| Opcode/Instruction | Op/En | 64/32 -bit Mode | CPUID Feature Flag | Description |
|---|---|---|---|---|
|
VEX.NDS.LZ.F3.0F38.W0 F5 /r PEXT r32a, r32b, r/m32 |
RVM | V/V | BMI2 | Parallel extract of bits from r32b using mask in r/m32, result is writ-ten to r32a. |
|
VEX.NDS.LZ.F3.0F38.W1 F5 /r PEXT r64a, r64b, r/m64 |
RVM | V/N.E. | BMI2 | Parallel extract of bits from r64b using mask in r/m64, result is writ-ten to r64a. |
| Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
| RVM | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | NA |
PEXT uses a mask in the second source operand (the third operand) to transfer either contiguous or non-contig-uous bits in the first source operand (the second operand) to contiguous low order bit positions in the destination (the first operand). For each bit set in the MASK, PEXT extracts the corresponding bits from the first source operand and writes them into contiguous lower bits of destination operand. The remaining upper bits of destination are zeroed.
SRC1
S31 S30 S29 S28 S27
S7
S6
S5
S4
S3
S2
S1
S0
SRC2
0
0
0
0
1
0
1
0
1
0
1
0
0
(mask)
S2
0
0
0
0
0
0
0
0
0
S7
S5
DEST
S28
bit 0
bit 31
This instruction is not supported in real mode and virtual-8086 mode. The operand size is always 32 bits if not in 64-bit mode. In 64-bit mode operand size 64 requires VEX.W1. VEX.W1 is ignored in non-64-bit modes. An attempt to execute this instruction with VEX.L not equal to 0 will cause #UD.
TEMP ← SRC1;
MASK ← SRC2;
DEST ← 0 ;
m← 0, k← 0;
DO WHILE m< OperandSize
IF MASK[ m] = 1 THEN
DEST[ k] ← TEMP[ m];
k ← k+ 1;
FI
m ← m+ 1;
OD
None.
PEXT: unsigned __int32 _pext_u32(unsigned __int32 src, unsigned __int32 mask); PEXT: unsigned __int64 _pext_u64(unsigned __int64 src, unsigned __int32 mask);
None
See Section 2.5.1, “Exception Conditions for VEX-Encoded GPR Instructions”, Table 2-29; additionally
| #UD | If VEX.W = 1. |