diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index ffcf9ca..45bc93c 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -3187,3 +3187,43 @@ void helper_xvxsigsp(CPUPPCState *env, uint32_t opcode)
     }
     putVSR(xT(opcode), &xt, env);
 }
+
+/* VSX_TEST_DC - VSX floating point test data class
+ *   op    - instruction mnemonic
+ *   nels  - number of elements (1, 2 or 4)
+ *   xbn   - VSR register number
+ *   tp    - type (float32 or float64)
+ *   fld   - vsr_t field (VsrD(*) or VsrW(*))
+ *   tfld   - target vsr_t field (VsrD(*) or VsrW(*))
+ *   fld_max - target field max
+ */
+#define VSX_TEST_DC(op, nels, xbn, tp, fld, tfld, fld_max)  \
+void helper_##op(CPUPPCState *env, uint32_t opcode)         \
+{                                                           \
+    ppc_vsr_t xt, xb;                                       \
+    uint32_t i, sign, dcmx;                                 \
+    uint32_t match = 0;                                     \
+                                                            \
+    getVSR(xbn, &xb, env);                                  \
+    memset(&xt, 0, sizeof(xt));                             \
+    dcmx = DCMX_XV(opcode);                                 \
+                                                            \
+    for (i = 0; i < nels; i++) {                            \
+        sign = tp##_is_neg(xb.fld);                         \
+        if (tp##_is_any_nan(xb.fld)) {                      \
+            match = extract32(dcmx, 6, 1);                  \
+        } else if (tp##_is_infinity(xb.fld)) {              \
+            match = extract32(dcmx, 4 + !sign, 1);          \
+        } else if (tp##_is_zero(xb.fld)) {                  \
+            match = extract32(dcmx, 2 + !sign, 1);          \
+        } else if (tp##_is_zero_or_denormal(xb.fld)) {      \
+            match = extract32(dcmx, 0 + !sign, 1);          \
+        }                                                   \
+        xt.tfld = match ? fld_max : 0;                      \
+        match = 0;                                          \
+    }                                                       \
+    putVSR(xT(opcode), &xt, env);                           \
+}
+
+VSX_TEST_DC(xvtstdcdp, 2, xB(opcode), float64, VsrD(i), VsrD(i), UINT64_MAX)
+VSX_TEST_DC(xvtstdcsp, 4, xB(opcode), float32, VsrW(i), VsrW(i), UINT32_MAX)
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 9d4ed08..165e4a5 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -546,6 +546,8 @@ DEF_HELPER_2(xvcvsxdsp, void, env, i32)
 DEF_HELPER_2(xvcvuxdsp, void, env, i32)
 DEF_HELPER_2(xvcvsxwsp, void, env, i32)
 DEF_HELPER_2(xvcvuxwsp, void, env, i32)
+DEF_HELPER_2(xvtstdcsp, void, env, i32)
+DEF_HELPER_2(xvtstdcdp, void, env, i32)
 DEF_HELPER_2(xvrspi, void, env, i32)
 DEF_HELPER_2(xvrspic, void, env, i32)
 DEF_HELPER_2(xvrspim, void, env, i32)
diff --git a/target/ppc/internal.h b/target/ppc/internal.h
index c22d74e..4c3811a 100644
--- a/target/ppc/internal.h
+++ b/target/ppc/internal.h
@@ -68,7 +68,7 @@ static inline uint32_t name(uint32_t opcode)                                  \
             ((opcode >> (shift2)) & ((1 << (nb2)) - 1));                      \
 }
 
-#define EXTRACT_HELPER_DXFORM(name,                                           \
+#define EXTRACT_HELPER_SPLIT_3(name,                                          \
                               d0_bits, shift_op_d0, shift_d0,                 \
                               d1_bits, shift_op_d1, shift_d1,                 \
                               d2_bits, shift_op_d2, shift_d2)                 \
@@ -156,7 +156,7 @@ EXTRACT_HELPER(FPFLM, 17, 8);
 EXTRACT_HELPER(FPW, 16, 1);
 
 /* addpcis */
-EXTRACT_HELPER_DXFORM(DX, 10, 6, 6, 5, 16, 1, 1, 0, 0)
+EXTRACT_HELPER_SPLIT_3(DX, 10, 6, 6, 5, 16, 1, 1, 0, 0)
 #if defined(TARGET_PPC64)
 /* darn */
 EXTRACT_HELPER(L, 16, 2);
@@ -198,6 +198,7 @@ EXTRACT_HELPER(UIM, 16, 2);
 EXTRACT_HELPER(SHW, 8, 2);
 EXTRACT_HELPER(SP, 19, 2);
 EXTRACT_HELPER(IMM8, 11, 8);
+EXTRACT_HELPER_SPLIT_3(DCMX_XV, 5, 16, 0, 1, 2, 5, 1, 6, 6);
 
 typedef union _ppc_vsr_t {
     uint8_t u8[16];
diff --git a/target/ppc/translate/vsx-impl.inc.c b/target/ppc/translate/vsx-impl.inc.c
index 9bcc5af..adb6fc7 100644
--- a/target/ppc/translate/vsx-impl.inc.c
+++ b/target/ppc/translate/vsx-impl.inc.c
@@ -928,6 +928,8 @@ GEN_VSX_HELPER_2(xvrspic, 0x16, 0x0A, 0, PPC2_VSX)
 GEN_VSX_HELPER_2(xvrspim, 0x12, 0x0B, 0, PPC2_VSX)
 GEN_VSX_HELPER_2(xvrspip, 0x12, 0x0A, 0, PPC2_VSX)
 GEN_VSX_HELPER_2(xvrspiz, 0x12, 0x09, 0, PPC2_VSX)
+GEN_VSX_HELPER_2(xvtstdcsp, 0x14, 0x1A, 0, PPC2_VSX)
+GEN_VSX_HELPER_2(xvtstdcdp, 0x14, 0x1E, 0, PPC2_VSX)
 GEN_VSX_HELPER_2(xxperm, 0x08, 0x03, 0, PPC2_ISA300)
 GEN_VSX_HELPER_2(xxpermr, 0x08, 0x07, 0, PPC2_ISA300)
 
diff --git a/target/ppc/translate/vsx-ops.inc.c b/target/ppc/translate/vsx-ops.inc.c
index ee74312..6dd5d72 100644
--- a/target/ppc/translate/vsx-ops.inc.c
+++ b/target/ppc/translate/vsx-ops.inc.c
@@ -133,6 +133,14 @@ GEN_XX2FORM_EO(xvxsigdp, 0x16, 0x1D, 0x01, PPC2_ISA300),
 GEN_XX2FORM_EO(xvxexpsp, 0x16, 0x1D, 0x08, PPC2_ISA300),
 GEN_XX2FORM_EO(xvxsigsp, 0x16, 0x1D, 0x09, PPC2_ISA300),
 
+/* DCMX  =  bit[25] << 6 | bit[29] << 5 | bit[11:15] */
+#define GEN_XX2FORM_DCMX(name, opc2, opc3, fl2) \
+GEN_XX3FORM(name, opc2, opc3 | 0, fl2),         \
+GEN_XX3FORM(name, opc2, opc3 | 1, fl2)
+
+GEN_XX2FORM_DCMX(xvtstdcdp, 0x14, 0x1E, PPC2_ISA300),
+GEN_XX2FORM_DCMX(xvtstdcsp, 0x14, 0x1A, PPC2_ISA300),
+
 GEN_XX2FORM(xvabsdp, 0x12, 0x1D, PPC2_VSX),
 GEN_XX2FORM(xvnabsdp, 0x12, 0x1E, PPC2_VSX),
 GEN_XX2FORM(xvnegdp, 0x12, 0x1F, PPC2_VSX),
