From 6901def689b5c77465d34f07822989ec67e80c1e Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 24 May 2016 08:44:10 -0700 Subject: 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. --- config.h.in | 3 +++ 1 file changed, 3 insertions(+) (limited to 'config.h.in') diff --git a/config.h.in b/config.h.in index 0147ba3c34..2c902b0214 100644 --- a/config.h.in +++ b/config.h.in @@ -87,6 +87,9 @@ include/libc-symbols.h that avoid PLT slots in the shared objects. */ #undef NO_HIDDEN +/* Define this to disable lazy relocations in DSOs. */ +#undef BIND_NOW + /* AArch64 big endian ABI */ #undef HAVE_AARCH64_BE -- cgit v1.2.1