Re: [avr-llvm-devel] Inline assembly.

[Borja F. <bor...@gm...>]

I've tried different optimization levels and they all fail for me. The
interesting thing is that i've isolated the strtod function in a different
file and it compiles fine, so there's something in the huge file that
causes this.


2013/7/28 Stepan Dyatkovskiy <stp...@na...>

>
>
> > Ok this was a bit insane to reduce but I've found the offending lines.
> >
> > The problem is how uint32_t and uint16_t are defined:
> > typedef unsigned int uint16_t __attribute__ ((__mode__ (__HI__)));
> >
> > typedef unsigned int uint32_t __attribute__ ((__mode__ (__SI__)));
> >
> > I have no idea what this syntax is, but if you refedefine those types to
> unsigned int / long the problem goes away.
>
> Wow great. Never expected that wrong definition.
>
> >
> > Now im getting an error in llc: error: couldn't allocate input reg for
> constraint 'r'
> >
>
> Hm.. May be try with O2 instead of Os?
>
> > 2013/7/28 Borja Ferrer <bor...@gm...>
> >
> >> I've compiled the file you attached, ignoring all warnings i get from
> clang about the unknown attributes like progmem, i'm getting the assertion
> "multibyte index is out of range."
> >>
> >> 2013/7/28 Borja Ferrer <bor...@gm...>
> >>
> >>> Hello Stepan,
> >>>
> >>> 1) It seems clang mangles assembly functions names by prefixing a \01
> character. I haven't found yet the code that does this depending on the
> target used.
> >>>
> >>> 2) About the code above, I'm assuming you got that inline asm code
> from the __LPM_dword_classic__ macro. This is what I'm getting for the
> following C code:
> >>> typedef unsigned int uint16_t;
> >>> typedef unsigned long uint32_t;
> >>>
> >>> #define __LPM_dword_classic__(addr) \
> >>> (__extension__({ \
> >>> uint16_t __addr16 = (uint16_t)(addr); \
> >>> uint32_t __result; \
> >>> __asm__ __volatile__ \
> >>>
> >>> ( \
> >>> "lpm" "\n\t" \
> >>> "mov %A0, r0" "\n\t" \
> >>> "adiw r30, 1" "\n\t" \
> >>>
> >>> "lpm" "\n\t" \
> >>> "mov %B0, r0" "\n\t" \
> >>> "adiw r30, 1" "\n\t" \
> >>> "lpm" "\n\t" \
> >>>
> >>> "mov %C0, r0" "\n\t" \
> >>> "adiw r30, 1" "\n\t" \
> >>> "lpm" "\n\t" \
> >>> "mov %D0, r0" "\n\t" \
> >>>
> >>> : "=r" (__result), "=z" (__addr16) \
> >>> : "1" (__addr16) \
> >>> : "r0" \
> >>>
> >>> ); \
> >>>
> >>> __result; \
> >>> }))
> >>> unsigned long inlineasm(unsigned int addr)
> >>> {
> >>> return __LPM_dword_classic__(addr);
> >>> }
> >>>
> >>> clang produces:
> >>>
> >>> define i32 @inlineasm(i16 %addr) #0 {
> >>>
> >>> entry:
> >>> %0 = tail call { i32, i16 } asm sideeffect "lpm\0A\09mov ${0:A},
> r0\0A\09adiw r30, 1\0A\09lpm\0A\09mov ${0:B}, r0\0A\09adiw r30,
> 1\0A\09lpm\0A\09mov ${0:C}, r0\0A\09adiw r30, 1\0A\09lpm\0A\09mov ${0:D},
> r0\0A\09", "=r,=z,1,~{r0}"(i16 %addr) #2, !srcloc !4
> >>>
> >>> %asmresult = extractvalue { i32, i16 } %0, 0
> >>> ret i32 %asmresult
> >>> }
> >>>
> >>> No truncations here as far i can tell. Try this code and see what you
> get.
>
>
>  --
> Truly yours,
> Stepan Dyatkovskiy
>