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:
$ 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
Chris Lattner
2010-Jan-26 18:59 UTC
[LLVMdev] llc generated assembly does not work with gcc 3.4.4
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 > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
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
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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