CVTTSD2SI
Convert With Truncation Scalar Double Precision Floating
| Opcode/Instruction | Op / En | 64/32 bit Mode Support | CPUID Feature Flag | Description |
|---|---|---|---|---|
| F2 0F 2C /r CVTTSD2SI r32, xmm1/m64 | A | V/V | SSE2 | Convert one double precision floating-point value from xmm1/m64 to one signed doubleword integer in r32 using truncation. |
| F2 REX.W 0F 2C /r CVTTSD2SI r64, xmm1/m64 | A | V/N.E. | SSE2 | Convert one double precision floating-point value from xmm1/m64 to one signed quadword integer in r64 using truncation. |
| VEX.LIG.F2.0F.W0 2C /r 1 VCVTTSD2SI r32, xmm1/m64 | A | V/V | AVX | Convert one double precision floating-point value from xmm1/m64 to one signed doubleword integer in r32 using truncation. |
| VEX.LIG.F2.0F.W1 2C /r 1 VCVTTSD2SI r64, xmm1/m64 | B | V/N.E.2 | AVX | Convert one double precision floating-point value from xmm1/m64 to one signed quadword integer in r64 using truncation. |
| EVEX.LLIG.F2.0F.W0 2C /r VCVTTSD2SI r32, xmm1/m64{sae} | B | V/V | AVX512F | Convert one double precision floating-point value from xmm1/m64 to one signed doubleword integer in r32 using truncation. |
| EVEX.LLIG.F2.0F.W1 2C /r VCVTTSD2SI r64, xmm1/m64{sae} | B | V/N.E.2 | AVX512F | Convert one double precision floating-point value from xmm1/m64 to one signed quadword integer in r64 using truncation. |
- Software should ensure VCVTTSD2SI is encoded with VEX.L=0. Encoding VCVTTSD2SI with VEX.L=1 may encounter unpredictable behavior across different processor generations.
- For this specific instruction, VEX.W/EVEX.W in non-64 bit is ignored; the instructions behaves as if the W0 version is used.
Instruction Operand Encoding
| Op/En | Tuple Type | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
|---|---|---|---|---|---|
| A | N/A | ModRM:reg (w) | ModRM:r/m (r) | N/A | N/A |
| B | Tuple1 Fixed | ModRM:reg (w) | ModRM:r/m (r) | N/A | N/A |
Description
Converts a double precision floating-point value in the source operand (the second operand) to a signed double-word integer (or signed quadword integer if operand size is 64 bits) in the destination operand (the first operand). The source operand can be an XMM register or a 64-bit memory location. The destination operand is a general purpose register. When the source operand is an XMM register, the double precision floating-point value is contained in the low quadword of the register.
When a conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.
If a converted result exceeds the range limits of signed doubleword integer (in non-64-bit modes or 64-bit mode with REX.W/VEX.W/EVEX.W=0), the floating-point invalid exception is raised, and if this exception is masked, the indefinite integer value (80000000H) is returned.
If a converted result exceeds the range limits of signed quadword integer (in 64-bit mode and REX.W/VEX.W/EVEX.W = 1), the floating-point invalid exception is raised, and if this exception is masked, the indefinite integer value (80000000_00000000H) is returned.
Legacy SSE instructions: In 64-bit mode, Use of the REX.W prefix promotes the instruction to 64-bit operation. See the summary chart at the beginning of this section for encoding data and limits.
VEX.W1 and EVEX.W1 versions: promotes the instruction to produce 64-bit data in 64-bit mode.
Note: VEX.vvvv and EVEX.vvvv are reserved and must be 1111b, otherwise instructions will #UD.
Software should ensure VCVTTSD2SI is encoded with VEX.L=0. Encoding VCVTTSD2SI with VEX.L=1 may encounter unpredictable behavior across different processor generations.
Operation
(V)CVTTSD2SI (All Versions)
IF 64-Bit Mode and OperandSize = 64
THEN
DEST[63:0] := Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[63:0]);
ELSE
DEST[31:0] := Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[63:0]);
FI;
Intel C/C++ Compiler Intrinsic Equivalent
VCVTTSD2SI int _mm_cvttsd_i32( __m128d a);
VCVTTSD2SI int _mm_cvtt_roundsd_i32( __m128d a, int sae);
VCVTTSD2SI __int64 _mm_cvttsd_i64( __m128d a);
VCVTTSD2SI __int64 _mm_cvtt_roundsd_i64( __m128d a, int sae);
CVTTSD2SI int _mm_cvttsd_si32( __m128d a);
CVTTSD2SI __int64 _mm_cvttsd_si64( __m128d a);
SIMD Floating-Point Exceptions
Invalid, Precision.
Other Exceptions
VEX-encoded instructions, see Table 2-20, “Type 3 Class Exception Conditions,” additionally:
| #UD | If VEX.vvvv != 1111B. |
|---|
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.