Arm® A64 Instruction Set Architecture: Future Architecture Technologies in the A architecture profile

UCVTF (scalar, fixed-point)

Unsigned fixed-point Convert to Floating-point (scalar). 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.

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 Security state and Exception level in which the instruction is executed, an attempt to execute the instruction might be trapped.

integer d = UInt(Rd);
integer n = UInt(Rn);

integer intsize = if sf == '1' then 64 else 32;
integer fltsize;
FPRounding rounding;

case ftype of
    when '00' fltsize = 32;
    when '01' fltsize = 64;
    when '10' UNDEFINED;
    when '11'
        if HaveFP16Ext() then
            fltsize = 16;
        else
            UNDEFINED;

if sf == '0' && scale<5> == '0' then UNDEFINED;
integer fracbits = 64 - UInt(scale);

rounding = FPRoundingMode(FPCR);

Assembler Symbols

CheckFPAdvSIMDEnabled64();

bits(fltsize) fltval;
bits(intsize) intval;

intval = X[n];
fltval = FixedToFP(intval, fracbits, TRUE, FPCR, rounding);
V[d] = fltval;