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From: Andreas Schwab <schwab@linux-m68k.org>
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Date: Thu, 17 Sep 2009 18:35:32 +0200
In-Reply-To: <20090917120406.J54069@stanley.csl.cornell.edu> (Vince Weaver's
	message of "Thu, 17 Sep 2009 12:07:23 -0400 (EDT)")
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Subject: [Qemu-devel] Re: [PATCH] Fix extlh instruction on Alpha
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To: Vince Weaver <vince@csl.cornell.edu>
Cc: qemu-devel@nongnu.org, Aurelien Jarno <aurelien@aurel32.net>

Vince Weaver <vince@csl.cornell.edu> writes:

>              tcg_gen_andi_i64(tmp1, cpu_ir[rb], 7);
>              tcg_gen_shli_i64(tmp1, tmp1, 3);
> -            tmp2 = tcg_const_i64(64);
> -            tcg_gen_sub_i64(tmp1, tmp2, tmp1);
> -            tcg_temp_free(tmp2);
> +            tcg_gen_andi_i64(tmp1, tmp1, 0x3f);
> +            tcg_gen_neg_i64(tmp1, tmp1);
> +            tcg_gen_addi_i64(tmp1, tmp1, 64);

This wastes an operation.  If you switch andi and neg you don't need to
add 64.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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