tcg/mips: implement deposit op on MIPS32R2

deposit operations can be optimized on MIPS32 Release 2 using the INS
instruction.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

tcg/mips/tcg-target.c

@@ -328,6 +328,7 @@ enum {
     OPC_BGEZ     = OPC_REGIMM | (0x01 << 16),
 
     OPC_SPECIAL3 = 0x1f << 26,
+    OPC_INS      = OPC_SPECIAL3 | 0x004,
     OPC_WSBH     = OPC_SPECIAL3 | 0x0a0,
     OPC_SEB      = OPC_SPECIAL3 | 0x420,
     OPC_SEH      = OPC_SPECIAL3 | 0x620,
@@ -1455,6 +1456,11 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_ext16s(s, args[0], args[1]);
         break;
 
+    case INDEX_op_deposit_i32:
+        tcg_out_opc_imm(s, OPC_INS, args[0], args[2],
+                        ((args[3] + args[4] - 1) << 11) | (args[3] << 6));
+        break;
+
     case INDEX_op_brcond_i32:
         tcg_out_brcond(s, args[2], args[0], args[1], args[3]);
         break;
@@ -1550,6 +1556,8 @@ static const TCGTargetOpDef mips_op_defs[] = {
     { INDEX_op_ext8s_i32, { "r", "rZ" } },
     { INDEX_op_ext16s_i32, { "r", "rZ" } },
 
+    { INDEX_op_deposit_i32, { "r", "0", "rZ" } },
+
     { INDEX_op_brcond_i32, { "rZ", "rZ" } },
     { INDEX_op_setcond_i32, { "r", "rZ", "rZ" } },
     { INDEX_op_setcond2_i32, { "r", "rZ", "rZ", "rZ", "rZ" } },

tcg/mips/tcg-target.h

@@ -86,7 +86,6 @@ typedef enum {
 #define TCG_TARGET_HAS_orc_i32          0
 #define TCG_TARGET_HAS_eqv_i32          0
 #define TCG_TARGET_HAS_nand_i32         0
-#define TCG_TARGET_HAS_deposit_i32      0
 #define TCG_TARGET_HAS_movcond_i32      0
 
 /* optional instructions only implemented on MIPS32R2 */
@@ -94,10 +93,12 @@ typedef enum {
 #define TCG_TARGET_HAS_bswap16_i32      1
 #define TCG_TARGET_HAS_bswap32_i32      1
 #define TCG_TARGET_HAS_rot_i32          1
+#define TCG_TARGET_HAS_deposit_i32      1
 #else
 #define TCG_TARGET_HAS_bswap16_i32      0
 #define TCG_TARGET_HAS_bswap32_i32      0
 #define TCG_TARGET_HAS_rot_i32          0
+#define TCG_TARGET_HAS_deposit_i32      0
 #endif
 
 /* optional instructions automatically implemented */