* doc/c-xtensa.texi (Xtensa Syntax): Clarify handling of opcodes that

can only be encoded in FLIX instructions but are not specified as such.
	(Xtensa Automatic Alignment): Remove obsolete comment about debugging
	labels.
This commit is contained in:
Bob Wilson 2008-01-25 01:08:34 +00:00
parent 244e85c8df
commit cec28c9815
2 changed files with 12 additions and 7 deletions

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@ -1,3 +1,10 @@
2008-01-24 Bob Wilson <bob.wilson@acm.org>
* doc/c-xtensa.texi (Xtensa Syntax): Clarify handling of opcodes that
can only be encoded in FLIX instructions but are not specified as such.
(Xtensa Automatic Alignment): Remove obsolete comment about debugging
labels.
2008-01-24 H.J. Lu <hongjiu.lu@intel.com>
* NEWS: Mention new command line options for x86 targets.

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@ -144,10 +144,10 @@ specified on a single line by separating the opcodes with semicolons:
@{ [@var{format};] @var{opcode0} [@var{operands}]; @var{opcode1} [@var{operands}]; @var{opcode2} [@var{operands}]; @dots{} @}
@end smallexample
The assembler can automatically bundle opcodes into FLIX instructions.
It encodes the opcodes in order, one at a time,
choosing the smallest format where each opcode can be encoded and
filling unused instruction slots with no-ops.
If an opcode can only be encoded in a FLIX instruction but is not
specified as part of a FLIX bundle, the assembler will choose the
smallest format where the opcode can be encoded and
will fill unused instruction slots with no-ops.
@menu
* Xtensa Opcodes:: Opcode Naming Conventions.
@ -255,9 +255,7 @@ instruction fetch widths.) An
instruction immediately following a call is treated as a branch target
in this context, because it will be the target of a return from the
call. This alignment has the potential to reduce branch penalties at
some expense in code size. The assembler will not attempt to align
labels with the prefixes @code{.Ln} and @code{.LM}, since these labels
are used for debugging information and are not typically branch targets.
some expense in code size.
This optimization is enabled by default. You can disable it with the
@samp{--no-target-@-align} command-line option (@pxref{Xtensa Options,
,Command Line Options}).