CVTPI2PS
Convert Packed Dword Integers to Packed Single Precision Floating
| Opcode/Instruction | Op/En | 64-Bit Mode | Compat/Leg Mode | Description |
|---|---|---|---|---|
| NP 0F 2A /r CVTPI2PS xmm, mm/m64 | RM | Valid | Valid | Convert two signed doubleword integers from mm/m64 to two single precision floating-point values in xmm. |
Instruction Operand Encoding
| Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
|---|---|---|---|---|
| RM | ModRM:reg (r, w) | ModRM:r/m (r) | N/A | N/A |
Description
Converts two packed signed doubleword integers in the source operand (second operand) to two packed single precision floating-point values in the destination operand (first operand).
The source operand can be an MMX technology register or a 64-bit memory location. The destination operand is an XMM register. The results are stored in the low quadword of the destination operand, and the high quadword remains unchanged. When a conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.
This instruction causes a transition from x87 FPU to MMX technology operation (that is, the x87 FPU top-of-stack pointer is set to 0 and the x87 FPU tag word is set to all 0s [valid]). If this instruction is executed while an x87 FPU floating-point exception is pending, the exception is handled before the CVTPI2PS instruction is executed.
In 64-bit mode, use of the REX.R prefix permits this instruction to access additional registers (XMM8-XMM15).
Operation
DEST[31:0] := Convert_Integer_To_Single_Precision_Floating_Point(SRC[31:0]);
DEST[63:32] := Convert_Integer_To_Single_Precision_Floating_Point(SRC[63:32]);
(* High quadword of destination unchanged *)
Intel C/C++ Compiler Intrinsic Equivalent
CVTPI2PS __m128 _mm_cvtpi32_ps(__m128 a, __m64 b)
SIMD Floating-Point Exceptions
Precision.
Other Exceptions
See Table 23-5, “Exception Conditions for Legacy SIMD/MMX Instructions with XMM and FP Exception” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B.
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.