image/svg+xml PEXT — Parallel Bits Extract Instruction Operand Encoding Description 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. Figure 4-9. PEXT Example 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. Opcode/ Instruction Op/ En 64/32 -bit Mode CPUID Feature Flag Description VEX.LZ.F3.0F38.W0 F5 /r PEXT r32a, r32b, r/m32 RVMV/VBMI2Parallel extract of bits from r32b using mask in r/m32 , result is writ- ten to r32a . VEX.LZ.F3.0F38.W1 F5 /r PEXT r64a, r64b, r/m64 RVMV/N.E.BMI2Parallel extract of bits from r64b using mask in r/m64 , result is writ- ten to r64a . Op/EnOperand 1Operand 2Operand 3Operand 4 RVMModRM:reg (w)VEX.vvvv (r)ModRM:r/m (r)NA DEST SRC1 SRC2 (mask) S 31 S 30 S 29 S 28 S 27 S 7 S 6 S 5 S 3 S 4 S 2 S 1 S 0 001010101000 S 2 S 5 S 7 000000000 0 S 28 bit 0 bit 31 image/svg+xml Operation TEMP := SRC1; MASK := SRC2; DEST := 0 ; m := 0, k := 0; DOWHILE m < OperandSize IF MASK[ m] = 1 THEN DEST[ k] := TEMP[ m]; k := k+ 1; FI m := m+ 1; OD Flags Affected None. Intel C/C++ Compiler Intrinsic Equivalent PEXT:unsigned __int32 _pext_u32(unsigned __int32 src, unsigned __int32 mask); PEXT:unsigned __int64 _pext_u64(unsigned __int64 src, unsigned __int32 mask); SIMD Floating-Point Exceptions None Other Exceptions See Table2-29, “Type 13 Class Exception Conditions”. This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .