UMIN (immediate)

Unsigned minimum with immediate (unpredicated)

Determine the unsigned minimum of an immediate and each element of the source vector, and destructively place the results in the corresponding elements of the source vector. The immediate is an unsigned 8-bit value in the range 0 to 255, inclusive. This instruction is unpredicated.

Encoding: SVE

Variants: FEAT_SVE || FEAT_SME (FEAT_SVE || FEAT_SME)

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
0	0	1	0	0	1	0	1			1	0	1	0	1	1	1	1	0
								size							U			o2	imm8								Zdn

UMIN <Zdn>.<T>, <Zdn>.<T>, #<imm>

Decoding algorithm

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
    EndOfDecode(Decode_UNDEF);
constant integer esize = 8 << UInt(size);
constant integer dn = UInt(Zdn);
constant boolean unsigned = TRUE;
constant integer imm = Int(imm8, unsigned);

Operation

CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer elements = VL DIV esize;
constant bits(VL) operand1 = Z[dn, VL];
bits(VL) result;

for e = 0 to elements-1
    constant integer element1 = Int(Elem[operand1, e, esize], unsigned);
    Elem[result, e, esize] = Min(element1, imm);

Z[dn, VL] = result;

Explanations

<Zdn>: Is the name of the source and destination scalable vector register, encoded in the "Zdn" field.
<T>: <imm>: Is the unsigned immediate operand, in the range 0 to 255, encoded in the "imm8" field.

Operational Notes

If PSTATE.DIT is 1:

• The execution time of this instruction is independent of:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.
• The response of this instruction to asynchronous exceptions does not vary based on:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:

• The MOVPRFX must be unpredicated.
• The MOVPRFX must specify the same destination register as this instruction.
• The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.