[Qemu-ppc] [V2 PATCH 30/37] target-ppc: Introduce Round to DFP Short/Long

[Tom Musta]

Add emulation of the PowerPC Round to DFP Short (drsp[.]) and Round to
DFP Long (drdpq[.]) instructions.

Signed-off-by: Tom Musta <address@hidden>
---
V2: Modify post-processor handling per Richard Henderson's review.

 target-ppc/dfp_helper.c |   48 +++++++++++++++++++++++++++++++++++++++++++++++
 target-ppc/helper.h     |    2 +
 target-ppc/translate.c  |    4 +++
 3 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/target-ppc/dfp_helper.c b/target-ppc/dfp_helper.c
index 7a62ed0..3c92543 100644
--- a/target-ppc/dfp_helper.c
+++ b/target-ppc/dfp_helper.c
@@ -247,6 +247,20 @@ static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
     dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
 }
 
+static void dfp_set_FPRF_from_FRT_short(struct PPC_DFP *dfp)
+{
+    decContext shortContext;
+    decContextDefault(&shortContext, DEC_INIT_DECIMAL32);
+    dfp_set_FPRF_from_FRT_with_context(dfp, &shortContext);
+}
+
+static void dfp_set_FPRF_from_FRT_long(struct PPC_DFP *dfp)
+{
+    decContext longContext;
+    decContextDefault(&longContext, DEC_INIT_DECIMAL64);
+    dfp_set_FPRF_from_FRT_with_context(dfp, &longContext);
+}
+
 static void dfp_check_for_OX(struct PPC_DFP *dfp)
 {
     if (dfp->context.status & DEC_Overflow) {
@@ -870,3 +884,37 @@ void helper_dctqpq(CPUPPCState *env, uint64_t *t, uint64_t 
*b)
     t[0] = dfp.t64[HI_IDX];
     t[1] = dfp.t64[LO_IDX];
 }
+
+void helper_drsp(CPUPPCState *env, uint64_t *t, uint64_t *b)
+{
+    struct PPC_DFP dfp;
+    uint32_t t_short = 0;
+    dfp_prepare_decimal64(&dfp, 0, b, env);
+    decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
+    decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
+
+    dfp_set_FPRF_from_FRT_short(&dfp);
+    dfp_check_for_OX(&dfp);
+    dfp_check_for_UX(&dfp);
+    dfp_check_for_XX(&dfp);
+
+    *t = t_short;
+}
+
+void helper_drdpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
+{
+    struct PPC_DFP dfp;
+    dfp_prepare_decimal128(&dfp, 0, b, env);
+    decimal64FromNumber((decimal64 *)&dfp.t64, &dfp.b, &dfp.context);
+    decimal64ToNumber((decimal64 *)&dfp.t64, &dfp.t);
+
+    dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
+    dfp_set_FPRF_from_FRT_long(&dfp);
+    dfp_check_for_OX(&dfp);
+    dfp_check_for_UX(&dfp);
+    dfp_check_for_XX(&dfp);
+
+    decimal64FromNumber((decimal64 *)dfp.t64, &dfp.t, &dfp.context);
+    t[0] = dfp.t64[0];
+    t[1] = 0;
+}
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index a99ca1c..d9ef8f6 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -650,4 +650,6 @@ 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)
+DEF_HELPER_3(drsp, void, env, fprp, fprp)
+DEF_HELPER_3(drdpq, void, env, fprp, fprp)
 #include "exec/def-helper.h"
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index da70c8d..391f55d 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -8388,6 +8388,8 @@ 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)
+GEN_DFP_T_B_Rc(drsp)
+GEN_DFP_T_B_Rc(drdpq)
 /***                           SPE extension                               ***/
 /* Register moves */
 
@@ -11347,6 +11349,8 @@ 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),
+GEN_DFP_T_B_Rc(drsp, 0x02, 0x18),
+GEN_DFP_Tp_Bp_Rc(drdpq, 0x02, 0x18),
 #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)
-- 
1.7.1