[LLVMdev] Linux Kernel Compile for Sparc v8 Arch

[Török Edwin]

On 2008-10-05 06:26, Keun Soo Yim wrote:
>
> Thanks Edwin and Chris for interests!
>
>  
>
>  
>
> Now, at least GCC front-end for Sparc has a problem at compilation.
> Chris, is there any document describing the process of porting GCC
> front-end to LLVM or would you like to explain a bit so that anyone
> interested in can port GCC front-end for Sparc and Power architecture
> to LLVM? It will make LLVM keep its initial status as until its
> version 1.6, it supported Sparc and Power front-ends.
>
>  
>
> This is a description of current Sparc front-end. The first error that
> I had was caused by the LLVM’s GCC front-end for x86. As the front-end
> I used was compiled for x86 target,
>

If you want to build a cross-compiler, then --target must be the arch
you want to generate code for (sparc in this case), and --build and
--host must be the host you are building the compiler on (x86 for you).

> it cannot translate the inline assembly code into the LLVM byte code.
> I tried to compile both original GCC 4.2 and the GCC front-end for
> LLVM however both had at least one error. The GCC 4.2 for Sparc, MIPS,
> and ARM is currently broken (see,
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32101).
>
So you're trying to build a cross-compiler, right?

I have a cross-compiler package from emdebian.org, so it should be
possible to build one (though I haven't tried to build one manually
neither for upstream gcc, nor for llvm-gcc):

$ sparc-linux-gnu-gcc -v
Using built-in specs.
Target: sparc-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++,obj-c++
--prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/sparc-linux-gnu/include/c++/4.2.4
--program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug
--with-cpu=v8 --with-long-double-128 --enable-checking=release
--program-prefix=sparc-linux-gnu-
--includedir=/usr/sparc-linux-gnu/include --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=sparc-linux-gnu
Thread model: posix
gcc version 4.2.4 (Debian 4.2.4-3)

Of course you'll also need a sparc binutils:
$ sparc-linux-gnu-as --version
GNU assembler (GNU Binutils) 2.18.0.20080103
Copyright 2007 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `sparc-linux-gnu'.

>  
>
> Edwin, new errors are attached below as I identified the reason of the
> previously posted errors. First bug I previously posted was due to
> inline assembly and the second bug is due to the difference in linker
> option which I solved by changing the option.
>
>  
>
> (1) An error message generated when compile GCC for Sparc architecture.
>
>  
>
> /home/ksyim/workspace/compiler/llvm/gcc-4.2.2/objdir-sparc/./gcc/xgcc
> -B/home/ksyim/workspace/compiler/llvm/gcc-4.2.2/objdir-sparc/./gcc/
> -B/home/ksyim/workspace/compiler/llvm/gcc-4.2.2/release-sparc/sparc-sun-linux/bin/
> -B/home/ksyim/workspace/compiler/llvm/gcc-4.2.2/release-sparc/sparc-sun-linux/lib/
> -isystem
> /home/ksyim/workspace/compiler/llvm/gcc-4.2.2/release-sparc/sparc-sun-linux/include
> -isystem
> /home/ksyim/workspace/compiler/llvm/gcc-4.2.2/release-sparc/sparc-sun-linux/sys-include
> -O2 -O2 -g -O2  -DIN_GCC -DCROSS_COMPILE   -W -Wall -Wwrite-strings
> -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition 
> -isystem ./include  -I. -I. -I../../gcc -I../../gcc/.
> -I../../gcc/../include -I../../gcc/../libcpp/include 
> -I../../gcc/../libdecnumber -I../libdecnumber  -g0
> -finhibit-size-directive -fno-inline-functions -fno-exceptions
> -fno-zero-initialized-in-bss -fno-toplevel-reorder -Dinhibit_libc  \
>
>           -c ../../gcc/crtstuff.c -DCRT_BEGIN \
>
>           -o crtbegin.o
>
> /home/ksyim/workspace/compiler/llvm/gcc-4.2.2/objdir-sparc/./gcc/as:
> line 2: exec: -Q: invalid option
>
> exec: usage: exec [-cl] [-a name] file [redirection ...]
>
> make[2]: *** [crtbegin.o] Error 1
>
> make[2]: Leaving directory
> `/scr/ksyim/workspace/compiler/llvm/gcc-4.2.2/objdir-sparc/gcc'
>

Does --disable-multilib, or --with-cpu=v8 help?

>  
>
>  
>
> (2) If I runaround (1), there comes another error!
>
>  
>
> /scr/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/objdir-sparc/./gcc/xgcc
> -B/scr/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/objdir-sparc/./gcc/
> -B/home/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/release-sparc//sparc-sun-linux/bin/
> -B/home/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/release-sparc//sparc-sun-linux/lib/
> -isystem
> /home/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/release-sparc//sparc-sun-linux/include
> -isystem
> /home/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/release-sparc//sparc-sun-linux/sys-include 
> -O2  -O2 -g -O2  -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE   -W -Wall
> -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes
> -Wold-style-definition  -isystem ./include  -fPIC -g
> -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED
> -Dinhibit_libc -I. -I. -I../../gcc -I../../gcc/.
> -I../../gcc/../include -I../../gcc/../libcpp/include 
> -I../../gcc/../libdecnumber -I../libdecnumber
> -I/home/ksyim/workspace/compiler/llvm/llvm-2.3/objdir-sparc//include
> -I/scr/ksyim/workspace/compiler/llvm/llvm-2.3/include -DL_mulvsi3  -c
> ../../gcc/libgcc2.c -o libgcc/./_mulvsi3.o
>
> Cannot yet select: 0x8a92348: i32,i32 = smul_lohi 0x8aa5150, 0x8a925f8
>
> ../../gcc/libgcc2.c:177: internal compiler error: Aborted
>
> Please submit a full bug report,
>
> with preprocessed source if appropriate.
>
> See <URL:http://developer.apple.com/bugreporter> for instructions.
>
> make[3]: *** [libgcc/./_mulvsi3.o] Error 1
>
> make[3]: Leaving directory
> `/scr/ksyim/workspace/compiler/llvm/llvm-gcc4.2-2.3.source/objdir-sparc/gcc'
>

I think you can try by marking SMUL_LOHI as Expand, similar to how
UMUL_LOHI is marked in SparcISelLowering.cpp:

 // FIXME: Sparc provides these multiplies, but we don't have them yet.
  setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
  setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);

Or implement SMUL_LOHI ;)

Best regards,
--Edwin