FRINTM

Multi-vector floating-point round to integral value, toward minus Infinity

This instruction rounds down each element of the two or four source vectors to an integral floating-point value, and places the results in the corresponding elements of the two or four destination vectors.

This instruction follows SME2 floating-point numerical behaviors corresponding to instructions that place their results in one or more SVE Z vectors.

This instruction is unpredicated.

Encoding: Two registers

Variants: FEAT_SME2 (ARMv9.3)

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
1	1	0	0	0	0	0	1	1	0	1	0	1	0	1	0	1	1	1	0	0	0					0					0
								size					opc									Zn					Zd

FRINTM { <Zd1>.S-<Zd2>.S }, { <Zn1>.S-<Zn2>.S }

Decoding algorithm

if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF);
constant integer n = UInt(Zn:'0');
constant integer d = UInt(Zd:'0');
constant integer nreg = 2;
constant boolean exact = FALSE;
constant FPRounding rounding = FPRounding_NEGINF;

Encoding: Four registers

Variants: FEAT_SME2 (ARMv9.3)

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
1	1	0	0	0	0	0	1	1	0	1	1	1	0	1	0	1	1	1	0	0	0				0	0				0	0
								size					opc									Zn					Zd

FRINTM { <Zd1>.S-<Zd4>.S }, { <Zn1>.S-<Zn4>.S }

Decoding algorithm

if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF);
constant integer n = UInt(Zn:'00');
constant integer d = UInt(Zd:'00');
constant integer nreg = 4;
constant boolean exact = FALSE;
constant FPRounding rounding = FPRounding_NEGINF;

Operation

CheckStreamingSVEEnabled();
constant integer VL = CurrentVL;
constant integer elements = VL DIV 32;
array [0..3] of bits(VL) results;

for r = 0 to nreg-1
    constant bits(VL) operand = Z[n+r, VL];
    for e = 0 to elements-1
        constant bits(32) element = Elem[operand, e, 32];
        Elem[results[r], e, 32] = FPRoundInt(element, FPCR, rounding, exact);

for r = 0 to nreg-1
    Z[d+r, VL] = results[r];

Explanations

<Zd1>: For the "Two registers" variant: is the name of the first scalable vector register of the destination multi-vector group, encoded as "Zd" times 2.
<Zd1>: For the "Four registers" variant: is the name of the first scalable vector register of the destination multi-vector group, encoded as "Zd" times 4.
<Zd2>: Is the name of the second scalable vector register of the destination multi-vector group, encoded as "Zd" times 2 plus 1.
<Zn1>: For the "Two registers" variant: is the name of the first scalable vector register of the source multi-vector group, encoded as "Zn" times 2.
<Zn1>: For the "Four registers" variant: is the name of the first scalable vector register of the source multi-vector group, encoded as "Zn" times 4.
<Zn2>: Is the name of the second scalable vector register of the source multi-vector group, encoded as "Zn" times 2 plus 1.
<Zd4>: Is the name of the fourth scalable vector register of the destination multi-vector group, encoded as "Zd" times 4 plus 3.
<Zn4>: Is the name of the fourth scalable vector register of the source multi-vector group, encoded as "Zn" times 4 plus 3.