[Bug target/28366] Divide with vectors cause extra stores (and more stack space) (with VMX)

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=28366

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
What I meant by suboptimal is the eight vector stores when it seems that just
two instructions are needed to save the two vector registers that hold the
arguments like Clang does:

        addi 3, 1, -48
        addi 4, 1, -64
        stvx 3, 0, 3
        stvx 2, 0, 4
        addi 3, 1, -32
        nop
        lfs 0, -36(1)
        lfs 1, -52(1)
        lfs 2, -40(1)
        lfs 3, -56(1)
        lfs 4, -44(1)
        lfs 5, -60(1)
        lfs 12, -48(1)
        lfs 6, -64(1)
        fdivs 0, 1, 0
        fdivs 2, 3, 2
        fdivs 13, 5, 4
        fdivs 1, 6, 12
        stfs 0, -20(1)
        stfs 2, -24(1)
        stfs 13, -28(1)
        stfs 1, -32(1)
        nop
        lvx 2, 0, 3
        blr
        .long   0
        .quad   0