[haiku-commits] BRANCH xyzzy-github.x86_64 - in src/system: libroot/os/arch/x86_64 boot/platform/bios_ia32
- From: xyzzy-github.x86_64 <community@xxxxxxxxxxxx>
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Mon, 9 Jul 2012 10:49:13 +0200 (CEST)
added 1 changeset to branch 'refs/remotes/xyzzy-github/x86_64'
old head: 93cba1da96275eb617fcdc581ec4522e0b107adf
new head: bc3093488f72315d8474d45b3dfe34cdc15ef4d6
----------------------------------------------------------------------------
bc30934: Changes suggested by Ingo: style fix, and a system_time optimization.
[ Alex Smith <alex@xxxxxxxxxxxxxxxx> ]
----------------------------------------------------------------------------
Commit: bc3093488f72315d8474d45b3dfe34cdc15ef4d6
Author: Alex Smith <alex@xxxxxxxxxxxxxxxx>
Date: Mon Jul 9 08:03:11 2012 UTC
----------------------------------------------------------------------------
2 files changed, 11 insertions(+), 6 deletions(-)
src/system/boot/platform/bios_ia32/mmu.cpp | 2 +-
.../libroot/os/arch/x86_64/system_time_asm.S | 15 ++++++++++-----
----------------------------------------------------------------------------
diff --git a/src/system/boot/platform/bios_ia32/mmu.cpp
b/src/system/boot/platform/bios_ia32/mmu.cpp
index 05167e7..4eef5de 100644
--- a/src/system/boot/platform/bios_ia32/mmu.cpp
+++ b/src/system/boot/platform/bios_ia32/mmu.cpp
@@ -522,7 +522,7 @@ mmu_get_virtual_mapping(addr_t virtualAddress, addr_t
*_physicalAddress)
if ((tableEntry & (1 << 0)) == 0)
return false;
- *_physicalAddress = tableEntry & 0xFFFFF000;
+ *_physicalAddress = tableEntry & 0xfffff000;
return true;
}
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 f63bdf3..135b54a 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
@@ -28,7 +28,10 @@ FUNCTION_END(__x86_setup_system_time)
/* int64 system_time(); */
FUNCTION(system_time):
+ // (rdtsc * cv_factor) >> 32.
+
movq cv_factor, %rcx
+ shl $32, %rcx
// Load 64-bit TSC into %eax (low), %edx (high).
rdtsc
@@ -40,17 +43,19 @@ FUNCTION(system_time):
// Multiply by conversion factor, result in %rax (low), %rdx (high).
mulq %rcx
- // Shift the result right by 32 bits.
- shr $32, %rax
- shl $32, %rdx
- orq %rdx, %rax
+ // Conversion factor preshifted by 32, whole result in high.
+ movq %rdx, %rax
ret
FUNCTION_END(system_time)
/* int64 system_time_nsecs(); */
FUNCTION(system_time_nsecs):
- // Same algorithm as system_time(), just with a different factor.
+ // Same algorithm as system_time(), but with a different factor.
+ // (rdtsc * cv_factor_nsecs) >> 32.
+ // Cannot pre-shift the factor here, otherwise we may lose the upper
+ // 32 bits.
+
movq cv_factor_nsecs, %rcx
// Load 64-bit TSC into %eax (low), %edx (high).
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