UCVTF (scalar, fixed-point) -- A64

This instruction converts the unsigned value in the 32-bit or 64-bit general-purpose source register to a floating-point value using the rounding mode that is specified by the FPCR, and writes the result to the SIMD&FP destination register.

This instruction can generate a floating-point exception. 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 exceptions and 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.

Decode for all variants of this encoding

if ftype == '10' || (ftype == '11' && !IsFeatureImplemented(FEAT_FP16)) then EndOfDecode(Decode_UNDEF); if sf == '0' && scale<5> == '0' then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer intsize = 32 << UInt(sf); constant integer decode_fltsize = 8 << UInt(ftype EOR '10'); constant integer fracbits = 64 - UInt(scale); constant boolean unsigned = TRUE;

Assembler Symbols

<Hd>	Is the 16-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Wn>	Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field.

<fbits>	For the "32-bit to double-precision", "32-bit to half-precision", and "32-bit to single-precision" variants: is the number of bits after the binary point in the fixed-point source, in the range 1 to 32, encoded as 64 minus "scale".
	For the "64-bit to double-precision", "64-bit to half-precision", and "64-bit to single-precision" variants: is the number of bits after the binary point in the fixed-point source, in the range 1 to 64, encoded as 64 minus "scale".

<Xn>	Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field.

<Sd>	Is the 32-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Dd>	Is the 64-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

Operation

CheckFPEnabled64(); constant boolean merge = IsMerging(FPCR); constant integer fltsize = if merge then 128 else decode_fltsize; bits(fltsize) fltval = if merge then V[d, fltsize] else Zeros(fltsize); constant bits(intsize) intval = X[n, intsize]; constant FPRounding rounding = FPRoundingMode(FPCR); Elem[fltval, 0, decode_fltsize] = FixedToFP(intval, fracbits, unsigned, FPCR, rounding, decode_fltsize); V[d, fltsize] = fltval;

Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18