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VCVTTPH2UQQ

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Henk-Jan Lebbink edited this page Jun 4, 2026 · 1 revision

VCVTTPH2UQQ — Convert with Truncation Packed FP16 Values to Unsigned Quadword Integers

Opcode/ Instruction Op/ En 64/32 Bit Mode Support CPUID Feature Flag Description
EVEX.128.66.MAP5.W0 78 /r VCVTTPH2UQQ xmm1{k1}{z}, xmm2/m32/m16bcst A V/V (AVX512_FP16 AND AVX512VL) OR AVX10.1 Convert two packed FP16 values in xmm2/m32/m16bcst to two unsigned quadword integers, and store the result in xmm1 using truncation subject to writemask k1.
EVEX.256.66.MAP5.W0 78 /r VCVTTPH2UQQ ymm1{k1}{z}, xmm2/m64/m16bcst A V/V (AVX512_FP16 AND AVX512VL) OR AVX10.1 Convert four packed FP16 values in xmm2/m64/m16bcst to four unsigned quadword integers, and store the result in ymm1 using truncation subject to writemask k1.
EVEX.512.66.MAP5.W0 78 /r VCVTTPH2UQQ zmm1{k1}{z}, xmm2/m128/m16bcst {sae} A V/V AVX512_FP16 OR AVX10.1 Convert eight packed FP16 values in xmm2/m128/m16bcst to eight unsigned quadword integers, and store the result in zmm1 using truncation 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 in the source operand to unsigned quadword integers in the destination operand.

When a conversion is inexact, a truncated (round toward zero) value is returned. If a converted result cannot be represented in the destination format, the floating-point invalid exception is raised, and if this exception is masked, the integer value FFFFFFFF_FFFFFFFFH is returned.

The destination elements are updated according to the writemask.

Operation

VCVTTPH2UQQ 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.qword[j] ← Convert_fp16_to_unsigned_integer64_truncate(tsrc)
    ELSE IF *zeroing*:
        DEST.qword[j] ← 0
    // else dest.qword[j] remains unchanged

Intel C/C++ Compiler Intrinsic Equivalent

VCVTTPH2UQQ __m512i _mm512_cvtt_roundph_epu64 (__m128h a, int sae);
VCVTTPH2UQQ __m512i _mm512_mask_cvtt_roundph_epu64 (__m512i src, __mmask8 k, __m128h a, int sae);
VCVTTPH2UQQ __m512i _mm512_maskz_cvtt_roundph_epu64 (__mmask8 k, __m128h a, int sae);
VCVTTPH2UQQ __m128i _mm_cvttph_epu64 (__m128h a);
VCVTTPH2UQQ __m128i _mm_mask_cvttph_epu64 (__m128i src, __mmask8 k, __m128h a);
VCVTTPH2UQQ __m128i _mm_maskz_cvttph_epu64 (__mmask8 k, __m128h a);
VCVTTPH2UQQ __m256i _mm256_cvttph_epu64 (__m128h a);
VCVTTPH2UQQ __m256i _mm256_mask_cvttph_epu64 (__m256i src, __mmask8 k, __m128h a);
VCVTTPH2UQQ __m256i _mm256_maskz_cvttph_epu64 (__mmask8 k, __m128h a);
VCVTTPH2UQQ __m512i _mm512_cvttph_epu64 (__m128h a);
VCVTTPH2UQQ __m512i _mm512_mask_cvttph_epu64 (__m512i src, __mmask8 k, __m128h a);
VCVTTPH2UQQ __m512i _mm512_maskz_cvttph_epu64 (__mmask8 k, __m128h a);

SIMD Floating-Point Exceptions

Invalid, Precision.

Other Exceptions

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

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