From a55a04644e0bc7341397666e8236cbf1ff5e718c Mon Sep 17 00:00:00 2001 From: "Steinar H. Gunderson" Date: Sun, 27 Sep 2009 21:58:13 +0200 Subject: [PATCH] Use SSE intrinsics instead of asm() for vertical SSE, finally offloading the register allocation to the compiler. The speed gain is immeasurable, but it sounds like a better idea in general. --- README | 3 -- libqscale.c | 139 ++++++++++++++++++++-------------------------------- 2 files changed, 52 insertions(+), 90 deletions(-) diff --git a/README b/README index 98b88c3..be6feb9 100644 --- a/README +++ b/README @@ -75,9 +75,6 @@ The following optimizations are possible but not done (yet?): filter kernel is large (ie. large amounts of scaling). - qscale does not use multiple processors or cores (although different cores can of course work on different images at the same time). - - qscale does not make very good use of the extra eight SSE registers found - on 64-bit x86-compatible (usually called amd64 or x86-64) machines. In - fact, out of the box it might not even compile on such machines. Finally, a word of advice: Even the fastest scaler can never be as fast as not scaling. If you can do less work, or move it to a time where it is less user diff --git a/libqscale.c b/libqscale.c index 47b6fe8..9a37853 100644 --- a/libqscale.c +++ b/libqscale.c @@ -42,6 +42,13 @@ #define M_PI 3.14159265358979323846264 #endif +#if USE_VERTICAL_SSE || USE_HORIZONTAL_SSE +typedef float v4sf __attribute__((vector_size(16))); +typedef int v4si __attribute__((vector_size(16))); +typedef short v8hi __attribute__((vector_size(16))); +typedef char v16qi __attribute__((vector_size(16))); +#endif + qscale_img *qscale_load_jpeg(const char *filename) { FILE *file = fopen(filename, "rb"); @@ -411,93 +418,51 @@ static void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsi float *dptr = npix + x; for (y = 0; y < nh; ++y) { #if USE_VERTICAL_SSE - /* - * xmm0 - xmm3: acc[0..15] - * xmm4: current filter coefficient - * xmm5, xmm6, xmm7: scratchpad - */ - __asm__ ( - /* clear */ - "pxor %%xmm0, %%xmm0 \n" - "pxor %%xmm1, %%xmm1 \n" - "pxor %%xmm2, %%xmm2 \n" - "pxor %%xmm3, %%xmm3 \n" - - /* main loop */ - "0: \n" - - /* a zero is useful during unpacking */ - "pxor %%xmm4, %%xmm4 \n" - - /* fetch all 16 source bytes */ - "movups (%0), %%xmm5 \n" - "prefetcht0 (%0,%3,4) \n" - - /* unpack into words (xmm5, xmm7) */ - "movaps %%xmm5, %%xmm7 \n" - "punpcklbw %%xmm4, %%xmm5 \n" - "punpckhbw %%xmm4, %%xmm7 \n" - - /* unpack xmm5 into dwords (xmm5, xmm6) */ - "movaps %%xmm5, %%xmm6 \n" - "punpcklwd %%xmm4, %%xmm5 \n" - "punpckhwd %%xmm4, %%xmm6 \n" - - /* convert xmm5, xmm6 to floats */ - "cvtdq2ps %%xmm5, %%xmm5 \n" - "cvtdq2ps %%xmm6, %%xmm6 \n" - - /* fetch the coefficient */ - "movss (%2), %%xmm4 \n" - "shufps $0x0, %%xmm4, %%xmm4 \n" - - /* do the muls for xmm5 and xmm6 */ - "mulps %%xmm4, %%xmm5 \n" - "mulps %%xmm4, %%xmm6 \n" - "addps %%xmm5, %%xmm0 \n" - "addps %%xmm6, %%xmm1 \n" - - /* get the zero back again */ - "pxor %%xmm4, %%xmm4 \n" - - /* unpack xmm7 into dwords (xmm7, xmm6) */ - "movaps %%xmm7, %%xmm6 \n" - "punpcklwd %%xmm4, %%xmm7 \n" - "punpckhwd %%xmm4, %%xmm6 \n" - - /* convert xmm7, xmm6 to floats */ - "cvtdq2ps %%xmm7, %%xmm7 \n" - "cvtdq2ps %%xmm6, %%xmm6 \n" - - /* fetch the coefficient */ - "movss (%2), %%xmm4 \n" - "shufps $0x0, %%xmm4, %%xmm4 \n" - - /* do the second set of muls */ - "mulps %%xmm4, %%xmm7 \n" - "mulps %%xmm4, %%xmm6 \n" - "addps %%xmm7, %%xmm2 \n" - "addps %%xmm6, %%xmm3 \n" - - /* move along, and loop */ - "add $4, %2 \n" - "add %3, %0 \n" - "dec %1 \n" - "jnz 0b \n" - - /* store the values */ - "movaps %%xmm0, (%4) \n" - "movaps %%xmm1, 16(%4) \n" - "movaps %%xmm2, 32(%4) \n" - "movaps %%xmm3, 48(%4) \n" - : : - "r" (&sptr[pd[y].start * w]), /* 0: srcptr base */ - "r" (pd[y].end - pd[y].start + 1), /* 1: filter len */ - "r" (&coeffs[pd[y].startcoeff]), /* 2: coeffs base */ - "r" ((long)w), /* 3: stride */ - "r" (dptr) /* 4: dstptr base */ - : "memory", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7" - ); + /* A zero is useful during unpacking. */ + static const v4sf zero = { 0.0f, 0.0f, 0.0f, 0.0f }; + const unsigned char *sptr_xmm = &sptr[pd[y].start * w]; + const float *coeffptr = &coeffs[pd[y].startcoeff]; + const int filter_len = pd[y].end - pd[y].start + 1; + int i; + + v4sf acc0 = { 0.0f, 0.0f, 0.0f, 0.0f }; + v4sf acc1 = { 0.0f, 0.0f, 0.0f, 0.0f }; + v4sf acc2 = { 0.0f, 0.0f, 0.0f, 0.0f }; + v4sf acc3 = { 0.0f, 0.0f, 0.0f, 0.0f }; + + for (i = 0; i < filter_len; ++i, ++coeffptr, sptr_xmm += w) { + __builtin_prefetch(sptr_xmm + w, 0); + v16qi src = (v16qi)__builtin_ia32_loadups((float*)sptr_xmm); + + // unpack into words + v8hi src_lo = (v8hi)__builtin_ia32_punpcklbw128(src, (v16qi)zero); + v8hi src_hi = (v8hi)__builtin_ia32_punpckhbw128(src, (v16qi)zero); + + // unpack into dwords, convert to floats + v4si src0_i = (v4si)__builtin_ia32_punpcklwd128(src_lo, (v8hi)zero); + v4si src1_i = (v4si)__builtin_ia32_punpckhwd128(src_lo, (v8hi)zero); + v4si src2_i = (v4si)__builtin_ia32_punpcklwd128(src_hi, (v8hi)zero); + v4si src3_i = (v4si)__builtin_ia32_punpckhwd128(src_hi, (v8hi)zero); + + v4sf src0 = __builtin_ia32_cvtdq2ps(src0_i); + v4sf src1 = __builtin_ia32_cvtdq2ps(src1_i); + v4sf src2 = __builtin_ia32_cvtdq2ps(src2_i); + v4sf src3 = __builtin_ia32_cvtdq2ps(src3_i); + + // fetch the coefficient, and replicate it + v4sf coeff = { *coeffptr, *coeffptr, *coeffptr, *coeffptr }; + + // do the actual muladds + acc0 = __builtin_ia32_addps(acc0, __builtin_ia32_mulps(src0, coeff)); + acc1 = __builtin_ia32_addps(acc1, __builtin_ia32_mulps(src1, coeff)); + acc2 = __builtin_ia32_addps(acc2, __builtin_ia32_mulps(src2, coeff)); + acc3 = __builtin_ia32_addps(acc3, __builtin_ia32_mulps(src3, coeff)); + } + + *(v4sf *)(&dptr[0]) = acc0; + *(v4sf *)(&dptr[4]) = acc1; + *(v4sf *)(&dptr[8]) = acc2; + *(v4sf *)(&dptr[12]) = acc3; #else int i; float acc[CACHE_LINE_FACTOR]; -- 2.39.2