ARM Compiler 4.1 and later provide support for the ETSI basic
operations through the header file dspfns.h.
The dspfns.h header file contains definitions
of the ETSI basic operations as a combination of C code and intrinsics.
See dspfns.h for a complete list of the
ETSI basic operations supported in ARM Compiler 4.1 and later.
ARM Compiler 4.1 and later support the original ETSI family of basic operations as described in the ETSI G.729 recommendation Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction (CS-ACELP), including:
16-bit and 32-bit saturated arithmetic operations, such as
addandsub. For example,add(v1, v2)adds two 16-bit numbersv1andv2together, with overflow control and saturation, returning a 16-bit result.16-bit and 32-bit multiplication operations, such as
multandL_mult. For example,mult(v1, v2)multiplies two 16-bit numbersv1andv2together, returning a scaled 16-bit result.16-bit arithmetic shift operations, such as
shlandshr. For example, the saturating left shift operationshl(v1, v2)arithmetically shifts the 16-bit inputv1leftv2positions. A negative shift count shiftsv1rightv2positions.16-bit data conversion operations, such as
extract_l,extract_h, andround. For example,round(L_v1)rounds the lower 16 bits of the 32-bit inputL_v1into the most significant 16 bits with saturation.Note
Beware that both the
dspfns.hheader file and the ISO C99 header filemath.hboth define (different versions of) the functionround(). Take care to avoid this potential conflict.
See also- Concepts
- Reference
Compiler Reference:
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