After fixing a bug (crop was done after reading the cr) i run some
openssl speed benchmarks, and, at least here on an MPC7447A, got a
speed degradation, tiny but consistent.
IN:
0x40082295: movzbl (%eax),%eax
0x40082298: cmp $0x3d,%al
0x4008229a: setne %dl
0x4008229d: test %al,%al
0x4008229f: je 0x400822d2
OP after liveness analysis:
mov_i32 tmp2,eax
qemu_ld8u tmp0,tmp2,$0xffffffff
mov_i32 eax,tmp0
movi_i32 tmp1,$0x3d
mov_i32 tmp0,eax
nopn $0x2,$0x2
sub_i32 cc_dst,tmp0,tmp1
movi_i32 tmp13,$0xff
and_i32 tmp4,cc_dst,tmp13
movi_i32 tmp13,$0x0
setcond_i32 tmp0,tmp4,tmp13,ne
movi_i32 tmp14,$0xff
and_i32 tmp13,tmp0,tmp14
....
OUT: [size=204]
0x601051b0: lwz r14,0(r27)
0x601051b4: lbzx r14,0,r14
0x601051b8: mr r15,r14
0x601051bc: addi r15,r15,-61
0x601051c0: andi. r15,r15,255
0x601051c4: cmpwi cr6,r15,0
0x601051c8: crnot 4*cr7+eq,4*cr6+eq
0x601051cc: mfcr r0
0x601051d0: rlwinm r15,r0,31,31,31
0x601051d4: andi. r15,r15,255
...
So the fact that setcond produces 0/1 was never communicated to the
tcg, not that i would claim that it's possible at all...