now can pack/unpack 64-bit ints

Author: edwardhartnett

src/g2_gbytesc.F90

@@ -126,7 +126,9 @@ subroutine g2_gbytesc8(in, iout, iskip, nbits, nskip, n)
   integer, parameter :: ones(8) = (/ 1, 3, 7, 15, 31, 63, 127, 255 /)
 
   integer :: nbit, i, index, ibit, itmp
+  integer (kind = 8) :: itmp8, itmp8_2, itmp8_3
   integer, external :: mova2i
+  integer (kind = 8), external :: mova2i8
 
   !     nbit is the start position of the field in bits
   nbit = iskip
@@ -138,25 +140,30 @@ subroutine g2_gbytesc8(in, iout, iskip, nbits, nskip, n)
 
      !        first byte
      tbit = min(bitcnt, 8 - ibit)
+     itmp8 = iand(mova2i8(in(index)), int(ones(8 - ibit), kind = 8))
      itmp = iand(mova2i(in(index)), ones(8 - ibit))
      if (tbit .ne. 8 - ibit) itmp = ishft(itmp, tbit - 8 + ibit)
+     if (tbit .ne. 8 - ibit) itmp8 = ishft(itmp8, tbit - 8 + ibit)
      index = index + 1
      bitcnt = bitcnt - tbit
 
      !        now transfer whole bytes
      do while (bitcnt .ge. 8)
         itmp = ior(ishft(itmp,8), mova2i(in(index)))
+        itmp8 = ior(ishft(itmp8,8), mova2i8(in(index)))
         bitcnt = bitcnt - 8
         index = index + 1
      enddo
 
      !        get data from last byte
      if (bitcnt .gt. 0) then
-        itmp = ior(ishft(itmp, bitcnt), iand(ishft(mova2i(in(index)), &
-             - (8 - bitcnt)), ones(bitcnt)))
+        itmp = ior(ishft(itmp, bitcnt), iand(ishft(mova2i(in(index)), - (8 - bitcnt)), ones(bitcnt)))
+        itmp8_2 = ishft(mova2i8(in(index)), int(-(8 - bitcnt), kind(8)))
+        itmp8_3 = int(ones(bitcnt), kind(8))
+        itmp8 = ior(ishft(itmp8, bitcnt), iand(itmp8_2, itmp8_3))
      endif
 
-     iout(i) = itmp
+     iout(i) = itmp8
   enddo
 
 end subroutine g2_gbytesc8

src/mova2i.c

@@ -1,23 +1,41 @@
 /**
  * @file
- * @brief mova2i Moves a bit string from a char*1 to int
+ * @brief Move bits from a char*1 to an int.
  * @author Stephen Gilbert @date 2002-08-15
  */
 
 /**
- * This Function copies a bit string from a Character*1 variable
- * to an integer variable. It is intended to replace the Fortran Intrinsic
- * Function ICHAR, which only supports 0 <= ICHAR(a) <= 127 on the
- * IBM SP. If "a" is greater than 127 in the collating sequence,
- * ICHAR(a) does not return the expected bit value.
- * This function can be used for all values 0 <= ICHAR(a) <= 255.
+ * Derefrence char pointer and cast result as 32-bit int.
+ *
+ * This function is intended to replace the Fortran Intrinsic Function
+ * ICHAR, which only supports 0 <= ICHAR(a) <= 127 on the IBM SP. If
+ * "a" is greater than 127 in the collating sequence, ICHAR(a) does
+ * not return the expected bit value.  This function can be used for
+ * all values 0 <= ICHAR(a) <= 255.
  * 
- * @param[in] a - Character*1 variable that holds the bitstring to extract
- * @return - > mova2i - Integer value of the bitstring in character a
+ * @param a Pointer to char.
+ *
+ * @return 32-bit integer containing the value of the bits.
  * 
  * @author Stephen Gilbert @date 2002-08-15
  * */
 int mova2i_(unsigned char *a)
 {
     return (int)(*a);
 }
+
+/**
+ * Derefrence char pointer and cast result as 64-bit int.
+ *
+ * See mova2i_() for details.
+ * 
+ * @param a Pointer to char.
+ *
+ * @return 64-bit integer containing value of the bits.
+ * 
+ * @author Ed Hartnett @date Feb 7, 2024
+ * */
+int mova2i8_(unsigned char *a)
+{
+    return (long long int)(*a);
+}