PANDN — Logical AND NOT

1. See note in Section 2.5, “Intel® AVX and Intel® SSE Instruction Exception Classification,” in the Intel^® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A, and Section 23.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers,” in the Intel^® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B.

Instruction Operand Encoding ¶

Description ¶

Performs a bitwise logical NOT operation on the first source operand, then performs bitwise AND with second source operand and stores the result in the destination operand. Each bit of the result is set to 1 if the corresponding bit in the first operand is 0 and the corresponding bit in the second operand is 1, otherwise it is set to 0.

In 64-bit mode and not encoded with VEX/EVEX, using a REX prefix in the form of REX.R permits this instruction to access additional registers (XMM8-XMM15).

Legacy SSE instructions: The source operand can be an MMX technology register or a 64-bit memory location. The destination operand can be an MMX technology register.

128-bit Legacy SSE version: The first source operand is an XMM register. The second operand can be an XMM register or an 128-bit memory location. The destination is not distinct from the first source XMM register and the upper bits (MAXVL-1:128) of the corresponding ZMM register destination are unmodified.

EVEX encoded versions: The first source operand is a ZMM/YMM/XMM register. The second source operand can be a ZMM/YMM/XMM register, a 512/256/128-bit memory location or a 512/256/128-bit vector broadcasted from a 32/64-bit memory location. The destination operand is a ZMM/YMM/XMM register conditionally updated with write-mask k1 at 32/64-bit granularity.

VEX.256 encoded versions: The first source operand is a YMM register. The second source operand is a YMM register or a 256-bit memory location. The destination operand is a YMM register. The upper bits (MAXVL-1:256) of the corresponding ZMM register destination are zeroed.

VEX.128 encoded versions: The first source operand is an XMM register. The second source operand is an XMM register or 128-bit memory location. The destination operand is an XMM register. The upper bits (MAXVL-1:128) of the corresponding ZMM register destination are zeroed.

Operation ¶

PANDN (64-bit Operand) ¶

DEST := NOT(DEST) AND SRC

PANDN (128-bit Legacy SSE Version) ¶

DEST := NOT(DEST) AND SRC
DEST[MAXVL-1:128] (Unmodified)

VPANDN (VEX.128 Encoded Version) ¶

DEST := NOT(SRC1) AND SRC2
DEST[MAXVL-1:128] := 0

VPANDN (VEX.256 Encoded Instruction) ¶

DEST[255:0] := ((NOT SRC1[255:0]) AND SRC2[255:0])
DEST[MAXVL-1:256] := 0

VPANDND (EVEX Encoded Versions) ¶

(KL, VL) = (4, 128), (8, 256), (16, 512)
FOR j := 0 TO KL-1
    i := j * 32
    IF k1[j] OR *no writemask*
        THEN
            IF (EVEX.b = 1) AND (SRC2 *is memory*)
                THEN DEST[i+31:i] := ((NOT SRC1[i+31:i]) AND SRC2[31:0])
                ELSE DEST[i+31:i] := ((NOT SRC1[i+31:i]) AND SRC2[i+31:i])
            FI;
        ELSE
            IF *merging-masking* ; merging-masking
                THEN *DEST[i+31:i] remains unchanged*
                ELSE
                        ; zeroing-masking
                    DEST[i+31:i] := 0
            FI
    FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VPANDNQ (EVEX Encoded Versions) ¶

(KL, VL) = (2, 128), (4, 256), (8, 512)
FOR j := 0 TO KL-1
    i := j * 64
    IF k1[j] OR *no writemask*
        THEN
            IF (EVEX.b = 1) AND (SRC2 *is memory*)
                THEN DEST[i+63:i] := ((NOT SRC1[i+63:i]) AND SRC2[63:0])
                ELSE DEST[i+63:i] := ((NOT SRC1[i+63:i]) AND SRC2[i+63:i])
            FI;
        ELSE
            IF *merging-masking* ; merging-masking
                THEN *DEST[i+63:i] remains unchanged*
                ELSE ; zeroing-masking
                    DEST[i+63:i] := 0
            FI
    FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

Intel C/C++ Compiler Intrinsic Equivalents ¶

VPANDND __m512i _mm512_andnot_epi32( __m512i a, __m512i b);

VPANDND __m512i _mm512_mask_andnot_epi32(__m512i s, __mmask16 k, __m512i a, __m512i b);

VPANDND __m512i _mm512_maskz_andnot_epi32( __mmask16 k, __m512i a, __m512i b);

VPANDND __m256i _mm256_mask_andnot_epi32(__m256i s, __mmask8 k, __m256i a, __m256i b);

VPANDND __m256i _mm256_maskz_andnot_epi32( __mmask8 k, __m256i a, __m256i b);

VPANDND __m128i _mm_mask_andnot_epi32(__m128i s, __mmask8 k, __m128i a, __m128i b);

VPANDND __m128i _mm_maskz_andnot_epi32( __mmask8 k, __m128i a, __m128i b);

VPANDNQ __m512i _mm512_andnot_epi64( __m512i a, __m512i b);

VPANDNQ __m512i _mm512_mask_andnot_epi64(__m512i s, __mmask8 k, __m512i a, __m512i b);

VPANDNQ __m512i _mm512_maskz_andnot_epi64( __mmask8 k, __m512i a, __m512i b);

VPANDNQ __m256i _mm256_mask_andnot_epi64(__m256i s, __mmask8 k, __m256i a, __m256i b);

VPANDNQ __m256i _mm256_maskz_andnot_epi64( __mmask8 k, __m256i a, __m256i b);

VPANDNQ __m128i _mm_mask_andnot_epi64(__m128i s, __mmask8 k, __m128i a, __m128i b);

VPANDNQ __m128i _mm_maskz_andnot_epi64( __mmask8 k, __m128i a, __m128i b);

PANDN __m64 _mm_andnot_si64 (__m64 m1, __m64 m2)

(V)PANDN __m128i _mm_andnot_si128 ( __m128i a, __m128i b)

VPANDN __m256i _mm256_andnot_si256 ( __m256i a, __m256i b)

Flags Affected ¶

None.

Numeric Exceptions ¶

None.

Other Exceptions ¶

Non-EVEX-encoded instruction, see Table 2-21, “Type 4 Class Exception Conditions.”

EVEX-encoded instruction, see Table 2-49, “Type E4 Class Exception Conditions.”