[Bug target/84010] [sparc64] Problematic TLS code generation

[jrtc27 at jrtc27 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84010

--- Comment #5 from James Clarke <jrtc27 at jrtc27 dot com> ---
My patch seems to work for this case:

        sethi   %tie_hi22(tcg_ctx), %g2
...
        add     %g2, %tie_lo10(tcg_ctx), %g1
        ldx     [%l7 + %g1], %g1, %tie_ldx(tcg_ctx)
        stx     %g2, [%fp+1783] ! note this is %g2, i.e. just the hi22...
        call    gen_new_label, 0
         ldx    [%g7+%g1], %i5
...
        ldx     [%fp+1783], %g1 ! reload the hi22
        add     %g1, %tie_lo10(tcg_ctx), %i5
        ldx     [%l7 + %i5], %i5, %tie_ldx(tcg_ctx)
        ldx     [%g7+%i5], %g1

The code gen is something else; I don't understand why it spills the result of
the hi22 and re-adds the lo10 (which takes the worst aspects of
rematerialisation and spilling), but that's a whole other story.