National Instruments 320685D-01 ユーザーズマニュアル
Chapter 1
LabWindows/CVI Compiler
LabWindows/CVI Programmer Reference Manual
1-6
©
National Instruments Corporation
C Data Types and 32-Bit Compiler Issues
This section introduces the LabWindows/CVI compiler data types and discusses converting
16-bit source code to 32-bit source code.
16-bit source code to 32-bit source code.
Data Types
Table 1-2 shows the LabWindows/CVI allowable data types.
The size of an enumeration type depends on the value of its enumeration constant.
In LabWindows/CVI, characters are
In LabWindows/CVI, characters are
signed
, unless you explicitly declare them
unsigned
.
The types
float
and
double
conform to 4-byte and 8-byte IEEE standard formats.
Converting 16-Bit Source Code to 32-Bit Source Code
If you convert a LabWindows for DOS application to a LabWindows/CVI application, use
this section as a guide after you complete the steps in Chapter 12, Converting LabWindows
for DOS Applications, of the Getting Started with LabWindows/CVI manual.
this section as a guide after you complete the steps in Chapter 12, Converting LabWindows
for DOS Applications, of the Getting Started with LabWindows/CVI manual.
In general, if you make few assumptions about the sizes of data types, little difference exists
between a 16-bit compiler and a 32-bit compiler except for the larger capacity of integers and
the larger address space for arrays and pointers.
between a 16-bit compiler and a 32-bit compiler except for the larger capacity of integers and
the larger address space for arrays and pointers.
Table 1-2. LabWindows/CVI Allowable Data Types
Type
Size
Minimum
Maximum
char
8
–128
127
unsigned char
8
0
255
short
16
–32,768
32,767
unsigned short
16
0
65,535
int
;
long int
32
–2
31
2
31
–1
unsigned int
32
0
2
32
–1
unsigned long
32
0
2
32
–1
float
32
–3.40282E+38
3.40282E+38
double
;
long double
64
–1.79769E+308
1.79769E+308
pointers (
void *
)
32
N/A
N/A
enum
8, 16, or 32
–2
31
2
31
–1
00ProRef.book : 06chap01.fm Page 6 Monday, March 9, 1998 3:23 PM