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CRIS: Convert lz (leading zeros) to TCG. 

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4309 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
edgar_igl 2008-05-03 17:11:36 +00:00
parent 7dd7c987a8
commit d059c17270
1 changed files with 69 additions and 1 deletions
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70
target-cris/translate.c
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@ -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();