[PATCH v2 3/3] tools/nolibc: x86_64: use local label in memcpy/memmove

Thomas Weißschuh posted 3 patches 1 year, 6 months ago
[PATCH v2 3/3] tools/nolibc: x86_64: use local label in memcpy/memmove
Posted by Thomas Weißschuh 1 year, 6 months ago
Compiling arch-x86_64.h with clang and binutils LD yields
duplicate label errors:

.../gcc-13.2.0-nolibc/x86_64-linux/bin/x86_64-linux-ld: error: LLVM gold plugin: <inline asm>:44:1: symbol '.Lbackward_copy' is already defined
.Lbackward_copy:leaq -1(%rdi, %rcx, 1), %rdi

Instead of a local symbol use a local label which can be defined
multiple times and therefore avoids the error.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/arch-x86_64.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/include/nolibc/arch-x86_64.h b/tools/include/nolibc/arch-x86_64.h
index 65252c005a30..1e40620a2b33 100644
--- a/tools/include/nolibc/arch-x86_64.h
+++ b/tools/include/nolibc/arch-x86_64.h
@@ -193,10 +193,10 @@ __asm__ (
 	"movq %rdi, %rdx\n\t"
 	"subq %rsi, %rdx\n\t"
 	"cmpq %rcx, %rdx\n\t"
-	"jb   .Lbackward_copy\n\t"
+	"jb   1f\n\t"
 	"rep movsb\n\t"
 	"retq\n"
-".Lbackward_copy:"
+"1:" /* backward copy */
 	"leaq -1(%rdi, %rcx, 1), %rdi\n\t"
 	"leaq -1(%rsi, %rcx, 1), %rsi\n\t"
 	"std\n\t"

-- 
2.46.0

Re: [PATCH v2 3/3] tools/nolibc: x86_64: use local label in memcpy/memmove
Posted by Ammar Faizi 1 year, 6 months ago
On Mon, Aug 12, 2024 at 10:50:19PM +0200, Thomas Weißschuh wrote:
> Compiling arch-x86_64.h with clang and binutils LD yields
> duplicate label errors:
> 
> .../gcc-13.2.0-nolibc/x86_64-linux/bin/x86_64-linux-ld: error: LLVM gold plugin: <inline asm>:44:1: symbol '.Lbackward_copy' is already defined
> .Lbackward_copy:leaq -1(%rdi, %rcx, 1), %rdi
> 
> Instead of a local symbol use a local label which can be defined
> multiple times and therefore avoids the error.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---

Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>

-- 
Ammar Faizi