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authorTom Musta <tommusta@gmail.com>2014-04-21 15:54:54 -0500
committerAlexander Graf <agraf@suse.de>2014-06-16 13:24:29 +0200
commit79af3572250352c5eeacdd813b57ad5ba748654c (patch)
tree6131a6ba98cbbcfda6b7a7a9569e32642b0e66fd
parent8e706db21ecfba75da3f9f843f1fa36276085742 (diff)
libdecnumber: Introduce decNumberIntegralToInt64
Introduce a new conversion function to the libdecnumber library. This function converts a decNumber to a signed 64-bit integer. In order to support 64-bit integers (which may have up to 19 decimal digits), the existing "powers of 10" array is expanded from 10 to 19 entries. Signed-off-by: Tom Musta <tommusta@gmail.com> [agraf: fix 32bit host compile] Signed-off-by: Alexander Graf <agraf@suse.de>
-rw-r--r--include/libdecnumber/decNumber.h1
-rw-r--r--include/libdecnumber/decNumberLocal.h2
-rw-r--r--libdecnumber/decContext.c6
-rw-r--r--libdecnumber/decNumber.c46
4 files changed, 51 insertions, 4 deletions
diff --git a/include/libdecnumber/decNumber.h b/include/libdecnumber/decNumber.h
index f4bf99417c..9fa4e6a0c9 100644
--- a/include/libdecnumber/decNumber.h
+++ b/include/libdecnumber/decNumber.h
@@ -122,6 +122,7 @@
char * decNumberToEngString(const decNumber *, char *);
uint32_t decNumberToUInt32(const decNumber *, decContext *);
int32_t decNumberToInt32(const decNumber *, decContext *);
+ int64_t decNumberIntegralToInt64(const decNumber *dn, decContext *set);
uint8_t * decNumberGetBCD(const decNumber *, uint8_t *);
decNumber * decNumberSetBCD(decNumber *, const uint8_t *, uint32_t);
diff --git a/include/libdecnumber/decNumberLocal.h b/include/libdecnumber/decNumberLocal.h
index f5f508f294..cd4eb79e80 100644
--- a/include/libdecnumber/decNumberLocal.h
+++ b/include/libdecnumber/decNumberLocal.h
@@ -98,7 +98,7 @@
/* Shared lookup tables */
extern const uByte DECSTICKYTAB[10]; /* re-round digits if sticky */
- extern const uInt DECPOWERS[10]; /* powers of ten table */
+ extern const uLong DECPOWERS[19]; /* powers of ten table */
/* The following are included from decDPD.h */
extern const uShort DPD2BIN[1024]; /* DPD -> 0-999 */
extern const uShort BIN2DPD[1000]; /* 0-999 -> DPD */
diff --git a/libdecnumber/decContext.c b/libdecnumber/decContext.c
index 684710626d..8b6ae21be2 100644
--- a/libdecnumber/decContext.c
+++ b/libdecnumber/decContext.c
@@ -56,8 +56,10 @@ const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */
/* ------------------------------------------------------------------ */
/* Powers of ten (powers[n]==10**n, 0<=n<=9) */
/* ------------------------------------------------------------------ */
-const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000,
- 10000000, 100000000, 1000000000};
+const uLong DECPOWERS[19] = {1, 10, 100, 1000, 10000, 100000, 1000000,
+ 10000000, 100000000, 1000000000, 10000000000ULL, 100000000000ULL,
+ 1000000000000ULL, 10000000000000ULL, 100000000000000ULL, 1000000000000000ULL,
+ 10000000000000000ULL, 100000000000000000ULL, 1000000000000000000ULL, };
/* ------------------------------------------------------------------ */
/* decContextClearStatus -- clear bits in current status */
diff --git a/libdecnumber/decNumber.c b/libdecnumber/decNumber.c
index 6bd7565b34..6164a77509 100644
--- a/libdecnumber/decNumber.c
+++ b/libdecnumber/decNumber.c
@@ -465,6 +465,50 @@ decNumber *decNumberFromUInt64(decNumber *dn, uint64_t uin)
return dn;
} /* decNumberFromUInt64 */
+/* ------------------------------------------------------------------ */
+/* to-int64 -- conversion to int64 */
+/* */
+/* dn is the decNumber to convert. dn is assumed to have been */
+/* rounded to a floating point integer value. */
+/* set is the context for reporting errors */
+/* returns the converted decNumber, or 0 if Invalid is set */
+/* */
+/* Invalid is set if the decNumber is a NaN, Infinite or is out of */
+/* range for a signed 64 bit integer. */
+/* ------------------------------------------------------------------ */
+
+int64_t decNumberIntegralToInt64(const decNumber *dn, decContext *set)
+{
+ if (decNumberIsSpecial(dn) || (dn->exponent < 0) ||
+ (dn->digits + dn->exponent > 19)) {
+ goto Invalid;
+ } else {
+ int64_t d; /* work */
+ const Unit *up; /* .. */
+ uint64_t hi = 0;
+ up = dn->lsu; /* -> lsu */
+
+ for (d = 1; d <= dn->digits; up++, d += DECDPUN) {
+ uint64_t prev = hi;
+ hi += *up * powers[d-1];
+ if ((hi < prev) || (hi > INT64_MAX)) {
+ goto Invalid;
+ }
+ }
+
+ uint64_t prev = hi;
+ hi *= (uint64_t)powers[dn->exponent];
+ if ((hi < prev) || (hi > INT64_MAX)) {
+ goto Invalid;
+ }
+ return (decNumberIsNegative(dn)) ? -((int64_t)hi) : (int64_t)hi;
+ }
+
+Invalid:
+ decContextSetStatus(set, DEC_Invalid_operation);
+ return 0;
+} /* decNumberIntegralToInt64 */
+
/* ------------------------------------------------------------------ */
/* to-scientific-string -- conversion to numeric string */
@@ -4259,7 +4303,7 @@ static decNumber * decDivideOp(decNumber *res,
uByte bits; /* working sign */
Unit *target; /* work */
const Unit *source; /* .. */
- uInt const *pow; /* .. */
+ uLong const *pow; /* .. */
Int shift, cut; /* .. */
#if DECSUBSET
Int dropped; /* work */