turn on mem2reg, set mcpu

I've also added in a disabled path to do quasi -O1 / -Os
passes, but mem2reg is really all we need, and I think we
can eliminate the need for even that.

Codegen looks great now, e.g.

(lldb) dis -s fJITEntry -c 40
    0x10a48c000: movabsq $0x10a48d000, %rax        ; imm = 0x10A48D000
    0x10a48c00a: vbroadcastss (%rax), %zmm0
    0x10a48c010: cmpq   $0xf, %rdi
    0x10a48c014: jbe    0x10a48c04d
    0x10a48c016: nopw   %cs:(%rax,%rax)
    0x10a48c020: vmovups %zmm0, (%rsi)
    0x10a48c026: addq   $-0x10, %rdi
    0x10a48c02a: addq   $0x40, %rsi
    0x10a48c02e: cmpq   $0xf, %rdi
    0x10a48c032: ja     0x10a48c020
    0x10a48c034: jmp    0x10a48c04d
    0x10a48c036: nopw   %cs:(%rax,%rax)
    0x10a48c040: movl   $0x2a, (%rsi)
    0x10a48c046: decq   %rdi
    0x10a48c049: addq   $0x4, %rsi
    0x10a48c04d: testq  %rdi, %rdi
    0x10a48c050: jne    0x10a48c040
    0x10a48c052: vzeroupper
    0x10a48c055: retq

Change-Id: Ief5d12548d5b1a683060b2b5d207022d673fe761
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/273606
Reviewed-by: Herb Derby <herb@google.com>
1 file changed