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Source code

VCVTTPH2QQ

Convert with Truncation Packed FP16 Values to Signed Quadword Integers

stableVMJITAOTinstruction

Encodings

OpcodeInstructionOp/En64-bitCompat/LegacyDescription
EVEX.128.66.MAP5.W0 7A /rVCVTTPH2QQ xmm1{k1}{z}, xmm2/m32/m16bcstAValidValidConvert two packed FP16 values in AND AVX512VL) xmm2/m32/m16bcst to two signed quadword OR AVX10.1 integers, and store the result in xmm1 using truncation subject to writemask k1.
EVEX.256.66.MAP5.W0 7A /rVCVTTPH2QQ ymm1{k1}{z}, xmm2/m64/m16bcstAValidValidConvert four packed FP16 values in AND AVX512VL) xmm2/m64/m16bcst to four signed quadword OR AVX10.1 integers, and store the result in ymm1 using truncation subject to writemask k1.
EVEX.512.66.MAP5.W0 7A /rVCVTTPH2QQ zmm1{k1}{z}, xmm2/m128/m16bcst {sae}AValidValidConvert eight packed FP16 values in OR AVX10.1 xmm2/m128/m16bcst to eight signed quadword integers, and store the result in zmm1 using truncation subject to writemask k1.

Operand encoding

Each mode is a value of the Op/En column above. It says which field of the encoded instruction carries each operand, in the order they are written, and whether the instruction reads it, writes it or both.

A

  1. Quarter
  2. modrm.reg escrituraModRM byte, reg field (bits 5-3)
  3. modrm.rm lecturaModRM byte, r/m field (bits 2-0); with the SIB byte and the displacement when the mod field asks for them

Measured cost

Loading measurements from arch-data...

Description

This instruction converts packed FP16 values in the source operand to signed 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 indefinite integer value 80000000_00000000H is returned.

The destination elements are updated according to the writemask.

Operation

VCVTTPH2QQ 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_integer64_truncate(tsrc)
    ELSE IF *zeroing*:
          DEST.qword[j] := 0
    // else dest.qword[j] remains unchanged

DEST[MAXVL-1:VL] := 0

Intel C/C++ compiler intrinsics

VCVTTPH2QQ __m512i _mm512_cvtt_roundph_epi64 (__m128h a, int sae);
VCVTTPH2QQ __m512i _mm512_mask_cvtt_roundph_epi64 (__m512i src, __mmask8 k, __m128h a, int sae);
VCVTTPH2QQ __m512i _mm512_maskz_cvtt_roundph_epi64 (__mmask8 k, __m128h a, int sae);
VCVTTPH2QQ __m128i _mm_cvttph_epi64 (__m128h a);
VCVTTPH2QQ __m128i _mm_mask_cvttph_epi64 (__m128i src, __mmask8 k, __m128h a);
VCVTTPH2QQ __m128i _mm_maskz_cvttph_epi64 (__mmask8 k, __m128h a);
VCVTTPH2QQ __m256i _mm256_cvttph_epi64 (__m128h a);
VCVTTPH2QQ __m256i _mm256_mask_cvttph_epi64 (__m256i src, __mmask8 k, __m128h a);
VCVTTPH2QQ __m256i _mm256_maskz_cvttph_epi64 (__mmask8 k, __m128h a);
VCVTTPH2QQ __m512i _mm512_cvttph_epi64 (__m128h a);
VCVTTPH2QQ __m512i _mm512_mask_cvttph_epi64 (__m512i src, __mmask8 k, __m128h a);
VCVTTPH2QQ __m512i _mm512_maskz_cvttph_epi64 (__mmask8 k, __m128h a);

SIMD Floating-Point Exceptions

Invalid, Precision.

Other Exceptions

EVEX-encoded instructions, see Table 2-48, "Type E2 Class Exception Conditions."

Sources