[PATCH] MIPS/doc: Fix `d' constraint description

["Maciej W. Rozycki" <macro at imgtec dot com>]

Revert a part of the `d' constraint documentation update made with 
commit 111868 ("Use define_constraint for MIPS"), 
<https://gcc.gnu.org/ml/gcc-patches/2006-03/msg00460.html>, 
<https://gcc.gnu.org/ml/gcc-patches/2006-03/msg00541.html>, which 
inadvertently made the registers covered to be referred to as "address" 
rather than "general-purpose" registers, and then further clarify the 
set of registers allowed with MIPS16 code.

	gcc/
	* config/mips/constraints.md (d): Fix documentation.
	* doc/md.texi (Machine Constraints): Update accordingly.

 OK to apply?

  Maciej

gcc-mips-d-constraint-doc.diff
Index: gcc/gcc/config/mips/constraints.md
===================================================================
--- gcc.orig/gcc/config/mips/constraints.md	2016-08-11 20:02:03.000000000 +0100
+++ gcc/gcc/config/mips/constraints.md	2016-09-26 07:59:05.542592370 +0100
@@ -20,8 +20,8 @@
 ;; Register constraints
 
 (define_register_constraint "d" "TARGET_MIPS16 ? M16_REGS : GR_REGS"
-  "An address register.  This is equivalent to @code{r} unless
-   generating MIPS16 code.")
+  "A general-purpose register.  This is equivalent to @code{r} unless
+   generating MIPS16 code, in which case the MIPS16 register set is used.")
 
 (define_register_constraint "t" "T_REG"
   "@internal")
Index: gcc/gcc/doc/md.texi
===================================================================
--- gcc.orig/gcc/doc/md.texi	2016-08-11 20:02:07.000000000 +0100
+++ gcc/gcc/doc/md.texi	2016-09-26 07:59:13.283067222 +0100
@@ -2582,8 +2582,8 @@ A status register (@code{rmsr}, @code{$f
 @item MIPS---@file{config/mips/constraints.md}
 @table @code
 @item d
-An address register.  This is equivalent to @code{r} unless
-generating MIPS16 code.
+A general-purpose register.  This is equivalent to @code{r} unless
+generating MIPS16 code, in which case the MIPS16 register set is used.
 
 @item f
 A floating-point register (if available).