[Qemu-devel] [PATCH v5 4/4] target-ppc: Implement bcdctz. instruction

[Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>]

bcdctz. converts from BCD to Zoned numeric format. Zoned format uses
a byte to represent a digit where the most significant nibble is 0x3
or 0xf, depending on the preferred signal.

Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
---
 target-ppc/helper.h                 |  1 +
 target-ppc/int_helper.c             | 43 +++++++++++++++++++++++++++++++++++++
 target-ppc/translate/vmx-impl.inc.c |  7 ++++++
 3 files changed, 51 insertions(+)

diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 8546bb9..5412da5 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -374,6 +374,7 @@ DEF_HELPER_4(bcdsub, i32, avr, avr, avr, i32)
 DEF_HELPER_3(bcdcfn, i32, avr, avr, i32)
 DEF_HELPER_3(bcdctn, i32, avr, avr, i32)
 DEF_HELPER_3(bcdcfz, i32, avr, avr, i32)
+DEF_HELPER_3(bcdctz, i32, avr, avr, i32)
 
 DEF_HELPER_2(xsadddp, void, env, i32)
 DEF_HELPER_2(xssubdp, void, env, i32)
diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
index 3ecf9d6..c107cee 100644
--- a/target-ppc/int_helper.c
+++ b/target-ppc/int_helper.c
@@ -2768,6 +2768,49 @@ uint32_t helper_bcdcfz(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
     return cr;
 }
 
+uint32_t helper_bcdctz(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
+{
+    int i;
+    int cr = 0;
+    uint8_t digit = 0;
+    int sgnb = bcd_get_sgn(b);
+    int zone_lead = (ps) ? 0xF0 : 0x30;
+    int invalid = (sgnb == 0);
+    ppc_avr_t ret = { .u64 = { 0, 0 } };
+
+    int ox_flag = ((b->u64[HI_IDX] >> 4) != 0);
+
+    for (i = 0; i < 16; i++) {
+        digit = bcd_get_digit(b, i + 1, &invalid);
+
+        if (unlikely(invalid)) {
+            break;
+        }
+
+        ret.u8[BCD_DIG_BYTE(i * 2)] = zone_lead + digit;
+    }
+
+    if (ps) {
+        bcd_put_digit(&ret, (sgnb == 1) ? 0xC : 0xD, 1);
+    } else {
+        bcd_put_digit(&ret, (sgnb == 1) ? 0x3 : 0x7, 1);
+    }
+
+    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;
diff --git a/target-ppc/translate/vmx-impl.inc.c b/target-ppc/translate/vmx-impl.inc.c
index 7e902a9..b05c874 100644
--- a/target-ppc/translate/vmx-impl.inc.c
+++ b/target-ppc/translate/vmx-impl.inc.c
@@ -973,10 +973,14 @@ GEN_BCD(bcdsub)
 GEN_BCD2(bcdcfn)
 GEN_BCD2(bcdctn)
 GEN_BCD2(bcdcfz)
+GEN_BCD2(bcdctz)
 
 static void gen_xpnd04_1(DisasContext *ctx)
 {
     switch (opc4(ctx->opcode)) {
+    case 4:
+        gen_bcdctz(ctx);
+        break;
     case 5:
         gen_bcdctn(ctx);
         break;
@@ -995,6 +999,9 @@ static void gen_xpnd04_1(DisasContext *ctx)
 static void gen_xpnd04_2(DisasContext *ctx)
 {
     switch (opc4(ctx->opcode)) {
+    case 4:
+        gen_bcdctz(ctx);
+        break;
     case 6:
         gen_bcdcfz(ctx);
         break;
-- 
2.7.4