[PATCH] xtensa: Make full transition to LRA

[Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp>]

gcc/ChangeLog:

	* config/xtensa/constraints.md (R, T, U):
	Change define_constraint to define_memory_constraint.
	* config/xtensa/xtensa.cc
	(xtensa_lra_p, TARGET_LRA_P): Remove.
	(xtensa_emit_move_sequence): Remove "if (reload_in_progress)"
	clause as it can no longer be true.
	(xtensa_output_integer_literal_parts): Consider 16-bit wide
	constants.
	(xtensa_legitimate_constant_p): Add short-circuit path for
	integer load instructions.
	* config/xtensa/xtensa.md (movsf): Use can_create_pseudo_p()
	rather reload_in_progress and reload_completed.
	* config/xtensa/xtensa.opt (mlra): Remove.
---
 gcc/config/xtensa/constraints.md | 26 ++++++++------------------
 gcc/config/xtensa/xtensa.cc      | 26 +++++---------------------
 gcc/config/xtensa/xtensa.md      |  2 +-
 gcc/config/xtensa/xtensa.opt     |  4 ----
 4 files changed, 14 insertions(+), 44 deletions(-)

diff --git a/gcc/config/xtensa/constraints.md b/gcc/config/xtensa/constraints.md
index 53e4d0d8dd1..9b31e162941 100644
--- a/gcc/config/xtensa/constraints.md
+++ b/gcc/config/xtensa/constraints.md
@@ -123,29 +123,19 @@
       (and (match_code "const_int")
 	   (match_test "! xtensa_split1_finished_p ()"))))
 
-;; Memory constraints.  Do not use define_memory_constraint here.  Doing so
-;; causes reload to force some constants into the constant pool, but since
-;; the Xtensa constant pool can only be accessed with L32R instructions, it
-;; is always better to just copy a constant into a register.  Instead, use
-;; regular constraints but add a check to allow pseudos during reload.
+;; Memory constraints.
 
-(define_constraint "R"
+(define_memory_constraint "R"
  "Memory that can be accessed with a 4-bit unsigned offset from a register."
- (ior (and (match_code "mem")
-	   (match_test "smalloffset_mem_p (op)"))
-      (and (match_code "reg")
-	   (match_test "reload_in_progress
-			&& REGNO (op) >= FIRST_PSEUDO_REGISTER"))))
+ (and (match_code "mem")
+      (match_test "smalloffset_mem_p (op)")))
 
-(define_constraint "T"
+(define_memory_constraint "T"
  "Memory in a literal pool (addressable with an L32R instruction)."
  (and (match_code "mem")
       (match_test "!TARGET_CONST16 && constantpool_mem_p (op)")))
 
-(define_constraint "U"
+(define_memory_constraint "U"
  "Memory that is not in a literal pool."
- (ior (and (match_code "mem")
-	   (match_test "! constantpool_mem_p (op)"))
-      (and (match_code "reg")
-	   (match_test "reload_in_progress
-			&& REGNO (op) >= FIRST_PSEUDO_REGISTER"))))
+ (and (match_code "mem")
+      (match_test "! constantpool_mem_p (op)")))
diff --git a/gcc/config/xtensa/xtensa.cc b/gcc/config/xtensa/xtensa.cc
index 9e5d314e143..f4434ec6e2c 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -190,7 +190,6 @@ static void xtensa_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
 				    HOST_WIDE_INT delta,
 				    HOST_WIDE_INT vcall_offset,
 				    tree function);
-static bool xtensa_lra_p (void);
 
 static rtx xtensa_delegitimize_address (rtx);
 
@@ -286,9 +285,6 @@ static rtx xtensa_delegitimize_address (rtx);
 #undef TARGET_CANNOT_FORCE_CONST_MEM
 #define TARGET_CANNOT_FORCE_CONST_MEM xtensa_cannot_force_const_mem
 
-#undef TARGET_LRA_P
-#define TARGET_LRA_P xtensa_lra_p
-
 #undef TARGET_LEGITIMATE_ADDRESS_P
 #define TARGET_LEGITIMATE_ADDRESS_P	xtensa_legitimate_address_p
 
@@ -1266,14 +1262,6 @@ xtensa_emit_move_sequence (rtx *operands, machine_mode mode)
 
   operands[1] = xtensa_copy_incoming_a7 (operands[1]);
 
-  /* During reload we don't want to emit (subreg:X (mem:Y)) since that
-     instruction won't be recognized after reload, so we remove the
-     subreg and adjust mem accordingly.  */
-  if (reload_in_progress)
-    {
-      operands[0] = fixup_subreg_mem (operands[0]);
-      operands[1] = fixup_subreg_mem (operands[1]);
-    }
   return 0;
 }
 
@@ -3196,7 +3184,7 @@ xtensa_output_integer_literal_parts (FILE *file, rtx x, int size)
       fputs (", ", file);
       xtensa_output_integer_literal_parts (file, second, size / 2);
     }
-  else if (size == 4)
+  else if (size == 4 || size == 2)
     {
       output_addr_const (file, x);
     }
@@ -4876,6 +4864,10 @@ xtensa_trampoline_init (rtx m_tramp, tree fndecl, rtx chain)
 static bool
 xtensa_legitimate_constant_p (machine_mode mode ATTRIBUTE_UNUSED, rtx x)
 {
+  if (CONST_INT_P (x))
+    return TARGET_AUTO_LITPOOLS || TARGET_CONST16
+	   || xtensa_simm12b (INTVAL (x));
+
   return !xtensa_tls_referenced_p (x);
 }
 
@@ -5317,12 +5309,4 @@ xtensa_delegitimize_address (rtx op)
   return op;
 }
 
-/* Implement TARGET_LRA_P.  */
-
-static bool
-xtensa_lra_p (void)
-{
-  return TARGET_LRA;
-}
-
 #include "gt-xtensa.h"
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 3521fa33b47..195515d9427 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -1268,7 +1268,7 @@
   if ((!register_operand (operands[0], SFmode)
        && !register_operand (operands[1], SFmode))
       || (FP_REG_P (xt_true_regnum (operands[0]))
-	  && !(reload_in_progress | reload_completed)
+	  && can_create_pseudo_p ()
 	  && (constantpool_mem_p (operands[1])
 	      || CONSTANT_P (operands[1]))))
     operands[1] = force_reg (SFmode, operands[1]);
diff --git a/gcc/config/xtensa/xtensa.opt b/gcc/config/xtensa/xtensa.opt
index f16b53bf409..8574c12198e 100644
--- a/gcc/config/xtensa/xtensa.opt
+++ b/gcc/config/xtensa/xtensa.opt
@@ -37,10 +37,6 @@ mextra-l32r-costs=
 Target RejectNegative Joined UInteger Var(xtensa_extra_l32r_costs) Init(0)
 Set extra memory access cost for L32R instruction, in clock-cycle units.
 
-mlra
-Target Mask(LRA)
-Use LRA instead of reload (transitional).
-
 mtarget-align
 Target
 Automatically align branch targets to reduce branch penalties.
-- 
2.30.2