From 0061fabeb9393c362601486105202cfe837a5a68 Mon Sep 17 00:00:00 2001
From: Claudiu Zissulescu <claziss@synopsys.com>
Date: Wed, 9 Jun 2021 12:12:57 +0300
Subject: [PATCH] arc: Update 64bit move split patterns.

ARCv2HS can use a limited number of instructions to implement 64bit
moves. The VADD2 is used as a 64bit move, the LDD/STD are 64 bit loads
and stores. All those instructions are not baseline, hence we need to
provide alternatives when they are not available or cannot be generate
due to instruction restriction.

This patch is cleaning up those move patterns, and updates splits
instruction lengths.

This is a backport from mainline gcc.

gcc/
2021-06-09  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc-protos.h (arc_split_move_p): New prototype.
	* config/arc/arc.c (arc_split_move_p): New function.
	(arc_split_move): Clean up.
	* config/arc/arc.md (movdi_insn): Clean up, use arc_split_move_p.
	(movdf_insn): Likewise.
	* config/arc/simdext.md (mov<VWH>_insn): Likewise.

Upstream-Status: Backport [https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=0061fabeb9393c362601486105202cfe837a5a68]

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>
(cherry picked from commit c0ba7a8af5366c37241f20e8be41e362f7260389)
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
---
 gcc/config/arc/arc-protos.h |  1 +
 gcc/config/arc/arc.c        | 44 ++++++++++++----------
 gcc/config/arc/arc.md       | 91 +++++++++------------------------------------
 gcc/config/arc/simdext.md   | 38 ++++---------------
 4 files changed, 52 insertions(+), 122 deletions(-)

diff --git a/gcc/config/arc/arc-protos.h b/gcc/config/arc/arc-protos.h
index 1f56a0d82e4..62d7e45d29d 100644
--- a/gcc/config/arc/arc-protos.h
+++ b/gcc/config/arc/arc-protos.h
@@ -50,6 +50,7 @@ extern void arc_split_ior (rtx *);
 extern bool arc_check_mov_const (HOST_WIDE_INT );
 extern bool arc_split_mov_const (rtx *);
 extern bool arc_can_use_return_insn (void);
+extern bool arc_split_move_p (rtx *);
 #endif /* RTX_CODE */
 
 extern bool arc_ccfsm_branch_deleted_p (void);
diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index 3201c3fefd7..db541bc11f5 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -10129,6 +10129,31 @@ arc_process_double_reg_moves (rtx *operands)
   return true;
 }
 
+
+/* Check if we need to split a 64bit move.  We do not need to split it if we can
+   use vadd2 or ldd/std instructions.  */
+
+bool
+arc_split_move_p (rtx *operands)
+{
+  machine_mode mode = GET_MODE (operands[0]);
+
+  if (TARGET_LL64
+      && ((memory_operand (operands[0], mode)
+	   && (even_register_operand (operands[1], mode)
+	       || satisfies_constraint_Cm3 (operands[1])))
+	  || (memory_operand (operands[1], mode)
+	      && even_register_operand (operands[0], mode))))
+    return false;
+
+  if (TARGET_PLUS_QMACW
+      && even_register_operand (operands[0], mode)
+      && even_register_operand (operands[1], mode))
+    return false;
+
+  return true;
+}
+
 /* operands 0..1 are the operands of a 64 bit move instruction.
    split it into two moves with operands 2/3 and 4/5.  */
 
@@ -10146,25 +10171,6 @@ arc_split_move (rtx *operands)
       return;
   }
 
-  if (TARGET_LL64
-      && ((memory_operand (operands[0], mode)
-	   && (even_register_operand (operands[1], mode)
-	       || satisfies_constraint_Cm3 (operands[1])))
-	  || (memory_operand (operands[1], mode)
-	      && even_register_operand (operands[0], mode))))
-    {
-      emit_move_insn (operands[0], operands[1]);
-      return;
-    }
-
-  if (TARGET_PLUS_QMACW
-      && even_register_operand (operands[0], mode)
-      && even_register_operand (operands[1], mode))
-    {
-      emit_move_insn (operands[0], operands[1]);
-      return;
-    }
-
   if (TARGET_PLUS_QMACW
       && GET_CODE (operands[1]) == CONST_VECTOR)
     {
diff --git a/gcc/config/arc/arc.md b/gcc/config/arc/arc.md
index 7a52551eef5..91a838a38e4 100644
--- a/gcc/config/arc/arc.md
+++ b/gcc/config/arc/arc.md
@@ -1329,47 +1329,20 @@ core_3, archs4x, archs4xd, archs4xd_slow"
   "register_operand (operands[0], DImode)
    || register_operand (operands[1], DImode)
    || (satisfies_constraint_Cm3 (operands[1])
-      && memory_operand (operands[0], DImode))"
-  "*
-{
-  switch (which_alternative)
-    {
-    default:
-      return \"#\";
-
-    case 0:
-    if (TARGET_PLUS_QMACW
-	&& even_register_operand (operands[0], DImode)
-	&& even_register_operand (operands[1], DImode))
-      return \"vadd2%?\\t%0,%1,0\";
-    return \"#\";
-
-    case 2:
-    if (TARGET_LL64
-        && memory_operand (operands[1], DImode)
-	&& even_register_operand (operands[0], DImode))
-      return \"ldd%U1%V1 %0,%1%&\";
-    return \"#\";
-
-    case 3:
-    if (TARGET_LL64
-	&& memory_operand (operands[0], DImode)
-	&& (even_register_operand (operands[1], DImode)
-	    || satisfies_constraint_Cm3 (operands[1])))
-     return \"std%U0%V0 %1,%0\";
-    return \"#\";
-    }
-}"
-  "&& reload_completed"
+       && memory_operand (operands[0], DImode))"
+  "@
+   vadd2\\t%0,%1,0
+   #
+   ldd%U1%V1\\t%0,%1
+   std%U0%V0\\t%1,%0"
+  "&& reload_completed && arc_split_move_p (operands)"
   [(const_int 0)]
   {
    arc_split_move (operands);
    DONE;
   }
   [(set_attr "type" "move,move,load,store")
-   ;; ??? The ld/st values could be 4 if it's [reg,bignum].
-   (set_attr "length" "8,16,*,*")])
-
+   (set_attr "length" "8,16,16,16")])
 
 ;; Floating point move insns.
 
@@ -1408,50 +1381,22 @@ core_3, archs4x, archs4xd, archs4xd_slow"
 (define_insn_and_split "*movdf_insn"
   [(set (match_operand:DF 0 "move_dest_operand"      "=D,r,r,r,r,m")
 	(match_operand:DF 1 "move_double_src_operand" "r,D,r,E,m,r"))]
-  "register_operand (operands[0], DFmode)
-   || register_operand (operands[1], DFmode)"
-  "*
-{
- switch (which_alternative)
-   {
-    default:
-      return \"#\";
-
-    case 2:
-    if (TARGET_PLUS_QMACW
-	&& even_register_operand (operands[0], DFmode)
-	&& even_register_operand (operands[1], DFmode))
-      return \"vadd2%?\\t%0,%1,0\";
-    return \"#\";
-
-    case 4:
-    if (TARGET_LL64
-	&& ((even_register_operand (operands[0], DFmode)
-	     && memory_operand (operands[1], DFmode))
-	    || (memory_operand (operands[0], DFmode)
-	        && even_register_operand (operands[1], DFmode))))
-      return \"ldd%U1%V1 %0,%1%&\";
-    return \"#\";
-
-    case 5:
-    if (TARGET_LL64
-	&& ((even_register_operand (operands[0], DFmode)
-	     && memory_operand (operands[1], DFmode))
-	    || (memory_operand (operands[0], DFmode)
-		&& even_register_operand (operands[1], DFmode))))
-     return \"std%U0%V0 %1,%0\";
-    return \"#\";
-   }
-}"
-  "reload_completed"
+  "(register_operand (operands[0], DFmode)
+    || register_operand (operands[1], DFmode))"
+  "@
+   #
+   #
+   vadd2\\t%0,%1,0
+   #
+   ldd%U1%V1\\t%0,%1
+   std%U0%V0\\t%1,%0"
+  "&& reload_completed && arc_split_move_p (operands)"
   [(const_int 0)]
   {
    arc_split_move (operands);
    DONE;
   }
   [(set_attr "type" "move,move,move,move,load,store")
-   (set_attr "predicable" "no,no,no,yes,no,no")
-   ;; ??? The ld/st values could be 16 if it's [reg,bignum].
    (set_attr "length" "4,16,8,16,16,16")])
 
 (define_insn_and_split "*movdf_insn_nolrsr"
diff --git a/gcc/config/arc/simdext.md b/gcc/config/arc/simdext.md
index f0900757452..36f41a5c3d0 100644
--- a/gcc/config/arc/simdext.md
+++ b/gcc/config/arc/simdext.md
@@ -1402,41 +1402,19 @@
 	(match_operand:VWH 1 "general_operand"    "i,r,m,r"))]
   "(register_operand (operands[0], <MODE>mode)
        || register_operand (operands[1], <MODE>mode))"
-  "*
-{
-  switch (which_alternative)
-    {
-     default:
-       return \"#\";
-
-     case 1:
-       if (TARGET_PLUS_QMACW
-           && even_register_operand (operands[0], <MODE>mode)
-	   && even_register_operand (operands[1], <MODE>mode))
-         return \"vadd2%?\\t%0,%1,0\";
-       return \"#\";
-
-     case 2:
-       if (TARGET_LL64)
-         return \"ldd%U1%V1 %0,%1\";
-       return \"#\";
-
-     case 3:
-       if (TARGET_LL64)
-	   return \"std%U0%V0 %1,%0\";
-	 return \"#\";
-    }
-}"
-  "reload_completed"
+  "@
+   #
+   vadd2\\t%0,%1,0
+   ldd%U1%V1\\t%0,%1
+   std%U0%V0\\t%1,%0"
+  "&& reload_completed && arc_split_move_p (operands)"
   [(const_int 0)]
   {
    arc_split_move (operands);
    DONE;
   }
-  [(set_attr "type" "move,multi,load,store")
-   (set_attr "predicable" "no,no,no,no")
-   (set_attr "iscompact"  "false,false,false,false")
-   ])
+  [(set_attr "type" "move,move,load,store")
+   (set_attr "length" "16,8,16,16")])
 
 (define_expand "movmisalign<mode>"
  [(set (match_operand:VWH 0 "general_operand" "")
-- 
2.16.2