diff mbox

, PowerPC IEEE 128-bit patch #4c (revised)

Message ID 20150730192330.GA14081@ibm-tiger.the-meissners.org
State New
Headers show

Commit Message

Michael Meissner July 30, 2015, 7:23 p.m. UTC
Seger pointed out that the altivec_high_bit insn was not safe if it was called
when it could not allocate pseudos. I have removed that insn in this patch. I
will revise the patch.  I had meant to tie it in with easy_altivec_constant
originally, and I will do a patch with that change.

Is this revised patch ok to install?  There are no references to
altivec_high_bit in this patch set, so I just made sure it builds ok just
removing the insn.

2015-07-30  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/vector.md (VEC_L): Add KFmode and TFmode.
	(VEC_M): Likewise.
	(VEC_N): Likewise.
	(mov<mode>, VEC_M iterator): Add support for IEEE 128-bit floating
	point in VSX registers.

	* config/rs6000/constraints.md (wb constraint): Document unused
	w<x> constraint.
	(we constraint): Likewise.
	(wo constraint): Likewise.
	(wp constraint): New constraint for IEEE 128-bit floating point in
	VSX registers.
	(wq constraint): Likewise.

	* config/rs6000/predicates.md (easy_fp_constant): Add support for
	IEEE 128-bit floating point in VSX registers.
	(easy_scalar_constant): Likewise.

	* config/rs6000/rs6000.c (rs6000_debug_reg_global): Add new
	constraints (wp, wq) for IEEE 128-bit floating point in VSX
	registers.
	(rs6000_init_hard_regno_mode_ok): Likewise.

	* config/rs6000/vsx.md (VSX_LE_128): Add support for IEEE 128-bit
	floating point in VSX registers.
	(VSX_L): Likewise.
	(VSX_M): Likewise.
	(VSX_M2): Likewise.
	(VSm): Likewise.
	(VSs): Likewise.
	(VSr): Likewise.
	(VSa): Likewise.
	(VSv): Likewise.
	(vsx_le_permute_<mode>): Add support to properly swap bytes for
	IEEE 128-bit floating point in VSX registers on little endian.
	(vsx_le_undo_permute_<mode>): Likewise.
	(vsx_le_perm_load_<mode>): Likewise.
	(vsx_le_perm_store_<mode>): Likewise.
	(splitters for IEEE 128-bit fp moves): Likewise.

	* config/rs6000/rs6000.h (enum r6000_reg_class_enum): Add wp and
	wq constraints.

	* config/rs6000/altivec.md (VM): Add support for IEEE 128-bit
	floating point in VSX registers.
	(VM2): Likewise.

	* doc/md.text (Machine Constraints): Document wp and wq
	constraints on PowerPC.

Comments

David Edelsohn Aug. 1, 2015, 7:48 p.m. UTC | #1
On Thu, Jul 30, 2015 at 3:23 PM, Michael Meissner
<meissner@linux.vnet.ibm.com> wrote:
> Seger pointed out that the altivec_high_bit insn was not safe if it was called
> when it could not allocate pseudos. I have removed that insn in this patch. I
> will revise the patch.  I had meant to tie it in with easy_altivec_constant
> originally, and I will do a patch with that change.
>
> Is this revised patch ok to install?  There are no references to
> altivec_high_bit in this patch set, so I just made sure it builds ok just
> removing the insn.
>
> 2015-07-30  Michael Meissner  <meissner@linux.vnet.ibm.com>
>
>         * config/rs6000/vector.md (VEC_L): Add KFmode and TFmode.
>         (VEC_M): Likewise.
>         (VEC_N): Likewise.
>         (mov<mode>, VEC_M iterator): Add support for IEEE 128-bit floating
>         point in VSX registers.
>
>         * config/rs6000/constraints.md (wb constraint): Document unused
>         w<x> constraint.
>         (we constraint): Likewise.
>         (wo constraint): Likewise.
>         (wp constraint): New constraint for IEEE 128-bit floating point in
>         VSX registers.
>         (wq constraint): Likewise.
>
>         * config/rs6000/predicates.md (easy_fp_constant): Add support for
>         IEEE 128-bit floating point in VSX registers.
>         (easy_scalar_constant): Likewise.
>
>         * config/rs6000/rs6000.c (rs6000_debug_reg_global): Add new
>         constraints (wp, wq) for IEEE 128-bit floating point in VSX
>         registers.
>         (rs6000_init_hard_regno_mode_ok): Likewise.
>
>         * config/rs6000/vsx.md (VSX_LE_128): Add support for IEEE 128-bit
>         floating point in VSX registers.
>         (VSX_L): Likewise.
>         (VSX_M): Likewise.
>         (VSX_M2): Likewise.
>         (VSm): Likewise.
>         (VSs): Likewise.
>         (VSr): Likewise.
>         (VSa): Likewise.
>         (VSv): Likewise.
>         (vsx_le_permute_<mode>): Add support to properly swap bytes for
>         IEEE 128-bit floating point in VSX registers on little endian.
>         (vsx_le_undo_permute_<mode>): Likewise.
>         (vsx_le_perm_load_<mode>): Likewise.
>         (vsx_le_perm_store_<mode>): Likewise.
>         (splitters for IEEE 128-bit fp moves): Likewise.
>
>         * config/rs6000/rs6000.h (enum r6000_reg_class_enum): Add wp and
>         wq constraints.
>
>         * config/rs6000/altivec.md (VM): Add support for IEEE 128-bit
>         floating point in VSX registers.
>         (VM2): Likewise.
>
>         * doc/md.text (Machine Constraints): Document wp and wq
>         constraints on PowerPC.

This is okay.

Thanks, David
diff mbox

Patch

Index: gcc/config/rs6000/vector.md
===================================================================
--- gcc/config/rs6000/vector.md	(revision 226275)
+++ gcc/config/rs6000/vector.md	(working copy)
@@ -36,13 +36,14 @@  (define_mode_iterator VEC_A [V16QI V8HI 
 (define_mode_iterator VEC_K [V16QI V8HI V4SI V4SF])
 
 ;; Vector logical modes
-(define_mode_iterator VEC_L [V16QI V8HI V4SI V2DI V4SF V2DF V1TI TI])
+(define_mode_iterator VEC_L [V16QI V8HI V4SI V2DI V4SF V2DF V1TI TI KF TF])
 
-;; Vector modes for moves.  Don't do TImode here.
-(define_mode_iterator VEC_M [V16QI V8HI V4SI V2DI V4SF V2DF V1TI])
+;; Vector modes for moves.  Don't do TImode or TFmode here, since their
+;; moves are handled elsewhere.
+(define_mode_iterator VEC_M [V16QI V8HI V4SI V2DI V4SF V2DF V1TI KF])
 
 ;; Vector modes for types that don't need a realignment under VSX
-(define_mode_iterator VEC_N [V4SI V4SF V2DI V2DF V1TI])
+(define_mode_iterator VEC_N [V4SI V4SF V2DI V2DF V1TI KF TF])
 
 ;; Vector comparison modes
 (define_mode_iterator VEC_C [V16QI V8HI V4SI V2DI V4SF V2DF])
@@ -95,12 +96,19 @@  (define_expand "mov<mode>"
 {
   if (can_create_pseudo_p ())
     {
-      if (CONSTANT_P (operands[1])
-	  && !easy_vector_constant (operands[1], <MODE>mode))
-	operands[1] = force_const_mem (<MODE>mode, operands[1]);
+      if (CONSTANT_P (operands[1]))
+	{
+	  if (FLOAT128_VECTOR_P (<MODE>mode))
+	    {
+	      if (!easy_fp_constant (operands[1], <MODE>mode))
+		operands[1] = force_const_mem (<MODE>mode, operands[1]);
+	    }
+	  else if (!easy_vector_constant (operands[1], <MODE>mode))
+	    operands[1] = force_const_mem (<MODE>mode, operands[1]);
+	}
 
-      else if (!vlogical_operand (operands[0], <MODE>mode)
-	       && !vlogical_operand (operands[1], <MODE>mode))
+      if (!vlogical_operand (operands[0], <MODE>mode)
+	  && !vlogical_operand (operands[1], <MODE>mode))
 	operands[1] = force_reg (<MODE>mode, operands[1]);
     }
   if (!BYTES_BIG_ENDIAN
Index: gcc/config/rs6000/constraints.md
===================================================================
--- gcc/config/rs6000/constraints.md	(revision 226275)
+++ gcc/config/rs6000/constraints.md	(working copy)
@@ -56,12 +56,16 @@  (define_register_constraint "z" "CA_REGS
 (define_register_constraint "wa" "rs6000_constraints[RS6000_CONSTRAINT_wa]"
   "Any VSX register if the -mvsx option was used or NO_REGS.")
 
+;; wb is not currently used
+
 ;; NOTE: For compatibility, "wc" is reserved to represent individual CR bits.
 ;; It is currently used for that purpose in LLVM.
 
 (define_register_constraint "wd" "rs6000_constraints[RS6000_CONSTRAINT_wd]"
   "VSX vector register to hold vector double data or NO_REGS.")
 
+;; we is not currently used
+
 (define_register_constraint "wf" "rs6000_constraints[RS6000_CONSTRAINT_wf]"
   "VSX vector register to hold vector float data or NO_REGS.")
 
@@ -93,6 +97,14 @@  (define_register_constraint "wm" "rs6000
 ;; There is a mode_attr that resolves to wm for SDmode and wn for SFmode
 (define_register_constraint "wn" "NO_REGS" "No register (NO_REGS).")
 
+;; wo is not currently used
+
+(define_register_constraint "wp" "rs6000_constraints[RS6000_CONSTRAINT_wp]"
+  "VSX register to use for IEEE 128-bit fp TFmode, or NO_REGS.")
+
+(define_register_constraint "wq" "rs6000_constraints[RS6000_CONSTRAINT_wq]"
+  "VSX register to use for IEEE 128-bit fp KFmode, or NO_REGS.")
+
 (define_register_constraint "wr" "rs6000_constraints[RS6000_CONSTRAINT_wr]"
   "General purpose register if 64-bit instructions are enabled or NO_REGS.")
 
Index: gcc/config/rs6000/predicates.md
===================================================================
--- gcc/config/rs6000/predicates.md	(revision 226275)
+++ gcc/config/rs6000/predicates.md	(working copy)
@@ -460,6 +460,8 @@  (define_predicate "easy_fp_constant"
 
   switch (mode)
     {
+    case KFmode:
+    case IFmode:
     case TFmode:
     case DFmode:
     case SFmode:
@@ -486,6 +488,12 @@  (define_predicate "easy_vector_constant"
   if (TARGET_PAIRED_FLOAT)
     return false;
 
+  /* Because IEEE 128-bit floating point is considered a vector type
+     in order to pass it in VSX registers, it might use this function
+     instead of easy_fp_constant.  */
+  if (FLOAT128_VECTOR_P (mode))
+    return easy_fp_constant (op, mode);
+
   if (VECTOR_MEM_ALTIVEC_OR_VSX_P (mode))
     {
       if (zero_constant (op, mode))
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 226275)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -2167,6 +2167,8 @@  rs6000_debug_reg_global (void)
 	   "wk reg_class = %s\n"
 	   "wl reg_class = %s\n"
 	   "wm reg_class = %s\n"
+	   "wp reg_class = %s\n"
+	   "wq reg_class = %s\n"
 	   "wr reg_class = %s\n"
 	   "ws reg_class = %s\n"
 	   "wt reg_class = %s\n"
@@ -2190,6 +2192,8 @@  rs6000_debug_reg_global (void)
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wk]],
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wl]],
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wm]],
+	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wp]],
+	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wq]],
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wr]],
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_ws]],
 	   reg_class_names[rs6000_constraints[RS6000_CONSTRAINT_wt]],
@@ -2856,6 +2860,13 @@  rs6000_init_hard_regno_mode_ok (bool glo
   if (TARGET_LFIWZX)
     rs6000_constraints[RS6000_CONSTRAINT_wz] = FLOAT_REGS;	/* DImode  */
 
+  if (TARGET_FLOAT128)
+    {
+      rs6000_constraints[RS6000_CONSTRAINT_wq] = VSX_REGS;	/* KFmode  */
+      if (rs6000_ieeequad)
+	rs6000_constraints[RS6000_CONSTRAINT_wp] = VSX_REGS;	/* TFmode  */
+    }
+
   /* Set up the reload helper and direct move functions.  */
   if (TARGET_VSX || TARGET_ALTIVEC)
     {
Index: gcc/config/rs6000/vsx.md
===================================================================
--- gcc/config/rs6000/vsx.md	(revision 226275)
+++ gcc/config/rs6000/vsx.md	(working copy)
@@ -31,6 +31,11 @@  (define_mode_iterator VSX_LE [V2DF
 			      V1TI
 			      (TI	"VECTOR_MEM_VSX_P (TImode)")])
 
+;; Mode iterator to handle swapping words on little endian for the 128-bit
+;; types that goes in a single vector register.
+(define_mode_iterator VSX_LE_128 [(KF   "FLOAT128_VECTOR_P (KFmode)")
+				  (TF   "FLOAT128_VECTOR_P (TFmode)")])
+
 ;; Iterator for the 2 32-bit vector types
 (define_mode_iterator VSX_W [V4SF V4SI])
 
@@ -41,11 +46,31 @@  (define_mode_iterator VSX_DF [V2DF DF])
 (define_mode_iterator VSX_F [V4SF V2DF])
 
 ;; Iterator for logical types supported by VSX
-(define_mode_iterator VSX_L [V16QI V8HI V4SI V2DI V4SF V2DF V1TI TI])
+;; Note, IFmode won't actually be used since it isn't a VSX type, but it simplifies
+;; the code by using 128-bit iterators for floating point.
+(define_mode_iterator VSX_L [V16QI
+			     V8HI
+			     V4SI
+			     V2DI
+			     V4SF
+			     V2DF
+			     V1TI
+			     TI
+			     (KF	"FLOAT128_VECTOR_P (KFmode)")
+			     (TF	"FLOAT128_VECTOR_P (TFmode)")
+			     (IF	"FLOAT128_VECTOR_P (IFmode)")])
 
 ;; Iterator for memory move.  Handle TImode specially to allow
 ;; it to use gprs as well as vsx registers.
-(define_mode_iterator VSX_M [V16QI V8HI V4SI V2DI V4SF V2DF V1TI])
+(define_mode_iterator VSX_M [V16QI
+			     V8HI
+			     V4SI
+			     V2DI
+			     V4SF
+			     V2DF
+			     V1TI
+			     (KF	"FLOAT128_VECTOR_P (KFmode)")
+			     (TF	"FLOAT128_VECTOR_P (TFmode)")])
 
 (define_mode_iterator VSX_M2 [V16QI
 			      V8HI
@@ -54,6 +79,8 @@  (define_mode_iterator VSX_M2 [V16QI
 			      V4SF
 			      V2DF
 			      V1TI
+			      (KF	"FLOAT128_VECTOR_P (KFmode)")
+			      (TF	"FLOAT128_VECTOR_P (TFmode)")
 			      (TI	"TARGET_VSX_TIMODE")])
 
 ;; Map into the appropriate load/store name based on the type
@@ -64,6 +91,8 @@  (define_mode_attr VSm  [(V16QI "vw4")
 			(V2DF  "vd2")
 			(V2DI  "vd2")
 			(DF    "d")
+			(TF    "vd2")
+			(KF    "vd2")
 			(V1TI  "vd2")
 			(TI    "vd2")])
 
@@ -76,6 +105,8 @@  (define_mode_attr VSs	[(V16QI "sp")
 			 (V2DI  "dp")
 			 (DF    "dp")
 			 (SF	"sp")
+			 (TF    "dp")
+			 (KF    "dp")
 			 (V1TI  "dp")
 			 (TI    "dp")])
 
@@ -89,6 +120,8 @@  (define_mode_attr VSr	[(V16QI "v")
 			 (DI	"wi")
 			 (DF    "ws")
 			 (SF	"ww")
+			 (TF	"wp")
+			 (KF	"wq")
 			 (V1TI  "v")
 			 (TI    "wt")])
 
@@ -132,7 +165,9 @@  (define_mode_attr VSa	[(V16QI "wa")
 			 (DF    "ws")
 			 (SF	"ww")
 			 (V1TI	"wa")
-			 (TI    "wt")])
+			 (TI    "wt")
+			 (TF	"wp")
+			 (KF	"wq")])
 
 ;; Same size integer type for floating point data
 (define_mode_attr VSi [(V4SF  "v4si")
@@ -157,7 +192,8 @@  (define_mode_attr VSv	[(V16QI "v")
 			 (V2DI  "v")
 			 (V2DF  "v")
 			 (V1TI  "v")
-			 (DF    "s")])
+			 (DF    "s")
+			 (KF	"v")])
 
 ;; Appropriate type for add ops (and other simple FP ops)
 (define_mode_attr VStype_simple	[(V2DF "vecdouble")
@@ -623,6 +659,105 @@  (define_split
                      (const_int 6) (const_int 7)])))]
   "")
 
+;; Little endian word swapping for 128-bit types that are either scalars or the
+;; special V1TI container class, which it is not appropriate to use vec_select
+;; for the type.
+(define_insn "*vsx_le_permute_<mode>"
+  [(set (match_operand:VSX_LE_128 0 "nonimmediate_operand" "=<VSa>,<VSa>,Z")
+	(rotate:VSX_LE_128
+	 (match_operand:VSX_LE_128 1 "input_operand" "<VSa>,Z,<VSa>")
+	 (const_int 64)))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX"
+  "@
+   xxpermdi %x0,%x1,%x1,2
+   lxvd2x %x0,%y1
+   stxvd2x %x1,%y0"
+  [(set_attr "length" "4")
+   (set_attr "type" "vecperm,vecload,vecstore")])
+
+(define_insn_and_split "*vsx_le_undo_permute_<mode>"
+  [(set (match_operand:VSX_LE_128 0 "vsx_register_operand" "=<VSa>,<VSa>")
+	(rotate:VSX_LE_128
+	 (rotate:VSX_LE_128
+	  (match_operand:VSX_LE_128 1 "vsx_register_operand" "0,<VSa>")
+	  (const_int 64))
+	 (const_int 64)))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX"
+  "@
+   #
+   xxlor %x0,%x1"
+  ""
+  [(set (match_dup 0) (match_dup 1))]
+{
+  if (reload_completed && REGNO (operands[0]) == REGNO (operands[1]))
+    {
+      emit_note (NOTE_INSN_DELETED);
+      DONE;
+    }
+}
+  [(set_attr "length" "0,4")
+   (set_attr "type" "vecsimple")])
+
+(define_insn_and_split "*vsx_le_perm_load_<mode>"
+  [(set (match_operand:VSX_LE_128 0 "vsx_register_operand" "=<VSa>")
+        (match_operand:VSX_LE_128 1 "memory_operand" "Z"))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX"
+  "#"
+  "!BYTES_BIG_ENDIAN && TARGET_VSX"
+  [(set (match_dup 2)
+	(rotate:VSX_LE_128 (match_dup 1)
+			   (const_int 64)))
+   (set (match_dup 0)
+	(rotate:VSX_LE_128 (match_dup 2)
+			   (const_int 64)))]
+  "
+{
+  operands[2] = can_create_pseudo_p () ? gen_reg_rtx_and_attrs (operands[0])
+                                       : operands[0];
+}
+  "
+  [(set_attr "type" "vecload")
+   (set_attr "length" "8")])
+
+(define_insn "*vsx_le_perm_store_<mode>"
+  [(set (match_operand:VSX_LE_128 0 "memory_operand" "=Z")
+        (match_operand:VSX_LE_128 1 "vsx_register_operand" "+<VSa>"))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX"
+  "#"
+  [(set_attr "type" "vecstore")
+   (set_attr "length" "12")])
+
+(define_split
+  [(set (match_operand:VSX_LE_128 0 "memory_operand" "")
+        (match_operand:VSX_LE_128 1 "vsx_register_operand" ""))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX && !reload_completed"
+  [(set (match_dup 2)
+	(rotate:VSX_LE_128 (match_dup 1)
+			   (const_int 64)))
+   (set (match_dup 0)
+	(rotate:VSX_LE_128 (match_dup 2)
+			   (const_int 64)))]
+{
+  operands[2] = can_create_pseudo_p () ? gen_reg_rtx_and_attrs (operands[0])
+                                       : operands[0];
+})
+
+;; The post-reload split requires that we re-permute the source
+;; register in case it is still live.
+(define_split
+  [(set (match_operand:VSX_LE_128 0 "memory_operand" "")
+        (match_operand:VSX_LE_128 1 "vsx_register_operand" ""))]
+  "!BYTES_BIG_ENDIAN && TARGET_VSX && reload_completed"
+  [(set (match_dup 1)
+	(rotate:VSX_LE_128 (match_dup 1)
+			   (const_int 64)))
+   (set (match_dup 0)
+	(rotate:VSX_LE_128 (match_dup 1)
+			   (const_int 64)))
+   (set (match_dup 1)
+	(rotate:VSX_LE_128 (match_dup 1)
+			   (const_int 64)))]
+  "")
 
 (define_insn "*vsx_mov<mode>"
   [(set (match_operand:VSX_M 0 "nonimmediate_operand" "=Z,<VSr>,<VSr>,?Z,?<VSa>,?<VSa>,wQ,?&r,??Y,??r,??r,<VSr>,?<VSa>,*r,v,wZ, v")
Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h	(revision 226275)
+++ gcc/config/rs6000/rs6000.h	(working copy)
@@ -1496,6 +1496,8 @@  enum r6000_reg_class_enum {
   RS6000_CONSTRAINT_wk,		/* FPR/VSX register for DFmode direct moves. */
   RS6000_CONSTRAINT_wl,		/* FPR register for LFIWAX */
   RS6000_CONSTRAINT_wm,		/* VSX register for direct move */
+  RS6000_CONSTRAINT_wp,		/* VSX reg for IEEE 128-bit fp TFmode. */
+  RS6000_CONSTRAINT_wq,		/* VSX reg for IEEE 128-bit fp KFmode.  */
   RS6000_CONSTRAINT_wr,		/* GPR register if 64-bit  */
   RS6000_CONSTRAINT_ws,		/* VSX register for DF */
   RS6000_CONSTRAINT_wt,		/* VSX register for TImode */
Index: gcc/config/rs6000/altivec.md
===================================================================
--- gcc/config/rs6000/altivec.md	(revision 226274)
+++ gcc/config/rs6000/altivec.md	(working copy)
@@ -167,10 +167,27 @@  (define_mode_iterator VF [V4SF])
 (define_mode_iterator V [V4SI V8HI V16QI V4SF])
 ;; Vec modes for move/logical/permute ops, include vector types for move not
 ;; otherwise handled by altivec (v2df, v2di, ti)
-(define_mode_iterator VM [V4SI V8HI V16QI V4SF V2DF V2DI V1TI TI])
+(define_mode_iterator VM [V4SI
+			  V8HI
+			  V16QI
+			  V4SF
+			  V2DF
+			  V2DI
+			  V1TI
+			  TI
+			  (KF "FLOAT128_VECTOR_P (KFmode)")
+			  (TF "FLOAT128_VECTOR_P (TFmode)")])
 
 ;; Like VM, except don't do TImode
-(define_mode_iterator VM2 [V4SI V8HI V16QI V4SF V2DF V2DI V1TI])
+(define_mode_iterator VM2 [V4SI
+			   V8HI
+			   V16QI
+			   V4SF
+			   V2DF
+			   V2DI
+			   V1TI
+			   (KF "FLOAT128_VECTOR_P (KFmode)")
+			   (TF "FLOAT128_VECTOR_P (TFmode)")])
 
 (define_mode_attr VI_char [(V2DI "d") (V4SI "w") (V8HI "h") (V16QI "b")])
 (define_mode_attr VI_scalar [(V2DI "DI") (V4SI "SI") (V8HI "HI") (V16QI "QI")])
Index: gcc/doc/md.texi
===================================================================
--- gcc/doc/md.texi	(revision 226275)
+++ gcc/doc/md.texi	(working copy)
@@ -3087,12 +3087,13 @@  Any VSX register if the -mvsx option was
 
 When using any of the register constraints (@code{wa}, @code{wd},
 @code{wf}, @code{wg}, @code{wh}, @code{wi}, @code{wj}, @code{wk},
-@code{wl}, @code{wm}, @code{ws}, @code{wt}, @code{wu}, @code{wv},
-@code{ww}, or @code{wy}) that take VSX registers, you must use
-@code{%x<n>} in the template so that the correct register is used.
-Otherwise the register number output in the assembly file will be
-incorrect if an Altivec register is an operand of a VSX instruction
-that expects VSX register numbering.
+@code{wl}, @code{wm}, @code{wp}, @code{wq}, @code{ws}, @code{wt},
+@code{wu}, @code{wv}, @code{ww}, or @code{wy})
+that take VSX registers, you must use @code{%x<n>} in the template so
+that the correct register is used.  Otherwise the register number
+output in the assembly file will be incorrect if an Altivec register
+is an operand of a VSX instruction that expects VSX register
+numbering.
 
 @smallexample
 asm ("xvadddp %x0,%x1,%x2" : "=wa" (v1) : "wa" (v2), "wa" (v3));
@@ -3136,6 +3137,12 @@  VSX register if direct move instructions
 @item wn
 No register (NO_REGS).
 
+@item wp
+VSX register to use for IEEE 128-bit floating point TFmode, or NO_REGS.
+
+@item wq
+VSX register to use for IEEE 128-bit floating point, or NO_REGS.
+
 @item wr
 General purpose register if 64-bit instructions are enabled or NO_REGS.