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author | Bob Wilson <bob.wilson@acm.org> | 2008-01-25 01:08:34 +0000 |
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committer | Bob Wilson <bob.wilson@acm.org> | 2008-01-25 01:08:34 +0000 |
commit | cec28c98152d659107cb32d270cd81e3fb0274ff (patch) | |
tree | ad4bda809991294102e7e440e49d7f887f5bceb7 | |
parent | 244e85c8dfd6144c3db4648dc9c9c5b569067d49 (diff) | |
download | gdb-cec28c98152d659107cb32d270cd81e3fb0274ff.zip gdb-cec28c98152d659107cb32d270cd81e3fb0274ff.tar.gz gdb-cec28c98152d659107cb32d270cd81e3fb0274ff.tar.bz2 |
* 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.
-rw-r--r-- | gas/ChangeLog | 7 | ||||
-rw-r--r-- | gas/doc/c-xtensa.texi | 12 |
2 files changed, 12 insertions, 7 deletions
diff --git a/gas/ChangeLog b/gas/ChangeLog index 3b3a922..f5334ea 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -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. diff --git a/gas/doc/c-xtensa.texi b/gas/doc/c-xtensa.texi index bc1f48e..e07eefe 100644 --- a/gas/doc/c-xtensa.texi +++ b/gas/doc/c-xtensa.texi @@ -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}). |