D.gnu - strange pointer casting (64 bit)
- Simon Buerger (17/17) Jun 29 2008 hi
- downs (26/47) Jun 29 2008 It's a bug with the integer conversion routines in DMD's frontend.
- Simon Buerger (3/4) Jun 29 2008 Yeah, that will fix it, thanks a lot. I hope this will be in svn soon,
hi From my point of view, the following piece of code does really strange thing: write("{}", cast(void*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffffffff, OK write(cast(ulong*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffffffff, OK write("{}", cast(ulong*)cast(void*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffff, not OK Its not a question of output routine, I've checked it in different envirovments and with different values. It simply cuts of the higher 32 bit part of the address. Could, please, somebody explain me that behavior? For me, it looks like a compiler bug, but that seems impossible for such an obvious thing... my system: AMD64, Ubuntu Linux, gdc (GCC) 4.1.2 20070214 ( gdc 0.24, using dmd 1.024) (according to gdc --version)
Jun 29 2008
Simon Buerger wrote:hi From my point of view, the following piece of code does really strange thing: write("{}", cast(void*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffffffff, OK write(cast(ulong*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffffffff, OK write("{}", cast(ulong*)cast(void*)0xFFFF_FFFF_FFFF_FFFF_UL); // prints ffffffff, not OK Its not a question of output routine, I've checked it in different envirovments and with different values. It simply cuts of the higher 32 bit part of the address. Could, please, somebody explain me that behavior? For me, it looks like a compiler bug, but that seems impossible for such an obvious thing... my system: AMD64, Ubuntu Linux, gdc (GCC) 4.1.2 20070214 ( gdc 0.24, using dmd 1.024) (according to gdc --version)It's a bug with the integer conversion routines in DMD's frontend. I quote expression.c: IntegerExp::toInteger case Tpointer: case Tdchar: case Tuns32: value = (d_uns32) value; break; The following (SVN) patch fixes it: Index: expression.c =================================================================== --- expression.c (Revision 231) +++ expression.c (Arbeitskopie) -1128,10 +1128,15 case Twchar: case Tuns16: value = (d_uns16) value; break; case Tint32: value = (d_int32) value; break; +#ifndef __x86_64__ case Tpointer: +#endif case Tdchar: case Tuns32: value = (d_uns32) value; break; case Tint64: value = (d_int64) value; break; +#ifdef __x86_64__ + case Tpointer: +#endif case Tuns64: value = (d_uns64) value; break; case Tenum:
Jun 29 2008
downs wrote:It's a bug with the integer conversion routines in DMD's frontend.Yeah, that will fix it, thanks a lot. I hope this will be in svn soon, cuz I think it could lead to really hard-to-find errors.
Jun 29 2008