You copied the Doc URL to your clipboard.

VCVT (between double-precision and single-precision)

Convert between double-precision and single-precision does one of the following:

  • Converts the value in a double-precision register to single-precision and writes the result to a single-precision register.
  • Converts the value in a single-precision register to double-precision and writes the result to a double-precision register.

Depending on settings in the CPACR, NSACR, HCPTR, and FPEXC registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be undefined, or trapped to Hyp mode. For more information see Enabling Advanced SIMD and floating-point support.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

A1

313029282726252423222120191817161514131211109876543210
!= 111111101D110111Vd101x11M0Vm
condsize

Single-precision to double-precision (size == 10)

VCVT{<c>}{<q>}.F64.F32 <Dd>, <Sm>

Double-precision to single-precision (size == 11)

VCVT{<c>}{<q>}.F32.F64 <Sd>, <Dm>

double_to_single = (size == '11');
d = if double_to_single then UInt(Vd:D) else UInt(D:Vd);
m = if double_to_single then UInt(M:Vm) else UInt(Vm:M);

T1

15141312111098765432101514131211109876543210
111011101D110111Vd101x11M0Vm
size

Single-precision to double-precision (size == 10)

VCVT{<c>}{<q>}.F64.F32 <Dd>, <Sm>

Double-precision to single-precision (size == 11)

VCVT{<c>}{<q>}.F32.F64 <Sd>, <Dm>

double_to_single = (size == '11');
d = if double_to_single then UInt(Vd:D) else UInt(D:Vd);
m = if double_to_single then UInt(M:Vm) else UInt(Vm:M);

Assembler Symbols

<c>

See Standard assembler syntax fields.

<q>

See Standard assembler syntax fields.

<Sd>

Is the 32-bit name of the SIMD&FP destination register, encoded in the "Vd:D" field.

<Dm>

Is the 64-bit name of the SIMD&FP source register, encoded in the "M:Vm" field.

<Dd>

Is the 64-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field.

<Sm>

Is the 32-bit name of the SIMD&FP source register, encoded in the "Vm:M" field.

Operation

if ConditionPassed() then
    EncodingSpecificOperations();  CheckVFPEnabled(TRUE);
    if double_to_single then
        S[d] = FPConvert(D[m], FPSCR);
    else
        D[d] = FPConvert(S[m], FPSCR);