[FFmpeg-devel] Why 'You can only build one library type at once on MinGW'?

Rich Felker dalias
Fri May 11 04:35:04 CEST 2007


On Wed, May 09, 2007 at 03:32:11PM -0700, Trent Piepho wrote:
> On Wed, 9 May 2007, Rich Felker wrote:
> > > On Wed, May 09, 2007 at 03:57:01PM +0100, M?ns Rullg?rd wrote:
> > > Rich Felker wrote:
> > > > Nope, this is not true. Rather, without PIC, relocations remain inline
> > > > in the code rather than isolated to GOT/PLT tables. This means that
> > > > the dynamic linker must modify large amounts of code at startup
> > > > (runtime), resulting in unsharable pages and bad initial performance.
> > > > However it in no way precludes relocation.
> > >
> > > On x86_64 it does, at least in the general case.  A 32-bit immediate operand
> > > might need 64 bits after relocation.  Theoretically, the compiler could have
> > > a flag telling it to make all relocatable values 64-bit, but gcc doesn't to
> > > my knowledge have such an option.
> >
> > This is a bug in the assembler..
> 
> How do you solve this?  The x86-64 ISA only allows for 32-bit displacements
> in addresses and (in general) 32-bit immediate operands.
> 
> I do not understand how you can do a 64-bit relocation on a 32-bit field.

There's no opcode variant with a 64bit value? Sorry I don't know
x86-64 asm so I don't know how to fix it.

Rich




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