when generating assembly code (as if by -march) and to determine the target processor for which to tune for performance (as if by -mtune). Where this option is used in conjunction

https://gcc.gnu.org/onlinedocs/gcc-8.3.0/gcc/AArch64-Options.html

It is more complicated than I thought: -mtune, -march in GCC

lemire.me25/7/2018 · For example, if GCC is configured for i686-pc-linux-gnu then -mtune=pentium4 generates code that is tuned for Pentium 4 but still runs on i686 machines. By default, when unspecified, “-mtune=generic” applies which means that the compiler will “produce code optimized for the most common processors”.

https://lemire.me/blog/2018/07/25/it-is-more-complicated-than-i-thought-mtune-march-in-gcc/

gcc – How does mtune actually work? – Stack Overflow

stackoverflow.comHowever, the existing answers don’t go much further than the GCC manual itself. At most, we get: If you use -mtune, then the compiler will generate code that works on any of them, but will favour instruction sequences that run fastest on the specific CPU you indicated.

https://stackoverflow.com/questions/44490331/how-does-mtune-actually-work

Using the GNU C/C++ compiler on AIX – IBM Developer

developer.ibm.com12/8/2008 · The GCC compiler is a part of the Free Software Foundation’s GNU Project. GCC is developed through an open source environment, as are all the GNU tools, and it supports many platforms including AIX. GCC stands for GNU Compiler Collection, and supports many languages such as C, C++, Objective C, Fortran, and Java.

https://developer.ibm.com/technologies/systems/articles/au-gnu/

Safe CFLAGS – Gentoo Wiki

wiki.gentoo.orgIn some cases – if you have unknown to GCC model – you will see suboptimal –mtune=generic (or even no –mtune?). You can select relevant –mtune= from manual. In some cases there are same to detected -march= or common –mtune=intel for (too) modern Intel CPUs. Also possible (???) suboptimal -march=native detection – full l2-cache-size to single CPU thread on multi-core CPUs. Currently it used …

https://wiki.gentoo.org/wiki/Safe_CFLAGS

GCC 10 Release Series — Changes, New Features, and Fixes …

gnu.orgThe GCC identifiers can be used as arguments to the -mcpu or –mtune options, for example: -mcpu=cortex-a77 or –mtune=cortex-m35p. Support has been extended for the ACLE data-processing intrinsics to include 32-bit SIMD, saturating arithmetic, 16-bit multiplication and other related intrinsics aimed at DSP algorithm optimization.

http://www.gnu.org/software/gcc/gcc-10/changes.html

GNU Compiler Collection Flags

spec.org7/8/2019 · Tells GCC to use the GNU semantics for "inline" functions, that is, the behavior prior to the C99 standard. This switch may resolve duplicate symbol errors, as noted in the 502.gcc

http://www.spec.org/cpu2017/flags/gcc.2019-08-07.html

Roland Bouman’s blog: GCC: -march and -mtune

rpbouman.blogspot.com22/1/2007 · Finally you may find that the model and name of your processor are passed to the gcc compiler. As far as I cans see the information is used to set the values of the –mtune and – …

https://rpbouman.blogspot.com/2007/01/gcc-march-and-mtune.html

gcc – mtune – march haswell – Code Examples

code-examples.netGCC: mtune vs march vs mcpu (1) -mcpu unfortunately has different semantics for different targets. It’s deprecated for x86 (being a synonym for -mtune) but not for ARM, where it’s a sum of -march and -mtune. So to answer your question – on ARM, always use -mcpu for best performance, unless you care for backwards compatibility.

https://code-examples.net/en/q/28bd56c

-march -mtune, What’s the Difference? – riley’s blog

sdf.org30/10/2014 · gcc… -march=native -mtune=native Using -march=native will cause the compiler to generate machine code that matches the processor where it is currently running when optimizing code.

http://sdf.org/~riley/blog/2014/10/30/march-mtune/

Create a gcc crosscompiler for Raspberry Pi | Freckled OG …

freckled.dev29/7/2019 · –with-tune (optional) like –with-arch it defines the standard setting for the parameter –mtune.–with-fpu (optional) sets the default value for what floating-point hardware is available on the target.–with-float (optional) tells the compiler to use the “hardware floating point support” for floating point operations.–with-sysroot gets used in the compilation process to link against …

https://freckled.dev/how-to/2019/07/29/create-gcc-crosscompiler/

can’t build gcc-4.1.2; error: bad value (generic) for …

bbs.archlinux.org12/3/2009 · The default CFLAGS use -mtune=generic (read GCC docs for more info on march and mtune). For whatever reason, the old GCC doesn’t like generic. Try removing mtune and setting march to your CPU (e.g. march=pentium2). This is usually smart anyways for any compiling.

https://bbs.archlinux.org/viewtopic.php?id=66378

Gentoo Forums :: View topic – march vs mtune

forums.gentoo.org11/3/2014 · Hi, since I started using Gentoo (AFAIR I started when GCC 4.5.x was current; now I am using 4.8.2) I set march and mtune. ~2 years ago I read in the old Gentoo wiki in the hardware flags/CFlags articles, that it is recommended to set march=yourcpu but mtune=generic due to some problems with gcc. I am unable to find these articles again.

https://forums.gentoo.org/viewtopic-p-7513794.html

D89025 [RISCV] Add -mtune support

reviews.llvm.org7/10/2020 · -mtune accept all valid option for -mcpu and extra alias processor option, e.g. generic, rocket and sifive-7-series, the purpose is option compatible with RISCV-V GCC. Processor alias for –mtune will resolve according the current target arch, rv32 or rv64, e.g. …

https://reviews.llvm.org/D89025

OpenWrt Forum Archive

forum.archive.openwrt.org16/4/2012 · -mtune=arch Optimize for arch. Among other things, this option controls the way instructions are scheduled, and the perceived cost of arithmetic operations. The list of arch values is the same as for -march. When this option is not used, GCC will optimize for the processor specified by -march. By using -march and –mtune together, it is possible to generate code that will run on a family of …

https://forum.archive.openwrt.org/viewtopic.php?id=35323

TinkerCliffs | Advanced Research Computing at Virginia Tech

arc.vt.eduFoss (GCC) toolchain: Use –mtune=znver2 -march=znver2 to target the Zen2 architecture; Use -mavx2 to get the optimal vectorization instruction set; AOCC Compiler: AMD compiler. Very fast on Rome architectures. ARC is working on getting AOCC integrated into a toolchain. Use –mtune=znver2 -march=znver2 to target the Zen2 architecture; Use -mavx2 to get the optimal vectorization instruction …

https://arc.vt.edu/tinkercliffs/

Hyperscan 5.3.0, gcc tune: -mtune=armv8-a+crc not valid …

askubuntu.comHyperscan 5.3.0, gcc tune: –mtune=armv8-a+crc not valid. Ask Question Asked 4 months ago. Active 4 months ago. Viewed 45 times 0. I’m using …

https://askubuntu.com/questions/1253651/hyperscan-5-3-0-gcc-tune-mtune-armv8-acrc-not-valid

Optimal GCC compile flags for 2nd gen i7 – Intel Community

community.intel.comThe -march=corei7 option of gcc 4.6 (replacing the pentium4 and barcelona options)is intended for the original Core I7 (still OK for I7-2). With gcc 4.5 on I7-2,you can use -mavx in place of -msse4and sometimes get an advantage. I expect 4.6 would get more out of -mavx.I’ve never tried …

https://community.intel.com/t5/Software-Tuning-Performance/Optimal-GCC-compile-flags-for-2nd-gen-i7/td-p/836503

SPARC Optimizations With GCC – OSnews

osnews.commtune flags works as the -mcpu has typically been used on the x86 platform, by tuning code for a particular platform but not taking advantage of additional instructions. (It should be noted that the -mcpu flag has actually been deprecated on x86 GCC in favor of –mtune.) So while –mtune is the same on both x86 and SPARC (creates backward compatible tuned binaries), -mcpu creates CPU-specific …

https://www.osnews.com/story/6136/sparc-optimizations-with-gcc/

Leave a Reply