Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
On Wed, 2005-06-08 at 19:20 -0700, Stephen Horner wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 18:00, Mon 06 Jun 05, Tres Melton wrote: Well, the pages I was reading used the nop trick but it looks like a better solution has been presented. I almost forgot that integers are still 32 bit on x86-64 so explaining the movl instead of movq. For those interested the gcc -S is (the #APP/#NO_APP is gcc's way of marking inline asm): - 8 -- #APP startit: #NO_APP movl$10, -20(%rbp) #APP stopit: #NO_APP - 8 -- Forgive me if this seems obvious to most, but i'm unclear on exactly what you are saying here about #APP and #NO_APP in regards to labelling assembly code. I'm very new to assembly, and this sounded to interesting for me to just say to myself meh i'll prolly learn it later . . . ^_^ Also I was curious why if you simply intend to lable a code block before assembly, that you don't just asm( pants on ); if asm() allows for such a thing ( couldn't find man 2 asm lol ). At any rate, thanks in advance. First, any blocks of asm([statements] [outputs] : [inputs] : [clobbers] ); that gcc encounters will be placed between #APP and #NO_APP. Second Mike's startit: and stopit: are labels or jump destinations and as such they must be one word (no spaces, dashes, etc.) but consume no space (except within the intermediate files). HTH, -- Tres --- This SF.Net email is sponsored by: NEC IT Guy Games. How far can you shotput a projector? How fast can you ride your desk chair down the office luge track? If you want to score the big prize, get to know the little guy. Play to win an NEC 61 plasma display: http://www.necitguy.com/?r=20 ___ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
On Thursday, 02 June 2005, at 15:56:40 (-0400),
John Ellson wrote:
RCS file: /cvsroot/enlightenment/eterm/libast/configure.in,v
retrieving revision 1.24
Got it, thanks.
On Thursday, 02 June 2005, at 16:02:00 (-0400),
Mike Frysinger wrote:
would an ifdef like:
#if STRICT_ISO_C99 || __GNUC__ 4
be unacceptable ? that way the installed libast wouldnt need to be
reconfigured/built/installed just to change STRICT_ISO_C99 ...
How about this:
#ifdef __GNUC__
# if __GNUC__ = 4
#define STRICT_ISO_C99
# fi
...
#endif
On Thursday, 02 June 2005, at 18:39:01 (-0600),
Tres Melton wrote:
#define BINSWAP(a, b) \
(((long) (a)) ^= ((long) (b)) ^= ((long) (a)) ^= ((long) (b)))
int main( void )
{
long a = 3;
long b = 8;
asm( noop;noop;noop );
BINSWAP(a,b);
asm( noop;noop;noop );
}
yields:
noop;noop;noop
movq-16(%rbp), %rdx
leaq-8(%rbp), %rax
xorq%rdx, (%rax)
movq-8(%rbp), %rdx
leaq-16(%rbp), %rax
xorq%rdx, (%rax)
movq-16(%rbp), %rdx
leaq-8(%rbp), %rax
xorq%rdx, (%rax)
noop;noop;noop
If you enable -O[123] then you will need to use the values a b before
and after the BINSWAP call or they will be optimized away. And simply
using immediate values like I did will cause the compiler to simply set
the different registers that are used to access them in reverse order.
In other words the swap gets optimized out. The above code is without
-O and is clearly more complicated (by more than double) than it needs
to be.
Interesting. You think I should just get rid of it then?
On Thursday, 02 June 2005, at 21:04:59 (-0400),
John Ellson wrote:
I understand that this is a ISO C99 restriction and that gcc4 is
just a bit more pedantic than gcc3.
gcc4 does C99 by default now, does it not?
In fact my first attempt at a fix was to just not use the xor
BINSWAP macro at all, but this is really a question for Michael. I
was just trying to get his code to compile.
It's actually slower normally but faster optimized:
-O0
Profiling SWAP() macro...300 iterations in 0.052468 seconds, 1.7489e-08
seconds per iteration
Profiling BINSWAP() macro...300 iterations in 0.067905 seconds, 2.2635e-08
seconds per iteration
-O2
Profiling SWAP() macro...300 iterations in 0.014328 seconds, 4.776e-09
seconds per iteration
Profiling BINSWAP() macro...300 iterations in 0.014183 seconds, 4.7277e-09
seconds per iteration
(Done with libast's make perf)
Michael
--
Michael Jennings (a.k.a. KainX) http://www.kainx.org/ [EMAIL PROTECTED]
n + 1, Inc., http://www.nplus1.net/ Author, Eterm (www.eterm.org)
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Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
On Monday 06 June 2005 07:09 pm, Tres Melton wrote:
The nop is just an easy way to place markers in the code so you
can find the interesting parts quickly. In reality it costs one clock
cycle for each nop.
i use asm label tricks:
$ cat test.c
int main(int argc, char *argv[])
{
int a;
asm(startit:);
a = 10;
asm(stopit:);
return 0;
}
$ gcc -c test.c objdump -d test.o
test.o: file format elf64-x86-64
Disassembly of section .text:
main:
0: 55 push %rbp
1: 48 89 e5mov%rsp,%rbp
4: 89 7d fcmov%edi,0xfffc(%rbp)
7: 48 89 75 f0 mov%rsi,0xfff0(%rbp)
000b startit:
b: c7 45 ec 0a 00 00 00movl $0xa,0xffec(%rbp)
0012 stopit:
12: b8 00 00 00 00 mov$0x0,%eax
17: c9 leaveq
18: c3 retq
-mike
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Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
Michael Jennings wrote: Why not just define STRICT_ISO_C99? I created it specifically for that purpose. Sure, but then there should be a configure test for the cases that need it. john --- This SF.Net email is sponsored by Yahoo. Introducing Yahoo! Search Developer Network - Create apps using Yahoo! Search APIs Find out how you can build Yahoo! directly into your own Applications - visit http://developer.yahoo.net/?fr=offad-ysdn-ostg-q22005 ___ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
On Thursday, 02 June 2005, at 13:56:28 (-0400), John Ellson wrote: Sure, but then there should be a configure test for the cases that need it. Patches welcome. :) Michael -- Michael Jennings (a.k.a. KainX) http://www.kainx.org/ [EMAIL PROTECTED] n + 1, Inc., http://www.nplus1.net/ Author, Eterm (www.eterm.org) --- If you can scrounge up another brain cell, you might captivate us further...but I doubt it. You couldn't get a clue during clue-mating season in a field full of horny clues if you smeared your body with clue musk and did the clue mating dance. -- OS2Bot --- This SF.Net email is sponsored by Yahoo. Introducing Yahoo! Search Developer Network - Create apps using Yahoo! Search APIs Find out how you can build Yahoo! directly into your own Applications - visit http://developer.yahoo.net/?fr=offad-ysdn-ostg-q22005 ___ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
Michael Jennings wrote:
On Thursday, 02 June 2005, at 13:56:28 (-0400),
John Ellson wrote:
Sure, but then there should be a configure test for the cases that need it.
Patches welcome. :)
Michael
RCS file: /cvsroot/enlightenment/eterm/libast/configure.in,v
retrieving revision 1.24
diff -u -r1.24 configure.in
--- configure.in7 Mar 2005 20:07:10 - 1.24
+++ configure.in2 Jun 2005 19:53:08 -
@@ -77,6 +77,24 @@
]
)
+AC_MSG_CHECKING(if STRICT_ISO_C99 required)
+AC_TRY_RUN([
+ int main () {
+ int a = 0, b = 0;
+ (long)a = (long)b;
+ return 0;
+ }]
+ ,
+ AC_MSG_RESULT(no)
+ ,
+ AC_MSG_RESULT(yes)
+ AC_DEFINE_UNQUOTED(STRICT_ISO_C99,1,[Define if compiler needs it])
+ ,
+ AC_MSG_RESULT(no - assumed because cross-compiling)
+ )
+
+
+
AST_X11_SUPPORT()
AST_IMLIB2_SUPPORT()
AST_MMX_SUPPORT()
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Re: [E-devel] Re: libast from Eterm CVS fails to build with gcc4 on x86_64
On Thursday 02 June 2005 01:01 pm, Michael Jennings wrote: On Thursday, 02 June 2005, at 10:28:15 (-0400), John Ellson wrote: The problem is that the xor trick isn't working for swapping pointers. One possible work around is to use the more straightfoward SWAP code: RCS file: /cvsroot/enlightenment/eterm/libast/include/libast.h,v retrieving revision 1.58 diff -u -r1.58 libast.h --- include/libast.h15 Dec 2004 00:00:19 - 1.58 +++ include/libast.h2 Jun 2005 14:25:33 - @@ -281,11 +281,11 @@ * @param a The first variable. * @param b The second variable. */ -#if STRICT_ISO_C99 +// #if STRICT_ISO_C99 Why not just define STRICT_ISO_C99? I created it specifically for that purpose. would an ifdef like: #if STRICT_ISO_C99 || __GNUC__ 4 be unacceptable ? that way the installed libast wouldnt need to be reconfigured/built/installed just to change STRICT_ISO_C99 ... -mike --- This SF.Net email is sponsored by Yahoo. Introducing Yahoo! Search Developer Network - Create apps using Yahoo! Search APIs Find out how you can build Yahoo! directly into your own Applications - visit http://developer.yahoo.net/?fr=offad-ysdn-ostg-q22005 ___ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
