[PATCH] xtensa: Fix for enabling LRA

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

This patch makes LRA well with some exceptions
(e.g. MI thunk generation due to pretending reload_completed).

gcc/ChangeLog:

	* config/xtensa/constraints.md (R, T, U):
	Change define_constraint to define_memory_constraint.
	* config/xtensa/xtensa.cc (xtensa_legitimate_constant_p):
	Add short-circuit path for integer load instructions when
	lra_in_progress.
	* config/xtensa/xtensa.md (movsf):
	Use can_create_pseudo_p() rather reload_in_progress and
	reload_completed.
---
 gcc/config/xtensa/constraints.md | 26 ++++++++------------------
 gcc/config/xtensa/xtensa.cc      |  4 ++++
 gcc/config/xtensa/xtensa.md      |  2 +-
 3 files changed, 13 insertions(+), 19 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 7287aa7a258..a500dc2a06e 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -4872,6 +4872,10 @@ xtensa_trampoline_init (rtx m_tramp, tree fndecl, rtx chain)
 static bool
 xtensa_legitimate_constant_p (machine_mode mode ATTRIBUTE_UNUSED, rtx x)
 {
+  if (lra_in_progress && CONST_INT_P (x))
+    return TARGET_AUTO_LITPOOLS || TARGET_CONST16
+	   || xtensa_simm12b (INTVAL (x));
+
   return !xtensa_tls_referenced_p (x);
 }
 
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]);
-- 
2.30.2