vcvta

Vector Convert to Integer (Nearest)

VCVTA<c>.<dt>.F32 <Qd>, <Qm>

Converts float to integer, rounding to nearest.

Details

Converts each floating-point element in the source Q register to a signed or unsigned integer, rounding towards positive infinity (towards +∞), and writes the results to the destination Q register. This is a vector operation where each lane is independently converted. No NEON flags are modified; results follow IEEE 754 rounding semantics. This instruction requires NEON support and executes in AArch32 state (T32/A32).

Pseudocode Operation

for i ← 0 to (128 / element_width) - 1 do; element ← Qm[i]; integer_result ← ConvertToInteger(element, RoundTowardsPlusInfinity, unsigned); Qd[i] ← integer_result; end

Example

VCVTA.dt.F32 q0, q2

Encoding

Binary Layout
111111101
D
111
1
00
Vd
10
10
op
1
M
0
Vm
 
Format NEON 2-Reg
Opcode 0xFEBC0A40
Extension NEON (SIMD)

Operands

  • Qd
    Destination 128-bit SIMD register
  • Qm
    Second source 128-bit SIMD register

Reference (Arm AArch32 ISA)

Instruction Forms

Encoding Instruction ISA Bit pattern
0xF3B30000 VCVTA{<q>}.<dt>.<dt2> <Dd>, <Dm> A32 111100111 | D | 11 | size | 11 | Vd | 0 | 0 | 00 | op | 0 | M | 0 | Vm
0xF3B30040 VCVTA{<q>}.<dt>.<dt2> <Qd>, <Qm> A32 111100111 | D | 11 | size | 11 | Vd | 0 | 0 | 00 | op | 1 | M | 0 | Vm
0xFFB30000 VCVTA{<q>}.<dt>.<dt2> <Dd>, <Dm> T32 111111111 | D | 11 | size | 11 | Vd | 0 | 0 | 00 | op | 0 | M | 0 | Vm
0xFFB30040 VCVTA{<q>}.<dt>.<dt2> <Qd>, <Qm> T32 111111111 | D | 11 | size | 11 | Vd | 0 | 0 | 00 | op | 1 | M | 0 | Vm
0xFEBC0940 VCVTA{<q>}.<dt>.F16 <Sd>, <Sm> A32 111111101 | D | 111 | 1 | 00 | Vd | 10 | 01 | op | 1 | M | 0 | Vm
0xFEBC0A40 VCVTA{<q>}.<dt>.F32 <Sd>, <Sm> A32 111111101 | D | 111 | 1 | 00 | Vd | 10 | 10 | op | 1 | M | 0 | Vm
0xFEBC0B40 VCVTA{<q>}.<dt>.F64 <Sd>, <Dm> A32 111111101 | D | 111 | 1 | 00 | Vd | 10 | 11 | op | 1 | M | 0 | Vm

Description

Convert floating-point to integer with Round to Nearest with Ties to Away converts a value in a register from floating-point to a 32-bit integer using the Round to Nearest with Ties to Away rounding mode, and places the result in a second 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.

Operation

EncodingSpecificOperations(); CheckVFPEnabled(TRUE);
case esize of
    when 16
        S[d] = FPToFixed(S[m]<15:0>, 0, unsigned, FPSCR[], rounding, 32);
    when 32
        S[d] = FPToFixed(S[m], 0, unsigned, FPSCR[], rounding, 32);
    when 64
        S[d] = FPToFixed(D[m], 0, unsigned, FPSCR[], rounding, 32);