diff options
Diffstat (limited to 'tcg/mips/tcg-target.c')
| -rw-r--r-- | tcg/mips/tcg-target.c | 46 |
1 files changed, 40 insertions, 6 deletions
diff --git a/tcg/mips/tcg-target.c b/tcg/mips/tcg-target.c index 0ae495c586..d4236c0828 100644 --- a/tcg/mips/tcg-target.c +++ b/tcg/mips/tcg-target.c @@ -222,6 +222,8 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type, /* instruction opcodes */ enum { + OPC_J = 0x02 << 26, + OPC_JAL = 0x03 << 26, OPC_BEQ = 0x04 << 26, OPC_BNE = 0x05 << 26, OPC_BLEZ = 0x06 << 26, @@ -345,6 +347,29 @@ static inline void tcg_out_opc_sa(TCGContext *s, int opc, } +/* + * Type jump. + * Returns true if the branch was in range and the insn was emitted. + */ +static bool tcg_out_opc_jmp(TCGContext *s, int opc, void *target) +{ + uintptr_t dest = (uintptr_t)target; + uintptr_t from = (uintptr_t)s->code_ptr + 4; + int32_t inst; + + /* The pc-region branch happens within the 256MB region of + the delay slot (thus the +4). */ + if ((from ^ dest) & -(1 << 28)) { + return false; + } + assert((dest & 3) == 0); + + inst = opc; + inst |= (dest >> 2) & 0x3ffffff; + tcg_out32(s, inst); + return true; +} + static inline void tcg_out_nop(TCGContext *s) { tcg_out32(s, 0); @@ -1247,10 +1272,17 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, #endif } -static void tcg_out_call(TCGContext *s, tcg_insn_unit *target) +static void tcg_out_call(TCGContext *s, tcg_insn_unit *arg) { - tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_T9, (intptr_t)target); - tcg_out_opc_reg(s, OPC_JALR, TCG_REG_RA, TCG_REG_T9, 0); + /* Note that the ABI requires the called function's address to be + loaded into T9, even if a direct branch is in range. */ + tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_T9, (uintptr_t)arg); + + /* But do try a direct branch, allowing the cpu better insn prefetch. */ + if (!tcg_out_opc_jmp(s, OPC_JAL, arg)) { + tcg_out_opc_reg(s, OPC_JALR, TCG_REG_RA, TCG_REG_T9, 0); + } + tcg_out_nop(s); } @@ -1259,9 +1291,11 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, { switch(opc) { case INDEX_op_exit_tb: - tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_V0, args[0]); - tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_AT, (uintptr_t)tb_ret_addr); - tcg_out_opc_reg(s, OPC_JR, 0, TCG_REG_AT, 0); + tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_V0, args[0]); + if (!tcg_out_opc_jmp(s, OPC_J, tb_ret_addr)) { + tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_AT, (uintptr_t)tb_ret_addr); + tcg_out_opc_reg(s, OPC_JR, 0, TCG_REG_AT, 0); + } tcg_out_nop(s); break; case INDEX_op_goto_tb: |