[LLVMdev] llc generated assembly does not work with gcc 3.4.4

[Alexander Herz]

Well, can I enforce gcc compatible output somehow? I tried playing with
the llc flags which didn't help.
A possible subtarget for windows might be masm,
the msvc compiler and the like.

Alex

Chris Lattner schrieb:
> Anton,
>
> This is a because the "windows" x86 target defaults to intel syntax asm.  I'm not even sure what the "windows" subtarget is if not for mingw or cygwin.  Does it make sense to remove the "Windows" target and have "i686-pc-win32" just be a synonym for mingw?
>
> -Chris
>
> On Jan 27, 2010, at 1:32 AM, herz wrote:
>
>   
>> The ll file:
>>
>> ; ModuleID = 't.bc'
>> target datalayout =
>> "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f80:128:128-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
>> target triple = "i686-pc-win32"
>>
>> @.str = private constant [13 x i8] c"hello world\0A\00" ; <[13 x i8]*>
>> [#uses=1]
>>
>> define i32 @main(i32 %argc, i8** %argv) nounwind {
>> entry:
>>  %retval = alloca i32                            ; <i32*> [#uses=2]
>>  %argc.addr = alloca i32                         ; <i32*> [#uses=1]
>>  %argv.addr = alloca i8**                        ; <i8***> [#uses=1]
>>  store i32 0, i32* %retval
>>  store i32 %argc, i32* %argc.addr
>>  store i8** %argv, i8*** %argv.addr
>>  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([13 x
>> i8]* @.str, i32 0, i32 0)) ; <i32> [#uses=0]
>>  %0 = load i32* %retval                          ; <i32> [#uses=1]
>>  ret i32 %0
>> }
>>
>> declare i32 @printf(i8*, ...)
>>
>> the llc command line is simply:  llc t.bc (where t.bc is the file used
>> to generate the ll file shown, of course)
>>
>> llc --version gives:
>>
>> Low Level Virtual Machine (http://llvm.org/):
>>  LLVM (win32 vc8.0) version 2.600000e+000
>>  DEBUG build.
>>  Built Dec  3 2009 (01:18:42).
>>
>>  Registered Targets:
>>    amdil  - ATI graphics cards
>>    x86    - 32-bit X86: Pentium-Pro and above
>>    x86-64 - 64-bit X86: EM64T and AMD64
>>
>>
>> I've read in the docu (which appears to be somewhat out of date) that
>> one cannot generate binaries on win32 systems.
>> The thing I don't understand is why I cannot generate assembly that is
>> compatible with gcc (albait the cygwin version of gcc, but
>> certainly cygwin gcc reads the same mnemonics as the unix version??).
>> I've tryed several llc switches to produce compatible output but failed.
>>
>> Alex
>>
>> Chris Lattner schrieb:
>>     
>>> On Jan 26, 2010, at 6:31 AM, herz wrote:
>>>
>>>       
>>>> Hi,
>>>>
>>>> I've generated a .bc file for a simple program using the clang front
>>>> end, the human readable output of llvm-dis looks good.
>>>> Running llc on the bc file generates an assembly file (.s using either
>>>> att or intel syntax).
>>>> Now, when I try to generate an executable with gcc (3.4.4 cygwin) I get
>>>> lot's of errors:
>>>>         
>>> What commands are you passing to llc?  Also, please attach the .ll
>>> file you're using.
>>>
>>> -Chris
>>>
>>>       
>>>> $ gcc t.S
>>>> t.S: Assembler messages:
>>>> t.S:4: Error: no such instruction: `align 16'
>>>> t.S:6: Error: invalid character '@' in mnemonic
>>>> t.S:7: Error: no such instruction: `bb'
>>>> t.S:20: Error: invalid character '@' in mnemonic
>>>> t.S:22: Error: no such instruction: `db "hello world\n\000"'
>>>>
>>>> here is the assembly file (t.s):
>>>>
>>>>   .text
>>>>   ALIGN    16
>>>>   .globl    _main
>>>> _main:                                                      ; @main
>>>> ; BB#0:                                                     ; %entry
>>>>   subl    $20, %esp
>>>>   movl    24(%esp), %eax
>>>>   movl    $0, 16(%esp)
>>>>   movl    $($_.str), (%esp)
>>>>   movl    %eax, 12(%esp)
>>>>   movl    28(%esp), %eax
>>>>   movl    %eax, 8(%esp)
>>>>   call    _printf
>>>>   movl    16(%esp), %eax
>>>>   addl    $20, %esp
>>>>   ret
>>>>   .data
>>>>                                                           ; @.str
>>>> $_.str:
>>>>   db    "hello world\n\000"
>>>>
>>>> Aparently, gcc doesn't recognize ; as comments nor can it handle the db
>>>> directive.
>>>> How can I generate assembly that is accepted by gcc ??
>>>>
>>>> Thx!
>>>>
>>>> Alex
>>>>
>>>> _______________________________________________
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>>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>>         
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>>     
>
>   


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