[haiku-commits] BRANCH xyzzy-github.x86_64 - src/system/libroot/os/arch/x86_64 src/system/kernel/arch/x86 headers/private/kernel/arch/x86
- From: xyzzy-github.x86_64 <community@xxxxxxxxxxxx>
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Sun, 8 Jul 2012 11:49:14 +0200 (CEST)
added 1 changeset to branch 'refs/remotes/xyzzy-github/x86_64'
old head: 7444a55ce55af4fecf298a1749c1c23228305385
new head: 5c7d52183c2182761151ba2f8f72bb7b39e50053
----------------------------------------------------------------------------
5c7d521: Implemented system_time() for x86_64.
* Uses 64-bit multiplication, special handling for CPUs clocked < 1 GHz
in system_time_nsecs() not required like on x86.
* Tested against a straight conversion of the x86 version, noticably
faster with a large number of system_time() calls.
[ Alex Smith <alex@xxxxxxxxxxxxxxxx> ]
----------------------------------------------------------------------------
Commit: 5c7d52183c2182761151ba2f8f72bb7b39e50053
Author: Alex Smith <alex@xxxxxxxxxxxxxxxx>
Date: Sun Jul 8 09:16:44 2012 UTC
----------------------------------------------------------------------------
3 files changed, 47 insertions(+), 113 deletions(-)
headers/private/kernel/arch/x86/arch_cpu.h | 7 +-
src/system/kernel/arch/x86/arch_cpu.cpp | 7 +
.../libroot/os/arch/x86_64/system_time_asm.S | 146 ++++------------
----------------------------------------------------------------------------
diff --git a/headers/private/kernel/arch/x86/arch_cpu.h
b/headers/private/kernel/arch/x86/arch_cpu.h
index f688a20..204c901 100644
--- a/headers/private/kernel/arch/x86/arch_cpu.h
+++ b/headers/private/kernel/arch/x86/arch_cpu.h
@@ -367,9 +367,14 @@ extern "C" {
struct arch_thread;
-
+#ifdef __x86_64__
+void __x86_setup_system_time(uint64 conversionFactor,
+ uint64 conversionFactorNsecs);
+#else
void __x86_setup_system_time(uint32 conversionFactor,
uint32 conversionFactorNsecs, bool conversionFactorNsecsShift);
+#endif
+
void x86_context_switch(struct arch_thread* oldState,
struct arch_thread* newState);
void x86_userspace_thread_exit(void);
diff --git a/src/system/kernel/arch/x86/arch_cpu.cpp
b/src/system/kernel/arch/x86/arch_cpu.cpp
index a618504..6a7a206 100644
--- a/src/system/kernel/arch/x86/arch_cpu.cpp
+++ b/src/system/kernel/arch/x86/arch_cpu.cpp
@@ -820,6 +820,12 @@ arch_cpu_init(kernel_args* args)
uint32 conversionFactor = args->arch_args.system_time_cv_factor;
uint64 conversionFactorNsecs = (uint64)conversionFactor * 1000;
+#ifdef __x86_64__
+ // The x86_64 system_time() implementation uses 64-bit multiplication
and
+ // therefore shifting is not necessary for low frequencies (it's also
not
+ // too likely that there'll be any x86_64 CPUs clocked under 1GHz).
+ __x86_setup_system_time(conversionFactor, conversionFactorNsecs);
+#else
if (conversionFactorNsecs >> 32 != 0) {
// the TSC frequency is < 1 GHz, which forces us to shift the
factor
__x86_setup_system_time(conversionFactor, conversionFactorNsecs
>> 16,
@@ -828,6 +834,7 @@ arch_cpu_init(kernel_args* args)
// the TSC frequency is >= 1 GHz
__x86_setup_system_time(conversionFactor,
conversionFactorNsecs, false);
}
+#endif
return B_OK;
}
diff --git a/src/system/libroot/os/arch/x86_64/system_time_asm.S
b/src/system/libroot/os/arch/x86_64/system_time_asm.S
index d6df8fa..f63bdf3 100644
--- a/src/system/libroot/os/arch/x86_64/system_time_asm.S
+++ b/src/system/libroot/os/arch/x86_64/system_time_asm.S
@@ -7,143 +7,65 @@
* Distributed under the terms of the NewOS License.
*/
-#include <asm_defs.h>
-
-FUNCTION(__x86_setup_system_time):
- ret
-FUNCTION_END(__x86_setup_system_time)
-
-// TODO: Implement these.
-
-/* int64 system_time(); */
-FUNCTION(system_time):
- ud2a
- ret
-FUNCTION_END(system_time)
+#include <asm_defs.h>
-/* int64 system_time_nsecs(); */
-FUNCTION(system_time_nsecs):
- ud2a
- ret
-FUNCTION_END(system_time_nsecs)
-#if 0
/* saves the conversion factor needed for system_time */
-.lcomm cv_factor 4
-.lcomm cv_factor_nsecs 4
-.lcomm cv_factor_nsecs_shift 1
+.lcomm cv_factor 8
+.lcomm cv_factor_nsecs 8
.text
FUNCTION(__x86_setup_system_time):
- movl 4(%esp), %eax
- movl %eax, cv_factor
- movl 8(%esp), %eax
- movl %eax, cv_factor_nsecs
- movb 12(%esp), %al
- movb %al, cv_factor_nsecs_shift
+ movq %rdi, cv_factor
+ movq %rsi, cv_factor_nsecs
ret
FUNCTION_END(__x86_setup_system_time)
/* int64 system_time(); */
FUNCTION(system_time):
- pushl %ebx
- pushl %ecx
- movl cv_factor, %ebx
-
- /* load 64-bit factor into %eax (low), %edx (high) */
- rdtsc /* time in %edx,%eax */
-
- movl %edx, %ecx /* save high half */
- mull %ebx /* truncate %eax, but keep %edx */
- movl %ecx, %eax
- movl %edx, %ecx /* save high half of low */
- mull %ebx /*, %eax*/
- /* now compute [%edx, %eax] + [%ecx], propagating carry */
- subl %ebx, %ebx /* need zero to propagate carry */
- addl %ecx, %eax
- adc %ebx, %edx
- popl %ecx
- popl %ebx
- ret
-FUNCTION_END(system_time)
-
-
-/* int64 system_time_nsecs(); */
-FUNCTION(system_time_nsecs):
- testb $0, cv_factor_nsecs_shift
- jne 1f
-
- /* same algorithm as system_time(), just with a different factor */
-
- pushl %ebx
- pushl %ecx
- movl cv_factor_nsecs, %ebx
-
- /* load 64-bit factor into %eax (low), %edx (high) */
- rdtsc /* time in %edx,%eax */
-
- movl %edx, %ecx /* save high half */
- mull %ebx /* truncate %eax, but keep %edx */
- movl %ecx, %eax
- movl %edx, %ecx /* save high half of low */
- mull %ebx /*, %eax*/
- /* now compute [%edx, %eax] + [%ecx], propagating carry */
- subl %ebx, %ebx /* need zero to propagate carry */
- addl %ecx, %eax
- adc %ebx, %edx
- popl %ecx
- popl %ebx
- ret
+ movq cv_factor, %rcx
-1:
- /* TSC frequency is less than 1 GHz -- we shift everything up 16 bit */
+ // Load 64-bit TSC into %eax (low), %edx (high).
+ rdtsc
- pushl %ebx
- pushl %ecx
- pushl %esi
- movl cv_factor_nsecs, %ebx
+ // Convert into a single 64-bit value.
+ shl $32, %rdx
+ orq %rdx, %rax
- /* load 64-bit factor into %eax (low), %edx (high) */
- rdtsc /* time in %edx,%eax */
+ // Multiply by conversion factor, result in %rax (low), %rdx (high).
+ mulq %rcx
- /* save high half */
- movl %edx, %ecx
-
- /* multiply low half by conversion factor */
- mull %ebx
+ // Shift the result right by 32 bits.
+ shr $32, %rax
+ shl $32, %rdx
+ orq %rdx, %rax
+ ret
+FUNCTION_END(system_time)
- /* save result */
- movl %eax, %esi /* low half -> %esi */
- movl %ecx, %eax
- movl %edx, %ecx /* high half -> %ecx */
- /* multiply high half by conversion factor */
- mull %ebx
+/* int64 system_time_nsecs(); */
+FUNCTION(system_time_nsecs):
+ // Same algorithm as system_time(), just with a different factor.
+ movq cv_factor_nsecs, %rcx
- /* now compute [%edx, %eax] + [%ecx], propagating carry */
- xorl %ebx, %ebx /* need zero to propagate carry */
- addl %ecx, %eax
- adc %ebx, %edx
+ // Load 64-bit TSC into %eax (low), %edx (high).
+ rdtsc
- /* shift the result left 16 bit */
- shl $16, %edx
- movl %eax, %ebx
- shr $16, %ebx
- orw %bx, %dx
- shl $16, %eax
+ // Convert into a single 64-bit value.
+ shl $32, %rdx
+ orq %rdx, %rax
- /* add the high 16 bit of the low half of the low product */
- shr $16, %esi
- orw %si, %ax
+ // Multiply by conversion factor, result in %rax (low), %rdx (high).
+ mulq %rcx
- popl %esi
- popl %ecx
- popl %ebx
+ // Shift the result right by 32 bits.
+ shr $32, %rax
+ shl $32, %rdx
+ orq %rdx, %rax
ret
FUNCTION_END(system_time_nsecs)
-#endif
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