From 08d337cc5186e47949b60e4b3eeebd1f763337e0 Mon Sep 17 00:00:00 2001
From: Lixing <lixing@loongosn.cn>
Date: Mon, 31 Jul 2023 09:46:12 +0800
Subject: [PATCH 1/2] LoongArch: Remove NOOP_TRUNCATION and fix extendsidi2

We can safely convert value from inprec to outprec because we hold on
extention if needed.
---
 gcc/config/loongarch/loongarch.c  | 11 --------
 gcc/config/loongarch/loongarch.md | 44 +++++++------------------------
 2 files changed, 9 insertions(+), 46 deletions(-)

diff --git a/gcc/config/loongarch/loongarch.c b/gcc/config/loongarch/loongarch.c
index a1dde5a0f..f8f96329c 100644
--- a/gcc/config/loongarch/loongarch.c
+++ b/gcc/config/loongarch/loongarch.c
@@ -10313,14 +10313,6 @@ loongarch_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
   return mode;
 }
 
-/* Implement TARGET_TRULY_NOOP_TRUNCATION.  */
-
-static bool
-loongarch_truly_noop_truncation (poly_uint64 outprec, poly_uint64 inprec)
-{
-  return !TARGET_64BIT || inprec <= 32 || outprec > 32;
-}
-
 /* Implement TARGET_STARTING_FRAME_OFFSET.  See loongarch_compute_frame_info
    for details about the frame layout.  */
 
@@ -10940,9 +10932,6 @@ loongarch_prefetch_cookie (rtx write, rtx locality)
 #undef TARGET_CAN_CHANGE_MODE_CLASS
 #define TARGET_CAN_CHANGE_MODE_CLASS loongarch_can_change_mode_class
 
-#undef TARGET_TRULY_NOOP_TRUNCATION
-#define TARGET_TRULY_NOOP_TRUNCATION loongarch_truly_noop_truncation
-
 #undef TARGET_CONSTANT_ALIGNMENT
 #define TARGET_CONSTANT_ALIGNMENT loongarch_constant_alignment
 
diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md
index 097c9f4db..a08c4a62c 100644
--- a/gcc/config/loongarch/loongarch.md
+++ b/gcc/config/loongarch/loongarch.md
@@ -1433,43 +1433,17 @@
 ;;
 ;;  ....................
 
-(define_insn_and_split "extendsidi2"
+(define_insn "extendsidi2"
   [(set (match_operand:DI 0 "register_operand" "=r,r,r,r")
-	(sign_extend:DI
-	    (match_operand:SI 1 "nonimmediate_operand" "0,ZC,m,k")))]
+        (sign_extend:DI
+            (match_operand:SI 1 "nonimmediate_operand" "r,ZC,m,k")))]
   "TARGET_64BIT"
-{
-  switch (which_alternative)
-    {
-    case 0:
-      return "#";
-    case 1:
-      {
-      rtx offset = XEXP (operands[1], 0);
-      if (GET_CODE (offset) == PLUS)
-	offset = XEXP (offset, 1);
-      else
-	offset = const0_rtx;
-      if (const_arith_operand (offset, Pmode) || (offset == const0_rtx))
-	return "ld.w\t%0,%1";
-      else
-	return "ldptr.w\t%0,%1";
-      }
-    case 2:
-	return "ld.w\t%0,%1";
-    case 3:
-	return "ldx.w\t%0,%1";
-    default:
-      gcc_unreachable ();
-    }
-}
-  "&& reload_completed && register_operand (operands[1], VOIDmode)"
-  [(const_int 0)]
-{
-  emit_note (NOTE_INSN_DELETED);
-  DONE;
-}
-  [(set_attr "move_type" "move,load,load,load")
+  "@
+   slli.w\t%0,%1,0
+   ldptr.w\t%0,%1
+   ld.w\t%0,%1
+   ldx.w\t%0,%1"
+  [(set_attr "move_type" "sll0,load,load,load")
    (set_attr "mode" "DI")])
 
 (define_insn "extend<SHORT:mode><GPR:mode>2"
-- 
2.39.3