Non-Confidential | PDF version | ARM DUI0375F | ||

| ||||

Home > ARMv6 SIMD Instruction Intrinsics > __smlad intrinsic |

This intrinsic inserts an `SMLAD`

instruction into the instruction stream generated by the compiler.

It enables
you to perform two signed 16-bit multiplications, adding both results
to a 32-bit accumulate operand. The Q bit is set if the addition
overflows. Overflow cannot occur during the multiplications.

```
unsigned int __smlad(unsigned int
````val1`

, unsigned int `val2`

, unsigned int `val3`

)

Where:

`val1`

- holds the first halfword operands for each multiplication
`val2`

- holds the second halfword operands for each multiplication
`val3`

- holds the accumulate value.

The

`__smlad`

intrinsic returns the product
of each multiplication added to the accumulate value, as a 32-bit
integer.unsigned int dual_multiply_accumulate(unsigned int val1, unsigned int val2, unsigned int val3) { unsigned int res; res = __smlad(val1,val2,val3); /* p1 = val1[15:0] × val2[15:0] p2 = val1[31:16] × val2[31:16] res[31:0] = p1 + p2 + val3[31:0] */ return res; }