[Qemu-devel] [PATCH v3 6/6] target-ppc: Implement bcdutrunc. instruction

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

bcdutrunc. Decimal unsigned truncate. Works like bcdtrunc. with
unsigned BCD numbers.

Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
---
 target-ppc/helper.h                 |  1 +
 target-ppc/int_helper.c             | 54 +++++++++++++++++++++++++++++++++++++
 target-ppc/translate/vmx-impl.inc.c |  4 +++
 target-ppc/translate/vmx-ops.inc.c  |  2 +-
 4 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 49965b0..52a2707 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -396,6 +396,7 @@ DEF_HELPER_4(bcds, i32, avr, avr, avr, i32)
 DEF_HELPER_4(bcdus, i32, avr, avr, avr, i32)
 DEF_HELPER_4(bcdsr, i32, avr, avr, avr, i32)
 DEF_HELPER_4(bcdtrunc, i32, avr, avr, avr, i32)
+DEF_HELPER_4(bcdutrunc, i32, avr, 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 dea08e6..e4f5980 100644
--- a/target-ppc/int_helper.c
+++ b/target-ppc/int_helper.c
@@ -3209,6 +3209,60 @@ uint32_t helper_bcdtrunc(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps)
     return bcd_cmp_zero(&ret) | ox_flag;
 }
 
+uint32_t helper_bcdutrunc(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps)
+{
+    int i;
+    uint64_t mask;
+    uint32_t bits;
+    uint32_t ox_flag = 0;
+    int invalid = 0;
+    ppc_avr_t ret = *b;
+
+#if defined(HOST_WORDS_BIGENDIAN)
+    int upper = ARRAY_SIZE(a->u16) - 1;
+#else
+    int upper = 0;
+#endif
+
+    for (i = 0; i < 32; i++) {
+        bcd_get_digit(b, i, &invalid);
+
+        if (unlikely(invalid)) {
+            return CRF_SO;
+        }
+    }
+
+    bits = (a->u16[upper] % 33) << 2;
+    if (bits == 128) {
+        if (ret.u64[HI_IDX] || ret.u64[LO_IDX]) {
+            ox_flag = CRF_SO;
+        }
+        ret.u64[HI_IDX] = ret.u64[LO_IDX] = 0;
+    } else if (bits >= 64) {
+        if (ret.u64[HI_IDX] || (ret.u64[LO_IDX] >> (128 - bits))) {
+            ox_flag = CRF_SO;
+        }
+
+        mask = (uint64_t)-1 >> (bits - 64);
+        ret.u64[HI_IDX] = 0;
+        ret.u64[LO_IDX] &= mask;
+    } else {
+        if (bits > 0 && (ret.u64[HI_IDX] >> (64 - bits))) {
+            ox_flag = CRF_SO;
+        }
+
+        mask = (uint64_t)-1 >> bits;
+        ret.u64[HI_IDX] &= mask;
+    }
+
+    *r = ret;
+    if (r->u64[HI_IDX] == 0 && r->u64[LO_IDX] == 0) {
+        return ox_flag | CRF_EQ;
+    }
+
+    return ox_flag | CRF_GT;
+}
+
 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 1683f42..3cb6fc2 100644
--- a/target-ppc/translate/vmx-impl.inc.c
+++ b/target-ppc/translate/vmx-impl.inc.c
@@ -1020,6 +1020,7 @@ GEN_BCD(bcds);
 GEN_BCD(bcdus);
 GEN_BCD(bcdsr);
 GEN_BCD(bcdtrunc);
+GEN_BCD(bcdutrunc);
 
 static void gen_xpnd04_1(DisasContext *ctx)
 {
@@ -1102,6 +1103,9 @@ GEN_VXFORM_DUAL(vsubsbs, PPC_ALTIVEC, PPC_NONE, \
                 bcdtrunc, PPC_NONE, PPC2_ISA300)
 GEN_VXFORM_DUAL(vsubuqm, PPC2_ALTIVEC_207, PPC_NONE, \
                 bcdtrunc, PPC_NONE, PPC2_ISA300)
+GEN_VXFORM_DUAL(vsubcuq, PPC2_ALTIVEC_207, PPC_NONE, \
+                bcdutrunc, PPC_NONE, PPC2_ISA300)
+
 
 static void gen_vsbox(DisasContext *ctx)
 {
diff --git a/target-ppc/translate/vmx-ops.inc.c b/target-ppc/translate/vmx-ops.inc.c
index e6167a4..139f80c 100644
--- a/target-ppc/translate/vmx-ops.inc.c
+++ b/target-ppc/translate/vmx-ops.inc.c
@@ -149,8 +149,8 @@ GEN_VXFORM_DUAL(vsubsws, xpnd04_2, 0, 30, PPC_ALTIVEC, PPC_NONE),
 GEN_VXFORM_207(vadduqm, 0, 4),
 GEN_VXFORM_207(vaddcuq, 0, 5),
 GEN_VXFORM_DUAL(vaddeuqm, vaddecuq, 30, 0xFF, PPC_NONE, PPC2_ALTIVEC_207),
-GEN_VXFORM_207(vsubcuq, 0, 21),
 GEN_VXFORM_DUAL(vsubuqm, bcdtrunc, 0, 20, PPC2_ALTIVEC_207, PPC2_ISA300),
+GEN_VXFORM_DUAL(vsubcuq, bcdutrunc, 0, 21, PPC2_ALTIVEC_207, PPC2_ISA300),
 GEN_VXFORM_DUAL(vsubeuqm, vsubecuq, 31, 0xFF, PPC_NONE, PPC2_ALTIVEC_207),
 GEN_VXFORM(vrlb, 2, 0),
 GEN_VXFORM(vrlh, 2, 1),
-- 
2.7.4