diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index 9550102714..47612fe260 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -611,6 +611,22 @@ static inline void tcg_out_bswap16(TCGContext *s, int cond, int rd, int rn) } } +/* swap the two low bytes assuming that the two high input bytes and the + two high output bit can hold any value. */ +static inline void tcg_out_bswap16st(TCGContext *s, int cond, int rd, int rn) +{ + if (use_armv6_instructions) { + /* rev16 */ + tcg_out32(s, 0x06bf0fb0 | (cond << 28) | (rd << 12) | rn); + } else { + tcg_out_dat_reg(s, cond, ARITH_MOV, + TCG_REG_R8, 0, rn, SHIFT_IMM_LSR(8)); + tcg_out_dat_imm(s, cond, ARITH_AND, TCG_REG_R8, TCG_REG_R8, 0xff); + tcg_out_dat_reg(s, cond, ARITH_ORR, + rd, TCG_REG_R8, rn, SHIFT_IMM_LSL(8)); + } +} + static inline void tcg_out_bswap32(TCGContext *s, int cond, int rd, int rn) { if (use_armv6_instructions) { @@ -1367,7 +1383,7 @@ static inline void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int opc) break; case 1: if (bswap) { - tcg_out_bswap16(s, COND_EQ, TCG_REG_R0, data_reg); + tcg_out_bswap16st(s, COND_EQ, TCG_REG_R0, data_reg); tcg_out_st16_r(s, COND_EQ, TCG_REG_R0, addr_reg, TCG_REG_R1); } else { tcg_out_st16_r(s, COND_EQ, data_reg, addr_reg, TCG_REG_R1); @@ -1453,7 +1469,7 @@ static inline void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int opc) break; case 1: if (bswap) { - tcg_out_bswap16(s, COND_AL, TCG_REG_R0, data_reg); + tcg_out_bswap16st(s, COND_AL, TCG_REG_R0, data_reg); tcg_out_st16_8(s, COND_AL, TCG_REG_R0, addr_reg, 0); } else { tcg_out_st16_8(s, COND_AL, data_reg, addr_reg, 0);