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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/36992] Very stange code for _mm_move_epi64
Date: Sat, 02 Aug 2008 13:10:00 -0000	[thread overview]
Message-ID: <20080802130859.20132.qmail@sourceware.org> (raw)
In-Reply-To: <bug-36992-682@http.gcc.gnu.org/bugzilla/>

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------- Comment #9 from ubizjak at gmail dot com  2008-08-02 13:08 -------
Hm, IA-32 Intel® Architecture Software Developer’s Manual says about movq:

Operation
MOVQ instruction when operating on MMX technology registers and memory
locations:
   DEST &#8592; SRC;
MOVQ instruction when source and destination operands are XMM registers:
   DEST[63:0] &#8592; SRC[63:0];
MOVQ instruction when source operand is XMM register and destination
operand is memory location:
   DEST &#8592; SRC[63:0];
MOVQ instruction when source operand is memory location and destination
operand is XMM register:
   DEST[63:0] &#8592; SRC;
   DEST[127:64] &#8592; 0000000000000000H;

Please note, that the documentation doesn't say anything about clearing
destination bits [127:64] when both source and destination are in XMM register.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36992


  parent reply	other threads:[~2008-08-02 13:10 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-01  3:30 [Bug target/36992] New: " hjl dot tools at gmail dot com
2008-08-01 11:59 ` [Bug target/36992] " rguenth at gcc dot gnu dot org
2008-08-01 12:05 ` rguenth at gcc dot gnu dot org
2008-08-01 12:08 ` rguenth at gcc dot gnu dot org
2008-08-01 12:54 ` hjl dot tools at gmail dot com
2008-08-01 12:57 ` hjl dot tools at gmail dot com
2008-08-01 13:22 ` rguenth at gcc dot gnu dot org
2008-08-01 13:27 ` hjl dot tools at gmail dot com
2008-08-01 19:34 ` ubizjak at gmail dot com
2008-08-02 13:10 ` ubizjak at gmail dot com [this message]
2008-08-02 13:11 ` ubizjak at gmail dot com
2008-08-02 13:23 ` ubizjak at gmail dot com
2008-08-02 15:08 ` ubizjak at gmail dot com
2008-08-02 15:20 ` hjl dot tools at gmail dot com
2008-08-02 16:03 ` ubizjak at gmail dot com
2008-08-02 18:45 ` ubizjak at gmail dot com
2008-08-03  6:15 ` uros at gcc dot gnu dot org
2008-08-03  6:50 ` ubizjak at gmail dot com
2008-08-05 14:20 ` hjl dot tools at gmail dot com
2008-08-05 17:35 ` hjl dot tools at gmail dot com
2008-08-05 17:42 ` hjl at gcc dot gnu dot org
2008-08-07 13:18 ` hjl at gcc dot gnu dot org
2008-08-07 13:19 ` hjl dot tools at gmail dot com

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