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From: Chad <chad.page@gmail.com>
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Subject: [Qemu-devel] Performance bug in tcg/i386 output:
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Running qemu[-i386] with -d out_asm and looking at qemu.out shows this
test/j**/jmp pattern repeatedly:

0xb1aa40f6:  test   %ecx,%ecx
0xb1aa40f8:  jne    0xb1aa4115
0xb1aa40fe:  jmp    0xb1aa4103
0xb1aa4103:  mov    $0xc0bf,%eax

Therefore there's a bug in the tcg generator creating many unnecessary
jmps.  It might get optimized out by the CPU, but it might not and it bloats
the asm output in any case...

- Chad

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Running qemu[-i386] with -d out_asm and looking at qemu.out shows this test=
/j**/jmp pattern repeatedly:<br><br>0xb1aa40f6:=A0 test=A0=A0 %ecx,%ecx<br>=
0xb1aa40f8:=A0 jne=A0=A0=A0 0xb1aa4115<br>0xb1aa40fe:=A0 jmp=A0=A0=A0 0xb1a=
a4103<br>0xb1aa4103:=A0 mov=A0=A0=A0 $0xc0bf,%eax<br>
<br>Therefore there&#39;s a bug in the tcg generator creating many unnecess=
ary jmps.=A0 It might get optimized out by the CPU, but it might not and it=
 bloats the asm output in any case...<br><br>- Chad<br>

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