vneg
Vector Negate (VFP)
VNEG<c>.F32 <Sd>, <Sm>
Negates the value.
Pseudocode Operation
Sd ← FP_Negate(Sm)
FPSCR ← updated with floating-point exception flagsExample
VNEG.F32 s0, s2
Encoding
Binary Layout
cond
31:28
11101
27:23
D
22
11
21:20
0
19
001
18:16
Vd
15:12
10
11:10
10
9:8
0
7
1
6
M
5
0
4
Vm
3:0
Operands
-
Sd
Destination 32-bit floating-point register -
Sm
Second source 32-bit floating-point register
Reference
View in Arm A64 ISA Reference ↗
Arm AArch32 ISA
Instruction Forms
| Encoding | Instruction | ISA | Bit pattern | ||
|---|---|---|---|---|---|
| 0xF3B10380 | VNEG{<c>}{<q>}.<dt> <Dd>, <Dm> | A32 | 111100111 | D | 11 | size | 01 | Vd | 0 | F | 111 | 0 | M | 0 | Vm | ||
| 0xF3B103C0 | VNEG{<c>}{<q>}.<dt> <Qd>, <Qm> | A32 | 111100111 | D | 11 | size | 01 | Vd | 0 | F | 111 | 1 | M | 0 | Vm | ||
| 0x0EB10940 | VNEG{<c>}{<q>}.F16 <Sd>, <Sm> | A32 | cond | 11101 | D | 11 | 0 | 001 | Vd | 10 | 01 | 0 | 1 | M | 0 | Vm | ||
| 0x0EB10A40 | VNEG{<c>}{<q>}.F32 <Sd>, <Sm> | A32 | cond | 11101 | D | 11 | 0 | 001 | Vd | 10 | 10 | 0 | 1 | M | 0 | Vm | ||
| 0x0EB10B40 | VNEG{<c>}{<q>}.F64 <Dd>, <Dm> | A32 | cond | 11101 | D | 11 | 0 | 001 | Vd | 10 | 11 | 0 | 1 | M | 0 | Vm | ||
| 0xFFB10380 | VNEG{<c>}{<q>}.<dt> <Dd>, <Dm> | T32 | 111111111 | D | 11 | size | 01 | Vd | 0 | F | 111 | 0 | M | 0 | Vm | ||
| 0xFFB103C0 | VNEG{<c>}{<q>}.<dt> <Qd>, <Qm> | T32 | 111111111 | D | 11 | size | 01 | Vd | 0 | F | 111 | 1 | M | 0 | Vm | ||
| 0xEEB10940 | VNEG{<c>}{<q>}.F16 <Sd>, <Sm> | T32 | 111011101 | D | 11 | 0 | 001 | Vd | 10 | 01 | 0 | 1 | M | 0 | Vm | ||
| 0xEEB10A40 | VNEG{<c>}{<q>}.F32 <Sd>, <Sm> | T32 | 111011101 | D | 11 | 0 | 001 | Vd | 10 | 10 | 0 | 1 | M | 0 | Vm | ||
| 0xEEB10B40 | VNEG{<c>}{<q>}.F64 <Dd>, <Dm> | T32 | 111011101 | D | 11 | 0 | 001 | Vd | 10 | 11 | 0 | 1 | M | 0 | Vm |
Description
Vector Negate negates each element in a vector, and places the results in a second vector. The floating-point version only inverts the sign bit. 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
if ConditionPassed() then
EncodingSpecificOperations(); CheckAdvSIMDOrVFPEnabled(TRUE, advsimd);
if advsimd then // Advanced SIMD instruction
for r = 0 to regs-1
for e = 0 to elements-1
if floating_point then
Elem[D[d+r],e,esize] = FPNeg(Elem[D[m+r],e,esize]);
else
result = -SInt(Elem[D[m+r],e,esize]);
Elem[D[d+r],e,esize] = result<esize-1:0>;
else // VFP instruction
case esize of
when 16 S[d] = Zeros(16) : FPNeg(S[m]<15:0>);
when 32 S[d] = FPNeg(S[m]);
when 64 D[d] = FPNeg(D[m]);