* gdb.texinfo (Registers): Describe how to refer to SSE and MMX

registers and the likes.
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Eli Zaretskii 2005-12-28 20:05:49 +00:00
parent a1b06f3564
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@ -1,3 +1,8 @@
2005-12-28 Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Registers): Describe how to refer to SSE and MMX
registers and the likes.
2005-12-24 Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Target Commands, Bug Reporting, File Options)

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@ -6279,6 +6279,36 @@ cases, @value{GDBN} normally works with the virtual format only (the format
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