doc/md.texi: Fix some typos

It says "size N/2" in a few places where "size S/2" is meant.


	* doc/md.texi (vec_pack_trunc_@var{m}): Fix typo.
	(vec_pack_sfix_trunc_@var{m}, vec_pack_ufix_trunc_@var{m}): Ditto.
	(vec_packs_float_@var{m}, vec_packu_float_@var{m}): Ditto.

From-SVN: r276387

gcc/ChangeLog

+2019-10-01  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* doc/md.texi (vec_pack_trunc_@var{m}): Fix typo.
+	(vec_pack_sfix_trunc_@var{m}, vec_pack_ufix_trunc_@var{m}): Ditto.
+	(vec_packs_float_@var{m}, vec_packu_float_@var{m}): Ditto.
+
 2019-09-30  David Malcolm  <dmalcolm@redhat.com>
 
 	* diagnostic-show-locus.c (line_label::line_label): Initialize

gcc/doc/md.texi

@@ -5454,7 +5454,7 @@ The output and input vectors should have the same modes.
 Narrow (demote) and merge the elements of two vectors. Operands 1 and 2
 are vectors of the same mode having N integral or floating point elements
 of size S@.  Operand 0 is the resulting vector in which 2*N elements of
-size N/2 are concatenated after narrowing them down using truncation.
+size S/2 are concatenated after narrowing them down using truncation.
 
 @cindex @code{vec_pack_sbool_trunc_@var{m}} instruction pattern
 @item @samp{vec_pack_sbool_trunc_@var{m}}
@@ -5481,7 +5481,7 @@ saturating arithmetic.
 Narrow, convert to signed/unsigned integral type and merge the elements
 of two vectors.  Operands 1 and 2 are vectors of the same mode having N
 floating point elements of size S@.  Operand 0 is the resulting vector
-in which 2*N elements of size N/2 are concatenated.
+in which 2*N elements of size S/2 are concatenated.
 
 @cindex @code{vec_packs_float_@var{m}} instruction pattern
 @cindex @code{vec_packu_float_@var{m}} instruction pattern
@@ -5489,7 +5489,7 @@ in which 2*N elements of size N/2 are concatenated.
 Narrow, convert to floating point type and merge the elements
 of two vectors.  Operands 1 and 2 are vectors of the same mode having N
 signed/unsigned integral elements of size S@.  Operand 0 is the resulting vector
-in which 2*N elements of size N/2 are concatenated.
+in which 2*N elements of size S/2 are concatenated.
 
 @cindex @code{vec_unpacks_hi_@var{m}} instruction pattern
 @cindex @code{vec_unpacks_lo_@var{m}} instruction pattern