You copied the Doc URL to your clipboard.

FMLALB (indexed)

Half-precision floating-point multiply-add long to single-precision (bottom, indexed).

This half-precision floating-point multiply-add long instruction widens the even-numbered 16-bit half-precision elements in the first source vector and the indexed element from the corresponding 128-bit segment in the second source vector to single-precision format and then destructively multiplies and adds these values without intermediate rounding to the overlapping 32-bit single-precision elements of the addend and destination vector. This instruction is unpredicated.



FMLALB <Zda>.S, <Zn>.H, <Zm>.H[<imm>]

if !HaveSVE2() then UNDEFINED;
integer esize = 32;
integer n = UInt(Zn);
integer m = UInt(Zm);
integer da = UInt(Zda);
integer index = UInt(i3h:i3l);
boolean op1_neg = FALSE;

Assembler Symbols


Is the name of the third source and destination scalable vector register, encoded in the "Zda" field.


Is the name of the first source scalable vector register, encoded in the "Zn" field.


Is the name of the second source scalable vector register Z0-Z7, encoded in the "Zm" field.


Is the immediate index, in the range 0 to 7, encoded in the "i3h:i3l" fields.


integer elements = VL DIV esize;
integer eltspersegment = 128 DIV esize;
bits(VL) operand1 = Z[n];
bits(VL) operand2 = Z[m];
bits(VL) operand3 = Z[da];
bits(VL) result;

for e = 0 to elements-1
    integer segmentbase = e - e MOD eltspersegment;
    integer s = 2 * segmentbase + index;
    bits(esize DIV 2) element1 = Elem[operand1, 2 * e + 0, esize DIV 2];
    bits(esize DIV 2) element2 = Elem[operand2, s, esize DIV 2];
    bits(esize) element3 = Elem[operand3, e, esize];
    if op1_neg then element1 = FPNeg(element1);
    Elem[result, e, esize] = FPMulAddH(element3, element1, element2, FPCR);

Z[da] = result;