x86doc › VCVTW2PH - Convert Packed Signed Word Integers to FP16 Values

VCVTW2PH—Convert Packed Signed Word Integers to FP16 Values

Opcode/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
EVEX.128.F3.MAP5.W0 7D /r VCVTW2PH xmm1{k1}{z}, xmm2/m128/m16bcst	A	V/V	AVX512-FP16 AVX512VL	Convert eight packed signed word integers from xmm2/m128/m16bcst to FP16 values, and store the result in xmm1 subject to writemask k1.
EVEX.256.F3.MAP5.W0 7D /r VCVTW2PH ymm1{k1}{z}, ymm2/m256/m16bcst	A	V/V	AVX512-FP16 AVX512VL	Convert sixteen packed signed word integers from ymm2/m256/m16bcst to FP16 values, and store the result in ymm1 subject to writemask k1.
EVEX.512.F3.MAP5.W0 7D /r VCVTW2PH zmm1{k1}{z}, zmm2/m512/m16bcst {er}	A	V/V	AVX512-FP16	Convert thirty-two packed signed word integers from zmm2/m512/m16bcst to FP16 values, and store the result in zmm1 subject to writemask k1.

Instruction Operand Encoding

Op/En	Tuple	Operand 1	Operand 2	Operand 3	Operand 4
A	Full	ModRM:reg (w)	ModRM:r/m (r)	N/A	N/A

Description

This instruction converts packed signed word integers in the source operand to FP16 values in the destination operand. When conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register or embedded rounding controls.

The destination elements are updated according to the writemask.

Operation

VCVTW2PH dest, src

VL = 128, 256 or 512

KL := VL / 16

IF *SRC is a register* and (VL = 512) AND (EVEX.b = 1):

SET_RM(EVEX.RC)

ELSE:

SET_RM(MXCSR.RC)

FOR j := 0 TO KL-1:

IF k1[j] OR *no writemask*:

IF *SRC is memory* and EVEX.b = 1:

tsrc := SRC.word[0]

ELSE

tsrc := SRC.word[j]

DEST.fp16[j] := Convert_integer16_to_fp16(tsrc)

ELSE IF *zeroing*:

DEST.fp16[j] := 0

// else dest.fp16[j] remains unchanged

DEST[MAXVL-1:VL] := 0

Intel C/C++ Compiler Intrinsic Equivalent

VCVTW2PH __m512h _mm512_cvt_roundepi16_ph (__m512i a, int rounding);

VCVTW2PH __m512h _mm512_mask_cvt_roundepi16_ph (__m512h src, __mmask32 k, __m512i a, int rounding);

VCVTW2PH __m512h _mm512_maskz_cvt_roundepi16_ph (__mmask32 k, __m512i a, int rounding);

VCVTW2PH __m128h _mm_cvtepi16_ph (__m128i a);

VCVTW2PH __m128h _mm_mask_cvtepi16_ph (__m128h src, __mmask8 k, __m128i a);

VCVTW2PH __m128h _mm_maskz_cvtepi16_ph (__mmask8 k, __m128i a);

VCVTW2PH __m256h _mm256_cvtepi16_ph (__m256i a);

VCVTW2PH __m256h _mm256_mask_cvtepi16_ph (__m256h src, __mmask16 k, __m256i a);

VCVTW2PH __m256h _mm256_maskz_cvtepi16_ph (__mmask16 k, __m256i a);

VCVTW2PH __m512h _mm512_cvtepi16_ph (__m512i a);

VCVTW2PH __m512h _mm512_mask_cvtepi16_ph (__m512h src, __mmask32 k, __m512i a);

VCVTW2PH __m512h _mm512_maskz_cvtepi16_ph (__mmask32 k, __m512i a);

SIMD Floating-Point Exceptions

Precision.

Other Exceptions

EVEX-encoded instructions, see Table 2-46, “Type E2 Class Exception Conditions.”