x86-64: Implement strcat family IFUNC selectors in C
commit9ed0aa15d316fb30e056d3a2e8f3361460c67e78
authorH.J. Lu <hjl.tools@gmail.com>
Thu, 15 Jun 2017 15:56:48 +0000 (15 08:56 -0700)
committerH.J. Lu <hjl.tools@gmail.com>
Thu, 15 Jun 2017 15:56:59 +0000 (15 08:56 -0700)
tree202758d5e45fbb9093bfbb3fbf442f25417f9da1
parentb91a52d0d77d8c532d2cfa13be0db92faa397c4b
x86-64: Implement strcat family IFUNC selectors in C

Implement strcat family IFUNC selectors in C.

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register.  For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized.  Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcat family functions within libc.

* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
strcat-sse2.
* sysdeps/x86_64/multiarch/strcat-sse2.S: New file.
* sysdeps/x86_64/multiarch/strcat.c: Likewise.
* sysdeps/x86_64/multiarch/strncat.c: Likewise.
* sysdeps/x86_64/multiarch/strcat.S: Removed.
* sysdeps/x86_64/multiarch/strncat.S: Likewise.
ChangeLog
sysdeps/x86_64/multiarch/Makefile
sysdeps/x86_64/multiarch/strcat-sse2.S [new file with mode: 0644]
sysdeps/x86_64/multiarch/strcat.S [deleted file]
sysdeps/x86_64/multiarch/strcat.c [new file with mode: 0644]
sysdeps/x86_64/multiarch/strncat.S [deleted file]
sysdeps/x86_64/multiarch/strncat.c [new file with mode: 0644]