VADDPH

VADDPH — Add Packed FP16 Values

Opcode/ Instruction	Op/ En	64/32 Bit Mode Support	CPUID Feature Flag	Description
EVEX.128.NP.MAP5.W0 58 /r VADDPH xmm1{k1}{z}, xmm2, xmm3/m128/m16bcst	A	V/V	(AVX512_FP16 AND AVX512VL) OR AVX10.1	Add packed FP16 value from xmm3/m128/m16bcst to xmm2, and store result in xmm1 subject to writemask k1.
EVEX.256.NP.MAP5.W0 58 /r VADDPH ymm1{k1}{z}, ymm2, ymm3/m256/m16bcst	A	V/V	(AVX512_FP16 AND AVX512VL) OR AVX10.1	Add packed FP16 value from ymm3/m256/m16bcst to ymm2, and store result in ymm1 subject to writemask k1.
EVEX.512.NP.MAP5.W0 58 /r VADDPH zmm1{k1}{z}, zmm2, zmm3/m512/m16bcst {er}	A	V/V	AVX512_FP16 OR AVX10.1	Add packed FP16 value from zmm3/m512/m16bcst to zmm2, and store 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)	VEX.vvvv (r)	ModRM:r/m (r)	N/A

Description

This instruction adds packed FP16 values from source operands and stores the packed FP16 result in the destination operand. The destination elements are updated according to the writemask.

Operation

VADDPH (EVEX Encoded Versions) When SRC2 Operand is a Register

VL = 128, 256 or 512
KL ← VL/16
IF (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*:
        DEST.fp16[j] ← SRC1.fp16[j] + SRC2.fp16[j]
    ELSEIF *zeroing*:
        DEST.fp16[j] ← 0
    // else dest.fp16[j] remains unchanged

VADDPH (EVEX Encoded Versions) When SRC2 Operand is a Memory Source

VL = 128, 256 or 512
KL ← VL/16
FOR j ← 0 TO KL-1:
    IF k1[j] OR *no writemask*:
        IF EVEX.b = 1:
            DEST.fp16[j] ← SRC1.fp16[j] + SRC2.fp16[0]
        ELSE:
            DEST.fp16[j] ← SRC1.fp16[j] + SRC2.fp16[j]
    ELSE IF *zeroing*:
        DEST.fp16[j] ← 0
    // else dest.fp16[j] remains unchanged

Intel C/C++ Compiler Intrinsic Equivalent

VADDPH __m128h _mm_add_ph (__m128h a, __m128h b);
VADDPH __m128h _mm_mask_add_ph (__m128h src, __mmask8 k, __m128h a, __m128h b);
VADDPH __m128h _mm_maskz_add_ph (__mmask8 k, __m128h a, __m128h b);
VADDPH __m256h _mm256_add_ph (__m256h a, __m256h b);
VADDPH __m256h _mm256_mask_add_ph (__m256h src, __mmask16 k, __m256h a, __m256h b);
VADDPH __m256h _mm256_maskz_add_ph (__mmask16 k, __m256h a, __m256h b);
VADDPH __m512h _mm512_add_ph (__m512h a, __m512h b);
VADDPH __m512h _mm512_add_ph (__m512h a, __m512h b);
VADDPH __m512h _mm512_mask_add_ph (__m512h src, __mmask32 k, __m512h a, __m512h b);
VADDPH __m512h _mm512_maskz_add_ph (__mmask32 k, __m512h a, __m512h b);
VADDPH __m512h _mm512_add_round_ph (__m512h a, __m512h b, int rounding);
VADDPH __m512h _mm512_mask_add_round_ph (__m512h src, __mmask32 k, __m512h a, __m512h b, int rounding);
VADDPH __m512h _mm512_maskz_add_round_ph (__mmask32 k, __m512h a, __m512h b, int rounding);

SIMD Floating-Point Exceptions

Invalid, Underflow, Overflow, Precision, Denormal.

Other Exceptions

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Source: Intel® 64 and IA-32 Architectures Software Developer's Manual, Combined Volumes (Order Number 325462-091US, March 2026)
Generated: 7-6-2026