[LLVMdev] Fwd: hexcode from llvm

[Paul Davey]

sorry keep forgetting to send to list instead of last person who replied :(

On Fri, May 21, 2010 at 1:18 PM, JayaSus <jayasnair at gmail.com> wrote:
>
> Hi Bill Wendling.
> I am trying to get a hexcode as shown below for mips processor using llvm
>
> Disassembly of section .text:
>
> 00000000 <main>:
>   0:   27bdffe8        addiu   sp,sp,-24
>   4:   afbe0010        sw      s8,16(sp)
>   8:   03a0f021        move    s8,sp
>   c:   24020004        li      v0,4
>  10:   afc20008        sw      v0,8(s8)
>  14:   24020005        li      v0,5
>  18:   afc20004        sw      v0,4(s8)
>  1c:   8fc30008        lw      v1,8(s8)
>  20:   8fc20004        lw      v0,4(s8)
>  24:   00000000        nop
>  28:   00621021        addu    v0,v1,v0
>  2c:   afc20000        sw      v0,0(s8)
>  30:   03c0e821        move    sp,s8
> ....
>
> Is there any pass or buildin command for llvm to generate this. llvm-dis
> will only generate the assembly code and not the hexcode.

This is not done by llvm, you create native assembly from the llvm IR
then assemble that and then you can use objdump to get your hexcode
just like from gcc.
LLVM does not deal with native code, it uses llvm IR, llvm-dis is
simply a converter from the bitcode format of the IR to the human
readable assembly text format of the IR.

>
> Moreover how can I compile c code for mips using llvm-gcc? llvm-gcc -b mips
> t.c complains it wouldn't know the -b option.
>

You might want -march or other -m options...