FRINTX (vector)

Floating-point Round to Integral exact, using current rounding mode (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 rounding mode that is determined by the FPCR, and writes the result to the SIMD&FP destination register.

When a result value is not numerically equal to the corresponding input value, an Inexact exception is raised. 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

Half-precision
(FEAT_FP16)

if !HaveFP16Ext() then UNDEFINED; 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' UNDEFINED; when '110' rounding = FPRoundingMode(FPCR[]); exact = TRUE; when '111' rounding = FPRoundingMode(FPCR[]);

Single-precision and double-precision

integer d = UInt(Rd); integer n = UInt(Rn); if sz:Q == '10' then UNDEFINED; 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' UNDEFINED; when '110' rounding = FPRoundingMode(FPCR[]); exact = TRUE; when '111' rounding = FPRoundingMode(FPCR[]);