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Source code

KORTESTW, KORTESTB, KORTESTQ, KORTESTD

OR Masks and Set Flags

stableVMJITAOTinstruction

Encodings

OpcodeInstructionOp/En64-bitCompat/LegacyDescription
VEX.L0.0F.W0 98 /rKORTESTW k1, k2RRValidValidBitwise OR 16 bits masks k1 and k2 and update ZF and CF accordingly. OR AVX10.1
VEX.L0.66.0F.W0 98 /rKORTESTB k1, k2RRValidValidBitwise OR 8 bits masks k1 and k2 and update ZF and CF accordingly. OR AVX10.1
VEX.L0.0F.W1 98 /rKORTESTQ k1, k2RRValidValidBitwise OR 64 bits masks k1 and k2 and update ZF and CF accordingly. OR AVX10.1
VEX.L0.66.0F.W1 98 /rKORTESTD k1, k2RRValidValidBitwise OR 32 bits masks k1 and k2 and update ZF and CF accordingly. OR AVX10.1

Operand encoding

Each mode is a value of the Op/En column above. It says which field of the encoded instruction carries each operand, in the order they are written, and whether the instruction reads it, writes it or both.

RR

  1. modrm.reg escrituraModRM byte, reg field (bits 5-3)
  2. modrm.rm lecturaModRM byte, r/m field (bits 2-0); with the SIB byte and the displacement when the mod field asks for them

Measured cost

Loading measurements from arch-data...

Flags named

Description

Performs a bitwise OR between the vector mask register k2, and the vector mask register k1, and sets CF and ZF based on the operation result.

ZF flag is set if both sources are 0x0. CF is set if, after the OR operation is done, the operation result is all 1's.

Operation

KORTESTW
TMP[15:0] := DEST[15:0] BITWISE OR SRC[15:0]
IF(TMP[15:0]=0)

    THEN ZF := 1
    ELSE ZF := 0
FI;
IF(TMP[15:0]=FFFFh)
    THEN CF := 1
    ELSE CF := 0
FI;

KORTESTB
TMP[7:0] := DEST[7:0] BITWISE OR SRC[7:0]
IF(TMP[7:0]=0)

    THEN ZF := 1
    ELSE ZF := 0
FI;
IF(TMP[7:0]==FFh)
    THEN CF := 1
    ELSE CF := 0

FI;


KORTESTQ
TMP[63:0] := DEST[63:0] BITWISE OR SRC[63:0]
IF(TMP[63:0]=0)

    THEN ZF := 1
    ELSE ZF := 0
FI;
IF(TMP[63:0]==FFFFFFFF_FFFFFFFFh)
    THEN CF := 1
    ELSE CF := 0
FI;

KORTESTD
TMP[31:0] := DEST[31:0] BITWISE OR SRC[31:0]
IF(TMP[31:0]=0)

    THEN ZF := 1
    ELSE ZF := 0
FI;
IF(TMP[31:0]=FFFFFFFFh)
    THEN CF := 1
    ELSE CF := 0
FI;

Intel C/C++ compiler intrinsics

KORTESTW __mmask16 _mm512_kortest[cz](__mmask16 a, __mmask16 b);

Flags affected

The ZF flag is set if the result of OR-ing both sources is all 0s.

The CF flag is set if the result of OR-ing both sources is all 1s.

The OF, SF, AF, and PF flags are set to 0.

Other Exceptions

See Table 2-65, "TYPE K20 Exception Definition (VEX-Encoded OpMask Instructions w/o Memory Arg)."

Sources