diff options
Diffstat (limited to 'src/gallium/auxiliary/util')
| -rw-r--r-- | src/gallium/auxiliary/util/u_sse.h | 92 |
1 files changed, 80 insertions, 12 deletions
diff --git a/src/gallium/auxiliary/util/u_sse.h b/src/gallium/auxiliary/util/u_sse.h index 7f8e5a1a3cf..cae4138ba01 100644 --- a/src/gallium/auxiliary/util/u_sse.h +++ b/src/gallium/auxiliary/util/u_sse.h @@ -166,14 +166,49 @@ _mm_shuffle_epi8(__m128i a, __m128i mask) #endif /* !PIPE_ARCH_SSSE3 */ +/* + * Provide an SSE implementation of _mm_mul_epi32() in terms of + * _mm_mul_epu32(). + * + * Basically, albeit surprising at first (and second, and third...) look + * if a * b is done signed instead of unsigned, can just + * subtract b from the high bits of the result if a is negative + * (and the same for a if b is negative). Modular arithmetic at its best! + * + * So for int32 a,b in crude pseudo-code ("*" here denoting a widening mul) + * fixupb = (signmask(b) & a) << 32ULL + * fixupa = (signmask(a) & b) << 32ULL + * a * b = (unsigned)a * (unsigned)b - fixupb - fixupa + * = (unsigned)a * (unsigned)b -(fixupb + fixupa) + * + * This does both lo (dwords 0/2) and hi parts (1/3) at the same time due + * to some optimization potential. + */ +static inline __m128i +mm_mullohi_epi32(const __m128i a, const __m128i b, __m128i *res13) +{ + __m128i a13, b13, mul02, mul13; + __m128i anegmask, bnegmask, fixup, fixup02, fixup13; + a13 = _mm_shuffle_epi32(a, _MM_SHUFFLE(2,3,0,1)); + b13 = _mm_shuffle_epi32(b, _MM_SHUFFLE(2,3,0,1)); + anegmask = _mm_srai_epi32(a, 31); + bnegmask = _mm_srai_epi32(b, 31); + fixup = _mm_add_epi32(_mm_and_si128(anegmask, b), + _mm_and_si128(bnegmask, a)); + mul02 = _mm_mul_epu32(a, b); + mul13 = _mm_mul_epu32(a13, b13); + fixup02 = _mm_slli_epi64(fixup, 32); + fixup13 = _mm_and_si128(fixup, _mm_set_epi32(-1,0,-1,0)); + *res13 = _mm_sub_epi64(mul13, fixup13); + return _mm_sub_epi64(mul02, fixup02); +} /* Provide an SSE2 implementation of _mm_mullo_epi32() in terms of * _mm_mul_epu32(). * - * I suspect this works fine for us because one of our operands is - * always positive, but not sure that this can be used for general - * signed integer multiplication. + * This always works regardless the signs of the operands, since + * the high bits (which would be different) aren't used. * * This seems close enough to the speed of SSE4 and the real * _mm_mullo_epi32() intrinsic as to not justify adding an sse4 @@ -188,6 +223,12 @@ static inline __m128i mm_mullo_epi32(const __m128i a, const __m128i b) /* Interleave the results, either with shuffles or (slightly * faster) direct bit operations: + * XXX: might be only true for some cpus (in particular 65nm + * Core 2). On most cpus (including that Core 2, but not Nehalem...) + * using _mm_shuffle_ps/_mm_shuffle_epi32 might also be faster + * than using the 3 instructions below. But logic should be fine + * as well, we can't have optimal solution for all cpus (if anything, + * should just use _mm_mullo_epi32() if sse41 is available...). */ #if 0 __m128i ba8 = _mm_shuffle_epi32(ba, 8); @@ -214,17 +255,44 @@ transpose4_epi32(const __m128i * restrict a, __m128i * restrict q, __m128i * restrict r) { - __m128i t0 = _mm_unpacklo_epi32(*a, *b); - __m128i t1 = _mm_unpacklo_epi32(*c, *d); - __m128i t2 = _mm_unpackhi_epi32(*a, *b); - __m128i t3 = _mm_unpackhi_epi32(*c, *d); - - *o = _mm_unpacklo_epi64(t0, t1); - *p = _mm_unpackhi_epi64(t0, t1); - *q = _mm_unpacklo_epi64(t2, t3); - *r = _mm_unpackhi_epi64(t2, t3); + __m128i t0 = _mm_unpacklo_epi32(*a, *b); + __m128i t1 = _mm_unpacklo_epi32(*c, *d); + __m128i t2 = _mm_unpackhi_epi32(*a, *b); + __m128i t3 = _mm_unpackhi_epi32(*c, *d); + + *o = _mm_unpacklo_epi64(t0, t1); + *p = _mm_unpackhi_epi64(t0, t1); + *q = _mm_unpacklo_epi64(t2, t3); + *r = _mm_unpackhi_epi64(t2, t3); } + +/* + * Same as above, except the first two values are already interleaved + * (i.e. contain 64bit values). + */ +static inline void +transpose2_64_2_32(const __m128i * restrict a01, + const __m128i * restrict a23, + const __m128i * restrict c, + const __m128i * restrict d, + __m128i * restrict o, + __m128i * restrict p, + __m128i * restrict q, + __m128i * restrict r) +{ + __m128i t0 = *a01; + __m128i t1 = _mm_unpacklo_epi32(*c, *d); + __m128i t2 = *a23; + __m128i t3 = _mm_unpackhi_epi32(*c, *d); + + *o = _mm_unpacklo_epi64(t0, t1); + *p = _mm_unpackhi_epi64(t0, t1); + *q = _mm_unpacklo_epi64(t2, t3); + *r = _mm_unpackhi_epi64(t2, t3); +} + + #define SCALAR_EPI32(m, i) _mm_shuffle_epi32((m), _MM_SHUFFLE(i,i,i,i)) |