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| author | H.J. Lu <hjl.tools@gmail.com> | 2016-05-24 08:44:10 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2016-05-24 08:44:23 -0700 |
| commit | 6901def689b5c77465d34f07822989ec67e80c1e (patch) | |
| tree | 2efde72294545c6b0129133d43d1f7335182fa61 /configure.ac | |
| parent | 4c011268960c6f24650672597deed756f21ad363 (diff) | |
Avoid an extra branch to PLT for -z now
When --enable-bind-now is used to configure glibc build, we can avoid
an extra branch to the PLT entry by using indirect branch via the GOT
slot instead, which is similar to the first instructuon in the PLT
entry. Changes in the shared library sizes in text sections:
Shared library Before (bytes) After (bytes)
libm.so 1060813 1060797
libmvec.so 160881 160805
libpthread.so 94992 94984
librt.so 25064 25048
* config.h.in (BIND_NOW): New.
* configure.ac (BIND_NOW): New. Defined for --enable-bind-now.
* configure: Regenerated.
* sysdeps/x86_64/sysdep.h (JUMPTARGET)[BIND_NOW]: Defined to
indirect branch via the GOT slot.
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 3c766b7409..123f0d26ee 100644 --- a/configure.ac +++ b/configure.ac @@ -231,6 +231,9 @@ AC_ARG_ENABLE([bind-now], [bindnow=$enableval], [bindnow=no]) AC_SUBST(bindnow) +if test "x$bindnow" = xyes; then + AC_DEFINE(BIND_NOW) +fi dnl On some platforms we cannot use dynamic loading. We must provide dnl static NSS modules. |