Computer Hardware User's Manual

Vol. 2A 3-225
INSTRUCTION SET REFERENCE, A-M
CVTSI2SD—Convert Doubleword Integer to Scalar Double-Precision Floating-Point Value
CVTSI2SD—Convert Doubleword Integer to Scalar Double-Precision
Floating-Point Value
Description
Converts a signed doubleword integer (or signed quadword integer if operand size is
64 bits) in the source operand (second operand) to a double-precision floating-point
value in the destination operand (first operand). The source operand can be a
general-purpose register or a memory location. The destination operand is an XMM
register. The result is stored in the low quadword of the destination operand, and the
high quadword left unchanged.
In 64-bit mode, the instruction can access additional registers (XMM8-XMM15,
R8-R15) when used with a REX.R prefix. Use of the REX.W prefix promotes the
instruction to 64-bit operands. See the summary chart at the beginning of this
section for encoding data and limits.
Operation
IF 64-Bit Mode And OperandSize = 64
THEN
DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC[63:0]);
(* DEST[127:64] unchanged *)
ELSE
DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC[31:0]);
(* DEST[127:64] unchanged *)
FI;
Intel C/C++ Compiler Intrinsic Equivalent
CVTSI2SD __m128d _mm_cvtsi32_sd(__m128d a, int b)
SIMD Floating-Point Exceptions
None.
Opcode Instruction 64-Bit
Mode
Compat/
Leg Mode
Description
F2 0F 2A /r CVTSI2SD xmm,
r/m32
Valid Valid Convert one signed doubleword
integer from r/m32 to one
double-precision floating-point
value in xmm.
F2 REX.W 0F 2A /r CVTSI2SD xmm,
r/m64
Valid N.E. Convert one signed quadword
integer from r/m64 to one
double-precision floating-point
value in xmm.