From: Andreas Schwab <schwab@linux-m68k.org>
To: Vince Weaver <vince@csl.cornell.edu>
Cc: qemu-devel@nongnu.org, Aurelien Jarno <aurelien@aurel32.net>
Subject: [Qemu-devel] Re: [PATCH] Fix extlh instruction on Alpha
Date: Thu, 17 Sep 2009 18:35:32 +0200 [thread overview]
Message-ID: <m23a6lcywb.fsf@igel.home> (raw)
In-Reply-To: <20090917120406.J54069@stanley.csl.cornell.edu> (Vince Weaver's message of "Thu, 17 Sep 2009 12:07:23 -0400 (EDT)")
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
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
next prev parent reply other threads:[~2009-09-17 16:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-09 16:08 [Qemu-devel] [PATCH] Fix extlh instruction on Alpha Vince Weaver
2009-09-16 19:52 ` Aurelien Jarno
2009-09-16 20:45 ` Vince Weaver
2009-09-16 20:56 ` Aurelien Jarno
2009-09-17 16:07 ` Vince Weaver
2009-09-17 16:25 ` Laurent Desnogues
2009-09-17 16:35 ` Andreas Schwab [this message]
2009-09-17 17:19 ` Aurelien Jarno
2009-09-16 21:14 ` [Qemu-devel] " Andreas Schwab
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