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authorUlrich Drepper <drepper@redhat.com>2009-08-07 20:36:53 -0700
committerUlrich Drepper <drepper@redhat.com>2009-08-07 20:36:53 -0700
commit9083bcc5dc747eeec24c2bb8bf5b7055b3bd4dbf (patch)
treee5078f60592dcf86fcd638a7db7a5fa530ec668e /nptl
parent57b378ac895c346d74758b54f9e388ed3ca30751 (diff)
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Small optimizations to cancellable x86-64 code.
Diffstat (limited to 'nptl')
-rw-r--r--nptl/ChangeLog9
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S1
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S2
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S40
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S58
5 files changed, 49 insertions, 61 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 3a74b5f..0f5c231 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,3 +1,12 @@
+2009-08-07 Ulrich Drepper <drepper@redhat.com>
+
+ * sysdeps/unix/sysv/linux/x86_64/sem_wait.S: Little optimizations
+ enabled by the special *_asynccancel functions.
+ * sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise.
+ * sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise.
+
+ * sysdeps/unix/sysv/linux/x86_64/cancellation.S: Include lowlevellock.h.
+
2009-08-04 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/x86_64/cancellation.S: New file.
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S b/nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S
index a51df3e..0d48ec6 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S
@@ -20,6 +20,7 @@
#include <sysdep.h>
#include <tcb-offsets.h>
#include <kernel-features.h>
+#include "lowlevellock.h"
#ifdef IS_IN_libpthread
# ifdef SHARED
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
index 4913beb..86bdac1 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
@@ -157,7 +157,6 @@ __pthread_cond_timedwait:
.LcleanupSTART1:
34: callq __pthread_enable_asynccancel
movl %eax, (%rsp)
- movq 8(%rsp), %rdi
movq %r13, %r10
movl $FUTEX_WAIT_BITSET, %esi
@@ -511,7 +510,6 @@ __pthread_cond_timedwait:
.LcleanupSTART2:
4: callq __pthread_enable_asynccancel
movl %eax, (%rsp)
- movq 8(%rsp), %rdi
leaq 32(%rsp), %r10
cmpq $-1, dep_mutex(%rdi)
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
index a66523e..45116b1 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
@@ -45,14 +45,11 @@ __pthread_cond_wait:
cfi_lsda(DW_EH_PE_udata4, .LexceptSTART)
#endif
- pushq %r12
- cfi_adjust_cfa_offset(8)
- cfi_rel_offset(%r12, 0)
pushq %r13
cfi_adjust_cfa_offset(8)
cfi_rel_offset(%r13, 0)
#define FRAME_SIZE 32
- subq $FRAME_SIZE, %rsp
+ leaq -FRAME_SIZE(%rsp), %rsp
cfi_adjust_cfa_offset(FRAME_SIZE)
/* Stack frame:
@@ -112,7 +109,7 @@ __pthread_cond_wait:
movl %edx, 4(%rsp)
/* Unlock. */
-8: movl cond_futex(%rdi), %r12d
+8: movl cond_futex(%rdi), %edx
LOCK
#if cond_lock == 0
decl (%rdi)
@@ -125,9 +122,7 @@ __pthread_cond_wait:
4: callq __pthread_enable_asynccancel
movl %eax, (%rsp)
- movq 8(%rsp), %rdi
xorq %r10, %r10
- movq %r12, %rdx
cmpq $-1, dep_mutex(%rdi)
leaq cond_futex(%rdi), %rdi
movl $FUTEX_WAIT, %esi
@@ -243,21 +238,14 @@ __pthread_cond_wait:
callq __pthread_mutex_cond_lock
-14: addq $FRAME_SIZE, %rsp
- cfi_adjust_cfa_offset(-FRAME_SIZE)
-
- popq %r13
- cfi_adjust_cfa_offset(-8)
- cfi_restore(%r13)
- popq %r12
- cfi_adjust_cfa_offset(-8)
- cfi_restore(%r12)
+14: movq FRAME_SIZE(%rsp), %r13
+ leaq FRAME_SIZE+8(%rsp), %rsp
+ cfi_adjust_cfa_offset(-(FRAME_SIZE + 8))
/* We return the result of the mutex_lock operation. */
retq
- cfi_adjust_cfa_offset(16 + FRAME_SIZE)
- cfi_rel_offset(%r12, FRAME_SIZE + 8)
+ cfi_adjust_cfa_offset(8 + FRAME_SIZE)
cfi_rel_offset(%r13, FRAME_SIZE)
18: callq __pthread_mutex_cond_lock_adjust
@@ -285,7 +273,11 @@ __pthread_cond_wait:
movl $LLL_PRIVATE, %eax
movl $LLL_SHARED, %esi
cmovne %eax, %esi
+ /* The call preserves %rdx. */
callq __lll_unlock_wake
+#if cond_lock != 0
+ subq $cond_lock, %rdi
+#endif
jmp 4b
/* Locking in loop failed. */
@@ -349,9 +341,7 @@ versioned_symbol (libpthread, __pthread_cond_wait, pthread_cond_wait,
__condvar_cleanup1:
/* Stack frame:
- rsp + 48
- +--------------------------+
- rsp + 40 | %r12 |
+ rsp + 40
+--------------------------+
rsp + 32 | %r13 |
+--------------------------+
@@ -410,7 +400,7 @@ __condvar_cleanup1:
3: subl $(1 << nwaiters_shift), cond_nwaiters(%rdi)
/* Wake up a thread which wants to destroy the condvar object. */
- xorq %r12, %r12
+ xorl %ecx, %ecx
cmpq $0xffffffffffffffff, total_seq(%rdi)
jne 4f
movl cond_nwaiters(%rdi), %eax
@@ -433,7 +423,7 @@ __condvar_cleanup1:
movl $SYS_futex, %eax
syscall
subq $cond_nwaiters, %rdi
- movl $1, %r12d
+ movl $1, %ecx
4: LOCK
#if cond_lock == 0
@@ -449,10 +439,11 @@ __condvar_cleanup1:
movl $LLL_PRIVATE, %eax
movl $LLL_SHARED, %esi
cmovne %eax, %esi
+ /* The call preserves %rcx. */
callq __lll_unlock_wake
/* Wake up all waiters to make sure no signal gets lost. */
-2: testq %r12, %r12
+2: testl %ecx, %ecx
jnz 5f
addq $cond_futex, %rdi
cmpq $-1, dep_mutex-cond_futex(%rdi)
@@ -474,7 +465,6 @@ __condvar_cleanup1:
callq __pthread_mutex_cond_lock
movq 24(%rsp), %rdi
- movq 40(%rsp), %r12
movq 32(%rsp), %r13
.LcallUR:
call _Unwind_Resume@PLT
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
index a01d745..2cf6ec1 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
@@ -61,16 +61,13 @@ sem_wait:
xorl %eax, %eax
retq
-1: pushq %r12
+ /* This push is only needed to store the sem_t pointer for the
+ exception handler. */
+1: pushq %rdi
cfi_adjust_cfa_offset(8)
- cfi_rel_offset(%r12, 0)
- pushq %r13
- cfi_adjust_cfa_offset(8)
- cfi_rel_offset(%r13, 0)
- movq %rdi, %r13
LOCK
- addq $1, NWAITERS(%r13)
+ addq $1, NWAITERS(%rdi)
.LcleanupSTART:
6: call __pthread_enable_asynccancel
@@ -78,7 +75,6 @@ sem_wait:
xorq %r10, %r10
movl $SYS_futex, %eax
- movq %r13, %rdi
#if FUTEX_WAIT == 0
movl PRIVATE(%rdi), %esi
#else
@@ -87,22 +83,23 @@ sem_wait:
#endif
xorl %edx, %edx
syscall
- movq %rax, %r12
+ movq %rax, %rcx
- movl %r8d, %edi
+ xchgq %r8, %rdi
call __pthread_disable_asynccancel
.LcleanupEND:
+ movq %r8, %rdi
- testq %r12, %r12
+ testq %rcx, %rcx
je 3f
- cmpq $-EWOULDBLOCK, %r12
+ cmpq $-EWOULDBLOCK, %rcx
jne 4f
3:
#if VALUE == 0
- movl (%r13), %eax
+ movl (%rdi), %eax
#else
- movl VALUE(%r13), %eax
+ movl VALUE(%rdi), %eax
#endif
5: testl %eax, %eax
je 6b
@@ -110,50 +107,43 @@ sem_wait:
leal -1(%rax), %edx
LOCK
#if VALUE == 0
- cmpxchgl %edx, (%r13)
+ cmpxchgl %edx, (%rdi)
#else
- cmpxchgl %edx, VALUE(%r13)
+ cmpxchgl %edx, VALUE(%rdi)
#endif
jne 5b
- LOCK
- subq $1, NWAITERS(%r13)
-
xorl %eax, %eax
-9: popq %r13
- cfi_adjust_cfa_offset(-8)
- cfi_restore(%r13)
- popq %r12
+9: LOCK
+ subq $1, NWAITERS(%rdi)
+
+ leaq 8(%rsp), %rsp
cfi_adjust_cfa_offset(-8)
- cfi_restore(%r12)
retq
- cfi_adjust_cfa_offset(2 * 8)
- cfi_rel_offset(%r12, 8)
- cfi_rel_offset(%r13, 0)
-4: negq %r12
+ cfi_adjust_cfa_offset(8)
+4: negq %rcx
#if USE___THREAD
movq errno@gottpoff(%rip), %rdx
- movl %r12d, %fs:(%rdx)
+ movl %ecx, %fs:(%rdx)
#else
+# error "not supported. %rcx and %rdi must be preserved"
callq __errno_location@plt
- movl %r12d, (%rax)
+ movl %ecx, (%rax)
#endif
orl $-1, %eax
- LOCK
- subq $1, NWAITERS(%r13)
-
jmp 9b
.size sem_wait,.-sem_wait
.type sem_wait_cleanup,@function
sem_wait_cleanup:
+ movq (%rsp), %rdi
LOCK
- subq $1, NWAITERS(%r13)
+ subq $1, NWAITERS(%rdi)
movq %rax, %rdi
.LcallUR:
call _Unwind_Resume@PLT