From: "Jonas Pfeil" <jonas.pfeil@uni-ulm.de>
To: "'Segher Boessenkool'" <segher@kernel.crashing.org>,
"'Jeff Law'" <law@redhat.com>
Cc: <gcc-patches@gcc.gnu.org>
Subject: BUMP: AW: [PATCH] Microblaze: Type confusion in fprintf
Date: Fri, 04 Oct 2019 08:14:00 -0000 [thread overview]
Message-ID: <0ded01d57a8b$c6709f10$5351dd30$@uni-ulm.de> (raw)
Yes, it is a 32-bit host and 32-bit target.
HOST_WIDE_INT is long long (on ARM).
Also it says 4 lines above that the type of value_long is unsigned long, so
lets use the specifier for unsigned long.
Jonas
-----Ursprüngliche Nachricht-----
Von: Segher Boessenkool <segher@kernel.crashing.org>
Gesendet: Sonntag, 22. September 2019 02:52
An: Jeff Law <law@redhat.com>
Cc: Jonas Pfeil <jonas.pfeil@uni-ulm.de>; gcc-patches@gcc.gnu.org
Betreff: Re: [PATCH] Microblaze: Type confusion in fprintf
On Fri, Sep 20, 2019 at 04:50:12PM -0600, Jeff Law wrote:
> 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.
This is a 32-bit target though, so INT64_T_IS_LONG is false.
Segher
reply other threads:[~2019-10-04 8:14 UTC|newest]
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