| Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description |
|---|---|---|---|---|
| EVEX.LLIG.F3.MAP5.W0 78 /r VCVTTSH2USI r32, xmm1/m16 {sae} | A | V/V1 | AVX512-FP16 | Convert FP16 value in the low element of xmm1/m16 to an unsigned integer and store the result in r32 using truncation. |
| EVEX.LLIG.F3.MAP5.W1 78 /r VCVTTSH2USI r64, xmm1/m16 {sae} | A | V/N.E. | AVX512-FP16 | Convert FP16 value in the low element of xmm1/m16 to an unsigned integer and store the result in r64 using truncation. |
NOTES:
1. Outside of 64b mode, the EVEX.W field is ignored. The instruction behaves as if W=0 was used.
| Op/En | Tuple | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
|---|---|---|---|---|---|
| A | Scalar | ModRM:reg (w) | ModRM:r/m (r) | N/A | N/A |
Description
This instruction converts the low FP16 element in the source operand to an unsigned integer in the destination general purpose register.
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 indefinite value is returned.
Operation
VCVTTSH2USI dest, src
IF 64-mode and OperandSize == 64:
DEST.qword := Convert_fp16_to_unsigned_integer64_truncate(SRC.fp16[0])
ELSE:
DEST.dword := Convert_fp16_to_unsigned_integer32_truncate(SRC.fp16[0])
Intel C/C++ Compiler Intrinsic Equivalent
VCVTTSH2USI unsigned int _mm_cvtt_roundsh_u32 (__m128h a, int sae);
VCVTTSH2USI unsigned __int64 _mm_cvtt_roundsh_u64 (__m128h a, int sae);
VCVTTSH2USI unsigned int _mm_cvttsh_u32 (__m128h a);
VCVTTSH2USI unsigned __int64 _mm_cvttsh_u64 (__m128h a);
SIMD Floating-Point Exceptions
Invalid, Precision.
Other Exceptions
EVEX-encoded instructions, see Table 2-48, “Type E3NF Class Exception Conditions.”