Arm® A64 Instruction Set Architecture: Armv8, for Armv8-A architecture profile

FRINT<r>

Floating-point round to integral value (predicated).

Round to an integral floating-point value with the specified rounding option from each active floating-point element of the source vector, and place the results in the corresponding elements of the destination vector. Inactive elements in the destination vector register remain unmodified.

The <r> symbol specifies one of the following rounding options: N (to nearest, with ties to even), A (to nearest, with ties away from zero), M (toward minus Infinity), P (toward plus Infinity), Z (toward zero), I (current FPCR rounding mode), or X (current FPCR rounding mode, signalling inexact).

It has encodings from 7 classes: Current mode , Current mode signalling inexact , Nearest with ties to away , Nearest with ties to even , Toward zero , Toward minus infinity and Toward plus infinity

Current mode

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRoundingMode(FPCR[]);

Current mode signalling inexact

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = TRUE;
FPRounding rounding = FPRoundingMode(FPCR[]);

Nearest with ties to away

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRounding_TIEAWAY;

Nearest with ties to even

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRounding_TIEEVEN;

Toward zero

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRounding_ZERO;

Toward minus infinity

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRounding_NEGINF;

Toward plus infinity

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer n = UInt(Zn);
integer d = UInt(Zd);
boolean exact = FALSE;
FPRounding rounding = FPRounding_POSINF;

Assembler Symbols

CheckSVEEnabled();
integer elements = VL DIV esize;
bits(PL) mask = P[g];
bits(VL) operand = Z[n];
bits(VL) result = Z[d];

for e = 0 to elements-1
    bits(esize) element = Elem[operand, e, esize];
    if ElemP[mask, e, esize] == '1' then
        Elem[result, e, esize] = FPRoundInt(element, FPCR[], rounding, exact);

Z[d] = result;

Operational information

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

• The MOVPRFX instruction must be unpredicated, or be predicated using the same governing predicate register and source element size as this instruction.
• The MOVPRFX instruction 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.