[gcc(refs/users/meissner/heads/work042)] Use VEC_DUPLICATE for V4SF duplicate constants.

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:569f389f022a47010f7e527b5f5ac0fde7cf0b6b

commit 569f389f022a47010f7e527b5f5ac0fde7cf0b6b
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Fri Mar 19 13:46:02 2021 -0400

    Use VEC_DUPLICATE for V4SF duplicate constants.
    
    This code rewrites the handling for the __builtin_vec_xxspltiw builtin in
    handling V4SF constants to use VEC_DUPLICATE instead of an UNSPEC.
    
    gcc/
    2021-03-19  Michael Meissner  <meissner@linux.ibm.com>
    
            * config/rs6000/altivec.md (UNSPEC_XXSPLTIW): Delete.
            (xxspltiw_v4sf): Rewrite to use VEC_DUPLICATE.
            (xxspltiw_v4sf_inst): Delete.
            * config/rs6000/rs6000.c (xxspltiw_constant_p): Add V4SFmode
            support.
            (output_vec_const_move): Add support for V4SFmode constants.
            (rs6000_expand_vector_init): If we have XXSPLTIW, use
            VEC_DUPLICATE to create a vector of SF constants that are all the
            same.

Diff:
---
 gcc/config/rs6000/altivec.md | 28 +++++++++++-----------------
 gcc/config/rs6000/rs6000.c   |  8 +++++---
 2 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/gcc/config/rs6000/altivec.md b/gcc/config/rs6000/altivec.md
index ec071bbd0a4..2fb22172bec 100644
--- a/gcc/config/rs6000/altivec.md
+++ b/gcc/config/rs6000/altivec.md
@@ -176,7 +176,6 @@
    UNSPEC_VSTRIL
    UNSPEC_SLDB
    UNSPEC_SRDB
-   UNSPEC_XXSPLTIW
    UNSPEC_XXSPLTID
    UNSPEC_XXSPLTI32DX
    UNSPEC_XXBLEND
@@ -835,26 +834,21 @@
   (set_attr "prefixed" "*,*,*,yes")
   (set_attr "prefixed_prepend_p" "*,*,*,no")])
 
-(define_expand "xxspltiw_v4sf"
-  [(set (match_operand:V4SF 0 "register_operand" "=wa")
-	(unspec:V4SF [(match_operand:SF 1 "const_double_operand" "n")]
-		     UNSPEC_XXSPLTIW))]
+(define_insn "xxspltiw_v4sf"
+  [(set (match_operand:V4SF 0 "register_operand" "=wa,wa")
+	(vec_duplicate:V4SF
+	 (match_operand:SF 1 "const_double_operand" "j,F")))]
  "TARGET_POWER10"
 {
-  long long value = rs6000_const_f32_to_i32 (operands[1]);
-  emit_insn (gen_xxspltiw_v4sf_inst (operands[0], GEN_INT (value)));
-  DONE;
-})
+  if (operands[1] == CONST0_RTX (SFmode))
+    return "xxspltib %x0,0";
 
-(define_insn "xxspltiw_v4sf_inst"
-  [(set (match_operand:V4SF 0 "register_operand" "=wa")
-	(unspec:V4SF [(match_operand:SI 1 "c32bit_cint_operand" "n")]
-		     UNSPEC_XXSPLTIW))]
- "TARGET_POWER10"
- "xxspltiw %x0,%1"
+  operands[2] = GEN_INT (rs6000_const_f32_to_i32 (operands[1]));
+  return "xxspltiw %x0,%2";
+}
  [(set_attr "type" "vecperm")
-  (set_attr "prefixed" "yes")
-  (set_attr "prefixed_prepend_p" "no")])
+  (set_attr "prefixed" "*,yes")
+  (set_attr "prefixed_prepend_p" "*,no")])
 
 (define_expand "xxspltidp_v2df"
   [(set (match_operand:V2DF 0 "register_operand" )
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 63525e764cf..af46a00e139 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -6338,7 +6338,7 @@ xxspltiw_constant_p (rtx op, machine_mode mode, rtx *constant_ptr)
   else if (mode != GET_MODE (op))
     return false;
 
-  if (mode != V4SImode)
+  if (mode != V4SImode && mode != V4SFmode)
     return false;
 
   rtx element;
@@ -6541,11 +6541,13 @@ output_vec_const_move (rtx *operands)
 	{
 	  if (CONST_INT_P (element))
 	    operands[2] = element;
+	  else if (CONST_DOUBLE_P (element))
+	    operands[2] = GEN_INT (rs6000_const_f32_to_i32 (element));
 	  else
 	    gcc_unreachable ();
 
 	  HOST_WIDE_INT value = INTVAL (operands[2]);
-	  if (IN_RANGE (value, -16, 15) && dest_vmx_p)
+	  if (IN_RANGE (value, -16, 15) && dest_vmx_p && mode == V4SImode)
 	    return "vspltisw %0,%2";
 
 	  else
@@ -6634,7 +6636,7 @@ rs6000_expand_vector_init (rtx target, rtx vals)
   if (n_var == 0)
     {
       /* Generate XXSPLTIW if we can.  */
-      if (TARGET_POWER10 && all_same && mode == V4SImode)
+      if (TARGET_POWER10 && all_same && (mode == V4SImode || mode == V4SFmode))
 	{
 	  rtx dup = gen_rtx_VEC_DUPLICATE (mode, XVECEXP (vals, 0, 0));
 	  emit_insn (gen_rtx_SET (target, dup));