From: Xi Ruoyao <xry111@xry111.site>
Date: Tue, 5 Dec 2023 19:05:47 +0000 (+0800)
Subject: LoongArch: Allow la.got -> la.pcrel relaxation for shared object
X-Git-Tag: binutils-2_42~529
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=15aacf324fb871871e2162ea8769a9f82c043909;p=thirdparty%2Fbinutils-gdb.git

LoongArch: Allow la.got -> la.pcrel relaxation for shared object

Even in shared objects, la.got -> la.pcrel relaxation can still be
performed for symbols with hidden visibility. For example, if a.c is:

    extern int x;
    int f() { return x++; }

and b.c is:

    int x = 114514;

If compiling and linking with:

    gcc -shared -fPIC -O2 -fvisibility=hidden a.c b.c

Then the la.got in a.o should be relaxed to la.pcrel, and the resulted f
should be like:

    pcaddi  $t0, x
    ldptr.w $a0, $t0, 0
    addi.w  $t1, $a0, 1
    stptr.w $t1, $t0, 0
    ret

Remove bfd_link_executable from the condition of la.got -> la.pcrel
relaxation so this will really happen.  The SYMBOL_REFERENCES_LOCAL
check is enough not to wrongly relax preemptable symbols (for e.g.
when -fvisibility=hidden is not used).

Note that on x86_64 this is also relaxed and the produced code is like:

    lea x(%rip), %rdx
    mov (%rdx), %rax
    lea 1(%rax), %ecx
    mov %ecx, (%rdx)
    ret

Tested by running ld test suite, bootstrapping and regtesting GCC with
the patched ld, and building and testing Glibc with the patched ld.  No
regression is observed.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
---

diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index aa88ee8f928..87eb65ab9f7 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -3993,8 +3993,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 	  else
 	    continue;
 
-	  if (h && bfd_link_executable (info)
-	      && SYMBOL_REFERENCES_LOCAL (info, h))
+	  if (h && SYMBOL_REFERENCES_LOCAL (info, h))
 	    local_got = true;
 	  symtype = h->type;
 	}