SQDMLAL, SQDMLAL2 (by element)

Signed saturating doubling multiply-add long (by element)

This instruction multiplies each vector element in the lower or upper half of the first source SIMD&FP register by the specified vector element of the second source SIMD&FP register, doubles the results, and accumulates the final results with the vector elements of the destination SIMD&FP register. The destination vector elements are twice as long as the elements that are multiplied.

If overflow occurs with any of the results, those results are saturated. If saturation occurs, the cumulative saturation bit FPSR.QC is set.

The SQDMLAL instruction extracts vector elements from the lower half of the first source register. The SQDMLAL2 instruction extracts vector elements from the upper half of the first source register.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

It has encodings from 2 classes: Scalar and Vector

Scalar
(FEAT_AdvSIMD)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); constant integer idxdsize = 64 << UInt(H); integer index; bit Rmhi; case size of when '01' index = UInt(H:L:M); Rmhi = '0'; when '10' index = UInt(H:L); Rmhi = M; otherwise EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rmhi:Rm); constant integer esize = 8 << UInt(size); constant integer datasize = esize; constant integer elements = 1; constant integer part = 0;

Vector
(FEAT_AdvSIMD)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); constant integer idxdsize = 64 << UInt(H); integer index; bit Rmhi; case size of when '01' index = UInt(H:L:M); Rmhi = '0'; when '10' index = UInt(H:L); Rmhi = M; otherwise EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rmhi:Rm); constant integer esize = 8 << UInt(size); constant integer datasize = 64; constant integer part = UInt(Q); constant integer elements = datasize DIV esize;