ARM DSP-Enhanced Intrinsic Functions

To implement the intrinsic functions for the ARM DSP-Enhanced instruction set, use the /QRdsp compiler option when compiling your code.

All ARM DSP and XSCALE Multiply/Accumulate(MAC) instructions will be supported as intrinsic functions.

The following tables show the ARM DSP Instructions for which intrinsic functions are defined.

Intrinsic function	Corresponding ARM DSP instruction	Description
_SmulAddLo_SW_SL _SmulAddHi_SW_SL _SmulAddHiLo_SW_SL _SmulAddLoHi_SW_SL	SMLAxy	A signed-integer multiply and accumulate operation: 16x16-bit multiply followed by a 32-bit add.
_SmulAddWLo_SW_SL _SmulAddWHi_SW_SL	SMLAWy	A 32x16-bit multiply, followed by 32-bit add of upper 32 bits of the 48 bit product.
_SmulAddHi_SW_SQ _SmulAddLo_SW_SQ _SmulAddHiLo_SW_SQ _SmulAddLoHi_SW_SQ	SMLALxy	A 16x16-bit multiply, followed by a 64-bit add of the product, with a 64-bit integer.
_SmulLo_SW_SL _SmulHi_SW_SL _SmulHiLo_SW_SL _SmulLoHi_SW_SL	SMULxy	A signed-integer 16x16-bit multiply operation.
_SmulWLo_SW_SL _SmulWHi_SW_SL	SMULWy	A signed-integer 32x16-bit multiply, returning the upper 32-bits.
_AddSatInt	QADD	Saturating add instruction.
_SubSatInt	QSUB	Saturating subtract instruction.
_DAddSatInt	QDADD	Double an integer and saturate, then add to a second integer and saturate.
_DSubSatInt	QDSUB	Double an integer and saturate, then subtract from a second integer and saturate.
_ReadCoProcessor	MRRC	Transfer values from coprocessor to two ARM registers.
_WriteCoProcessor	MCRR	Transfer two ARM register values to a coprocessor.

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