[LLVMdev] clang builds on Sparc/Linux!

[wilsonk at cpsc.ucalgary.ca]

Hello everyone,

I am running an Enterprise 250 with Dual UltraSparc II's and 2 Gb ram
running Aurora Sparc Linux 2.0 (2.6.13 kernel for Aurora is based on
Fedora Core 3). GCC version 3.4.2.

I built llvm-2.0 (the svn version) by just typing "./configure;make". I
then downloaded clang from the svn repository (revision 40382) and changed
to it's directory under .../llvm/tools/clang. I did a "make" without
incident for clang, as well. Woohoo.

I tried a few examples and everything seemed to work fine, as far as
llvm, some simple clang functionality and the JIT examples go. Then I
ran this contrived example through clang and llvm:

int x;
int func1 (int g) {
   return g;
}
int main()
{
   printf("Hello World %d times\n", func1(5));
}


with this command:

clang ./ex1.c -emit-llvm | llvm-as | opt -std-compile-opts | llc
-march=sparc > ex1.S




This worked fine and the code gen looked fine, except for two things:

         .text
         .align  16
         .globl  func1
         .type   func1, #function
func1:
         save -96, %o6, %o6<---------------change
         restore %g0, %g0, %g0
         retl
         nop


         .align  16
         .globl  main
         .type   main, #function
main:
         save -96, %o6, %o6<---------------change
         sethi %hi(.str), %l0
         add %l0, %lo(.str), %o0
         or %g0, 5, %o1
         call printf
         nop
         !IMPLICIT_DEF %i0
         restore %g0, %g0, %g0
         retl
         nop


         .globl x
.bss <-------------------------------------remove
         .align 4
         .type x,#object
         .size x,4
x:
         .skip   4


.data
         .align 1
         .type .str,#object
         .size .str,22
.str:
         .asciz  "Hello World %d times\n"



The two problems with this output. "save -96, %o6, %o6" should read
"save %o6, -96, %o6" at both function entry points, and the ".bss"
section identifier needs to be removed. THEN GCC CAN ASSEMBLE/LINK THIS
AND IT RUNS!!!!! Cool, now you have a new OS/arch pair to run LLVM on,
though I may be the only one running this pair ;)

There are a couple patches attached to fix things for Sparc/Linux/gcc.

Let me know if anyone wants anymore information. I will do some more
testing and let you know how it goes.

Thanks,
Kelly Wilson

P.S. Chris already replied on another list to this post.

On Tue, 24 Jul 2007, Chris Lattner wrote:

>> The two problems with this output. "save -96, %o6, %o6" should read
>> "save %o6, -96, %o6" at both function entry points, and the ".bss"
>> section identifier needs to be removed. THEN GCC CAN ASSEMBLE/LINK
>> THIS
>> AND IT RUNS!!!!! Cool, now you have a new OS/arch pair to run LLVM on,
>> though I may be the only one running this pair ;)

>Very nice!  I'm not sure how the arguments to save got transposed, it
>must be a regression somewhere along the way.  We don't have too many
>people testing sparc :)


This isn't actually an error of transposition for Sparc/SunOS when using
the "cc" compiler. This "save -96, %o6, %o6" (and the .bss section
identifier) work when using SunOS "cc" but not "gcc" under SunOS.

My patches will assume that everyone is using "cc" under SunOS...because
we can't check in llc whether someone will use "cc" or "gcc" to assemble
and link in the future ;)




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