PCMPGTB/PCMPGTW/PCMPGTD—Compare Packed Signed Integers for Greater Than

NOTES:

1. See note in Section 2.4, “AVX and SSE Instruction Exception Specification” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A and Section 22.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A.

Instruction Operand Encoding

Description

Performs an SIMD signed compare for the greater value of the packed byte, word, or doubleword integers in the destination operand (first operand) and the source operand (second operand). If a data element in the destination operand is greater than the corresponding date element in the source operand, the corresponding data element in the destination operand is set to all 1s; otherwise, it is set to all 0s.

The PCMPGTB instruction compares the corresponding signed byte integers in the destination and source oper-ands; the PCMPGTW instruction compares the corresponding signed word integers in the destination and source operands; and the PCMPGTD instruction compares the corresponding signed doubleword integers in the destina-tion and source operands.

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 second source operand can be an XMM register or a 128-bit memory location. The first source operand and destination operand are XMM registers. Bits (VLMAX-1:128) of the corresponding YMM destination register remain unchanged.

VEX.128 encoded version: The second source operand can be an XMM register or a 128-bit memory location. The first source operand and destination operand are XMM registers. Bits (VLMAX-1:128) of the corresponding YMM register are zeroed.

VEX.256 encoded version: 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.

EVEX encoded VPCMPGTD: The first source operand (second 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-bit memory location. The destination operand (first operand) is a mask register updated according to the writemask k2.

EVEX encoded VPCMPGTB/W: The first source operand (second 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. The destination operand (first operand) is a mask register updated according to the writemask k2.

Operation

PCMPGTB (with 64-bit operands)

    IF DEST[7:0] > SRC[7:0]
         THEN DEST[7:0) ← FFH;
         ELSE DEST[7:0] ← 0; FI;
    (* Continue comparison of 2nd through 7th bytes in DEST and SRC *)
    IF DEST[63:56] > SRC[63:56]
         THEN DEST[63:56] ← FFH;
         ELSE DEST[63:56] ← 0; FI;

COMPARE_BYTES_GREATER (SRC1, SRC2)

    IF SRC1[7:0] > SRC2[7:0]
    THEN DEST[7:0] (cid:197)FFH;
    ELSE DEST[7:0] (cid:197)0; FI;
(* Continue comparison of 2nd through 15th bytes in SRC1 and SRC2 *)
    IF SRC1[127:120] > SRC2[127:120]
    THEN DEST[127:120] (cid:197)FFH;
    ELSE DEST[127:120] (cid:197)0; FI;

COMPARE_WORDS_GREATER (SRC1, SRC2)

    IF SRC1[15:0] > SRC2[15:0]
    THEN DEST[15:0] (cid:197)FFFFH;
    ELSE DEST[15:0] (cid:197)0; FI;
(* Continue comparison of 2nd through 7th 16-bit words in SRC1 and SRC2 *)
    IF SRC1[127:112] > SRC2[127:112]
    THEN DEST[127:112] (cid:197)FFFFH;
    ELSE DEST[127:112] (cid:197)0; FI;

COMPARE_DWORDS_GREATER (SRC1, SRC2)

    IF SRC1[31:0] > SRC2[31:0]
    THEN DEST[31:0] (cid:197)FFFFFFFFH;
    ELSE DEST[31:0] (cid:197)0; FI;
(* Continue comparison of 2nd through 3rd 32-bit dwords in SRC1 and SRC2 *)
    IF SRC1[127:96] > SRC2[127:96]
    THEN DEST[127:96] (cid:197)FFFFFFFFH;
    ELSE DEST[127:96] (cid:197)0; FI;

PCMPGTB (with 128-bit operands)

DEST[127:0] (cid:197)COMPARE_BYTES_GREATER(DEST[127:0],SRC[127:0])
DEST[MAX_VL-1:128] (Unmodified)

VPCMPGTB (VEX.128 encoded version)

DEST[127:0] (cid:197)COMPARE_BYTES_GREATER(SRC1,SRC2)
DEST[VLMAX-1:128] (cid:197) 0

VPCMPGTB (VEX.256 encoded version)

DEST[127:0] (cid:197)COMPARE_BYTES_GREATER(SRC1[127:0],SRC2[127:0])
DEST[255:128] (cid:197)COMPARE_BYTES_GREATER(SRC1[255:128],SRC2[255:128])
DEST[VLMAX-1:256] (cid:197) 0

VPCMPGTB (EVEX encoded versions)

(KL, VL) = (16, 128), (32, 256), (64, 512)
FOR j (cid:197) 0 TO KL-1
    i (cid:197) j * 8
    IF k2[j] OR *no writemask*
         THEN
              /* signed comparison */
              CMP (cid:197) SRC1[i+7:i] > SRC2[i+7:i];
              IF CMP = TRUE
                    THEN DEST[j] (cid:197) 1;
                    ELSE DEST[j] (cid:197) 0; FI;
         ELSE
                    DEST[j] (cid:197) 0
                                                    ; zeroing-masking onlyFI;
    FI;
ENDFOR
DEST[MAX_KL-1:KL] (cid:197) 0

PCMPGTW (with 64-bit operands)

    IF DEST[15:0] > SRC[15:0]
         THEN DEST[15:0] ← FFFFH;
         ELSE DEST[15:0] ← 0; FI;
    (* Continue comparison of 2nd and 3rd words in DEST and SRC *)
    IF DEST[63:48] > SRC[63:48]
         THEN DEST[63:48] ← FFFFH;
         ELSE DEST[63:48] ← 0; FI;

PCMPGTW (with 128-bit operands)

DEST[127:0] (cid:197)COMPARE_WORDS_GREATER(DEST[127:0],SRC[127:0])
DEST[MAX_VL-1:128] (Unmodified)

VPCMPGTW (VEX.128 encoded version)

DEST[127:0] (cid:197)COMPARE_WORDS_GREATER(SRC1,SRC2)
DEST[VLMAX-1:128] (cid:197) 0

VPCMPGTW (VEX.256 encoded version)

DEST[127:0] (cid:197)COMPARE_WORDS_GREATER(SRC1[127:0],SRC2[127:0])
DEST[255:128] (cid:197)COMPARE_WORDS_GREATER(SRC1[255:128],SRC2[255:128])
DEST[VLMAX-1:256] (cid:197) 0

VPCMPGTW (EVEX encoded versions)

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO KL-1
    i (cid:197) j * 16
    IF k2[j] OR *no writemask*
         THEN
              /* signed comparison */
              CMP (cid:197) SRC1[i+15:i] > SRC2[i+15:i];
              IF CMP = TRUE
                    THEN DEST[j] (cid:197) 1;
                    ELSE DEST[j] (cid:197) 0; FI;
         ELSE
                    DEST[j] (cid:197) 0
                                                    ; zeroing-masking onlyFI;
    FI;
ENDFOR
DEST[MAX_KL-1:KL] (cid:197) 0

PCMPGTD (with 64-bit operands)

    IF DEST[31:0] > SRC[31:0]
         THEN DEST[31:0] ← FFFFFFFFH;
         ELSE DEST[31:0] ← 0; FI;
    IF DEST[63:32] > SRC[63:32]
         THEN DEST[63:32] ← FFFFFFFFH;
         ELSE DEST[63:32] ← 0; FI;

PCMPGTD (with 128-bit operands)

DEST[127:0] (cid:197)COMPARE_DWORDS_GREATER(DEST[127:0],SRC[127:0])
DEST[MAX_VL-1:128] (Unmodified)

VPCMPGTD (VEX.128 encoded version)

DEST[127:0] (cid:197)COMPARE_DWORDS_GREATER(SRC1,SRC2)
DEST[VLMAX-1:128] (cid:197) 0

VPCMPGTD (VEX.256 encoded version)

DEST[127:0] (cid:197)COMPARE_DWORDS_GREATER(SRC1[127:0],SRC2[127:0])
DEST[255:128] (cid:197)COMPARE_DWORDS_GREATER(SRC1[255:128],SRC2[255:128])
DEST[VLMAX-1:256] (cid:197) 0

VPCMPGTD (EVEX encoded versions)

(KL, VL) = (4, 128), (8, 256), (8, 512)
FOR j (cid:197) 0 TO KL-1
    i (cid:197) j * 32
    IF k2[j] OR *no writemask*
         THEN
              /* signed comparison */
              IF (EVEX.b = 1) AND (SRC2 *is memory*)
                    THEN CMP (cid:197) SRC1[i+31:i] > SRC2[31:0];
                    ELSE CMP (cid:197) SRC1[i+31:i] > SRC2[i+31:i];
              FI;
              IF CMP = TRUE
                    THEN DEST[j] (cid:197) 1;
                    ELSE DEST[j] (cid:197) 0; FI;
         ELSE
                    DEST[j] (cid:197) 0
                                                    ; zeroing-masking only
    FI;
ENDFOR
DEST[MAX_KL-1:KL] (cid:197) 0

Intel C/C++ Compiler Intrinsic Equivalents

VPCMPGTB __mmask64 _mm512_cmpgt_epi8_mask(__m512i a, __m512i b);

VPCMPGTB __mmask64 _mm512_mask_cmpgt_epi8_mask(__mmask64 k, __m512i a, __m512i b);

VPCMPGTB __mmask32 _mm256_cmpgt_epi8_mask(__m256i a, __m256i b);

VPCMPGTB __mmask32 _mm256_mask_cmpgt_epi8_mask(__mmask32 k, __m256i a, __m256i b);

VPCMPGTB __mmask16 _mm_cmpgt_epi8_mask(__m128i a, __m128i b);

VPCMPGTB __mmask16 _mm_mask_cmpgt_epi8_mask(__mmask16 k, __m128i a, __m128i b);

VPCMPGTD __mmask16 _mm512_cmpgt_epi32_mask(__m512i a, __m512i b);

VPCMPGTD __mmask16 _mm512_mask_cmpgt_epi32_mask(__mmask16 k, __m512i a, __m512i b);

VPCMPGTD __mmask8 _mm256_cmpgt_epi32_mask(__m256i a, __m256i b);

VPCMPGTD __mmask8 _mm256_mask_cmpgt_epi32_mask(__mmask8 k, __m256i a, __m256i b);

VPCMPGTD __mmask8 _mm_cmpgt_epi32_mask(__m128i a, __m128i b);

VPCMPGTD __mmask8 _mm_mask_cmpgt_epi32_mask(__mmask8 k, __m128i a, __m128i b);

VPCMPGTW __mmask32 _mm512_cmpgt_epi16_mask(__m512i a, __m512i b);

VPCMPGTW __mmask32 _mm512_mask_cmpgt_epi16_mask(__mmask32 k, __m512i a, __m512i b);

VPCMPGTW __mmask16 _mm256_cmpgt_epi16_mask(__m256i a, __m256i b);

VPCMPGTW __mmask16 _mm256_mask_cmpgt_epi16_mask(__mmask16 k, __m256i a, __m256i b);

VPCMPGTW __mmask8 _mm_cmpgt_epi16_mask(__m128i a, __m128i b);

VPCMPGTW __mmask8 _mm_mask_cmpgt_epi16_mask(__mmask8 k, __m128i a, __m128i b);

PCMPGTB:__m64 _mm_cmpgt_pi8 (__m64 m1, __m64 m2)

PCMPGTW:__m64 _mm_pcmpgt_pi16 (__m64 m1, __m64 m2)

PCMPGTD:__m64 _mm_pcmpgt_pi32 (__m64 m1, __m64 m2)

(V)PCMPGTB:__m128i _mm_cmpgt_epi8 ( __m128i a, __m128i b)

(V)PCMPGTW:__m128i _mm_cmpgt_epi16 ( __m128i a, __m128i b)

(V)DCMPGTD:__m128i _mm_cmpgt_epi32 ( __m128i a, __m128i b)

VPCMPGTB:

__m256i _mm256_cmpgt_epi8 ( __m256i a, __m256i b)

VPCMPGTW:

__m256i _mm256_cmpgt_epi16 ( __m256i a, __m256i b)

VPCMPGTD:

__m256i _mm256_cmpgt_epi32 ( __m256i a, __m256i b)

Flags Affected

None.

Numeric Exceptions

None.

Other Exceptions

Non-EVEX-encoded instruction, see Exceptions Type 4.