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Compiler-specific Features
4.7.77 __smuadx intrinsic
This intrinsic inserts an SMUADX instruction into the instruction stream generated by the
compiler. It enables you to exchange the halfwords of the second operand, perform two
16-bit signed integer multiplications, and add the products together. Exchanging the
halfwords of the second operand produces top × bottom and bottom × top
multiplication. The Q flag is set if the addition overflows. The multiplications cannot
overflow.
unsigned int__smuadx(unsigned int val1, unsigned int val2)
Where:
val1
val2
holds the first halfword operands for each multiplication
holds the second halfword operands for each multiplication.
The __smuadx intrinsic returns the products of the two 16-bit signed multiplications.
Example:
unsigned int exchange_dual_multiply_prods(unsigned int val1, unsigned int val2)
{
unsigned int res;
}
res = __smuadx(val1,val2); /* val2[31:16][15:0] = val2[15:0][31:16]
p1 = val1[15:0] × val2[15:0]
p2 = val1[31:16] × val2[31:16]
res[31:0] = p1 + p2
*/
return res;
See also
• ARMv6 SIMD intrinsics on page 4-109
• Instruction summary on page 4-2 in the Assembler Guide
• SMUAD{X} and SMUSD{X} on page 4-82 in the Assembler Guide.
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