1bf9c0e133
Add emulation of the PowerPC Decimal Floating Point Test Data Group instructions dtstdg[q][.]. Signed-off-by: Tom Musta <tommusta@gmail.com> Signed-off-by: Alexander Graf <agraf@suse.de>
507 lines
18 KiB
C
507 lines
18 KiB
C
/*
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* PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
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*
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* Copyright (c) 2014 IBM Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "cpu.h"
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#include "exec/helper-proto.h"
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#define DECNUMDIGITS 34
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#include "libdecnumber/decContext.h"
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#include "libdecnumber/decNumber.h"
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#include "libdecnumber/dpd/decimal32.h"
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#include "libdecnumber/dpd/decimal64.h"
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#include "libdecnumber/dpd/decimal128.h"
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#if defined(HOST_WORDS_BIGENDIAN)
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#define HI_IDX 0
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#define LO_IDX 1
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#else
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#define HI_IDX 1
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#define LO_IDX 0
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#endif
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struct PPC_DFP {
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CPUPPCState *env;
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uint64_t t64[2], a64[2], b64[2];
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decNumber t, a, b;
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decContext context;
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uint8_t crbf;
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};
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static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
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{
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enum rounding rnd;
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switch ((fpscr >> 32) & 0x7) {
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case 0:
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rnd = DEC_ROUND_HALF_EVEN;
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break;
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case 1:
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rnd = DEC_ROUND_DOWN;
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break;
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case 2:
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rnd = DEC_ROUND_CEILING;
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break;
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case 3:
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rnd = DEC_ROUND_FLOOR;
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break;
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case 4:
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rnd = DEC_ROUND_HALF_UP;
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break;
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case 5:
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rnd = DEC_ROUND_HALF_DOWN;
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break;
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case 6:
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rnd = DEC_ROUND_UP;
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break;
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case 7:
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rnd = DEC_ROUND_05UP;
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break;
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default:
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g_assert_not_reached();
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}
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decContextSetRounding(context, rnd);
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}
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static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
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uint64_t *b, CPUPPCState *env)
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{
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decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
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dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
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dfp->env = env;
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if (a) {
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dfp->a64[0] = *a;
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decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
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} else {
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dfp->a64[0] = 0;
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decNumberZero(&dfp->a);
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}
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if (b) {
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dfp->b64[0] = *b;
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decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
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} else {
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dfp->b64[0] = 0;
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decNumberZero(&dfp->b);
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}
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}
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static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
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uint64_t *b, CPUPPCState *env)
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{
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decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
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dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
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dfp->env = env;
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if (a) {
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dfp->a64[0] = a[HI_IDX];
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dfp->a64[1] = a[LO_IDX];
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decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
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} else {
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dfp->a64[0] = dfp->a64[1] = 0;
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decNumberZero(&dfp->a);
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}
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if (b) {
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dfp->b64[0] = b[HI_IDX];
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dfp->b64[1] = b[LO_IDX];
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decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
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} else {
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dfp->b64[0] = dfp->b64[1] = 0;
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decNumberZero(&dfp->b);
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}
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}
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#define FP_FX (1ull << FPSCR_FX)
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#define FP_FEX (1ull << FPSCR_FEX)
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#define FP_OX (1ull << FPSCR_OX)
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#define FP_OE (1ull << FPSCR_OE)
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#define FP_UX (1ull << FPSCR_UX)
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#define FP_UE (1ull << FPSCR_UE)
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#define FP_XX (1ull << FPSCR_XX)
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#define FP_XE (1ull << FPSCR_XE)
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#define FP_ZX (1ull << FPSCR_ZX)
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#define FP_ZE (1ull << FPSCR_ZE)
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#define FP_VX (1ull << FPSCR_VX)
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#define FP_VXSNAN (1ull << FPSCR_VXSNAN)
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#define FP_VXISI (1ull << FPSCR_VXISI)
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#define FP_VXIMZ (1ull << FPSCR_VXIMZ)
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#define FP_VXZDZ (1ull << FPSCR_VXZDZ)
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#define FP_VXIDI (1ull << FPSCR_VXIDI)
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#define FP_VXVC (1ull << FPSCR_VXVC)
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#define FP_VXCVI (1ull << FPSCR_VXCVI)
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#define FP_VE (1ull << FPSCR_VE)
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#define FP_FI (1ull << FPSCR_FI)
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static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
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uint64_t enabled)
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{
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dfp->env->fpscr |= (flag | FP_FX);
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if (dfp->env->fpscr & enabled) {
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dfp->env->fpscr |= FP_FEX;
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}
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}
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static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
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decContext *context)
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{
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uint64_t fprf = 0;
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/* construct FPRF */
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switch (decNumberClass(&dfp->t, context)) {
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case DEC_CLASS_SNAN:
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fprf = 0x01;
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break;
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case DEC_CLASS_QNAN:
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fprf = 0x11;
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break;
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case DEC_CLASS_NEG_INF:
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fprf = 0x09;
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break;
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case DEC_CLASS_NEG_NORMAL:
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fprf = 0x08;
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break;
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case DEC_CLASS_NEG_SUBNORMAL:
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fprf = 0x18;
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break;
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case DEC_CLASS_NEG_ZERO:
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fprf = 0x12;
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break;
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case DEC_CLASS_POS_ZERO:
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fprf = 0x02;
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break;
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case DEC_CLASS_POS_SUBNORMAL:
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fprf = 0x14;
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break;
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case DEC_CLASS_POS_NORMAL:
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fprf = 0x04;
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break;
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case DEC_CLASS_POS_INF:
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fprf = 0x05;
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break;
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default:
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assert(0); /* should never get here */
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}
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dfp->env->fpscr &= ~(0x1F << 12);
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dfp->env->fpscr |= (fprf << 12);
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}
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static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
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{
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dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
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}
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static void dfp_check_for_OX(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Overflow) {
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dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
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}
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}
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static void dfp_check_for_UX(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Underflow) {
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dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
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}
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}
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static void dfp_check_for_XX(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Inexact) {
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dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
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}
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}
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static void dfp_check_for_ZX(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Division_by_zero) {
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dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
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}
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}
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static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Invalid_operation) {
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if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
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}
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}
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}
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static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
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{
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if (dfp->context.status & DEC_Invalid_operation) {
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if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
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int same = decNumberClass(&dfp->a, &dfp->context) ==
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decNumberClass(&dfp->b, &dfp->context);
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if ((same && testForSameSign) || (!same && !testForSameSign)) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
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}
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}
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}
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}
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static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
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{
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dfp_check_for_VXISI(dfp, 0);
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}
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static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
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{
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dfp_check_for_VXISI(dfp, 1);
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}
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static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Invalid_operation) {
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if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
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(decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
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}
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}
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}
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static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Division_undefined) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
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}
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}
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static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
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{
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if (dfp->context.status & DEC_Invalid_operation) {
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if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
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}
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}
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}
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static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
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{
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if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
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dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
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}
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}
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static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
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{
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if (decNumberIsNaN(&dfp->t)) {
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dfp->crbf = 1;
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} else if (decNumberIsZero(&dfp->t)) {
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dfp->crbf = 2;
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} else if (decNumberIsNegative(&dfp->t)) {
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dfp->crbf = 8;
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} else {
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dfp->crbf = 4;
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}
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}
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static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
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{
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dfp->env->fpscr &= ~(0xF << 12);
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dfp->env->fpscr |= (dfp->crbf << 12);
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}
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#define DFP_HELPER_TAB(op, dnop, postprocs, size) \
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void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
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{ \
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struct PPC_DFP dfp; \
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dfp_prepare_decimal##size(&dfp, a, b, env); \
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dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
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decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
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postprocs(&dfp); \
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if (size == 64) { \
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t[0] = dfp.t64[0]; \
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} else if (size == 128) { \
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t[0] = dfp.t64[HI_IDX]; \
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t[1] = dfp.t64[LO_IDX]; \
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} \
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}
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static void ADD_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_FPRF_from_FRT(dfp);
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dfp_check_for_OX(dfp);
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dfp_check_for_UX(dfp);
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dfp_check_for_XX(dfp);
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dfp_check_for_VXSNAN(dfp);
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dfp_check_for_VXISI_add(dfp);
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}
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DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
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DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
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static void SUB_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_FPRF_from_FRT(dfp);
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dfp_check_for_OX(dfp);
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dfp_check_for_UX(dfp);
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dfp_check_for_XX(dfp);
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dfp_check_for_VXSNAN(dfp);
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dfp_check_for_VXISI_subtract(dfp);
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}
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DFP_HELPER_TAB(dsub, decNumberSubtract, SUB_PPs, 64)
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DFP_HELPER_TAB(dsubq, decNumberSubtract, SUB_PPs, 128)
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static void MUL_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_FPRF_from_FRT(dfp);
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dfp_check_for_OX(dfp);
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dfp_check_for_UX(dfp);
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dfp_check_for_XX(dfp);
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dfp_check_for_VXSNAN(dfp);
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dfp_check_for_VXIMZ(dfp);
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}
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DFP_HELPER_TAB(dmul, decNumberMultiply, MUL_PPs, 64)
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DFP_HELPER_TAB(dmulq, decNumberMultiply, MUL_PPs, 128)
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static void DIV_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_FPRF_from_FRT(dfp);
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dfp_check_for_OX(dfp);
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dfp_check_for_UX(dfp);
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dfp_check_for_ZX(dfp);
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dfp_check_for_XX(dfp);
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dfp_check_for_VXSNAN(dfp);
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dfp_check_for_VXZDZ(dfp);
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dfp_check_for_VXIDI(dfp);
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}
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DFP_HELPER_TAB(ddiv, decNumberDivide, DIV_PPs, 64)
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DFP_HELPER_TAB(ddivq, decNumberDivide, DIV_PPs, 128)
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#define DFP_HELPER_BF_AB(op, dnop, postprocs, size) \
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uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b) \
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{ \
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struct PPC_DFP dfp; \
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dfp_prepare_decimal##size(&dfp, a, b, env); \
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dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
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decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
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postprocs(&dfp); \
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return dfp.crbf; \
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}
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static void CMPU_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_CRBF_from_T(dfp);
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dfp_set_FPCC_from_CRBF(dfp);
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dfp_check_for_VXSNAN(dfp);
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}
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DFP_HELPER_BF_AB(dcmpu, decNumberCompare, CMPU_PPs, 64)
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DFP_HELPER_BF_AB(dcmpuq, decNumberCompare, CMPU_PPs, 128)
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static void CMPO_PPs(struct PPC_DFP *dfp)
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{
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dfp_set_CRBF_from_T(dfp);
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dfp_set_FPCC_from_CRBF(dfp);
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dfp_check_for_VXSNAN(dfp);
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dfp_check_for_VXVC(dfp);
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}
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DFP_HELPER_BF_AB(dcmpo, decNumberCompare, CMPO_PPs, 64)
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DFP_HELPER_BF_AB(dcmpoq, decNumberCompare, CMPO_PPs, 128)
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#define DFP_HELPER_TSTDC(op, size) \
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uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm) \
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{ \
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struct PPC_DFP dfp; \
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int match = 0; \
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\
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dfp_prepare_decimal##size(&dfp, a, 0, env); \
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\
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match |= (dcm & 0x20) && decNumberIsZero(&dfp.a); \
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match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
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match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context); \
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match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a); \
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match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a); \
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match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a); \
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\
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if (decNumberIsNegative(&dfp.a)) { \
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dfp.crbf = match ? 0xA : 0x8; \
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} else { \
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dfp.crbf = match ? 0x2 : 0x0; \
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} \
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\
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dfp_set_FPCC_from_CRBF(&dfp); \
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return dfp.crbf; \
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}
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DFP_HELPER_TSTDC(dtstdc, 64)
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DFP_HELPER_TSTDC(dtstdcq, 128)
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#define DFP_HELPER_TSTDG(op, size) \
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uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm) \
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{ \
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struct PPC_DFP dfp; \
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int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero, \
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is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero, \
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match; \
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\
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dfp_prepare_decimal##size(&dfp, a, 0, env); \
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\
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if ((size) == 64) { \
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minexp = -398; \
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maxexp = 369; \
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nzero_digits = 16; \
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nzero_idx = 5; \
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} else if ((size) == 128) { \
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minexp = -6176; \
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maxexp = 6111; \
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nzero_digits = 34; \
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nzero_idx = 11; \
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} \
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\
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is_negative = decNumberIsNegative(&dfp.a); \
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is_zero = decNumberIsZero(&dfp.a); \
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is_extreme_exp = (dfp.a.exponent == maxexp) || \
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(dfp.a.exponent == minexp); \
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is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context); \
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is_normal = decNumberIsNormal(&dfp.a, &dfp.context); \
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leftmost_is_nonzero = (dfp.a.digits == nzero_digits) && \
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(dfp.a.lsu[nzero_idx] != 0); \
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match = 0; \
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\
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match |= (dcm & 0x20) && is_zero && !is_extreme_exp; \
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match |= (dcm & 0x10) && is_zero && is_extreme_exp; \
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match |= (dcm & 0x08) && \
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(is_subnormal || (is_normal && is_extreme_exp)); \
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match |= (dcm & 0x04) && is_normal && !is_extreme_exp && \
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!leftmost_is_nonzero; \
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match |= (dcm & 0x02) && is_normal && !is_extreme_exp && \
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leftmost_is_nonzero; \
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match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a); \
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\
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if (is_negative) { \
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dfp.crbf = match ? 0xA : 0x8; \
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} else { \
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dfp.crbf = match ? 0x2 : 0x0; \
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} \
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\
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dfp_set_FPCC_from_CRBF(&dfp); \
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return dfp.crbf; \
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}
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DFP_HELPER_TSTDG(dtstdg, 64)
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DFP_HELPER_TSTDG(dtstdgq, 128)
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