[hurd,commited] x86-64: Use 32-bit zero idiom for shorter encoding
Samuel Thibault <[email protected]>
| Newsgroups | gmane.os.hurd.cvs,gmane.comp.lib.glibc.alpha |
|---|---|
| Message-ID | <[email protected]> |
From: George Hu <[email protected]> Replace the 64-bit zero idiom with the 32-bit form. In 64-bit mode, zeroing the lower 32 bits of a GPR implicitly clears the entire register. The 32-bit encoding is one byte shorter while preserving identical semantics. Reviewed-by: Samuel Thibault <[email protected]> --- sysdeps/mach/hurd/x86_64/static-start.S | 2 +- sysdeps/mach/hurd/x86_64/tst-sig-redzone.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/sysdeps/mach/hurd/x86_64/static-start.S b/sysdeps/mach/hurd/x86_64/static-start.S index ec9c50239e..d670d45210 100644 --- a/sysdeps/mach/hurd/x86_64/static-start.S +++ b/sysdeps/mach/hurd/x86_64/static-start.S @@ -27,7 +27,7 @@ _start: movq %rsp, %rdi call _hurd_stack_setup - xorq %rdx, %rdx + xorl %edx, %edx jmp _start1 #define _start _start1 diff --git a/sysdeps/mach/hurd/x86_64/tst-sig-redzone.c b/sysdeps/mach/hurd/x86_64/tst-sig-redzone.c index 32c7ab90f4..24b510c0aa 100644 --- a/sysdeps/mach/hurd/x86_64/tst-sig-redzone.c +++ b/sysdeps/mach/hurd/x86_64/tst-sig-redzone.c @@ -103,7 +103,7 @@ asm ( "repe scasq\n" " jne fail\n" -" xor %rax,%rax\n" +" xor %eax,%eax\n" " ret\n" "fail:\n" " movq $1,%rax\n" -- 2.51.0