VCVTPH2PD — Convert Packed FP16 Values to FP64 Values

Instruction En Bit Mode Flag Support Instruction En Bit Mode Flag Support 64/32 CPUID Feature Instruction En Bit Mode Flag CPUID Feature Instruction En Bit Mode Flag Op/ 64/32 CPUID Feature Instruction En Bit Mode Flag 64/32 CPUID Feature Instruction En Bit Mode Flag CPUID Feature Instruction En Bit Mode Flag Op/ 64/32 CPUID Feature		Support		Description
EVEX.128.NP.MAP5.W0 5A /r VCVTPH2PD xmm1{k1}{z}, xmm2/m32/m16bcst	A	V/V	AVX512-FP16 AVX512VL	Convert packed FP16 values in xmm2/m32/m16bcst to FP64 values, and store result in xmm1 subject to writemask k1.
EVEX.256.NP.MAP5.W0 5A /r VCVTPH2PD ymm1{k1}{z}, xmm2/m64/m16bcst	A	V/V	AVX512-FP16 AVX512VL	Convert packed FP16 values in xmm2/m64/m16bcst to FP64 values, and store result in ymm1 subject to writemask k1.
EVEX.512.NP.MAP5.W0 5A /r VCVTPH2PD zmm1{k1}{z}, xmm2/m128/m16bcst {sae}	A	V/V	AVX512-FP16	Convert packed FP16 values in xmm2/m128/m16bcst to FP64 values, and store result in zmm1 subject to writemask k1.

Instruction Operand Encoding ¶

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

Description ¶

This instruction converts packed FP16 values to FP64 values in the destination register. The destination elements are updated according to the writemask.

This instruction handles both normal and denormal FP16 inputs.

Operation ¶

VCVTPH2PD DEST, SRC ¶

VL = 128, 256, or 512
KL := VL/64
FOR j := 0 TO KL-1:
    IF k1[j] OR *no writemask*:
        IF *SRC is memory* and EVEX.b = 1:
            tsrc := SRC.fp16[0]
        ELSE
            tsrc := SRC.fp16[j]
        DEST.fp64[j] := Convert_fp16_to_fp64(tsrc)
    ELSE IF *zeroing*:
        DEST.fp64[j] := 0
    // else dest.fp64[j] remains unchanged
DEST[MAXVL-1:VL] := 0

Intel C/C++ Compiler Intrinsic Equivalent ¶

VCVTPH2PD __m512d _mm512_cvt_roundph_pd (__m128h a, int sae);

VCVTPH2PD __m512d _mm512_mask_cvt_roundph_pd (__m512d src, __mmask8 k, __m128h a, int sae);

VCVTPH2PD __m512d _mm512_maskz_cvt_roundph_pd (__mmask8 k, __m128h a, int sae);

VCVTPH2PD __m128d _mm_cvtph_pd (__m128h a);

VCVTPH2PD __m128d _mm_mask_cvtph_pd (__m128d src, __mmask8 k, __m128h a);

VCVTPH2PD __m128d _mm_maskz_cvtph_pd (__mmask8 k, __m128h a);

VCVTPH2PD __m256d _mm256_cvtph_pd (__m128h a);

VCVTPH2PD __m256d _mm256_mask_cvtph_pd (__m256d src, __mmask8 k, __m128h a);

VCVTPH2PD __m256d _mm256_maskz_cvtph_pd (__mmask8 k, __m128h a);

VCVTPH2PD __m512d _mm512_cvtph_pd (__m128h a);

VCVTPH2PD __m512d _mm512_mask_cvtph_pd (__m512d src, __mmask8 k, __m128h a);

VCVTPH2PD __m512d _mm512_maskz_cvtph_pd (__mmask8 k, __m128h a);

SIMD Floating-Point Exceptions ¶

Invalid, Denormal.

Other Exceptions ¶

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