From: DRC Date: Thu, 18 Dec 2014 10:12:29 +0000 (+0000) Subject: AltiVec SIMD implementation of fast integer inverse DCT X-Git-Tag: 1.4.90~144 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6cb7f40a1814e528b53a0ed35fdcbb7b4d583b99;p=libjpeg-turbo AltiVec SIMD implementation of fast integer inverse DCT git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1445 632fc199-4ca6-4c93-a231-07263d6284db --- diff --git a/simd/jsimd.h b/simd/jsimd.h index 4dcdfc1..f339611 100644 --- a/simd/jsimd.h +++ b/simd/jsimd.h @@ -667,6 +667,10 @@ EXTERN(void) jsimd_idct_ifast_rows_mips_dspr2 (DCTELEM * wsptr, JSAMPARRAY output_buf, JDIMENSION output_col, const int * idct_coefs); +EXTERN(void) jsimd_idct_ifast_altivec + (void * dct_table, JCOEFPTR coef_block, JSAMPARRAY output_buf, + JDIMENSION output_col); + /* Floating Point Inverse DCT */ EXTERN(void) jsimd_idct_float_3dnow (void * dct_table, JCOEFPTR coef_block, JSAMPARRAY output_buf, diff --git a/simd/jsimd_powerpc.c b/simd/jsimd_powerpc.c index ff37c5f..eb977d7 100644 --- a/simd/jsimd_powerpc.c +++ b/simd/jsimd_powerpc.c @@ -339,6 +339,17 @@ jsimd_can_idct_islow (void) GLOBAL(int) jsimd_can_idct_ifast (void) { + init_simd(); + + /* The code is optimised for these values only */ + if (DCTSIZE != 8) + return 0; + if (sizeof(DCTELEM) != 2) + return 0; + + if (simd_support & JSIMD_ALTIVEC) + return 1; + return 0; } @@ -360,6 +371,8 @@ jsimd_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info * compptr, JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col) { + jsimd_idct_ifast_altivec(compptr->dct_table, coef_block, output_buf, + output_col); } GLOBAL(void) diff --git a/simd/jsimd_powerpc_altivec.c b/simd/jsimd_powerpc_altivec.c index 6f26bd5..b77208c 100644 --- a/simd/jsimd_powerpc_altivec.c +++ b/simd/jsimd_powerpc_altivec.c @@ -478,3 +478,217 @@ jsimd_fdct_islow_altivec (DCTELEM *data) *(__vector short *)&data[48] = out6; *(__vector short *)&data[56] = out7; } + + +/* FAST INTEGER INVERSE DCT + * + * This is similar to the SSE2 implementation, except that we left-shift the + * constants by 1 less bit (the -1 in IFAST_CONST_SHIFT.) This is because + * vec_madds(arg1, arg2, arg3) generates the 16-bit saturated sum of: + * the elements in arg3 + the most significant 17 bits of + * (the elements in arg1 * the elements in arg2). + */ + +#define F_1_082 277 /* FIX(1.082392200) */ +#define F_1_414 362 /* FIX(1.414213562) */ +#define F_1_847 473 /* FIX(1.847759065) */ +#define F_2_613 669 /* FIX(2.613125930) */ +#define F_1_613 (F_2_613 - 256) /* FIX(2.613125930) - FIX(1) */ + +#define IFAST_PASS1_BITS 2 +#define IFAST_CENTERJSAMPLE 128 + +static const __vector short jconst_idct_ifast __attribute__((aligned(16))) = +{ + F_1_414 << IFAST_CONST_SHIFT, + F_1_847 << IFAST_CONST_SHIFT, + -F_1_613 << IFAST_CONST_SHIFT, + F_1_082 << IFAST_CONST_SHIFT +}; + +static const __vector signed char jconst_idct_ifast2 + __attribute__((aligned(16))) = +{ + IFAST_CENTERJSAMPLE +}; + +#define DO_IDCT_IFAST(in) \ +{ \ + /* Even part */ \ + \ + tmp10 = vec_add(in##0, in##4); \ + tmp11 = vec_sub(in##0, in##4); \ + tmp13 = vec_add(in##2, in##6); \ + \ + tmp12 = vec_sub(in##2, in##6); \ + tmp12 = vec_sl(tmp12, PRE_MULTIPLY_SCALE_BITS); \ + tmp12 = vec_madds(tmp12, PW_F1414, zero); \ + tmp12 = vec_sub(tmp12, tmp13); \ + \ + tmp0 = vec_add(tmp10, tmp13); \ + tmp3 = vec_sub(tmp10, tmp13); \ + tmp1 = vec_add(tmp11, tmp12); \ + tmp2 = vec_sub(tmp11, tmp12); \ + \ + /* Odd part */ \ + \ + z13 = vec_add(in##5, in##3); \ + z10 = vec_sub(in##5, in##3); \ + z10s = vec_sl(z10, PRE_MULTIPLY_SCALE_BITS); \ + z11 = vec_add(in##1, in##7); \ + z12s = vec_sub(in##1, in##7); \ + z12s = vec_sl(z12s, PRE_MULTIPLY_SCALE_BITS); \ + \ + tmp11 = vec_sub(z11, z13); \ + tmp11 = vec_sl(tmp11, PRE_MULTIPLY_SCALE_BITS); \ + tmp11 = vec_madds(tmp11, PW_F1414, zero); \ + \ + tmp7 = vec_add(z11, z13); \ + \ + z5 = vec_add(z10s, z12s); \ + z5 = vec_madds(z5, PW_F1847, zero); \ + \ + tmp10 = vec_madds(z12s, PW_F1082, zero); \ + tmp10 = vec_sub(tmp10, z5); \ + tmp12 = vec_madds(z10s, PW_MF1613, zero); \ + tmp12 = vec_sub(tmp12, z10); \ + tmp12 = vec_add(tmp12, z5); \ + \ + tmp6 = vec_sub(tmp12, tmp7); \ + tmp5 = vec_sub(tmp11, tmp6); \ + tmp4 = vec_add(tmp10, tmp5); \ + \ + out0 = vec_add(tmp0, tmp7); \ + out1 = vec_add(tmp1, tmp6); \ + out2 = vec_add(tmp2, tmp5); \ + out3 = vec_sub(tmp3, tmp4); \ + out4 = vec_add(tmp3, tmp4); \ + out5 = vec_sub(tmp2, tmp5); \ + out6 = vec_sub(tmp1, tmp6); \ + out7 = vec_sub(tmp0, tmp7); \ +} + +void +jsimd_idct_ifast_altivec (void * dct_table_, JCOEFPTR coef_block, + JSAMPARRAY output_buf, JDIMENSION output_col) +{ + short *dct_table = (short *)dct_table_; + __vector short row0, row1, row2, row3, row4, row5, row6, row7, + col0, col1, col2, col3, col4, col5, col6, col7, + quant0, quant1, quant2, quant3, quant4, quant5, quant6, quant7, + tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp10, tmp11, tmp12, tmp13, + z5, z10, z10s, z11, z12s, z13, + out0, out1, out2, out3, out4, out5, out6, out7; + __vector signed char outb; + long long *outptr, *outbptr = (long long *)(&outb); + + /* Constants */ + __vector short zero = vec_splat_s16(0), + PW_F1414 = vec_splat(jconst_idct_ifast, 0), + PW_F1847 = vec_splat(jconst_idct_ifast, 1), + PW_MF1613 = vec_splat(jconst_idct_ifast, 2), + PW_F1082 = vec_splat(jconst_idct_ifast, 3); + __vector unsigned short + PRE_MULTIPLY_SCALE_BITS = vec_splat_u16(IFAST_PRE_MULTIPLY_SCALE_BITS), + PASS1_BITS3 = vec_splat_u16(IFAST_PASS1_BITS + 3); + __vector signed char PB_CENTERJSAMP = vec_splat(jconst_idct_ifast2, 0); + + /* Pass 1: process columns. */ + + col0 = *(__vector short *)&coef_block[0]; + col1 = *(__vector short *)&coef_block[8]; + col2 = *(__vector short *)&coef_block[16]; + col3 = *(__vector short *)&coef_block[24]; + col4 = *(__vector short *)&coef_block[32]; + col5 = *(__vector short *)&coef_block[40]; + col6 = *(__vector short *)&coef_block[48]; + col7 = *(__vector short *)&coef_block[56]; + + tmp1 = vec_or(col1, col2); + tmp2 = vec_or(col3, col4); + tmp1 = vec_or(tmp1, tmp2); + tmp3 = vec_or(col5, col6); + tmp3 = vec_or(tmp3, col7); + tmp1 = vec_or(tmp1, tmp3); + + quant0 = *(__vector short *)&dct_table[0]; + col0 = vec_mladd(col0, quant0, zero); + + if (vec_all_eq(tmp1, zero)) { + /* AC terms all zero */ + + row0 = vec_splat(col0, 0); + row1 = vec_splat(col0, 1); + row2 = vec_splat(col0, 2); + row3 = vec_splat(col0, 3); + row4 = vec_splat(col0, 4); + row5 = vec_splat(col0, 5); + row6 = vec_splat(col0, 6); + row7 = vec_splat(col0, 7); + + } else { + + quant1 = *(__vector short *)&dct_table[8]; + quant2 = *(__vector short *)&dct_table[16]; + quant3 = *(__vector short *)&dct_table[24]; + quant4 = *(__vector short *)&dct_table[32]; + quant5 = *(__vector short *)&dct_table[40]; + quant6 = *(__vector short *)&dct_table[48]; + quant7 = *(__vector short *)&dct_table[56]; + + col1 = vec_mladd(col1, quant1, zero); + col2 = vec_mladd(col2, quant2, zero); + col3 = vec_mladd(col3, quant3, zero); + col4 = vec_mladd(col4, quant4, zero); + col5 = vec_mladd(col5, quant5, zero); + col6 = vec_mladd(col6, quant6, zero); + col7 = vec_mladd(col7, quant7, zero); + + DO_IDCT_IFAST(col); + + TRANSPOSE(out, row); + } + + /* Pass 2: process rows. */ + + DO_IDCT_IFAST(row); + + out0 = vec_sra(out0, PASS1_BITS3); + out1 = vec_sra(out1, PASS1_BITS3); + out2 = vec_sra(out2, PASS1_BITS3); + out3 = vec_sra(out3, PASS1_BITS3); + out4 = vec_sra(out4, PASS1_BITS3); + out5 = vec_sra(out5, PASS1_BITS3); + out6 = vec_sra(out6, PASS1_BITS3); + out7 = vec_sra(out7, PASS1_BITS3); + + TRANSPOSE(out, col); + + outb = vec_packs(col0, col1); + outb = vec_add(outb, PB_CENTERJSAMP); + outptr = (long long *)(output_buf[0] + output_col); + *outptr = outbptr[0]; + outptr = (long long *)(output_buf[1] + output_col); + *outptr = outbptr[1]; + + outb = vec_packs(col2, col3); + outb = vec_add(outb, PB_CENTERJSAMP); + outptr = (long long *)(output_buf[2] + output_col); + *outptr = outbptr[0]; + outptr = (long long *)(output_buf[3] + output_col); + *outptr = outbptr[1]; + + outb = vec_packs(col4, col5); + outb = vec_add(outb, PB_CENTERJSAMP); + outptr = (long long *)(output_buf[4] + output_col); + *outptr = outbptr[0]; + outptr = (long long *)(output_buf[5] + output_col); + *outptr = outbptr[1]; + + outb = vec_packs(col6, col7); + outb = vec_add(outb, PB_CENTERJSAMP); + outptr = (long long *)(output_buf[6] + output_col); + *outptr = outbptr[0]; + outptr = (long long *)(output_buf[7] + output_col); + *outptr = outbptr[1]; +}