Developer Guide and Reference

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Floating Point Rounding Intrinsics

These Intel® Streaming SIMD Extensions 4 (Intel® SSE4) rounding intrinsics cover scalar and packed single-precision and double-precision floating-point operands. The prototypes for these intrinsics are in the
smmintrin.h
file.
To use these intrinsics, include the
immintrin.h
file as follows:
#include <immintrin.h>
The
floor
and
ceil
intrinsics correspond to the definitions of
floor
and
ceil
in the ISO 9899:1999 standard for the C programming language.
Intrinsic Syntax
Operation
Corresponding
Intel® SSE4 Instruction
__m128d _mm_round_pd(__m128d s1, int iRoundMode)
__m128d _mm_floor_pd(__m128d s1)
__m128d _mm_ceil_pd(__m128d s1)
Packed double-precision float rounding
ROUNDPD
__m128 _mm_round_ps(__m128 s1, int iRoundMode)
__m128 _mm_floor_ps(__m128 s1)
__m128 _mm_ceil_ps(__m128 s1)
Packed single-precision float rounding
ROUNDPS
__m128d _mm_round_sd(__m128d dst, __m128d s1, int iRoundMode)
__m128d _mm_floor_sd(__m128d dst, __m128d s1)