[PATCH] Microblaze: Type confusion in fprintf

[Jeff Law]

On 9/12/19 7:33 AM, Jonas Pfeil wrote:
> A type confusion leads to illegal (and nonsensical) assembly on certain host
> architectures (e.g. ARM), where HOST_WIDE_INT (64 bit) and unsigned long (32
> bit) have different alignments. So this has printed an uninitialized
> register instead of the intended value. This fixes float constant
> initialization on an ARM->Microblaze cross compiler.
> 
> --- a/gcc/config/microblaze/microblaze.c
> +++ b/gcc/config/microblaze/microblaze.c
> @@ -2468,7 +2468,7 @@ print_operand (FILE * file, rtx op, int letter)
>           unsigned long value_long;
>           REAL_VALUE_TO_TARGET_SINGLE (*CONST_DOUBLE_REAL_VALUE (op),
>                                        value_long);
> -         fprintf (file, HOST_WIDE_INT_PRINT_HEX, value_long);
> +         fprintf (file, "%#lx", value_long);
>         }
>        else
>         {
> 
But shouldn't HOST_WIDE_INT_PRINT_HEX here result in the same thing?

>From hwint.h:

#ifndef HAVE_INTTYPES_H
#if INT64_T_IS_LONG
# define GCC_PRI64 HOST_LONG_FORMAT
#else
# define GCC_PRI64 HOST_LONG_LONG_FORMAT
#endif

[ ... ]

#undef PRIx64
#define PRIx64 GCC_PRI64 "x"
[ ... ]

#define HOST_WIDE_INT_PRINT_HEX "%#" PRIx64


If that's not giving us back %#lx, then it seems to me like something is
wrong elsewhere.

jeff