RealView Compilation Tools Compiler Reference Guide - ARM ...

Compiler-specific Features
Table 4-13 ETSI basic operations supported in RVCT (continued)
Intrinsics
extract_l L_macNs L_shr mult_r shr
L_abs L_msu L_shr_r negate shr_r
L_add L_msuNs L_sub norm_s sub
The header file dspfns.h also exposes certain status flags as global variables for use in
your C or C++ programs. The status flags exposed by dspfns.h are listed in Table 4-14.
Table 4-14 ETSI status flags exposed in RVCT
Status flag
Overflow
Carry
Description
Overflow status flag.
Generally, saturating functions have a sticky effect on overflow.
Carry status flag.
Example
#include
#include
#include
// include ETSI basic operations
int32_t C_L_add(int32_t a, int32_t b)
{
int32_t c = a + b;
if (((a ^ b) & INT_MIN) == 0)
{
if ((c ^ a) & INT_MIN)
{
c = (a < 0) INT_MIN : INT_MAX;
}
}
}
return c;
__asm int32_t asm_L_add(int32_t a, int32_t b)
{
qadd r0, r0, r1
bx lr
}
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