[PATCH][rs6000] use index form addresses more often for ldbrx/stdbrx

[Aaron Sawdey]

I had to make one more change to make this actually work. In
rs6000_force_indexed_or_indirect_mem() it was necessary to
return the updated rtx.

Bootstrap/regtest passes on ppc64le (power7, power9), ok for trunk?

Thanks!
   Aaron

2018-10-30  Aaron Sawdey  <acsawdey@linux.ibm.com>

	* config/rs6000/rs6000.md (bswapdi2): Force address into register
	if not in indexed or indirect form.
	(bswapdi2_load): Change predicate to indexed_or_indirect_operand.
	(bswapdi2_store): Ditto.
	* config/rs6000/rs6000.c (rs6000_force_indexed_or_indirect_mem): New
	helper function.
	* config/rs6000/rs6000-protos.h (rs6000_force_indexed_or_indirect_mem):
	Prototype for helper function.


Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h	(revision 265588)
+++ gcc/config/rs6000/rs6000-protos.h	(working copy)
@@ -47,6 +47,7 @@
 extern bool legitimate_indirect_address_p (rtx, int);
 extern bool legitimate_indexed_address_p (rtx, int);
 extern bool avoiding_indexed_address_p (machine_mode);
+extern rtx rs6000_force_indexed_or_indirect_mem (rtx x);

 extern rtx rs6000_got_register (rtx);
 extern rtx find_addr_reg (rtx);
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 265588)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -8423,7 +8423,23 @@
   return false;
 }

+/* Helper function for making sure we will make full
+   use of indexed addressing.  */

+rtx
+rs6000_force_indexed_or_indirect_mem (rtx x)
+{
+  machine_mode m = GET_MODE (x);
+  if (!indexed_or_indirect_operand (x, m))
+    {
+      rtx addr = XEXP (x, 0);
+      addr = force_reg (Pmode, addr);
+      x = replace_equiv_address_nv (x, addr);
+    }
+  return x;
+}
+
+
 /* Implement the TARGET_LEGITIMATE_COMBINED_INSN hook.  */

 static bool
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md	(revision 265588)
+++ gcc/config/rs6000/rs6000.md	(working copy)
@@ -2512,9 +2512,15 @@
   if (TARGET_POWERPC64 && TARGET_LDBRX)
     {
       if (MEM_P (src))
-	emit_insn (gen_bswapdi2_load (dest, src));
+        {
+	  src = rs6000_force_indexed_or_indirect_mem (src);
+	  emit_insn (gen_bswapdi2_load (dest, src));
+        }
       else if (MEM_P (dest))
-	emit_insn (gen_bswapdi2_store (dest, src));
+        {
+	  dest = rs6000_force_indexed_or_indirect_mem (dest);
+	  emit_insn (gen_bswapdi2_store (dest, src));
+        }
       else if (TARGET_P9_VECTOR)
 	emit_insn (gen_bswapdi2_xxbrd (dest, src));
       else
@@ -2535,13 +2541,13 @@
 ;; Power7/cell has ldbrx/stdbrx, so use it directly
 (define_insn "bswapdi2_load"
   [(set (match_operand:DI 0 "gpc_reg_operand" "=r")
-	(bswap:DI (match_operand:DI 1 "memory_operand" "Z")))]
+	(bswap:DI (match_operand:DI 1 "indexed_or_indirect_operand" "Z")))]
   "TARGET_POWERPC64 && TARGET_LDBRX"
   "ldbrx %0,%y1"
   [(set_attr "type" "load")])

 (define_insn "bswapdi2_store"
-  [(set (match_operand:DI 0 "memory_operand" "=Z")
+  [(set (match_operand:DI 0 "indexed_or_indirect_operand" "=Z")
 	(bswap:DI (match_operand:DI 1 "gpc_reg_operand" "r")))]
   "TARGET_POWERPC64 && TARGET_LDBRX"
   "stdbrx %1,%y0"



-- 
Aaron Sawdey, Ph.D.  acsawdey@linux.vnet.ibm.com
050-2/C113  (507) 253-7520 home: 507/263-0782
IBM Linux Technology Center - PPC Toolchain