VCVTTSH2SI
Convert with Truncation Low FP
| 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.LLIG.F3.MAP5.W0 2C /r VCVTTSH2SI r32, xmm1/m16 {sae} | A | V/V1 | AVX512-FP16 | Convert FP16 value in the low element of xmm1/m16 to a signed integer and store the result in r32 using truncation. |
| EVEX.LLIG.F3.MAP5.W1 2C /r VCVTTSH2SI r64, xmm1/m16 {sae} | A | V/N.E. | AVX512-FP16 | Convert FP16 value in the low element of xmm1/m16 to a signed integer and store the result in r64 using truncation. |
- Outside of 64b mode, the EVEX.W field is ignored. The instruction behaves as if W=0 was used.
Instruction Operand Encoding
| 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 a signed 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
VCVTTSH2SI dest, src
IF 64-mode and OperandSize == 64:
DEST.qword := Convert_fp16_to_integer64_truncate(SRC.fp16[0])
ELSE:
DEST.dword := Convert_fp16_to_integer32_truncate(SRC.fp16[0])
Intel C/C++ Compiler Intrinsic Equivalent
VCVTTSH2SI int _mm_cvtt_roundsh_i32 (__m128h a, int sae);
VCVTTSH2SI __int64 _mm_cvtt_roundsh_i64 (__m128h a, int sae);
VCVTTSH2SI int _mm_cvttsh_i32 (__m128h a);
VCVTTSH2SI __int64 _mm_cvttsh_i64 (__m128h a);
SIMD Floating-Point Exceptions
Invalid, Precision.
Other Exceptions
EVEX-encoded instructions, see Table 2-48, “Type E3NF Class Exception Conditions.”
This UNOFFICIAL, mechanically-separated, non-verified reference is provided for convenience, but it may be incomplete or broken in various obvious or non-obvious ways. Refer to Intel® 64 and IA-32 Architectures Software Developer’s Manual for anything serious.