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Floating-point Round to Integral, to nearest with ties to even (vector). This instruction rounds a vector of floating-point values in the SIMD&FP source register to integral floating-point values of the same size using the Round to Nearest rounding mode, and writes the result to the SIMD&FP destination register.
A zero input gives a zero result with the same sign, an infinite input gives an infinite result with the same sign, and a NaN is propagated as for normal arithmetic.
A floating-point exception can be generated by this instruction. Depending on the settings in FPCR, the exception results in either a flag being set in FPSR, or a synchronous exception being generated. For more information, see Floating-point exception traps.
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: Half-precision and Single-precision and double-precision
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 | Q | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | Rn | Rd | ||||||||
U | o2 | o1 |
if !HaveFP16Ext() then UNDEFINED;
integer d =() then UnallocatedEncoding();
integer d = UInt(Rd);
integer n = UInt(Rn);
integer esize = 16;
integer datasize = if Q == '1' then 128 else 64;
integer elements = datasize DIV esize;
boolean exact = FALSE;
FPRounding rounding;
case U:o1:o2 of
when '0xx' rounding = FPDecodeRounding(o1:o2);
when '100' rounding = FPRounding_TIEAWAY;
when '101' UnallocatedEncoding;
when '101' UNDEFINED;
();
when '110' rounding = FPRoundingMode(FPCR); exact = TRUE;
when '111' rounding = FPRoundingMode(FPCR);
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0 | Q | 0 | 0 | 1 | 1 | 1 | 0 | 0 | sz | 1 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | Rn | Rd | ||||||||
U | o2 | o1 |
integer d = UInt(Rd);
integer n = UInt(Rn);
if sz:Q == '10' then UNDEFINED;
integer esize = 32 <<if sz:Q == '10' then ReservedValue();
integer esize = 32 << UInt(sz);
integer datasize = if Q == '1' then 128 else 64;
integer elements = datasize DIV esize;
boolean exact = FALSE;
FPRounding rounding;
case U:o1:o2 of
when '0xx' rounding = FPDecodeRounding(o1:o2);
when '100' rounding = FPRounding_TIEAWAY;
when '101' UnallocatedEncoding;
when '101' UNDEFINED;
();
when '110' rounding = FPRoundingMode(FPCR); exact = TRUE;
when '111' rounding = FPRoundingMode(FPCR);
<Vd> | Is the name of the SIMD&FP destination register, encoded in the "Rd" field. |
<Vn> | Is the name of the SIMD&FP source register, encoded in the "Rn" field. |
CheckFPAdvSIMDEnabled64(); bits(datasize) operand = V[n]; bits(datasize) result; bits(esize) element; for e = 0 to elements-1 element = Elem[operand, e, esize]; Elem[result, e, esize] = FPRoundInt(element, FPCR, rounding, exact); V[d] = result;
Internal version only: isa v30.25v29.05, AdvSIMD v27.01v26.0, pseudocode v85-xml-00bet8_rc3v35.3
; Build timestamp: 2018-09-13T132018-06-16T09:0445
Copyright © 2010-2018 ARM Limited or its affiliates. All rights reserved. This document is Non-Confidential.
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