(0) exportieren Drucken
Alle erweitern
Erweitern Minimieren

_mm_cmpestrc

Microsoft Specific

Emits the Streaming SIMD Extensions 4 (SSE4) instruction pcmpestr. This instruction compares two parameters.


int _mm_cmpestrc (
   __m128i a, 
   int la,
   __m128i b,
   int lb, 
   const int mode
); 

Parameter

Description

[in] a

A string fragment with a maximum size of 16 byte characters or 8 word characters.

[in] la

An integer that specifies the size of the string in a.

[in] b

A string fragment with a maximum size of 16 byte characters or 8 word characters.

[in] lb

An integer that specifies the size of the string in b.

[in] mode

A constant that indicates whether characters are bytes or words, the type of comparison to do, and the format of the returned value.

Zero if the resulting mask is equal to zero. Otherwise, one. The pcmpestri instruction computes the bitmask, where bit0, bit1, bit2… in the mask correspond to the result of the executed operation on a0, a1, a2… in a.

Intrinsic

Architecture

_mm_cmpestrc

x86, x64

Header file <nmmintrin.h>

b0, b1, b2… indicate the first, second, third… characters in b. b0 is stored in the least significant bits of b. The same notation applies to a. MaxSize is either 16 for byte characters or 8 for word characters. MaxSize is the maximum number of characters that fit into a __m128i data type. The lower 7 bits in mode determine the type of the input characters, which comparison to run, and the format of the return value. They are described in the following table:

mode in binary

Defined constant

Description

xxxxxx00

SIDD_UBYTE_OPS

a and b contain strings of unsigned 8-bit characters.

xxxxxx01

SIDD_UWORD_OPS

a and b contain strings of unsigned 16-bit characters.

xxxxxx10

SIDD_SBYTE_OPS

a and b contain strings of signed 8-bit characters.

xxxxxx11

SIDD_SWORD_OPS

a and b contain strings of signed 16-bit characters.

xxxx00xx

SIDD_CMP_EQUAL_ANY

Find if equal any mode:

For each character c in a, determine whether any character in b is equal to c.

xxxx01xx

SIDD_CMP_RANGES

Find in ranges mode:

For each character c in a, determine whether b0 <= c <= b1or b2 <= c <= b3

xxxx10xx

SIDD_CMP_EQUAL_EACH

Find if equal each mode:

This implements the string equality algorithm.

xxxx11xx

SIDD_CMP_EQUAL_ORDERED

Find if equal ordered mode:

This implements the substring search algorithm.

xx01xxxx

SIDD_NEGATIVE_POLARITY

Negation of resulting bitmask.

xx11xxxx

SIDD_MASKED_NEGATIVE_POLARITY

Negation of resulting bitmask except for bits that have an index larger than the size of a or b (see details of pcmpestri instruction).

Before using this intrinsic, software must ensure that the processor supports the instruction.

See the example for _mm_cmpestra.

Community-Beiträge

HINZUFÜGEN
Anzeigen:
© 2014 Microsoft