[Bug target/79439] Missing nop instruction after recursive call corrupts TOC register

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79439

--- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> ---
What command line options does this need?  I get different assembly
(also with GCC 6), since GCC recognises that rec can never return:

        .globl rec
        .type   rec, @function
rec:
.LCF1:
0:      addis 2,12,.TOC.-.LCF1@ha
        addi 2,2,.TOC.-.LCF1@l
        .localentry     rec,.-rec
        mflr 0
        std 31,-8(1)
        mr 31,3
        std 0,16(1)
        stdu 1,-48(1)
        .p2align 4,,15
.L3:
        bl f
        nop
        cmpdi 7,3,0
        beq 7,.L3
        addi 3,31,1
        extsw 3,3
        bl rec
        .long 0
        .byte 0,0,0,1,128,1,0,0