[PATCH,i386][4.3][RFC] PIC Generation on windows/cygwin

[Andrew Pinski]

> 
> *** gcc/config/i386/i386.c	(revision 121238)
> --- gcc/config/i386/i386.c	(working copy)
> *************** static void x86_64_elf_unique_section (t
> *** 1404,1409 ****
> --- 1404,1421 ----
>   static section *x86_64_elf_select_section (tree decl, int reloc,
>   					   unsigned HOST_WIDE_INT align)
>   					     ATTRIBUTE_UNUSED;
> + #if TARGET_CYGMING
> + /* Support for position independent code on target cygming.
> +    In position independent mode, references to static and global
> +    symbols are generated as offsets relative to a base label. The same
> +    base label is used for computing relative offsets of labels
> +    in the address diff vector for a switch statement. There is
> +    one base label in each function. */
> +
> + /* The base label used for all relative offsets in pic mode. */
> + static rtx base_label;
> + #endif

This is not really GC safe.

> + #if ! TARGET_CYGMING
>     xops[1] = gen_rtx_SYMBOL_REF (Pmode, GOT_SYMBOL_NAME);
> + #endif

Use:
if (!TARGET_CYGMING)

instead.

> + #if ! TARGET_CYGMING
>     if (!flag_pic || TARGET_DEEP_BRANCH_PREDICTION)
>       output_asm_insn ("add{l}\t{%1, %0|%0, %1}", xops);
>     else
>       output_asm_insn ("add{l}\t{%1+[.-%a2], %0|%0, %1+(.-%a2)}", xops);
> + #else
> +   base_label = xops[2];
> + #endif

Likewise.

> + #if TARGET_CYGMING
> + 	  addr = i386_pe_generate_imported_symbol_ref(addr);
> + 	  new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), UNSPEC_GOTOFF);
> + #else
>   	  new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), UNSPEC_GOT);
> + #endif

This one needs to stay #if because it uses a function from a non x86 generic
file.

> + #if ! TARGET_CYGMING
>   	  fputs ("@GOTOFF", file);
> + #else
> + 	  /* On target CYGMING, we interpret GOTOFF of a symbol
> + 	     as the offset of the symbol from the PIC base label. */
> + 	  putc ('-', file);
> + 	  output_pic_addr_const (file, base_label, code);
> + #endif

Again if(!TARGET_CYGMING)

> + #if TARGET_CYGMING
> +   else if (TARGET_CYGMING)
> +     {
> +       fprintf (file, "%s%s%d-%s%d\n",
> + 	       ASM_LONG, LPREFIX, value, LPREFIX,
> + 	       CODE_LABEL_NUMBER(XEXP(base_label,0)));
> +     }
> + #endif

Don't need "#if TARGET_CYGMING" really.

> ! #if TARGET_CYGMING
> ! 	  {
> ! 	    /* On target CYGMING, there is no PLT. Convert
> ! 	       the function address to a PIC reference. */
> ! 	    rtx reg;
> ! 	    reg = legitimize_pic_address (XEXP (fnaddr, 0), 0);
> ! 	    XEXP (fnaddr, 0) = reg;
> ! 	  }
> ! #endif

Again if (TARGET_CYGMING)

Thanks,
Andrew Pinski