Add qemu 2.4.0
[kvmfornfv.git] / qemu / target-ppc / dfp_helper.c
diff --git a/qemu/target-ppc/dfp_helper.c b/qemu/target-ppc/dfp_helper.c
new file mode 100644 (file)
index 0000000..49820bf
--- /dev/null
@@ -0,0 +1,1316 @@
+/*
+ *  PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
+ *
+ *  Copyright (c) 2014 IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "cpu.h"
+#include "exec/helper-proto.h"
+
+#define DECNUMDIGITS 34
+#include "libdecnumber/decContext.h"
+#include "libdecnumber/decNumber.h"
+#include "libdecnumber/dpd/decimal32.h"
+#include "libdecnumber/dpd/decimal64.h"
+#include "libdecnumber/dpd/decimal128.h"
+
+#if defined(HOST_WORDS_BIGENDIAN)
+#define HI_IDX 0
+#define LO_IDX 1
+#else
+#define HI_IDX 1
+#define LO_IDX 0
+#endif
+
+struct PPC_DFP {
+    CPUPPCState *env;
+    uint64_t t64[2], a64[2], b64[2];
+    decNumber t, a, b;
+    decContext context;
+    uint8_t crbf;
+};
+
+static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
+{
+    enum rounding rnd;
+
+    switch ((fpscr >> 32) & 0x7) {
+    case 0:
+        rnd = DEC_ROUND_HALF_EVEN;
+        break;
+    case 1:
+        rnd = DEC_ROUND_DOWN;
+        break;
+    case 2:
+         rnd = DEC_ROUND_CEILING;
+         break;
+    case 3:
+         rnd = DEC_ROUND_FLOOR;
+         break;
+    case 4:
+         rnd = DEC_ROUND_HALF_UP;
+         break;
+    case 5:
+         rnd = DEC_ROUND_HALF_DOWN;
+         break;
+    case 6:
+         rnd = DEC_ROUND_UP;
+         break;
+    case 7:
+         rnd = DEC_ROUND_05UP;
+         break;
+    default:
+        g_assert_not_reached();
+    }
+
+    decContextSetRounding(context, rnd);
+}
+
+static void dfp_set_round_mode_from_immediate(uint8_t r, uint8_t rmc,
+                                                  struct PPC_DFP *dfp)
+{
+    enum rounding rnd;
+    if (r == 0) {
+        switch (rmc & 3) {
+        case 0:
+            rnd = DEC_ROUND_HALF_EVEN;
+            break;
+        case 1:
+            rnd = DEC_ROUND_DOWN;
+            break;
+        case 2:
+            rnd = DEC_ROUND_HALF_UP;
+            break;
+        case 3: /* use FPSCR rounding mode */
+            return;
+        default:
+            assert(0); /* cannot get here */
+        }
+    } else { /* r == 1 */
+        switch (rmc & 3) {
+        case 0:
+            rnd = DEC_ROUND_CEILING;
+            break;
+        case 1:
+            rnd = DEC_ROUND_FLOOR;
+            break;
+        case 2:
+            rnd = DEC_ROUND_UP;
+            break;
+        case 3:
+            rnd = DEC_ROUND_HALF_DOWN;
+            break;
+        default:
+            assert(0); /* cannot get here */
+        }
+    }
+    decContextSetRounding(&dfp->context, rnd);
+}
+
+static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
+                uint64_t *b, CPUPPCState *env)
+{
+    decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
+    dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
+    dfp->env = env;
+
+    if (a) {
+        dfp->a64[0] = *a;
+        decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
+    } else {
+        dfp->a64[0] = 0;
+        decNumberZero(&dfp->a);
+    }
+
+    if (b) {
+        dfp->b64[0] = *b;
+        decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
+    } else {
+        dfp->b64[0] = 0;
+        decNumberZero(&dfp->b);
+    }
+}
+
+static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
+                uint64_t *b, CPUPPCState *env)
+{
+    decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
+    dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
+    dfp->env = env;
+
+    if (a) {
+        dfp->a64[0] = a[HI_IDX];
+        dfp->a64[1] = a[LO_IDX];
+        decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
+    } else {
+        dfp->a64[0] = dfp->a64[1] = 0;
+        decNumberZero(&dfp->a);
+    }
+
+    if (b) {
+        dfp->b64[0] = b[HI_IDX];
+        dfp->b64[1] = b[LO_IDX];
+        decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
+    } else {
+        dfp->b64[0] = dfp->b64[1] = 0;
+        decNumberZero(&dfp->b);
+    }
+}
+
+#define FP_FX       (1ull << FPSCR_FX)
+#define FP_FEX      (1ull << FPSCR_FEX)
+#define FP_OX       (1ull << FPSCR_OX)
+#define FP_OE       (1ull << FPSCR_OE)
+#define FP_UX       (1ull << FPSCR_UX)
+#define FP_UE       (1ull << FPSCR_UE)
+#define FP_XX       (1ull << FPSCR_XX)
+#define FP_XE       (1ull << FPSCR_XE)
+#define FP_ZX       (1ull << FPSCR_ZX)
+#define FP_ZE       (1ull << FPSCR_ZE)
+#define FP_VX       (1ull << FPSCR_VX)
+#define FP_VXSNAN   (1ull << FPSCR_VXSNAN)
+#define FP_VXISI    (1ull << FPSCR_VXISI)
+#define FP_VXIMZ    (1ull << FPSCR_VXIMZ)
+#define FP_VXZDZ    (1ull << FPSCR_VXZDZ)
+#define FP_VXIDI    (1ull << FPSCR_VXIDI)
+#define FP_VXVC     (1ull << FPSCR_VXVC)
+#define FP_VXCVI    (1ull << FPSCR_VXCVI)
+#define FP_VE       (1ull << FPSCR_VE)
+#define FP_FI       (1ull << FPSCR_FI)
+
+static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
+                uint64_t enabled)
+{
+    dfp->env->fpscr |= (flag | FP_FX);
+    if (dfp->env->fpscr & enabled) {
+        dfp->env->fpscr |= FP_FEX;
+    }
+}
+
+static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
+                decContext *context)
+{
+    uint64_t fprf = 0;
+
+    /* construct FPRF */
+    switch (decNumberClass(&dfp->t, context)) {
+    case DEC_CLASS_SNAN:
+        fprf = 0x01;
+        break;
+    case DEC_CLASS_QNAN:
+        fprf = 0x11;
+        break;
+    case DEC_CLASS_NEG_INF:
+        fprf = 0x09;
+        break;
+    case DEC_CLASS_NEG_NORMAL:
+        fprf = 0x08;
+        break;
+    case DEC_CLASS_NEG_SUBNORMAL:
+        fprf = 0x18;
+        break;
+    case DEC_CLASS_NEG_ZERO:
+        fprf = 0x12;
+        break;
+    case DEC_CLASS_POS_ZERO:
+        fprf = 0x02;
+        break;
+    case DEC_CLASS_POS_SUBNORMAL:
+        fprf = 0x14;
+        break;
+    case DEC_CLASS_POS_NORMAL:
+        fprf = 0x04;
+        break;
+    case DEC_CLASS_POS_INF:
+        fprf = 0x05;
+        break;
+    default:
+        assert(0); /* should never get here */
+    }
+    dfp->env->fpscr &= ~(0x1F << 12);
+    dfp->env->fpscr |= (fprf << 12);
+}
+
+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) {
+        dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
+    }
+}
+
+static void dfp_check_for_UX(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Underflow) {
+        dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
+    }
+}
+
+static void dfp_check_for_XX(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Inexact) {
+        dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
+    }
+}
+
+static void dfp_check_for_ZX(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Division_by_zero) {
+        dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
+    }
+}
+
+static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Invalid_operation) {
+        if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
+            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
+        }
+    }
+}
+
+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) {
+        if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
+            int same = decNumberClass(&dfp->a, &dfp->context) ==
+                       decNumberClass(&dfp->b, &dfp->context);
+            if ((same && testForSameSign) || (!same && !testForSameSign)) {
+                dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
+            }
+        }
+    }
+}
+
+static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
+{
+    dfp_check_for_VXISI(dfp, 0);
+}
+
+static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
+{
+    dfp_check_for_VXISI(dfp, 1);
+}
+
+static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Invalid_operation) {
+        if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
+            (decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
+            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
+        }
+    }
+}
+
+static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Division_undefined) {
+        dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
+    }
+}
+
+static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
+{
+    if (dfp->context.status & DEC_Invalid_operation) {
+        if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
+            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
+        }
+    }
+}
+
+static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
+{
+    if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
+        dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
+    }
+}
+
+static void dfp_check_for_VXCVI(struct PPC_DFP *dfp)
+{
+    if ((dfp->context.status & DEC_Invalid_operation) &&
+        (!decNumberIsSNaN(&dfp->a)) &&
+        (!decNumberIsSNaN(&dfp->b))) {
+        dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
+    }
+}
+
+static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
+{
+    if (decNumberIsNaN(&dfp->t)) {
+        dfp->crbf = 1;
+    } else if (decNumberIsZero(&dfp->t)) {
+        dfp->crbf = 2;
+    } else if (decNumberIsNegative(&dfp->t)) {
+        dfp->crbf = 8;
+    } else {
+        dfp->crbf = 4;
+    }
+}
+
+static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
+{
+    dfp->env->fpscr &= ~(0xF << 12);
+    dfp->env->fpscr |= (dfp->crbf << 12);
+}
+
+static inline void dfp_makeQNaN(decNumber *dn)
+{
+    dn->bits &= ~DECSPECIAL;
+    dn->bits |= DECNAN;
+}
+
+static inline int dfp_get_digit(decNumber *dn, int n)
+{
+    assert(DECDPUN == 3);
+    int unit = n / DECDPUN;
+    int dig = n % DECDPUN;
+    switch (dig) {
+    case 0:
+        return dn->lsu[unit] % 10;
+    case 1:
+        return (dn->lsu[unit] / 10) % 10;
+    case 2:
+        return dn->lsu[unit] / 100;
+    }
+    g_assert_not_reached();
+}
+
+#define DFP_HELPER_TAB(op, dnop, postprocs, size)                              \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b)      \
+{                                                                              \
+    struct PPC_DFP dfp;                                                        \
+    dfp_prepare_decimal##size(&dfp, a, b, env);                                \
+    dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
+    postprocs(&dfp);                                                           \
+    if (size == 64) {                                                          \
+        t[0] = dfp.t64[0];                                                     \
+    } else if (size == 128) {                                                  \
+        t[0] = dfp.t64[HI_IDX];                                                \
+        t[1] = dfp.t64[LO_IDX];                                                \
+    }                                                                          \
+}
+
+static void ADD_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_OX(dfp);
+    dfp_check_for_UX(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXISI_add(dfp);
+}
+
+DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
+DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
+
+static void SUB_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_OX(dfp);
+    dfp_check_for_UX(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXISI_subtract(dfp);
+}
+
+DFP_HELPER_TAB(dsub, decNumberSubtract, SUB_PPs, 64)
+DFP_HELPER_TAB(dsubq, decNumberSubtract, SUB_PPs, 128)
+
+static void MUL_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_OX(dfp);
+    dfp_check_for_UX(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXIMZ(dfp);
+}
+
+DFP_HELPER_TAB(dmul, decNumberMultiply, MUL_PPs, 64)
+DFP_HELPER_TAB(dmulq, decNumberMultiply, MUL_PPs, 128)
+
+static void DIV_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_OX(dfp);
+    dfp_check_for_UX(dfp);
+    dfp_check_for_ZX(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXZDZ(dfp);
+    dfp_check_for_VXIDI(dfp);
+}
+
+DFP_HELPER_TAB(ddiv, decNumberDivide, DIV_PPs, 64)
+DFP_HELPER_TAB(ddivq, decNumberDivide, DIV_PPs, 128)
+
+#define DFP_HELPER_BF_AB(op, dnop, postprocs, size)                            \
+uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)               \
+{                                                                              \
+    struct PPC_DFP dfp;                                                        \
+    dfp_prepare_decimal##size(&dfp, a, b, env);                                \
+    dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
+    postprocs(&dfp);                                                           \
+    return dfp.crbf;                                                           \
+}
+
+static void CMPU_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_CRBF_from_T(dfp);
+    dfp_set_FPCC_from_CRBF(dfp);
+    dfp_check_for_VXSNAN(dfp);
+}
+
+DFP_HELPER_BF_AB(dcmpu, decNumberCompare, CMPU_PPs, 64)
+DFP_HELPER_BF_AB(dcmpuq, decNumberCompare, CMPU_PPs, 128)
+
+static void CMPO_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_CRBF_from_T(dfp);
+    dfp_set_FPCC_from_CRBF(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXVC(dfp);
+}
+
+DFP_HELPER_BF_AB(dcmpo, decNumberCompare, CMPO_PPs, 64)
+DFP_HELPER_BF_AB(dcmpoq, decNumberCompare, CMPO_PPs, 128)
+
+#define DFP_HELPER_TSTDC(op, size)                                       \
+uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm)        \
+{                                                                        \
+    struct PPC_DFP dfp;                                                  \
+    int match = 0;                                                       \
+                                                                         \
+    dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
+                                                                         \
+    match |= (dcm & 0x20) && decNumberIsZero(&dfp.a);                    \
+    match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
+    match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context);    \
+    match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a);                \
+    match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a);                    \
+    match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a);                    \
+                                                                         \
+    if (decNumberIsNegative(&dfp.a)) {                                   \
+        dfp.crbf = match ? 0xA : 0x8;                                    \
+    } else {                                                             \
+        dfp.crbf = match ? 0x2 : 0x0;                                    \
+    }                                                                    \
+                                                                         \
+    dfp_set_FPCC_from_CRBF(&dfp);                                        \
+    return dfp.crbf;                                                     \
+}
+
+DFP_HELPER_TSTDC(dtstdc, 64)
+DFP_HELPER_TSTDC(dtstdcq, 128)
+
+#define DFP_HELPER_TSTDG(op, size)                                       \
+uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm)        \
+{                                                                        \
+    struct PPC_DFP dfp;                                                  \
+    int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero,   \
+        is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero,    \
+        match;                                                           \
+                                                                         \
+    dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
+                                                                         \
+    if ((size) == 64) {                                                  \
+        minexp = -398;                                                   \
+        maxexp = 369;                                                    \
+        nzero_digits = 16;                                               \
+        nzero_idx = 5;                                                   \
+    } else if ((size) == 128) {                                          \
+        minexp = -6176;                                                  \
+        maxexp = 6111;                                                   \
+        nzero_digits = 34;                                               \
+        nzero_idx = 11;                                                  \
+    }                                                                    \
+                                                                         \
+    is_negative = decNumberIsNegative(&dfp.a);                           \
+    is_zero = decNumberIsZero(&dfp.a);                                   \
+    is_extreme_exp = (dfp.a.exponent == maxexp) ||                       \
+                     (dfp.a.exponent == minexp);                         \
+    is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context);           \
+    is_normal = decNumberIsNormal(&dfp.a, &dfp.context);                 \
+    leftmost_is_nonzero = (dfp.a.digits == nzero_digits) &&              \
+                          (dfp.a.lsu[nzero_idx] != 0);                   \
+    match = 0;                                                           \
+                                                                         \
+    match |= (dcm & 0x20) && is_zero && !is_extreme_exp;                 \
+    match |= (dcm & 0x10) && is_zero && is_extreme_exp;                  \
+    match |= (dcm & 0x08) &&                                             \
+             (is_subnormal || (is_normal && is_extreme_exp));            \
+    match |= (dcm & 0x04) && is_normal && !is_extreme_exp &&             \
+             !leftmost_is_nonzero;                                       \
+    match |= (dcm & 0x02) && is_normal && !is_extreme_exp &&             \
+             leftmost_is_nonzero;                                        \
+    match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a);                 \
+                                                                         \
+    if (is_negative) {                                                   \
+        dfp.crbf = match ? 0xA : 0x8;                                    \
+    } else {                                                             \
+        dfp.crbf = match ? 0x2 : 0x0;                                    \
+    }                                                                    \
+                                                                         \
+    dfp_set_FPCC_from_CRBF(&dfp);                                        \
+    return dfp.crbf;                                                     \
+}
+
+DFP_HELPER_TSTDG(dtstdg, 64)
+DFP_HELPER_TSTDG(dtstdgq, 128)
+
+#define DFP_HELPER_TSTEX(op, size)                                       \
+uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)         \
+{                                                                        \
+    struct PPC_DFP dfp;                                                  \
+    int expa, expb, a_is_special, b_is_special;                          \
+                                                                         \
+    dfp_prepare_decimal##size(&dfp, a, b, env);                          \
+                                                                         \
+    expa = dfp.a.exponent;                                               \
+    expb = dfp.b.exponent;                                               \
+    a_is_special = decNumberIsSpecial(&dfp.a);                           \
+    b_is_special = decNumberIsSpecial(&dfp.b);                           \
+                                                                         \
+    if (a_is_special || b_is_special) {                                  \
+        int atype = a_is_special ? (decNumberIsNaN(&dfp.a) ? 4 : 2) : 1; \
+        int btype = b_is_special ? (decNumberIsNaN(&dfp.b) ? 4 : 2) : 1; \
+        dfp.crbf = (atype ^ btype) ? 0x1 : 0x2;                          \
+    } else if (expa < expb) {                                            \
+        dfp.crbf = 0x8;                                                  \
+    } else if (expa > expb) {                                            \
+        dfp.crbf = 0x4;                                                  \
+    } else {                                                             \
+        dfp.crbf = 0x2;                                                  \
+    }                                                                    \
+                                                                         \
+    dfp_set_FPCC_from_CRBF(&dfp);                                        \
+    return dfp.crbf;                                                     \
+}
+
+DFP_HELPER_TSTEX(dtstex, 64)
+DFP_HELPER_TSTEX(dtstexq, 128)
+
+#define DFP_HELPER_TSTSF(op, size)                                       \
+uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)         \
+{                                                                        \
+    struct PPC_DFP dfp;                                                  \
+    unsigned k;                                                          \
+                                                                         \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                          \
+                                                                         \
+    k = *a & 0x3F;                                                       \
+                                                                         \
+    if (unlikely(decNumberIsSpecial(&dfp.b))) {                          \
+        dfp.crbf = 1;                                                    \
+    } else if (k == 0) {                                                 \
+        dfp.crbf = 4;                                                    \
+    } else if (unlikely(decNumberIsZero(&dfp.b))) {                      \
+        /* Zero has no sig digits */                                     \
+        dfp.crbf = 4;                                                    \
+    } else {                                                             \
+        unsigned nsd = dfp.b.digits;                                     \
+        if (k < nsd) {                                                   \
+            dfp.crbf = 8;                                                \
+        } else if (k > nsd) {                                            \
+            dfp.crbf = 4;                                                \
+        } else {                                                         \
+            dfp.crbf = 2;                                                \
+        }                                                                \
+    }                                                                    \
+                                                                         \
+    dfp_set_FPCC_from_CRBF(&dfp);                                        \
+    return dfp.crbf;                                                     \
+}
+
+DFP_HELPER_TSTSF(dtstsf, 64)
+DFP_HELPER_TSTSF(dtstsfq, 128)
+
+static void QUA_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+    dfp_check_for_VXCVI(dfp);
+}
+
+static void dfp_quantize(uint8_t rmc, struct PPC_DFP *dfp)
+{
+    dfp_set_round_mode_from_immediate(0, rmc, dfp);
+    decNumberQuantize(&dfp->t, &dfp->b, &dfp->a, &dfp->context);
+    if (decNumberIsSNaN(&dfp->a)) {
+        dfp->t = dfp->a;
+        dfp_makeQNaN(&dfp->t);
+    } else if (decNumberIsSNaN(&dfp->b)) {
+        dfp->t = dfp->b;
+        dfp_makeQNaN(&dfp->t);
+    } else if (decNumberIsQNaN(&dfp->a)) {
+        dfp->t = dfp->a;
+    } else if (decNumberIsQNaN(&dfp->b)) {
+        dfp->t = dfp->b;
+    }
+}
+
+#define DFP_HELPER_QUAI(op, size)                                       \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,            \
+                 uint32_t te, uint32_t rmc)                             \
+{                                                                       \
+    struct PPC_DFP dfp;                                                 \
+                                                                        \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
+                                                                        \
+    decNumberFromUInt32(&dfp.a, 1);                                     \
+    dfp.a.exponent = (int32_t)((int8_t)(te << 3) >> 3);                 \
+                                                                        \
+    dfp_quantize(rmc, &dfp);                                            \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
+                              &dfp.context);                            \
+    QUA_PPs(&dfp);                                                      \
+                                                                        \
+    if (size == 64) {                                                   \
+        t[0] = dfp.t64[0];                                              \
+    } else if (size == 128) {                                           \
+        t[0] = dfp.t64[HI_IDX];                                         \
+        t[1] = dfp.t64[LO_IDX];                                         \
+    }                                                                   \
+}
+
+DFP_HELPER_QUAI(dquai, 64)
+DFP_HELPER_QUAI(dquaiq, 128)
+
+#define DFP_HELPER_QUA(op, size)                                        \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
+                 uint64_t *b, uint32_t rmc)                             \
+{                                                                       \
+    struct PPC_DFP dfp;                                                 \
+                                                                        \
+    dfp_prepare_decimal##size(&dfp, a, b, env);                         \
+                                                                        \
+    dfp_quantize(rmc, &dfp);                                            \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
+                              &dfp.context);                            \
+    QUA_PPs(&dfp);                                                      \
+                                                                        \
+    if (size == 64) {                                                   \
+        t[0] = dfp.t64[0];                                              \
+    } else if (size == 128) {                                           \
+        t[0] = dfp.t64[HI_IDX];                                         \
+        t[1] = dfp.t64[LO_IDX];                                         \
+    }                                                                   \
+}
+
+DFP_HELPER_QUA(dqua, 64)
+DFP_HELPER_QUA(dquaq, 128)
+
+static void _dfp_reround(uint8_t rmc, int32_t ref_sig, int32_t xmax,
+                             struct PPC_DFP *dfp)
+{
+    int msd_orig, msd_rslt;
+
+    if (unlikely((ref_sig == 0) || (dfp->b.digits <= ref_sig))) {
+        dfp->t = dfp->b;
+        if (decNumberIsSNaN(&dfp->b)) {
+            dfp_makeQNaN(&dfp->t);
+            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FPSCR_VE);
+        }
+        return;
+    }
+
+    /* Reround is equivalent to quantizing b with 1**E(n) where */
+    /* n = exp(b) + numDigits(b) - reference_significance.      */
+
+    decNumberFromUInt32(&dfp->a, 1);
+    dfp->a.exponent = dfp->b.exponent + dfp->b.digits - ref_sig;
+
+    if (unlikely(dfp->a.exponent > xmax)) {
+        dfp->t.digits = 0;
+        dfp->t.bits &= ~DECNEG;
+        dfp_makeQNaN(&dfp->t);
+        dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
+        return;
+    }
+
+    dfp_quantize(rmc, dfp);
+
+    msd_orig = dfp_get_digit(&dfp->b, dfp->b.digits-1);
+    msd_rslt = dfp_get_digit(&dfp->t, dfp->t.digits-1);
+
+    /* If the quantization resulted in rounding up to the next magnitude, */
+    /* then we need to shift the significand and adjust the exponent.     */
+
+    if (unlikely((msd_orig == 9) && (msd_rslt == 1))) {
+
+        decNumber negone;
+
+        decNumberFromInt32(&negone, -1);
+        decNumberShift(&dfp->t, &dfp->t, &negone, &dfp->context);
+        dfp->t.exponent++;
+
+        if (unlikely(dfp->t.exponent > xmax)) {
+            dfp_makeQNaN(&dfp->t);
+            dfp->t.digits = 0;
+            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
+            /* Inhibit XX in this case */
+            decContextClearStatus(&dfp->context, DEC_Inexact);
+        }
+    }
+}
+
+#define DFP_HELPER_RRND(op, size)                                       \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
+                 uint64_t *b, uint32_t rmc)                             \
+{                                                                       \
+    struct PPC_DFP dfp;                                                 \
+    int32_t ref_sig = *a & 0x3F;                                        \
+    int32_t xmax = ((size) == 64) ? 369 : 6111;                         \
+                                                                        \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
+                                                                        \
+    _dfp_reround(rmc, ref_sig, xmax, &dfp);                             \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
+                              &dfp.context);                            \
+    QUA_PPs(&dfp);                                                      \
+                                                                        \
+    if (size == 64) {                                                   \
+        t[0] = dfp.t64[0];                                              \
+    } else if (size == 128) {                                           \
+        t[0] = dfp.t64[HI_IDX];                                         \
+        t[1] = dfp.t64[LO_IDX];                                         \
+    }                                                                   \
+}
+
+DFP_HELPER_RRND(drrnd, 64)
+DFP_HELPER_RRND(drrndq, 128)
+
+#define DFP_HELPER_RINT(op, postprocs, size)                                   \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,                   \
+             uint32_t r, uint32_t rmc)                                         \
+{                                                                              \
+    struct PPC_DFP dfp;                                                        \
+                                                                               \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
+                                                                               \
+    dfp_set_round_mode_from_immediate(r, rmc, &dfp);                           \
+    decNumberToIntegralExact(&dfp.t, &dfp.b, &dfp.context);                    \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
+    postprocs(&dfp);                                                           \
+                                                                               \
+    if (size == 64) {                                                          \
+        t[0] = dfp.t64[0];                                                     \
+    } else if (size == 128) {                                                  \
+        t[0] = dfp.t64[HI_IDX];                                                \
+        t[1] = dfp.t64[LO_IDX];                                                \
+    }                                                                          \
+}
+
+static void RINTX_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_XX(dfp);
+    dfp_check_for_VXSNAN(dfp);
+}
+
+DFP_HELPER_RINT(drintx, RINTX_PPs, 64)
+DFP_HELPER_RINT(drintxq, RINTX_PPs, 128)
+
+static void RINTN_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_VXSNAN(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];
+}
+
+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;
+}
+
+#define DFP_HELPER_CFFIX(op, size)                                             \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                   \
+{                                                                              \
+    struct PPC_DFP dfp;                                                        \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
+    decNumberFromInt64(&dfp.t, (int64_t)(*b));                                 \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
+    CFFIX_PPs(&dfp);                                                           \
+                                                                               \
+    if (size == 64) {                                                          \
+        t[0] = dfp.t64[0];                                                     \
+    } else if (size == 128) {                                                  \
+        t[0] = dfp.t64[HI_IDX];                                                \
+        t[1] = dfp.t64[LO_IDX];                                                \
+    }                                                                          \
+}
+
+static void CFFIX_PPs(struct PPC_DFP *dfp)
+{
+    dfp_set_FPRF_from_FRT(dfp);
+    dfp_check_for_XX(dfp);
+}
+
+DFP_HELPER_CFFIX(dcffix, 64)
+DFP_HELPER_CFFIX(dcffixq, 128)
+
+#define DFP_HELPER_CTFIX(op, size)                                            \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                  \
+{                                                                             \
+    struct PPC_DFP dfp;                                                       \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                               \
+                                                                              \
+    if (unlikely(decNumberIsSpecial(&dfp.b))) {                               \
+        uint64_t invalid_flags = FP_VX | FP_VXCVI;                            \
+        if (decNumberIsInfinite(&dfp.b)) {                                    \
+            dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
+        } else { /* NaN */                                                    \
+            dfp.t64[0] = INT64_MIN;                                           \
+            if (decNumberIsSNaN(&dfp.b)) {                                    \
+                invalid_flags |= FP_VXSNAN;                                   \
+            }                                                                 \
+        }                                                                     \
+        dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE);                       \
+    } else if (unlikely(decNumberIsZero(&dfp.b))) {                           \
+        dfp.t64[0] = 0;                                                       \
+    } else {                                                                  \
+        decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context);               \
+        dfp.t64[0] = decNumberIntegralToInt64(&dfp.b, &dfp.context);          \
+        if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) {      \
+            dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
+            dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE);                \
+        } else {                                                              \
+            dfp_check_for_XX(&dfp);                                           \
+        }                                                                     \
+    }                                                                         \
+                                                                              \
+    *t = dfp.t64[0];                                                          \
+}
+
+DFP_HELPER_CTFIX(dctfix, 64)
+DFP_HELPER_CTFIX(dctfixq, 128)
+
+static inline void dfp_set_bcd_digit_64(uint64_t *t, uint8_t digit,
+                                            unsigned n)
+{
+    *t |= ((uint64_t)(digit & 0xF) << (n << 2));
+}
+
+static inline void dfp_set_bcd_digit_128(uint64_t *t, uint8_t digit,
+                                             unsigned n)
+{
+    t[(n & 0x10) ? HI_IDX : LO_IDX] |=
+        ((uint64_t)(digit & 0xF) << ((n & 15) << 2));
+}
+
+static inline void dfp_set_sign_64(uint64_t *t, uint8_t sgn)
+{
+    *t <<= 4;
+    *t |= (sgn & 0xF);
+}
+
+static inline void dfp_set_sign_128(uint64_t *t, uint8_t sgn)
+{
+    t[HI_IDX] <<= 4;
+    t[HI_IDX] |= (t[LO_IDX] >> 60);
+    t[LO_IDX] <<= 4;
+    t[LO_IDX] |= (sgn & 0xF);
+}
+
+#define DFP_HELPER_DEDPD(op, size)                                        \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t sp) \
+{                                                                         \
+    struct PPC_DFP dfp;                                                   \
+    uint8_t digits[34];                                                   \
+    int i, N;                                                             \
+                                                                          \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
+                                                                          \
+    decNumberGetBCD(&dfp.b, digits);                                      \
+    dfp.t64[0] = dfp.t64[1] = 0;                                          \
+    N = dfp.b.digits;                                                     \
+                                                                          \
+    for (i = 0; (i < N) && (i < (size)/4); i++) {                         \
+        dfp_set_bcd_digit_##size(dfp.t64, digits[N-i-1], i);              \
+    }                                                                     \
+                                                                          \
+    if (sp & 2) {                                                         \
+        uint8_t sgn;                                                      \
+                                                                          \
+        if (decNumberIsNegative(&dfp.b)) {                                \
+            sgn = 0xD;                                                    \
+        } else {                                                          \
+            sgn = ((sp & 1) ? 0xF : 0xC);                                 \
+        }                                                                 \
+        dfp_set_sign_##size(dfp.t64, sgn);                                \
+    }                                                                     \
+                                                                          \
+    if (size == 64) {                                                     \
+        t[0] = dfp.t64[0];                                                \
+    } else if (size == 128) {                                             \
+        t[0] = dfp.t64[HI_IDX];                                           \
+        t[1] = dfp.t64[LO_IDX];                                           \
+    }                                                                     \
+}
+
+DFP_HELPER_DEDPD(ddedpd, 64)
+DFP_HELPER_DEDPD(ddedpdq, 128)
+
+static inline uint8_t dfp_get_bcd_digit_64(uint64_t *t, unsigned n)
+{
+    return *t >> ((n << 2) & 63) & 15;
+}
+
+static inline uint8_t dfp_get_bcd_digit_128(uint64_t *t, unsigned n)
+{
+    return t[(n & 0x10) ? HI_IDX : LO_IDX] >> ((n << 2) & 63) & 15;
+}
+
+#define DFP_HELPER_ENBCD(op, size)                                           \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t s)     \
+{                                                                            \
+    struct PPC_DFP dfp;                                                      \
+    uint8_t digits[32];                                                      \
+    int n = 0, offset = 0, sgn = 0, nonzero = 0;                             \
+                                                                             \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                              \
+                                                                             \
+    decNumberZero(&dfp.t);                                                   \
+                                                                             \
+    if (s) {                                                                 \
+        uint8_t sgnNibble = dfp_get_bcd_digit_##size(dfp.b64, offset++);     \
+        switch (sgnNibble) {                                                 \
+        case 0xD:                                                            \
+        case 0xB:                                                            \
+            sgn = 1;                                                         \
+            break;                                                           \
+        case 0xC:                                                            \
+        case 0xF:                                                            \
+        case 0xA:                                                            \
+        case 0xE:                                                            \
+            sgn = 0;                                                         \
+            break;                                                           \
+        default:                                                             \
+            dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
+            return;                                                          \
+        }                                                                    \
+        }                                                                    \
+                                                                             \
+    while (offset < (size)/4) {                                              \
+        n++;                                                                 \
+        digits[(size)/4-n] = dfp_get_bcd_digit_##size(dfp.b64, offset++);    \
+        if (digits[(size)/4-n] > 10) {                                       \
+            dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
+            return;                                                          \
+        } else {                                                             \
+            nonzero |= (digits[(size)/4-n] > 0);                             \
+        }                                                                    \
+    }                                                                        \
+                                                                             \
+    if (nonzero) {                                                           \
+        decNumberSetBCD(&dfp.t, digits+((size)/4)-n, n);                     \
+    }                                                                        \
+                                                                             \
+    if (s && sgn)  {                                                         \
+        dfp.t.bits |= DECNEG;                                                \
+    }                                                                        \
+    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,              \
+                              &dfp.context);                                 \
+    dfp_set_FPRF_from_FRT(&dfp);                                             \
+    if ((size) == 64) {                                                      \
+        t[0] = dfp.t64[0];                                                   \
+    } else if ((size) == 128) {                                              \
+        t[0] = dfp.t64[HI_IDX];                                              \
+        t[1] = dfp.t64[LO_IDX];                                              \
+    }                                                                        \
+}
+
+DFP_HELPER_ENBCD(denbcd, 64)
+DFP_HELPER_ENBCD(denbcdq, 128)
+
+#define DFP_HELPER_XEX(op, size)                               \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)   \
+{                                                              \
+    struct PPC_DFP dfp;                                        \
+                                                               \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                \
+                                                               \
+    if (unlikely(decNumberIsSpecial(&dfp.b))) {                \
+        if (decNumberIsInfinite(&dfp.b)) {                     \
+            *t = -1;                                           \
+        } else if (decNumberIsSNaN(&dfp.b)) {                  \
+            *t = -3;                                           \
+        } else if (decNumberIsQNaN(&dfp.b)) {                  \
+            *t = -2;                                           \
+        } else {                                               \
+            assert(0);                                         \
+        }                                                      \
+    } else {                                                   \
+        if ((size) == 64) {                                    \
+            *t = dfp.b.exponent + 398;                         \
+        } else if ((size) == 128) {                            \
+            *t = dfp.b.exponent + 6176;                        \
+        } else {                                               \
+            assert(0);                                         \
+        }                                                      \
+    }                                                          \
+}
+
+DFP_HELPER_XEX(dxex, 64)
+DFP_HELPER_XEX(dxexq, 128)
+
+static void dfp_set_raw_exp_64(uint64_t *t, uint64_t raw)
+{
+    *t &= 0x8003ffffffffffffULL;
+    *t |= (raw << (63-13));
+}
+
+static void dfp_set_raw_exp_128(uint64_t *t, uint64_t raw)
+{
+    t[HI_IDX] &= 0x80003fffffffffffULL;
+    t[HI_IDX] |= (raw << (63-17));
+}
+
+#define DFP_HELPER_IEX(op, size)                                          \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
+{                                                                         \
+    struct PPC_DFP dfp;                                                   \
+    uint64_t raw_qnan, raw_snan, raw_inf, max_exp;                        \
+    int bias;                                                             \
+    int64_t exp = *((int64_t *)a);                                        \
+                                                                          \
+    dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
+                                                                          \
+    if ((size) == 64) {                                                   \
+        max_exp = 767;                                                    \
+        raw_qnan = 0x1F00;                                                \
+        raw_snan = 0x1F80;                                                \
+        raw_inf = 0x1E00;                                                 \
+        bias = 398;                                                       \
+    } else if ((size) == 128) {                                           \
+        max_exp = 12287;                                                  \
+        raw_qnan = 0x1f000;                                               \
+        raw_snan = 0x1f800;                                               \
+        raw_inf = 0x1e000;                                                \
+        bias = 6176;                                                      \
+    } else {                                                              \
+        assert(0);                                                        \
+    }                                                                     \
+                                                                          \
+    if (unlikely((exp < 0) || (exp > max_exp))) {                         \
+        dfp.t64[0] = dfp.b64[0];                                          \
+        dfp.t64[1] = dfp.b64[1];                                          \
+        if (exp == -1) {                                                  \
+            dfp_set_raw_exp_##size(dfp.t64, raw_inf);                     \
+        } else if (exp == -3) {                                           \
+            dfp_set_raw_exp_##size(dfp.t64, raw_snan);                    \
+        } else {                                                          \
+            dfp_set_raw_exp_##size(dfp.t64, raw_qnan);                    \
+        }                                                                 \
+    } else {                                                              \
+        dfp.t = dfp.b;                                                    \
+        if (unlikely(decNumberIsSpecial(&dfp.t))) {                       \
+            dfp.t.bits &= ~DECSPECIAL;                                    \
+        }                                                                 \
+        dfp.t.exponent = exp - bias;                                      \
+        decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,       \
+                                  &dfp.context);                          \
+    }                                                                     \
+    if (size == 64) {                                                     \
+        t[0] = dfp.t64[0];                                                \
+    } else if (size == 128) {                                             \
+        t[0] = dfp.t64[HI_IDX];                                           \
+        t[1] = dfp.t64[LO_IDX];                                           \
+    }                                                                     \
+}
+
+DFP_HELPER_IEX(diex, 64)
+DFP_HELPER_IEX(diexq, 128)
+
+static void dfp_clear_lmd_from_g5msb(uint64_t *t)
+{
+
+    /* The most significant 5 bits of the PowerPC DFP format combine bits  */
+    /* from the left-most decimal digit (LMD) and the biased exponent.     */
+    /* This  routine clears the LMD bits while preserving the exponent     */
+    /*  bits.  See "Figure 80: Encoding of bits 0:4 of the G field for     */
+    /*  Finite Numbers" in the Power ISA for additional details.           */
+
+    uint64_t g5msb = (*t >> 58) & 0x1F;
+
+    if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
+       *t &= ~(7ULL << 58);
+    } else {
+       switch (g5msb & 7) {
+       case 0:
+       case 1:
+           g5msb = 0;
+           break;
+       case 2:
+       case 3:
+           g5msb = 0x8;
+           break;
+       case 4:
+       case 5:
+           g5msb = 0x10;
+           break;
+       case 6:
+           g5msb = 0x1E;
+           break;
+       case 7:
+           g5msb = 0x1F;
+           break;
+       }
+
+        *t &= ~(0x1fULL << 58);
+        *t |= (g5msb << 58);
+    }
+}
+
+#define DFP_HELPER_SHIFT(op, size, shift_left)                      \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,        \
+                 uint32_t sh)                                       \
+{                                                                   \
+    struct PPC_DFP dfp;                                             \
+    unsigned max_digits = ((size) == 64) ? 16 : 34;                 \
+                                                                    \
+    dfp_prepare_decimal##size(&dfp, a, 0, env);                     \
+                                                                    \
+    if (sh <= max_digits) {                                         \
+                                                                    \
+        decNumber shd;                                              \
+        unsigned special = dfp.a.bits & DECSPECIAL;                 \
+                                                                    \
+        if (shift_left) {                                           \
+            decNumberFromUInt32(&shd, sh);                          \
+        } else {                                                    \
+            decNumberFromInt32(&shd, -((int32_t)sh));               \
+        }                                                           \
+                                                                    \
+        dfp.a.bits &= ~DECSPECIAL;                                  \
+        decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context);         \
+                                                                    \
+        dfp.t.bits |= special;                                      \
+        if (special && (dfp.t.digits >= max_digits)) {              \
+            dfp.t.digits = max_digits - 1;                          \
+        }                                                           \
+                                                                    \
+        decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
+                                  &dfp.context);                    \
+    } else {                                                        \
+        if ((size) == 64) {                                         \
+            dfp.t64[0] = dfp.a64[0] & 0xFFFC000000000000ULL;        \
+            dfp_clear_lmd_from_g5msb(dfp.t64);                      \
+        } else {                                                    \
+            dfp.t64[HI_IDX] = dfp.a64[HI_IDX] &                     \
+                              0xFFFFC00000000000ULL;                \
+            dfp_clear_lmd_from_g5msb(dfp.t64 + HI_IDX);             \
+            dfp.t64[LO_IDX] = 0;                                    \
+        }                                                           \
+    }                                                               \
+                                                                    \
+    if ((size) == 64) {                                             \
+        t[0] = dfp.t64[0];                                          \
+    } else {                                                        \
+        t[0] = dfp.t64[HI_IDX];                                     \
+        t[1] = dfp.t64[LO_IDX];                                     \
+    }                                                               \
+}
+
+DFP_HELPER_SHIFT(dscli, 64, 1)
+DFP_HELPER_SHIFT(dscliq, 128, 1)
+DFP_HELPER_SHIFT(dscri, 64, 0)
+DFP_HELPER_SHIFT(dscriq, 128, 0)