Re: [avr-llvm-devel] Windows build

[Weddington, E. <Eri...@at...>]

 

> -----Original Message-----
> From: John Myers [mailto:ato...@gm...] 
> Sent: Tuesday, December 08, 2009 6:46 PM
> To: Weddington, Eric
> Cc: avr...@li...
> Subject: Re: [avr-llvm-devel] Windows build
> 
> 
> 
> The redudant mov is gone now. So it looks like whatever they 
> changed  in the LLVM trunk fixed it.

That's great!

Question: Is the assembler output of llvm supposed to closely match the assembler output of avr-gcc? Is that what we're aiming for?
  
> C:\_projects_\build_llvm\bin\Debug>llc.exe -O0 -o - 
> -filetype=asm -mcpu=atmega128 reti8.ll
>         .file   "reti8.ll"
> 
>         .text
>         .align  16
>         .global func
>         .type   func,@function
> func:
> # BB#0:
>         ldi r24, #1
>         ret
>         .size   func, .-func

If so, then we need to drop the .align directive above. This is the equivalent from avr-gcc:

	.file	"test.c"
__SREG__ = 0x3f
__SP_H__ = 0x3e
__SP_L__ = 0x3d
__CCP__  = 0x34
__tmp_reg__ = 0
__zero_reg__ = 1
	.text
.global	func
	.type	func, @function
func:
/* prologue: function */
/* frame size = 0 */
	ldi r24,lo8(1)
/* epilogue start */
	ret
	.size	func, .-func