target-ppc: Introduce DFP Convert to Long/Extended

Add emulation of the PowerPC Convert to DFP Long (dctdp[.]) and
Convert to DFP Extended (dctqpq[.]) instructions.
Signed-off-by: NTom Musta <tommusta@gmail.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/dfp_helper.c

@@ -286,6 +286,15 @@ static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
     }
 }
 
+static void dfp_check_for_VXSNAN_and_convert_to_QNaN(struct PPC_DFP *dfp)
+{
+    if (decNumberIsSNaN(&dfp->t)) {
+        dfp->t.bits &= ~DECSNAN;
+        dfp->t.bits |= DECNAN;
+        dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
+    }
+}
+
 static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
 {
     if (dfp->context.status & DEC_Invalid_operation) {
@@ -840,3 +849,27 @@ static void RINTN_PPs(struct PPC_DFP *dfp)
 
 DFP_HELPER_RINT(drintn, RINTN_PPs, 64)
 DFP_HELPER_RINT(drintnq, RINTN_PPs, 128)
+
+void helper_dctdp(CPUPPCState *env, uint64_t *t, uint64_t *b)
+{
+    struct PPC_DFP dfp;
+    uint32_t b_short = *b;
+    dfp_prepare_decimal64(&dfp, 0, 0, env);
+    decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
+    decimal64FromNumber((decimal64 *)t, &dfp.t, &dfp.context);
+    dfp_set_FPRF_from_FRT(&dfp);
+}
+
+void helper_dctqpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
+{
+    struct PPC_DFP dfp;
+    dfp_prepare_decimal128(&dfp, 0, 0, env);
+    decimal64ToNumber((decimal64 *)b, &dfp.t);
+
+    dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
+    dfp_set_FPRF_from_FRT(&dfp);
+
+    decimal128FromNumber((decimal128 *)&dfp.t64, &dfp.t, &dfp.context);
+    t[0] = dfp.t64[HI_IDX];
+    t[1] = dfp.t64[LO_IDX];
+}

target-ppc/helper.h

@@ -646,3 +646,5 @@ DEF_HELPER_5(drintx, void, env, fprp, fprp, i32, i32)
 DEF_HELPER_5(drintxq, void, env, fprp, fprp, i32, i32)
 DEF_HELPER_5(drintn, void, env, fprp, fprp, i32, i32)
 DEF_HELPER_5(drintnq, void, env, fprp, fprp, i32, i32)
+DEF_HELPER_3(dctdp, void, env, fprp, fprp)
+DEF_HELPER_3(dctqpq, void, env, fprp, fprp)

target-ppc/translate.c

@@ -8386,6 +8386,8 @@ GEN_DFP_T_B_U32_U32_Rc(drintx, FPW, RMC)
 GEN_DFP_T_B_U32_U32_Rc(drintxq, FPW, RMC)
 GEN_DFP_T_B_U32_U32_Rc(drintn, FPW, RMC)
 GEN_DFP_T_B_U32_U32_Rc(drintnq, FPW, RMC)
+GEN_DFP_T_B_Rc(dctdp)
+GEN_DFP_T_B_Rc(dctqpq)
 /***                           SPE extension                               ***/
 /* Register moves */
 
@@ -11343,6 +11345,8 @@ GEN_DFP_R_T_B_RMC_Rc(drintx, 0x03, 0x03),
 GEN_DFP_R_Tp_Bp_RMC_Rc(drintxq, 0x03, 0x03),
 GEN_DFP_R_T_B_RMC_Rc(drintn, 0x03, 0x07),
 GEN_DFP_R_Tp_Bp_RMC_Rc(drintnq, 0x03, 0x07),
+GEN_DFP_T_B_Rc(dctdp, 0x02, 0x08),
+GEN_DFP_Tp_B_Rc(dctqpq, 0x02, 0x08),
 #undef GEN_SPE
 #define GEN_SPE(name0, name1, opc2, opc3, inval0, inval1, type) \
     GEN_OPCODE_DUAL(name0##_##name1, 0x04, opc2, opc3, inval0, inval1, type, PPC_NONE)