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

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

Found it, the isfinite() function takes in a double, and since our backend
treats them as 64bit types this fails in inline asm. Removing the function
implementation and just leaving it as an extern compiles successfully.


2013/7/28 Borja Ferrer <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
>>
>
>