From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31586 invoked by alias); 28 Dec 2005 20:07:46 -0000 Received: (qmail 31414 invoked by uid 22791); 28 Dec 2005 20:07:45 -0000 X-Spam-Check-By: sourceware.org Received: from nitzan.inter.net.il (HELO nitzan.inter.net.il) (192.114.186.20) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 28 Dec 2005 20:07:44 +0000 Received: from HOME-C4E4A596F7 (IGLD-83-130-250-156.inter.net.il [83.130.250.156]) by nitzan.inter.net.il (MOS 3.7.2-GA) with ESMTP id CHS12984 (AUTH halo1); Wed, 28 Dec 2005 22:07:40 +0200 (IST) Date: Sat, 31 Dec 2005 05:41:00 -0000 Message-Id: From: Eli Zaretskii To: Guillaume POIRIER CC: gdb-patches@sources.redhat.com In-reply-to: <4e03026a0512280015m39499343rf96f8075fad23eeb@mail.gmail.com> (message from Guillaume POIRIER on Wed, 28 Dec 2005 09:15:45 +0100) Subject: Re: Setting an SSE register to a certain value Reply-to: Eli Zaretskii References: <4e03026a0512270816p2ea883cfj42934c557ec7f4a5@mail.gmail.com> <8f2776cb0512271615g54aa91a4t3bc89777105d33b7@mail.gmail.com> <4e03026a0512280015m39499343rf96f8075fad23eeb@mail.gmail.com> X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2005-12/txt/msg00313.txt.bz2 > Date: Wed, 28 Dec 2005 09:15:45 +0100 > From: Guillaume POIRIER > > > That is, try this: > > > > set $xmm2.uint128 = 0x000000000000000000000000FFFFFFFF > > Thanks you so much! That worked beautifully. I hope this information > can be added to your documentation as this will probably come in handy > to other people, don't you think? :-) Yes, I've just added the following to the manual: 2005-12-28 Eli Zaretskii * gdb.texinfo (Registers): Describe how to refer to SSE and MMX registers and the likes. Index: gdb/doc/gdb.texinfo =================================================================== RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v retrieving revision 1.302 diff -u -r1.302 gdb.texinfo --- gdb/doc/gdb.texinfo 24 Dec 2005 15:28:44 -0000 1.302 +++ gdb/doc/gdb.texinfo 28 Dec 2005 20:04:30 -0000 @@ -6279,6 +6279,36 @@ that makes sense for your program), but the @code{info registers} command prints the data in both formats. +@cindex SSE registers (x86) +@cindex MMX registers (x86) +Some machines have special registers whose contents can be interpreted +in several different ways. For example, modern x86-based machines +have SSE and MMX registers that can hold several values packed +together in several different formats. @value{GDBN} refers to such +registers in @code{struct} notation: + +@smallexample +(@value{GDBP}) print $xmm1 +$1 = @{ + v4_float = @{0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044@}, + v2_double = @{9.92129282474342e-303, 2.7585945287983262e-313@}, + v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000", + v8_int16 = @{0, 0, 14072, 315, 11, 0, 13, 0@}, + v4_int32 = @{0, 20657912, 11, 13@}, + v2_int64 = @{88725056443645952, 55834574859@}, + uint128 = 0x0000000d0000000b013b36f800000000 +@} +@end smallexample + +@noindent +To set values of such registers, you need to tell @value{GDBN} which +view of the register you wish to change, as if you were assigning +value to a @code{struct} member: + +@smallexample + (@value{GDBP}) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF +@end smallexample + Normally, register values are relative to the selected stack frame (@pxref{Selection, ,Selecting a frame}). This means that you get the value that the register would contain if all stack frames farther in