Precision-preserving number decode and conversion (#211)
This is part of dCBOR support. It decodes a number (int or float) into the best C representation. It's good for more than just dCBOR.
* Remove more stuff related to QCBOREncode_AddBytesLenOnly
* Commit beginnings so dev can be merged in
* Precision-preserving number decode
* Fix ifdefs for precise number decoding
* blank lines
* blank lines
* 65-bit negs without float HW
---------
Co-authored-by: Laurence Lundblade <lgl@securitytheory.com>
diff --git a/src/qcbor_decode.c b/src/qcbor_decode.c
index bb8d4d4..64818df 100644
--- a/src/qcbor_decode.c
+++ b/src/qcbor_decode.c
@@ -7042,3 +7042,92 @@
}
#endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
+
+
+#if !defined(USEFULBUF_DISABLE_ALL_FLOAT) && !defined(QCBOR_DISABLE_PREFERRED_FLOAT)
+/*
+ * Public function, see header qcbor/qcbor_spiffy_decode.h file
+ */
+void
+QCBORDecode_GetNumberConvertPrecisely(QCBORDecodeContext *pMe,
+ QCBORItem *pNumber)
+{
+ QCBORItem Item;
+ struct IEEE754_ToInt ToInt;
+ double d;
+ QCBORError uError;
+
+ if(pMe->uLastError != QCBOR_SUCCESS) {
+ return;
+ }
+
+ uError = QCBORDecode_GetNext(pMe, &Item);
+ if(uError != QCBOR_SUCCESS) {
+ pMe->uLastError = (uint8_t)uError;
+ return;
+ }
+
+ switch(Item.uDataType) {
+ case QCBOR_TYPE_INT64:
+ case QCBOR_TYPE_UINT64:
+ *pNumber = Item;
+ break;
+
+ case QCBOR_TYPE_DOUBLE:
+ ToInt = IEEE754_DoubleToInt(Item.val.dfnum);
+ if(ToInt.type == IEEE754_ToInt_IS_INT) {
+ pNumber->uDataType = QCBOR_TYPE_INT64;
+ pNumber->val.int64 = ToInt.integer.is_signed;
+ } else if(ToInt.type == IEEE754_ToInt_IS_UINT) {
+ if(ToInt.integer.un_signed <= INT64_MAX) {
+ /* Do the same as base QCBOR integer decoding */
+ pNumber->uDataType = QCBOR_TYPE_INT64;
+ pNumber->val.int64 = (int64_t)ToInt.integer.un_signed;
+ } else {
+ pNumber->uDataType = QCBOR_TYPE_UINT64;
+ pNumber->val.uint64 = ToInt.integer.un_signed;
+ }
+ } else {
+ *pNumber = Item;
+ }
+ break;
+
+ case QCBOR_TYPE_FLOAT:
+ ToInt = IEEE754_SingleToInt(Item.val.fnum);
+ if(ToInt.type == IEEE754_ToInt_IS_INT) {
+ pNumber->uDataType = QCBOR_TYPE_INT64;
+ pNumber->val.int64 = ToInt.integer.is_signed;
+ } else if(ToInt.type == IEEE754_ToInt_IS_UINT) {
+ if(ToInt.integer.un_signed <= INT64_MAX) {
+ /* Do the same as base QCBOR integer decoding */
+ pNumber->uDataType = QCBOR_TYPE_INT64;
+ pNumber->val.int64 = (int64_t)ToInt.integer.un_signed;
+ } else {
+ pNumber->uDataType = QCBOR_TYPE_UINT64;
+ pNumber->val.uint64 = ToInt.integer.un_signed;
+ }
+ } else {
+ *pNumber = Item;
+ }
+ break;
+
+
+ case QCBOR_TYPE_65BIT_NEG_INT:
+ d = IEEE754_UintToDouble(Item.val.uint64, 1);
+ if(d == IEEE754_UINT_TO_DOUBLE_OOB) {
+ *pNumber = Item;
+ } else {
+ pNumber->uDataType = QCBOR_TYPE_DOUBLE;
+ /* -1 is because of CBOR offset of negative numbers */
+ pNumber->val.dfnum = d - 1;
+ }
+ break;
+
+ default:
+ pMe->uLastError = QCBOR_ERR_UNEXPECTED_TYPE;
+ pNumber->uDataType = QCBOR_TYPE_NONE;
+ break;
+ }
+}
+
+#endif /* ! USEFULBUF_DISABLE_ALL_FLOAT && ! QCBOR_DISABLE_PREFERRED_FLOAT */