From a14c918ddd41c66bc2163ee6c17bdc77bd1e67de Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 30 May 2003 17:49:37 +0000 Subject: [PATCH] (__lll_mutex_lock_wait): Replace one memory operation with one register operation. --- .../unix/sysv/linux/i386/i486/lowlevelmutex.S | 21 +++++++++++++-------- nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelmutex.S | 10 ++++++---- 2 files changed, 19 insertions(+), 12 deletions(-) diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevelmutex.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevelmutex.S index 484beaf..a54e48c 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevelmutex.S +++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevelmutex.S @@ -45,21 +45,23 @@ __lll_mutex_lock_wait: pushl %ebx pushl %edx + /* In the loop we are going to add 2 instead of 1 which is what + the caller did. Account for that. */ + subl $1, %eax + movl %ecx, %ebx xorl %esi, %esi /* No timeout. */ xorl %ecx, %ecx /* movl $FUTEX_WAIT, %ecx */ 1: - leal 1(%eax), %edx /* account for the preceeded xadd. */ + leal 2(%eax), %edx /* account for the preceeded xadd. */ movl $SYS_futex, %eax ENTER_KERNEL - movl $1, %eax + movl $2, %eax LOCK xaddl %eax, (%ebx) testl %eax, %eax - jne 1b - - movl $2, (%ebx) + jne,pn 1b popl %edx popl %ebx @@ -83,13 +85,17 @@ __lll_mutex_timedlock_wait: pushl %ebx pushl %ebp + /* In the loop we are going to add 2 instead of 1 which is what + the caller did. Account for that. */ + subl $1, %eax + /* Stack frame for the timespec and timeval structs. */ subl $8, %esp movl %ecx, %ebp movl %edx, %edi -1: leal 1(%eax), %esi +1: leal 2(%eax), %esi /* Get current time. */ movl %esp, %ebx @@ -122,13 +128,12 @@ __lll_mutex_timedlock_wait: ENTER_KERNEL movl %eax, %ecx - movl $1, %eax + movl $2, %eax LOCK xaddl %eax, (%ebx) testl %eax, %eax jne 7f - movl $2, (%ebx) xorl %eax, %eax 6: addl $8, %esp diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelmutex.S b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelmutex.S index 1b2731a..2a2f847 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelmutex.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelmutex.S @@ -46,22 +46,24 @@ __lll_mutex_lock_wait: pushq %r10 pushq %rdx + /* In the loop we are going to add 2 instead of 1 which is what + the caller did. Account for that. */ + decq %rsi + xorq %r10, %r10 /* No timeout. */ 1: - leaq 1(%rsi), %rdx /* account for the preceeded xadd. */ + leaq 2(%rsi), %rdx /* account for the preceeded xadd. */ movq %r10, %rsi /* movq $FUTEX_WAIT, %rsi */ movq $SYS_futex, %rax syscall - movl $1, %esi + movl $2, %esi LOCK xaddl %esi, (%rdi) testl %esi, %esi jne 1b - movl $2, (%rdi) - popq %rdx popq %r10 retq -- 2.7.4