[patch] Update vectorizer documentation

[Ira Rosen <IRAR at il dot ibm dot com>]

Hi,

This patch adds basic block SLP flags documentation and updates vectorizer
verbosity levels documentation.

OK for trunk?

Thanks,
Ira


ChangeLog:

      * doc/invoke.texi (-fdump-tree-slp): Document.
      (-ftree-vectorizer-verbose): Update.
      (-ftree-slp-vectorize): Document.

Index: doc/invoke.texi
===================================================================
--- doc/invoke.texi     (revision 154906)
+++ doc/invoke.texi     (working copy)
@@ -5360,6 +5360,11 @@ file name.
 Dump each function after applying vectorization of loops.  The file name
is
 made by appending @file{.vect} to the source file name.

+@item slp
+@opindex fdump-tree-slp
+Dump each function after applying vectorization of basic blocks.  The file
name
+is made by appending @file{.slp} to the source file name.
+
 @item vrp
 @opindex fdump-tree-vrp
 Dump each function after Value Range Propagation (VRP).  The file name
@@ -5385,14 +5390,16 @@ inner-most, single-bb, single-entry/exit
 level that @option{-fdump-tree-vect-stats} uses.
 Higher verbosity levels mean either more information dumped for each
 reported loop, or same amount of information reported for more loops:
-If @var{n}=3, alignment related information is added to the reports.
-If @var{n}=4, data-references related information (e.g.@: memory
dependences,
+if @var{n}=3, vectorizer cost model information is reported.
+If @var{n}=4, alignment related information is added to the reports.
+If @var{n}=5, data-references related information (e.g.@: memory
dependences,
 memory access-patterns) is added to the reports.
-If @var{n}=5, the vectorizer reports also non-vectorized inner-most loops
+If @var{n}=6, the vectorizer reports also non-vectorized inner-most loops
 that did not pass the first analysis phase (i.e., may not be countable, or
 may have complicated control-flow).
-If @var{n}=6, the vectorizer reports also non-vectorized nested loops.
-For @var{n}=7, all the information the vectorizer generates during its
+If @var{n}=7, the vectorizer reports also non-vectorized nested loops.
+If @var{n}=8, SLP related information is added to the reports.
+For @var{n}=9, all the information the vectorizer generates during its
 analysis and transformation is reported.  This is the same verbosity level
 that @option{-fdump-tree-vect-details} uses.

@@ -6818,6 +6825,11 @@ enabled by default at @option{-O} and hi
 Perform loop vectorization on trees. This flag is enabled by default at
 @option{-O3}.

+@item -ftree-slp-vectorize
+@opindex ftree-slp-vectorize
+Perform basic block vectorization on trees. This flag is enabled by
default at
+@option{-O3} and when @option{-ftree-vectorize} is enabled.
+
 @item -ftree-vect-loop-version
 @opindex ftree-vect-loop-version
 Perform loop versioning when doing loop vectorization on trees.  When a
loop