diff options
| -rw-r--r-- | target-cris/translate.c | 70 |
1 files changed, 69 insertions, 1 deletions
diff --git a/target-cris/translate.c b/target-cris/translate.c index 72e5e3c06a..04632f57ec 100644 --- a/target-cris/translate.c +++ b/target-cris/translate.c @@ -307,6 +307,74 @@ static void t_gen_mulu(TCGv d, TCGv d2, TCGv a, TCGv b) tcg_gen_discard_i64(t1); } +/* 32bit branch-free binary search for counting leading zeros. */ +static void t_gen_lz_i32(TCGv d, TCGv x) +{ + TCGv y, m, n; + + y = tcg_temp_new(TCG_TYPE_I32); + m = tcg_temp_new(TCG_TYPE_I32); + n = tcg_temp_new(TCG_TYPE_I32); + + /* y = -(x >> 16) */ + tcg_gen_shri_i32(y, x, 16); + tcg_gen_sub_i32(y, tcg_const_i32(0), y); + + /* m = (y >> 16) & 16 */ + tcg_gen_sari_i32(m, y, 16); + tcg_gen_andi_i32(m, m, 16); + + /* n = 16 - m */ + tcg_gen_sub_i32(n, tcg_const_i32(16), m); + /* x = x >> m */ + tcg_gen_shr_i32(x, x, m); + + /* y = x - 0x100 */ + tcg_gen_subi_i32(y, x, 0x100); + /* m = (y >> 16) & 8 */ + tcg_gen_sari_i32(m, y, 16); + tcg_gen_andi_i32(m, m, 8); + /* n = n + m */ + tcg_gen_add_i32(n, n, m); + /* x = x << m */ + tcg_gen_shl_i32(x, x, m); + + /* y = x - 0x1000 */ + tcg_gen_subi_i32(y, x, 0x1000); + /* m = (y >> 16) & 4 */ + tcg_gen_sari_i32(m, y, 16); + tcg_gen_andi_i32(m, m, 4); + /* n = n + m */ + tcg_gen_add_i32(n, n, m); + /* x = x << m */ + tcg_gen_shl_i32(x, x, m); + + /* y = x - 0x4000 */ + tcg_gen_subi_i32(y, x, 0x4000); + /* m = (y >> 16) & 2 */ + tcg_gen_sari_i32(m, y, 16); + tcg_gen_andi_i32(m, m, 2); + /* n = n + m */ + tcg_gen_add_i32(n, n, m); + /* x = x << m */ + tcg_gen_shl_i32(x, x, m); + + /* y = x >> 14 */ + tcg_gen_shri_i32(y, x, 14); + /* m = y & ~(y >> 1) */ + tcg_gen_sari_i32(m, y, 1); + tcg_gen_xori_i32(m, m, 0xffffffff); + tcg_gen_and_i32(m, m, y); + + /* d = n + 2 - m */ + tcg_gen_addi_i32(d, n, 2); + tcg_gen_sub_i32(d, d, m); + + tcg_gen_discard_i32(y); + tcg_gen_discard_i32(m); + tcg_gen_discard_i32(n); +} + /* Extended arithmetics on CRIS. */ static inline void t_gen_add_flag(TCGv d, int flag) { @@ -632,7 +700,7 @@ static void crisv32_alu_op(DisasContext *dc, int op, int rd, int size) t_gen_subx_carry(cpu_T[0]); break; case CC_OP_LZ: - gen_op_lz_T0_T1(); + t_gen_lz_i32(cpu_T[0], cpu_T[1]); break; case CC_OP_BTST: gen_op_btst_T0_T1(); |