Re: [ros-dev] [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
30 Aug
2006
30 Aug
'06
9:29 p.m.
greatlrd(a)svn.reactos.org wrote:
Author: greatlrd
Date: Thu Aug 31 01:17:53 2006
New Revision: 23826
URL: http://svn.reactos.org/svn/reactos?rev=23826&view=rev
Log:
Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code.
but we need a C api for header to linking it right. Put the asm version to i386
sure there must be away to avoid this double-function-call overhead?
+.globl _UlongByteSwap
+
+.intel_syntax noprefix
+
+/* FUNCTIONS ***************************************************************/
+
+_UlongByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov eax,[ebp+8] // load the ULONG
+ bswap eax // swap the ULONG
+ pop ebp // restore the base
+ ret
this should work:
_UlongByteSwap:
mov eax,[esp+8] // load the ULONG
bswap eax // swap the ULONG
ret
+.globl _UlonglongByteSwap
+
+.intel_syntax noprefix
+
+/* FUNCTIONS ***************************************************************/
+
+_UlonglongByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov edx,[ebp+8] // load the higher part of ULONGLONG
+ mov eax,[ebp+12] // load the lower part of ULONGLONG
+ bswap edx // swap the higher part
+ bswap eax // swap the lower part
+ pop ebp // restore the base
+ ret
_UlonglongByteSwap:
mov edx,[esp+8] // load the higher part of ULONGLONG
mov eax,[esp+12] // load the lower part of ULONGLONG
bswap edx // swap the higher part
bswap eax // swap the lower part
ret
+_UshortByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov eax,[ebp+8] // load the USHORT
+ bswap eax // swap the USHORT, xchg is slow so we use
bswap with rol
+ rol eax,16 // make it USHORT
+ pop ebp // restore the base
+ ret
_UshortByteSwap:
mov eax,[esp+8] // load the USHORT
bswap eax // swap the USHORT, xchg is slow so we use bswap
with rol
rol eax,16 // make it USHORT
ret
or to save a byte...
_UshortByteSwap:
mov ebx,[esp+8] // load the USHORT
mov al, bh
mov ah, bl
ret
31 Aug
31 Aug
12:09 a.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
--- Reuel ben Yisrael <reuel(a)ev1.net> wrote:
greatlrd(a)svn.reactos.org wrote:
sure there must be away to avoid this double-function-call overhead?
The problem was probably the different calling conventions. If you changed
the asm versions to be FASTCALL then you wouldn't need the wrappers.
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Author: greatlrd
Date: Thu Aug 31 01:17:53 2006
New Revision: 23826
URL: http://svn.reactos.org/svn/reactos?rev=23826&view=rev
Log:
Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm
code.
but we need a C api for header to linking it
right. Put the asm version
to i386
5:58 p.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
Hi
Royce3
alex solv it
and he also wrote some other rtl* to asm
with some commit.
----- Original Message -----
From: "Reuel ben Yisrael" <reuel(a)ev1.net>
To: <ros-dev(a)reactos.org>
Sent: Wednesday, August 30, 2006 11:29 PM
Subject: Re: [ros-dev] [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap
RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api
for header to linking it right. Put the asm version to i386
sure there must be away to avoid this double-function-call overhead?
>+.globl _UlongByteSwap
>+
>+.intel_syntax noprefix
>+
>+/* FUNCTIONS ***************************************************************/
***************************************************************/
ULONGLONG
so we
use bswap with rol
greatlrd(a)svn.reactos.org wrote:
>Author: greatlrd
>Date: Thu Aug 31 01:17:53 2006
>New Revision: 23826
>
>URL: http://svn.reactos.org/svn/reactos?rev=23826&view=rev
>Log:
>Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm
code.
> but we need a C api for header to linking it
right. Put the asm
version to i386
+
+_UlongByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov eax,[ebp+8] // load the ULONG
+ bswap eax // swap the ULONG
+ pop ebp // restore the base
+ ret
this should work:
_UlongByteSwap:
mov eax,[esp+8] // load the ULONG
bswap eax // swap the ULONG
ret
>+.globl _UlonglongByteSwap
>+
>+.intel_syntax noprefix
>+
>+/* FUNCTIONS >+
>+_UlonglongByteSwap:
>+ push ebp // save base
>+ mov ebp,esp // move stack to base
>+ mov edx,[ebp+8] // load the higher part of
ULONGLONG
>+ mov eax,[ebp+12] // load
the lower part of
ULONGLONG
+
bswap edx // swap the higher part
+ bswap eax // swap the lower part
+ pop ebp // restore the base
+ ret
_UlonglongByteSwap:
mov edx,[esp+8] // load the higher part of mov eax,[esp+12] // load the
lower part of
ULONGLONG
bswap edx // swap the
higher part
bswap eax // swap the lower part
ret
>+_UshortByteSwap:
>+ push ebp // save base
>+ mov ebp,esp // move stack to base
>+ mov eax,[ebp+8] // load the USHORT
>+ bswap eax // swap the USHORT, xchg is
slow so
we use bswap with rol
+
rol eax,16 // make it USHORT
+ pop ebp // restore the base
+ ret
_UshortByteSwap:
mov eax,[esp+8] // load the USHORT
bswap eax // swap the USHORT, xchg is slow rol eax,16 // make it
USHORT
ret
or to save a byte...
_UshortByteSwap:
mov ebx,[esp+8] // load the USHORT
mov al, bh
mov ah, bl
ret
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11:40 p.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
The new implementations for RtlFillMemory, RtlZeroMemory, and RtlMoveMemory
have a bug where they don't write the last 1-3 bytes if the length isn't a
multiple of the word size. They have an "or ecx, ecx" which needs to be
"or
ecx, edx". Also the new RtlUlonglongByteSwap is sub-optimal, it swaps eax and
edx when they could have just been read in reverse order like the other
version did.
--- Magnus Olsen <magnus(a)itkonsult-olsen.com> wrote:
Hi
Royce3
alex solv it
and he also wrote some other rtl* to asm
with some commit.
----- Original Message -----
From: "Reuel ben Yisrael" <reuel(a)ev1.net>
To: <ros-dev(a)reactos.org>
Sent: Wednesday, August 30, 2006 11:29 PM
Subject: Re: [ros-dev] [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap
RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api
for header to linking it right. Put the asm version to i386
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greatlrd(a)svn.reactos.org wrote:
>Author: greatlrd
>Date: Thu Aug 31 01:17:53 2006
>New Revision: 23826
>
>URL: http://svn.reactos.org/svn/reactos?rev=23826&view=rev
>Log:
>Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to
asm
code.
> but we need a C api for header to linking
it right. Put the asm
version to i386
> >
> >
> sure there must be away to avoid this double-function-call overhead? 
1 Sep
1 Sep
3:12 a.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
mrnobo1024 wrote:
The new implementations for RtlFillMemory,
RtlZeroMemory, and RtlMoveMemory
have a bug where they don't write the last 1-3 bytes if the length isn't a
multiple of the word size. They have an "or ecx, ecx" which needs to be
"or
ecx, edx".
Noted, thanks! Surprised it still booted!
Also the new RtlUlonglongByteSwap is sub-optimal, it
swaps eax and
edx when they could have just been read in reverse order like the other
version did.
Not true. BSWAP will pair on the pipe and be executed much faster.
--
Best regards,
Alex Ionescu
Project Lead, TinyKRNL
Kernel-Mode Software Design Engineer, ReactOS
4:14 a.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
--- Alex Ionescu <ionucu(a)videotron.ca> wrote:
I meant that instead of mov edx,[esp+8] mov eax,[esp+4] it could be mov
edx,[esp+4] mov eax,[esp+8]. I don't think that would affect instruction pairing.
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mrnobo1024 wrote:
Looking at them again I noticed a couple other problems. At the end of
RtlCompareMemory it subtracts the length (esp+20) instead of the buffer start
(esp+12), and RtlCompareMemoryUlong subtracts from esi when it's using edi.
I also noticed some of the functions clear the direction flag, and some
don't. This would be either a bug or just unnecessary code. I don't know if
the Win32 calling conventions require the flag to be clear before calling a
function or not.
The new implementations for RtlFillMemory,
RtlZeroMemory, and
RtlMoveMemory
have a bug where they don't write the last
1-3 bytes if the length isn't
a
multiple of the word size. They have an "or
ecx, ecx" which needs to be
"or
ecx, edx".
Noted, thanks! Surprised it still booted! Also the new
RtlUlonglongByteSwap is sub-optimal, it swaps eax and
edx when they could have just been read in reverse order like the other
version did.
Not true. BSWAP will pair on the pipe and be executed much faster.
12:34 p.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
mrnobo1024 wrote:
--- Alex Ionescu <ionucu(a)videotron.ca> wrote:
I meant that instead of mov edx,[esp+8] mov eax,[esp+4] it could be mov
edx,[esp+4] mov eax,[esp+8]. I don't think that would affect instruction pairing.
That wouldn't swap them... you would just be inverting the bytes. Each
ULONG must be swapped here.
--
Best regards,
Alex Ionescu
Project Lead, TinyKRNL
Kernel-Mode Software Design Engineer, ReactOS
3:06 p.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
--- Alex Ionescu <ionucu(a)videotron.ca> wrote:
mrnobo1024 wrote:
That wouldn't swap them... you would just be inverting the bytes. Each
ULONG must be swapped here.
Which can be done without an explicit swap. Just change the way they're read
from the stack. As an example, suppose you're calling it with
0x0011223344556677:
edx eax ecx
mov edx, [esp+8] 00112233
mov eax, [esp+4] 00112233 44556677
bswap edx 33221100 44556677
bswap eax 33221100 77665544
mov ecx, eax 33221100 77665544 77665544
mov eax, edx 33221100 33221100 77665544
mov edx, ecx 77665544 33221100 77665544
mov edx, [esp+4] 44556677
mov eax, [esp+8] 44556677 00112233
bswap edx 77665544 00112233
bswap eax 77665544 33221100
They both give the correct answer in edx:eax, but the second would swap the
ulongs implicitly by reading the high ulong into eax and the low one into
edx. Much like how RtlUshortByteSwap works, but with ulongs instead of bytes.
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--- Alex Ionescu <ionucu(a)videotron.ca>
wrote:
I meant that instead of mov edx,[esp+8] mov eax,[esp+4] it could be mov
edx,[esp+4] mov eax,[esp+8]. I don't think that would affect instruction
pairing.
2 Sep
2 Sep
1:03 p.m.
New subject: [ros-diffs] [greatlrd] 23826: Wrote RtlUshotByteSwap RtlUlongByteSwap and RtlUlonglongByteSwap to asm code. but we need a C api for header to linking it right. Put the asm version to i386
If it should be optimized, inlined asm should be used as following:
Reuel ben Yisrael schrieb:
static force_inline ULONG UlongByteSwap(ULONG x)
{
asm volatile(
"bswap %0;"
: "=r" (x)
: "0" (x)
);
return x;
}
static force_inline ULONGLONG UlonglongByteSwap(ULONGLONG x)
{
ULONG h,l;
asm volatile ("": "=d" (l), "=a" (h): "A"
(x));
asm volatile (
"bswap %%eax;"
"bswap %%edx;"
: "=A" (x)
: "d" (l), "a" (h)
);
return x;
}
static force_inline USHORT UshortByteSwap(USHORT x)
{
asm volatile(
"rolw $8, %0;"
: "=r" (x)
: "0" (x)
);
return x;
}
+.globl
_UlongByteSwap
+
+.intel_syntax noprefix
+
+/* FUNCTIONS ***************************************************************/
+
+_UlongByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov eax,[ebp+8] // load the ULONG
+ bswap eax // swap the ULONG
+ pop ebp // restore the base
+ ret
this should work:
_UlongByteSwap:
mov eax,[esp+8] // load the ULONG
bswap eax // swap the ULONG
ret
+.globl
_UlonglongByteSwap
+
+.intel_syntax noprefix
+
+/* FUNCTIONS ***************************************************************/
+
+_UlonglongByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov edx,[ebp+8] // load the higher part of ULONGLONG
+ mov eax,[ebp+12] // load the lower part of ULONGLONG
+ bswap edx // swap the higher part
+ bswap eax // swap the lower part
+ pop ebp // restore the base
+ ret
_UlonglongByteSwap:
mov edx,[esp+8] // load the higher part of ULONGLONG
mov eax,[esp+12] // load the lower part of ULONGLONG
bswap edx // swap the higher part
bswap eax // swap the lower part
ret
+_UshortByteSwap:
+ push ebp // save base
+ mov ebp,esp // move stack to base
+ mov eax,[ebp+8] // load the USHORT
+ bswap eax // swap the USHORT, xchg is slow so we use
bswap with rol
+ rol eax,16 // make it USHORT
+ pop ebp // restore the base
+ ret
_UshortByteSwap:
mov eax,[esp+8] // load the USHORT
bswap eax // swap the USHORT, xchg is slow so we use
bswap with rol
rol eax,16 // make it USHORT
ret
or to save a byte...
_UshortByteSwap:
mov ebx,[esp+8] // load the USHORT
mov al, bh
mov ah, bl
ret
6688
days inactive
6691
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8 comments
5 participants
participants (5)
-
Alex Ionescu -
Magnus Olsen -
mrnobo1024 -
Reuel ben Yisrael -
Timo Kreuzer