BFCLAMP

Multi-vector BFloat16 clamp to minimum/maximum number

This instruction clamps each BFloat16 element in the two or four destination vectors to between the BFloat16 minimum value in the corresponding element of the first source vector and the BFloat16 maximum value in the corresponding element of the second source vector and destructively places the clamped results in the corresponding elements of the two or four destination vectors.

Regardless of the value of FPCR.AH, the behavior is as follows for each minimum number and maximum number operation:

• Negative zero compares less than positive zero.
• If one value is numeric and the other is a quiet NaN, the result is the numeric value.
• When FPCR.DN is 0, if either value is a signaling NaN or if both values are NaNs, the result is a quiet NaN.
• When FPCR.DN is 1, if either value is a signaling NaN or if both values are NaNs, the result is Default NaN.

This instruction follows SME2 non-widening BFloat16 numerical behaviors corresponding to instructions that place their results in two or four SVE Z vectors.

This instruction is unpredicated.

ID_AA64ZFR0_EL1.B16B16 indicates whether this instruction is implemented.

It has encodings from 2 classes: Two registers and Four registers

Two registers
(FEAT_SME2 && FEAT_SVE_B16B16)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) || !IsFeatureImplemented(FEAT_SVE_B16B16) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd::'0'); let nreg : integer{} = 2;

Four registers
(FEAT_SME2 && FEAT_SVE_B16B16)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) || !IsFeatureImplemented(FEAT_SVE_B16B16) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd::'00'); let nreg : integer{} = 4;