Each conversion intrinsic takes one data type and performs a conversion to a different type. Some conversions such as _mm_cvtpd_ps result in a loss of precision. The rounding mode used in such cases is determined by the value in the MXCSR register. The default rounding mode is round-to-nearest. Note that the rounding mode used by the C and C++ languages when performing a type conversion is to truncate. The _mm_cvttpd_epi32, _mm_cvttsd_si32, and _mm_cvttps_epi32 intrinsics use the truncate rounding mode regardless of the mode specified by the MXCSR register.
The conversion-operation intrinsics for Streaming SIMD Extensions 2 are listed in the following table followed by detailed descriptions.
| Intrinsic Name | Corresponding Instruction | Return Type | Parameters |
|---|---|---|---|
|
_mm_cvtpd_ps |
CVTPD2PS |
__m128 |
(__m128d a) |
|
_mm_cvtps_pd |
CVTPS2PD |
__m128d |
(__m128 a) |
|
_mm_cvtepi32_pd |
CVTDQ2PD |
__m128d |
(__m128i a) |
|
_mm_cvtpd_epi32 |
CVTPD2DQ |
__m128i |
(__m128d a) |
|
_mm_cvtsd_si32 |
CVTSD2SI |
int |
(__m128d a) |
|
_mm_cvtsd_ss |
CVTSD2SS |
__m128 |
(__m128 a, __m128d b) |
|
_mm_cvtsi32_sd |
CVTSI2SD |
__m128d |
(__m128d a, int b) |
|
_mm_cvtss_sd |
CVTSS2SD |
__m128d |
(__m128d a, __m128 b) |
|
_mm_cvttpd_epi32 |
CVTTPD2DQ |
__m128i |
(__m128d a) |
|
_mm_cvttsd_si32 |
CVTTSD2SI |
int |
(__m128d a) |
|
_mm_cvtepi32_ps |
CVTDQ2PS |
__m128 |
(__m128i a) |
|
_mm_cvtps_epi32 |
CVTPS2DQ |
__m128i |
(__m128 a) |
|
_mm_cvttps_epi32 |
CVTTPS2DQ |
__m128i |
(__m128 a) |
|
_mm_cvtpd_pi32 |
CVTPD2PI |
__m64 |
(__m128d a) |
|
_mm_cvttpd_pi32 |
CVTTPD2PI |
__m64 |
(__m128d a) |
|
_mm_cvtpi32_pd |
CVTPI2PD |
__m128d |
(__m64 a) |
__m128 _mm_cvtpd_ps ( __m128d a)
Converts the two DP FP values of a to SP FP values.
r0 := (float) a0
r1 := (float) a1
r2 := 0.0 ; r3 := 0.0
__m128d _mm_cvtps_pd ( __m128 a)
Converts the lower two SP FP values of a to DP FP values.
r0 := (double) a0
r1 := (double) a1
__m128d _mm_cvtepi32_pd ( __m128i a)
Converts the lower two signed 32-bit integer values of a to DP FP values.
r0 := (double) a0
r1 := (double) a1
__m128i _mm_cvtpd_epi32 ( __m128d a)
Converts the two DP FP values of a to 32-bit signed integer values.
r0 := (int) a0
r1 := (int) a1
r2 := 0x0 ; r3 := 0x0
int _mm_cvtsd_si32 ( __m128d a)
Converts the lower DP FP value of a to a 32-bit signed integer value.
r := (int) a0
__m128 _mm_cvtsd_ss ( __m128 a, __m128d b)
Converts the lower DP FP value of b to an SP FP value. The upper SP FP values in a are passed through.
r0 := (float) b0
r1 := a1; r2 := a2 ; r3 := a3
__m128d _mm_cvtsi32_sd ( __m128d a, int b)
Converts the signed integer value in b to a DP FP value. The upper DP FP value in a is passed through.
r0 := (double) b
r1 := a1
__m128d _mm_cvtss_sd ( __m128d a, __m128 b)
Converts the lower SP FP value of b to a DP FP value. The upper value DP FP value in a is passed through.
r0 := (double) b0
r1 := a1
__m128i _mm_cvttpd_epi32 ( __m128d a)
Converts the two DP FP values of a to 32 bit signed integers using truncate.
r0 := (int) a0
r1 := (int) a1
r2 := 0x0 ; r3 := 0x0
int _mm_cvttsd_si32 ( __m128d a)
Converts the lower DP FP value of a to a 32 bit signed integer using truncate.
r := (int) a0
__m128 _mm_cvtepi32_ps ( __m128i a)
Converts the 4 signed 32 bit integer values of a to SP FP values.
r0 := (float) a0
r1 := (float) a1
r2 := (float) a2
r3 := (float) a3
__m128i _mm_cvtps_epi32 ( __m128 a)
Converts the 4 SP FP values of a to signed 32 bit integer values.
r0 := (int) a0
r1 := (int) a1
r2 := (int) a2
r3 := (int) a3
__m128i _mm_cvttps_epi32 ( __m128 a)
Converts the 4 SP FP values of a to signed 32 bit integer values using truncate.
r0 := (int) a0
r1 := (int) a1
r2 := (int) a2
r3 := (int) a3
__m64 _mm_cvtpd_pi32 (__m128d a)
Converts the two DP FP values of a to 32-bit signed integer values.
r0 := (int) a0
r1 := (int) a1
__m64 _mm_cvttpd_pi32 (__m128d a)
Converts the two DP FP values of a to 32-bit signed integer values using truncate.
r0 := (int) a0
r1 := (int) a1
__m128d _mm_cvtpi32_pd (__m64 a)
Converts the two 32-bit signed integer values of a to DP FP values.
r0 := (double) a0
r1 := (double) a1