CRIS: Convert lz (leading zeros) to TCG.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4309 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/target-cris/translate.c b/target-cris/translate.c
index 72e5e3c..04632f5 100644
--- a/target-cris/translate.c
+++ b/target-cris/translate.c
@@ -307,6 +307,74 @@
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 @@
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();
