target-ppc: Implement bcdctn. instruction

bcdctn. converts from BCD to National numeric format. National format
uses a byte to represent a digit where the most significant nibble is
always 0x3 and the least sign. nibbles is the digit itself.

Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 43 insertions, 0 deletions

diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
index c79d3ecba7..d4106a94ae 100644
--- a/target-ppc/int_helper.c
+++ b/target-ppc/int_helper.c
@@ -2578,6 +2578,15 @@ static uint16_t get_national_digit(ppc_avr_t *reg, int n)
 #endif
 }
 
+static void set_national_digit(ppc_avr_t *reg, uint8_t val, int n)
+{
+#if defined(HOST_WORDS_BIGENDIAN)
+    reg->u16[8 - n] = val;
+#else
+    reg->u16[n] = val;
+#endif
+}
+
 static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b)
 {
     int i;
@@ -2744,6 +2753,40 @@ uint32_t helper_bcdcfn(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
     return cr;
 }
 
+uint32_t helper_bcdctn(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
+{
+    int i;
+    int cr = 0;
+    int sgnb = bcd_get_sgn(b);
+    int invalid = (sgnb == 0);
+    ppc_avr_t ret = { .u64 = { 0, 0 } };
+
+    int ox_flag = (b->u64[HI_IDX] != 0) || ((b->u64[LO_IDX] >> 32) != 0);
+
+    for (i = 1; i < 8; i++) {
+        set_national_digit(&ret, 0x30 + bcd_get_digit(b, i, &invalid), i);
+
+        if (unlikely(invalid)) {
+            break;
+        }
+    }
+    set_national_digit(&ret, (sgnb == -1) ? NATIONAL_NEG : NATIONAL_PLUS, 0);
+
+    cr = bcd_cmp_zero(b);
+
+    if (ox_flag) {
+        cr |= 1 << CRF_SO;
+    }
+
+    if (unlikely(invalid)) {
+        cr = 1 << CRF_SO;
+    }
+
+    *r = ret;
+
+    return cr;
+}
+
 void helper_vsbox(ppc_avr_t *r, ppc_avr_t *a)
 {
     int i;