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Differential D19458

Add address space 258 to Clang documentation
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Authored by mlemay-intel on Apr 23 2016, 10:13 AM.

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rGd8984101e570: Add address space 258 (X86 SS segment) to clang documentation. The change…
rC268432: Add address space 258 (X86 SS segment) to clang documentation.
rL268432: Add address space 258 (X86 SS segment) to clang documentation.

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mlemay-intel updated this revision to Diff 54782.Apr 23 2016, 10:13 AM

mlemay-intel retitled this revision from to Add address space 258 to Clang documentation.

mlemay-intel updated this object.

mlemay-intel added a reviewer: mkuper.Apr 23 2016, 10:14 AM

mlemay-intel added a subscriber: cfe-commits.

LGTM with a small nit - can you change the heading from "Memory references off the GS segment" to something more general?

This revision is now accepted and ready to land.Apr 23 2016, 11:38 AM

In D19458#410042, @mkuper wrote:

LGTM with a small nit - can you change the heading from "Memory references off the GS segment" to something more general?

Good idea! Thanks for noticing that inconsistency.

Update heading.

LGTM

mlemay-intel mentioned this in D17093: [X86] Add address space for SS segment.May 2 2016, 7:27 AM

Closed by commit rL268432: Add address space 258 (X86 SS segment) to clang documentation. (authored by dlkreitz). · Explain WhyMay 3 2016, 1:26 PM

This revision was automatically updated to reflect the committed changes.

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cfe/

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docs/

LanguageExtensions.rst

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cfe/trunk/docs/LanguageExtensions.rst

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	like simple arithmetic may be reordered around the intrinsic. If you expect to			like simple arithmetic may be reordered around the intrinsic. If you expect to
	have no reordering at all, use inline assembly instead.			have no reordering at all, use inline assembly instead.

	X86/X86-64 Language Extensions			X86/X86-64 Language Extensions
	------------------------------			------------------------------

	The X86 backend has these language extensions:			The X86 backend has these language extensions:

	Memory references off the GS segment			Memory references to specified segments
	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^			^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

	Annotating a pointer with address space #256 causes it to be code generated			Annotating a pointer with address space #256 causes it to be code generated
	relative to the X86 GS segment register, and address space #257 causes it to be			relative to the X86 GS segment register, address space #257 causes it to be
	relative to the X86 FS segment. Note that this is a very very low-level			relative to the X86 FS segment, and address space #258 causes it to be
				relative to the X86 SS segment. Note that this is a very very low-level
	feature that should only be used if you know what you're doing (for example in			feature that should only be used if you know what you're doing (for example in
	an OS kernel).			an OS kernel).

	Here is an example:			Here is an example:

	.. code-block:: c++			.. code-block:: c++

	#define GS_RELATIVE __attribute__((address_space(256)))			#define GS_RELATIVE __attribute__((address_space(256)))
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