Re: [PATCH v4] LoongArch: Add support for TLS descriptors

[Xi Ruoyao <xry111@xry111.site>]

On Wed, 2024-03-13 at 06:15 +0800, Xi Ruoyao wrote:
> > +(define_insn "@got_load_tls_desc<mode>"
> > +  [(set (match_operand:P 0 "register_operand" "=r")

Hmm, and it looks like we should use (reg:P 4) instead of match_operand
here, because the instruction does not work for a different register:
with TARGET_EXPLICIT_RELOCS we are hard coding r4, and without
TARGET_EXPLICIT_RELOCS the TLS desc function still only puts the return
value in r4.

> > +	(unspec:P
> > +	    [(match_operand:P 1 "symbolic_operand" "")]
> > +	    UNSPEC_TLS_DESC))
> > +    (clobber (reg:SI FCC0_REGNUM))
> > +    (clobber (reg:SI FCC1_REGNUM))
> > +    (clobber (reg:SI FCC2_REGNUM))
> > +    (clobber (reg:SI FCC3_REGNUM))
> > +    (clobber (reg:SI FCC4_REGNUM))
> > +    (clobber (reg:SI FCC5_REGNUM))
> > +    (clobber (reg:SI FCC6_REGNUM))
> > +    (clobber (reg:SI FCC7_REGNUM))
> > +    (clobber (reg:SI RETURN_ADDR_REGNUM))]
> > +  "TARGET_TLS_DESC"
> > +{
> > +  return TARGET_EXPLICIT_RELOCS
> > +    ? "pcalau12i\t$r4,%%desc_pc_hi20(%1)\n\
> > +      \taddi.d\t$r4,$r4,%%desc_pc_lo12(%1)\n\
> > +      \tld.d\t$r1,$r4,%%desc_ld(%1)\n\
> > +      \tjirl\t$r1,$r1,%%desc_call(%1)"
> 
> Use something like
> 
>     ? "pcalau12i\t$r4,%%desc_pc_hi20(%1)\n\t"
>       "addi.d\t$r4,$r4,%%desc_pc_lo12(%1)\n\t"
>       "ld.d\t$r1,$r4,%%desc_ld(%1)\n\t"
>       "jirl\t$r1,$r1,%%desc_call(%1)"
>     : "la.tls.desc\t%0,%1";
> 
> to prevent additional white spaces in the output asm before tabs.

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University