cvtsi2sd
Convert Doubleword Integer to Scalar Double-Precision
CVTSI2SD xmm, r/m32
Converts 32-bit int to double.
Details
Converts a 32-bit signed integer to a 64-bit double-precision floating-point value and stores the result in the low 64 bits of the destination XMM register, leaving the upper 64 bits unchanged. The conversion uses the current rounding mode from MXCSR. No EFLAGS are affected by this instruction.
Pseudocode Operation
dest.low64 ← (double)src32;Example
CVTSI2SD xmm0, ebx
Encoding
Binary Layout
F2
+0
0F
+1
2A
+2
Operands
-
dest
128-bit SSE/AVX register (XMM) -
src
32-bit register or memory
Reference (Intel® SDM)
Instruction Forms
| Opcode | Instruction | Op/En | 64/32-bit Mode | CPUID | Description |
|---|---|---|---|---|---|
| F2 0F 2A /r | CVTSI2SD xmm1, r32/m32 | A | V/V | SSE2 | Convert one signed doubleword integer from r32/m32 to one double precision floating-point value in xmm1. |
| F2 REX.W 0F 2A /r | CVTSI2SD xmm1, r/m64 | A | V/N.E. | SSE2 | Convert one signed quadword integer from r/m64 to one double precision floating-point value in xmm1. |
| VEX.LIG.F2.0F.W0 2A /r | VCVTSI2SD xmm1, xmm2, r/m32 | B | V/V | AVX | Convert one signed doubleword integer from r/m32 to one double precision floating-point value in xmm1. |
| VEX.LIG.F2.0F.W1 2A /r | VCVTSI2SD xmm1, xmm2, r/m64 | B | V/N.E.1 | AVX | Convert one signed quadword integer from r/m64 to one double precision floating-point value in xmm1. |
| EVEX.LLIG.F2.0F.W0 2A /r | VCVTSI2SD xmm1, xmm2, r/m32 | C | V/V | AVX512F | Convert one signed doubleword integer from OR AVX10.1 r/m32 to one double precision floating-point value in xmm1. |
| EVEX.LLIG.F2.0F.W1 2A /r | VCVTSI2SD xmm1, xmm2, r/m64{er} | C | V/N.E.1 | AVX512F OR AVX10.1 | Convert one signed quadword integer from r/m64 to one double precision floating-point value in xmm1. |
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 | N/A | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | N/A |
| C | Tuple1 Scalar | ModRM:reg (w) | EVEX.vvvv (r) | ModRM:r/m (r) | N/A |
Description
Converts a signed doubleword or quadword integer in the “convert-from” source operand to a double precision floating-point value in the destination operand. The result is stored in the low quadword of the destination operand, and the high quadword left unchanged. When conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.
The second source operand can be a general-purpose register or a 32/64-bit memory location. The first source and destination operands are XMM registers.
128-bit Legacy SSE version: Use of the REX.W prefix promotes the instruction to 64-bit operands. The “convertfrom” source operand (the second operand) is a general-purpose register or memory location. The destination is an XMM register Bits (MAXVL-1:64) of the corresponding destination register remain unchanged.
VEX.128 and EVEX encoded versions: The “convert-from” source operand (the third operand) can be a generalpurpose register or a memory location. The first source and destination operands are XMM registers. Bits (127:64) of the XMM register destination are copied from the corresponding bits in the first source operand. Bits (MAXVL1:128) of the destination register are zeroed.
EVEX.W0 version: attempt to encode this instruction with EVEX embedded rounding is ignored.
VEX.W1 and EVEX.W1 versions: promotes the instruction to use 64-bit input value in 64-bit mode.
Software should ensure VCVTSI2SD is encoded with VEX.L=0. Encoding VCVTSI2SD with VEX.L=1 may encounter unpredictable behavior across different processor generations.
CVTSI2SD—Convert Signed Integer to Scalar Double Precision Floating-Point Value Vol. 2A 3-236
Operation
VCVTSI2SD (EVEX Encoded Version) IF (SRC2 *is register*) AND (EVEX.b = 1) THEN SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC); ELSE SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC); FI; IF 64-Bit Mode And OperandSize = 64 THEN DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC2[63:0]); ELSE DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC2[31:0]); FI; DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 VCVTSI2SD (VEX.128 Encoded Version) IF 64-Bit Mode And OperandSize = 64 THEN DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC2[63:0]); ELSE DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC2[31:0]); FI; DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 CVTSI2SD IF 64-Bit Mode And OperandSize = 64 THEN DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC[63:0]); ELSE DEST[63:0] := Convert_Integer_To_Double_Precision_Floating_Point(SRC[31:0]); FI; DEST[MAXVL-1:64] (Unmodified)
Intel C/C++ Compiler Intrinsic Equivalent
VCVTSI2SD __m128d _mm_cvti32_sd(__m128d s, int a); VCVTSI2SD __m128d _mm_cvti64_sd(__m128d s, __int64 a); VCVTSI2SD __m128d _mm_cvt_roundi64_sd(__m128d s, __int64 a, int r); CVTSI2SD __m128d _mm_cvtsi64_sd(__m128d s, __int64 a); CVTSI2SD __m128d_mm_cvtsi32_sd(__m128d a, int b)
Exceptions
SIMD Floating-Point Exceptions
Precision.
Other Exceptions
VEX-encoded instructions, see Table 2-20, “Type 3 Class Exception Conditions,” if W1; else see Table 2-22, “Type
5 Class Exception Conditions.”
EVEX-encoded instructions, see Table 2-50, “Type E3NF Class Exception Conditions,” if W1; else see Table 2-61,
“Type E10NF Class Exception Conditions.”
CVTSI2SD—Convert Signed Integer to Scalar Double Precision Floating-Point Value Vol. 2A 3-237