[Bug target/78199] [PowerPC] Missing optimization for local-exec TLS model

[sebastian.huber@embedded-brains.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78199

--- Comment #1 from Sebastian Huber <sebastian.huber@embedded-brains.de> ---
A native 64-bit PowerPC GCC built on

uname -a
Linux gcc2-power8.osuosl.org 3.17.4-301.fc21.ppc64le #1 SMP Mon Dec 1 07:51:01
UTC 2014 ppc64le ppc64le ppc64le GNU/Linux

generates this

gcc -O2 -ftls-model=local-exec -S tls.c -o -
        .file   "tls.c"
        .machine power8
        .abiversion 2
        .section        ".text"
        .align 2
        .p2align 4,,15
        .globl fi
        .type   fi, @function
fi:
        addis 9,13,i@tprel@ha
        addi 9,9,i@tprel@l
        lwa 3,0(9)
        blr
        .long 0
        .byte 0,0,0,0,0,0,0,0
        .size   fi,.-fi
        .section        ".toc","aw"
        .align 3
.LC0:
        .quad   s
        .section        ".text"
        .align 2
        .p2align 4,,15
        .globl fs
        .type   fs, @function
fs:
.LCF1:
0:      addis 2,12,.TOC.-.LCF1@ha
        addi 2,2,.TOC.-.LCF1@l
        .localentry     fs,.-fs
        addis 9,2,.LC0@toc@ha           # gpr load fusion, type long
        ld 9,.LC0@toc@l(9)
        lwa 3,0(9)
        blr
        .long 0
        .byte 0,0,0,0,0,0,0,0
        .size   fs,.-fs
        .ident  "GCC: (GNU) 7.0.0 20161030 (experimental)"
        .section        .note.GNU-stack,"",@progbits