SW500010 Microchip Technology, SW500010 Datasheet - Page 93

• Manufacturer Part Number: SW500010
• Description: HI-TECH C PRO FOR PIC10/12/16
• Manufacturer: Microchip Technology
• Type: Compilerr
• Series: PIC10/12/16r

Specifications of SW500010

• Supported Families: PIC10, PIC12, PIC16
• Core Architecture: PIC
• Software Edition: Professional
• Kit Contents: Software And Docs
• Mcu Supported Families: PIC10/12/16
• Tool Type: Compiler
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: PIC10, PIC12, PIC14, PIC16, PIC16E
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 019P; 778-1006; 778-1006

C Language Features
The midrange PIC devices have larger stacks and are thus allow a higher degree of function nesting.
These devices do not use the lookup table method when calling functions.
compiler inserts the appropriate instructions to ensure this is true if required. Any functions callable
from C code that are written in assembler must also ensure that bank zero is selected before the
return.
3.7 Operators
HI-TECH C supports all the ANSI operators. The exact results of some of these are implementation
defined. The following sections illustrate code produced by the compiler.
3.7.1 Integral Promotion
When there is more than one operand to an operator, they typically must be of exactly the same type.
The compiler will automatically convert the operands, if necessary, so they have the same type. The
conversion is to a “larger” type so there is no loss of information. Even if the operands have the same
type, in some situations they are converted to a different type before the operation. This conversion
is called integral promotion. HI-TECH C performs these integral promotions where required. If you
are not aware that these changes of type have taken place, the results of some expressions are not
what would normally be expected.
rieties of char, short int or bit-field types to either signed int or unsigned int. If the
result of the conversion can be represented by an signed int, then that is the destination type,
otherwise the conversion is to unsigned int.
if(a - b < 10)
count++;
converted to signed int via integral promotion before the subtraction takes place. The result of
the subtraction with these data types is -50 (which is less than 10) and hence the body of the if()
statement is executed. If the result of the subtraction is to be an unsigned quantity, then apply a
cast. For example:
count++;
would not be executed.
The compiler assumes that bank zero will be selected after returning from any function call. The
Integral promotion is the implicit conversion of enumerated types, signed or unsigned va-
Consider the following example.
unsigned char count, a=0, b=50;
The unsigned char result of a - b is 206 (which is not less than 10), but both a and b are
if((unsigned int)(a - b) < 10)
The comparison is then done using unsigned int, in this case, and the body of the if()
Operators
93