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target-ppc: Introduce DFP Add

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Add emulation of the PowerPC Decimal Floating Point Add instructions dadd[q][.]

Various GCC unused annotations are removed since it is now safe to remove them.

Signed-off-by: Tom Musta <tommusta@gmail.com>
[agraf: move brace in function definition]
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Tom Musta 2014-04-21 15:55:01 -05:00 • committed by Alexander Graf
parent 27722744e9
commit a9d7ba03b0
3 changed files with 134 additions and 5 deletions
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129
target-ppc/dfp_helper.c
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@ -79,7 +79,6 @@ static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
decContextSetRounding(context, rnd);
}
__attribute__ ((unused))
static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
uint64_t *b, CPUPPCState *env)
{
@ -104,7 +103,6 @@ static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
}
}
__attribute__ ((unused))
static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
uint64_t *b, CPUPPCState *env)
{
@ -152,7 +150,6 @@ static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
#define FP_VE (1ull << FPSCR_VE)
#define FP_FI (1ull << FPSCR_FI)
__attribute__ ((unused))
static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
uint64_t enabled)
{
@ -161,3 +158,129 @@ static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
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_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_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_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);
}
#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)