x32 ABI

Source: Wikipedia, the free encyclopedia.

The x32 ABI is an

syscall instruction) while using 32-bit pointers and thus avoiding the overhead of 64-bit pointers.[1][2][3]

Details

Though the x32 ABI limits the program to a

SPEC CPU 2000 benchmark, in which the x32 ABI version was 40% faster than the x86-64 version.[3][4] On average, x32 is 5–8% faster on the SPEC CPU integer benchmarks compared to x86-64. There is no speed advantage over x86-64 in the SPEC CPU floating-point benchmarks.[5] There are also some application benchmarks that demonstrate the advantages of the x32 ABI.[6]
[7]

ABI comparison
Feature i386 ABI x32 ABI x86-64 ABI
Pointers 4 bytes 8 bytes
Max. memory per process 4 GiB 128 TiB
Integer registers 6 (PIC) 15
FP registers 8 16
64-bit
arithmetic 		No Yes
Floating-point
arithmetic 		x87 SSE
Calling convention Memory Registers
PIC prologue 2–3 instructions None

History

Running a userspace that consists mostly of programs compiled in

LP64 code,[8]
just like it has been shown for x86-64. In that regard, the x32 ABI extends the ILP32-on-64bit concept to the x86-64 platform.

Several people had discussed the benefits of an x86-64 ABI with 32-bit pointers in the years since the

Hans Peter Anvin announced to the Linux kernel mailing list that he and H. J. Lu had been working on the x32 ABI.[10]

That same day, Linus Torvalds replied with a concern that the use of 32-bit time values in the x32 ABI could cause problems in the future.[11][12] This is because the use of 32-bit time values would cause the time values to overflow in the year 2038.[11][12] Following this request, the developers of the x32 ABI changed the time values to 64-bit.[13]

A presentation at the

Linux Plumbers Conference on September 7, 2011, covered the x32 ABI.[2]

The x32 ABI was merged into the Linux kernel for the 3.4 release with support being added to the

GNU C Library in version 2.16.[14]

In December 2018 there was discussion as to whether to deprecate the x32 ABI, which has not happened as of April 2023.[15]

Adoption

Linux distribution More information
Debian X32 Port
Gentoo Multilib via abi_x86_x32 use-flags
Yocto Project X32 ABI
T2 SDE x86-64

References

  1. ^ a b Thorsten Leemhuis (2011-09-13). "Kernel Log: x32 ABI gets around 64-bit drawbacks". www.h-online.com. Archived from the original on 28 October 2011. Retrieved 2011-11-01.
  2. ^ a b c "x32 - a native 32-bit ABI for x86-64". linuxplumbersconf.org. Retrieved 2012-06-12.
  3. ^ a b c "x32-abi". Google Sites. Retrieved 2011-11-01.
  4. ^ "181.mcf SPEC CPU2000 Benchmark Description File". Standard Performance Evaluation Corporation. 1999-10-14. Retrieved 2011-11-01.
  5. ^ H. J. Lu; H. Peter Anvin; Milind Girkar (September 2011). "X32 - A Native 32bit ABI For X86-64".
  6. doi:10.1016/j.procs.2013.05.394
    .
  7. ^ "Applications that Profit from the Underrated x32-ABI". www.sempria.de. Retrieved 22 May 2023.
  8. ^ Tony Bourke (2004-01-22). "Are 64-bit Binaries Really Slower than 32-bit Binaries?". Retrieved 2014-03-25.
  9. ^ Donald Knuth (February 2008). "Recent News: A Flame About 64-bit Pointers". Retrieved 15 May 2012.
  10. ^ H. Peter Anvin (27 August 2011). "RFD: x32 ABI system call numbers". Retrieved 15 May 2012.
  11. ^ a b Jonathan Corbet (2011-08-29). "The x32 system call ABI". LWN.net. Retrieved 2011-11-01.
  12. ^ a b Linus Torvalds (2011-08-26). "Re: RFD: x32 ABI system call numbers". LWN.net. Retrieved 2016-02-26.
  13. ^ Lu, H. J. (2011-11-24). "X32 project status update". libc-alpha (Mailing list). Retrieved 2019-10-17.
  14. ^ O'Donell, Carlos (30 June 2012). "The GNU C Library version 2.16 is now available". libc-alpha (Mailing list). Retrieved 27 December 2016.
  15. ^ "Can we drop upstream Linux x32 support?". LKML. Retrieved 13 March 2019.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=X32_ABI&oldid=1180743122"