path: root/recipes/libxine/files/libxine-libavcodec.patch

TO be MERGED!!!


#
# Patch managed by http://www.holgerschurig.de/patcher.html
#

--- xine-lib-1-rc7/src/libffmpeg/libavcodec/Makefile.am~libxine-libavcodec
+++ xine-lib-1-rc7/src/libffmpeg/libavcodec/Makefile.am
@@ -9,9 +9,14 @@
 # we need to compile everything in debug mode, including the encoders,
 # otherwise we get unresolved symbols, because some unsatisfied function calls
 # are not optimized away with debug optimization
-AM_CFLAGS = $(LIBFFMPEG_CFLAGS) `test "$(CFLAGS)" = "$(DEBUG_CFLAGS)" && echo -DCONFIG_ENCODERS`
+#AM_CFLAGS = $(LIBFFMPEG_CFLAGS) `test "$(CFLAGS)" = "$(DEBUG_CFLAGS)" && echo -DCONFIG_ENCODERS`
 ASFLAGS =
 
+if HAVE_ARMV4L
+AM_CFLAGS = -DARCH_ARMV4L $(LIBFFMPEG_CFLAGS)
+else
+AM_CFLAGS = $(LIBFFMPEG_CFLAGS)
+endif
 noinst_LTLIBRARIES = libavcodec.la
 
 libavcodec_la_SOURCES = \
--- xine-lib-1-rc7/src/libffmpeg/libavcodec/dsputil.h~libxine-libavcodec
+++ xine-lib-1-rc7/src/libffmpeg/libavcodec/dsputil.h
@@ -45,6 +45,7 @@
 void ff_fdct248_islow (DCTELEM *data);
 
 void j_rev_dct (DCTELEM *data);
+void j_rev_dct_ARM ( DCTELEM *data );
 
 void ff_fdct_mmx(DCTELEM *block);
 void ff_fdct_mmx2(DCTELEM *block);
--- xine-lib-1-rc7/src/libffmpeg/libavcodec/mpegvideo.c~libxine-libavcodec
+++ xine-lib-1-rc7/src/libffmpeg/libavcodec/mpegvideo.c
@@ -218,6 +218,25 @@
 }
 #endif //CONFIG_ENCODERS
 
+
+#ifdef ARCH_ARMV4L
+
+static void ff_jref_idct_put_armv4l(UINT8 *dest, int line_size, DCTELEM *block)
+{
+//    fprintf(stderr, "src/libffmpeg/libavcodec/mpegvideo.c : ff_jref_idct_put_armv4l utilisant l'iDCT ARMv4l en ASM\n");
+    j_rev_dct_ARM (block);
+    ff_put_pixels_clamped(block, dest, line_size);
+}
+static void ff_jref_idct_add_armv4l(UINT8 *dest, int line_size, DCTELEM *block)
+{
+//    fprintf(stderr, "src/libffmpeg/libavcodec/mpegvideo.c : ff_jref_idct_add_armv4l utilisant l'iDCT ARMv4l en ASM\n");
+    j_rev_dct_ARM (block);
+    ff_add_pixels_clamped(block, dest, line_size);
+}
+
+#endif
+
+
 /* init common dct for both encoder and decoder */
 int DCT_common_init(MpegEncContext *s)
 {
@@ -246,7 +265,11 @@
     MPV_common_init_mmi(s);
 #endif
 #ifdef ARCH_ARMV4L
-    MPV_common_init_armv4l(s);
+/*    MPV_common_init_armv4l(s); */
+/* Methode bourrine, mais bon, c'est pour pas trop se prendre la tete a tout changer ce soir, a ameliorer plus tard*/
+    s->idct_put= ff_jref_idct_put_armv4l;
+    s->idct_add= ff_jref_idct_add_armv4l;
+    s->idct_permutation_type= FF_NO_IDCT_PERM;
 #endif
 #ifdef ARCH_POWERPC
     MPV_common_init_ppc(s);
--- xine-lib-1-rc7/src/libffmpeg/libavcodec/armv4l/jrevdct_arm.S~libxine-libavcodec
+++ xine-lib-1-rc7/src/libffmpeg/libavcodec/armv4l/jrevdct_arm.S
@@ -1,386 +1,491 @@
 /* 
-   C-like prototype :
-	void j_rev_dct_ARM(DCTBLOCK data)
+ * jrevdct_arm.S
+ * Copyright (C) 2002 Frederic 'dilb' Boulay.
+ * All Rights Reserved.
+ *
+ * Author: Frederic Boulay <dilb@handhelds.org>
+ *
+ * you can redistribute this file and/or modify
+ * it under the terms of the GNU General Public License (version 2)
+ * as published by the Free Software Foundation.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ * The function defined in this file, is derived from the simple_idct function from
+ * the libavcodec library part of the ffmpeg project. 
+ */
 
-   With DCTBLOCK being a pointer to an array of 64 'signed shorts'
 
-   Copyright (c) 2001 Lionel Ulmer (lionel.ulmer@free.fr / bbrox@bbrox.org)
 
-   Permission is hereby granted, free of charge, to any person obtaining a copy
-   of this software and associated documentation files (the "Software"), to deal
-   in the Software without restriction, including without limitation the rights
-   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-   copies of the Software, and to permit persons to whom the Software is
-   furnished to do so, subject to the following conditions:
 
-   The above copyright notice and this permission notice shall be included in
-   all copies or substantial portions of the Software.
+/* useful constants for the algorithm, they are save in __constant_ptr__ at the end of the source code.*/
+#define W1  22725
+#define W2  21407
+#define W3  19266
+#define W4  16383
+#define W5  12873
+#define W6  8867
+#define W7  4520
+#define MASK_MSHW 0xFFFF0000
+
+/* offsets of the constants in the vector*/
+#define offW1  0
+#define offW2  4
+#define offW3  8
+#define offW4  12
+#define offW5  16
+#define offW6  20
+#define offW7  24
+#define offMASK_MSHW 28
+
+#define ROW_SHIFT 11
+#define ROW_SHIFT2MSHW (16-11)
+#define COL_SHIFT 20
+#define ROW_SHIFTED_1 1024 /* 1<< (ROW_SHIFT-1)*/
+#define COL_SHIFTED_1 524288 /* 1<< (COL_SHIFT-1)*/
+
 
-   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-   COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-	
-*/
-#define FIX_0_298631336 2446
-#define FIX_0_541196100 4433
-#define FIX_0_765366865 6270
-#define FIX_1_175875602 9633
-#define FIX_1_501321110 12299
-#define FIX_2_053119869 16819
-#define FIX_3_072711026 25172
-#define FIX_M_0_390180644 -3196
-#define FIX_M_0_899976223 -7373
-#define FIX_M_1_847759065 -15137
-#define FIX_M_1_961570560 -16069
-#define FIX_M_2_562915447 -20995
-#define FIX_0xFFFF 0xFFFF	
-		
-#define FIX_0_298631336_ID      0
-#define FIX_0_541196100_ID      4
-#define FIX_0_765366865_ID      8
-#define FIX_1_175875602_ID     12
-#define FIX_1_501321110_ID     16
-#define FIX_2_053119869_ID     20
-#define FIX_3_072711026_ID     24
-#define FIX_M_0_390180644_ID   28
-#define FIX_M_0_899976223_ID   32
-#define FIX_M_1_847759065_ID   36
-#define FIX_M_1_961570560_ID   40
-#define FIX_M_2_562915447_ID   44
-#define FIX_0xFFFF_ID          48
 	.text
 	.align
-	
 	.global j_rev_dct_ARM
+
 j_rev_dct_ARM:
-	stmdb   sp!, { r4 - r12, lr }   @ all callee saved regs
+simple_idct3:
+simple_idct_ARM:
+        @@ void simple_idct_ARM(int16_t *block)
+        @@ save stack for reg needed (take all of them),
+        @@ R0-R3 are scratch regs, so no need to save them, but R0 contains the pointer to block
+        @@ so it must not be overwritten, if it is not saved!!
+        @@ R12 is another scratch register, so it should not be saved too
+        @@ save all registers
+        stmfd sp!, {r4-r11, r14} @ R14 is also called LR
+        @@ at this point, R0=block, other registers are free.
+        add r14, r0, #112        @ R14=&block[8*7], better start from the last row, and decrease the value until row=0, i.e. R12=block.
+        add r12, pc, #(__constant_ptr__-.-8) @ R12=__constant_ptr__, the vector containing the constants, probably not necessary to reserve a register for it
+        @@ add 2 temporary variables in the stack: R0 and R14
+        sub sp, sp, #8          @ allow 2 local variables
+        str r0, [sp, #0]        @ save block in sp[0]
+        @@ stack status
+        @@ sp+4   free
+        @@ sp+0   R0  (block)
 
-	sub sp, sp, #4                  @ reserve some space on the stack
-	str r0, [ sp ]                  @ save the DCT pointer to the stack
 
-	mov lr, r0                      @ lr = pointer to the current row
-	mov r12, #8                     @ r12 = row-counter
-	add r11, pc, #(const_array-.-8) @ r11 = base pointer to the constants array	
-row_loop:
-	ldrsh r0, [lr, # 0]             @ r0 = 'd0'
-	ldrsh r1, [lr, # 8]             @ r1 = 'd1'
+        @@ at this point, R0=block, R14=&block[56], R12=__const_ptr_, R1-R11 free
 
-	@ Optimization for row that have all items except the first set to 0
-	@ (this works as the DCTELEMS are always 4-byte aligned)
-	ldr r5, [lr, # 0]
-	ldr r2, [lr, # 4]
-	ldr r3, [lr, # 8]
-	ldr r4, [lr, #12]
-	orr r3, r3, r4
-	orr r3, r3, r2
-	orrs r5, r3, r5
-	beq end_of_row_loop             @ nothing to be done as ALL of them are '0'
-	orrs r2, r3, r1
-	beq empty_row
-	
-	ldrsh r2, [lr, # 2]             @ r2 = 'd2'
-	ldrsh r4, [lr, # 4]             @ r4 = 'd4'
-	ldrsh r6, [lr, # 6]             @ r6 = 'd6'
-	
-	ldr r3, [r11, #FIX_0_541196100_ID]
-	add r7, r2, r6
-	ldr r5, [r11, #FIX_M_1_847759065_ID]
-	mul r7, r3, r7                      @ r7 = z1
-	ldr r3, [r11, #FIX_0_765366865_ID]
-	mla r6, r5, r6, r7                  @ r6 = tmp2
-	add r5, r0, r4                      @ r5 = tmp0
-	mla r2, r3, r2, r7                  @ r2 = tmp3
-	sub r3, r0, r4                      @ r3 = tmp1
 
-	add r0, r2, r5, lsl #13             @ r0 = tmp10
-	rsb r2, r2, r5, lsl #13             @ r2 = tmp13
-	add r4, r6, r3, lsl #13             @ r4 = tmp11
-	rsb r3, r6, r3, lsl #13             @ r3 = tmp12
+__row_loop:
+        @@ read the row and check if it is null, almost null, or not, according to strongarm specs, it is not necessary to optimise ldr accesses (i.e. split 32bits in 2 16bits words), at least it gives more usable registers :)
+        ldr r1, [r14, #0]        @ R1=(int32)(R12)[0]=ROWr32[0] (relative row cast to a 32b pointer)
+        ldr r2, [r14, #4]        @ R2=(int32)(R12)[1]=ROWr32[1]
+        ldr r3, [r14, #8]        @ R3=ROWr32[2]
+        ldr r4, [r14, #12]       @ R4=ROWr32[3]
+        @@ check if the words are null, if all of them are null, then proceed with next row (branch __end_row_loop),
+        @@ if ROWr16[0] is the only one not null, then proceed with this special case (branch __almost_empty_row)
+        @@ else follow the complete algorithm.
+        @@ at this point, R0=block, R14=&block[n], R12=__const_ptr_, R1=ROWr32[0], R2=ROWr32[1],
+        @@                R3=ROWr32[2], R4=ROWr32[3], R5-R11 free
+        orr r5, r4, r3           @ R5=R4 | R3
+        orr r5, r5, r2           @ R5=R4 | R3 | R2
+        orrs r6, r5, r1          @ Test R5 | R1 (the aim is to check if everything is null)
+        beq __end_row_loop
+        mov r7, r1, asr #16      @ R7=R1>>16=ROWr16[1] (evaluate it now, as it could be useful later)
+        ldrsh r6, [r14, #0]      @ R6=ROWr16[0]
+        orrs r5, r5, r7          @ R5=R4 | R3 | R2 | R7
+        beq __almost_empty_row
 
-	stmdb   sp!, { r0, r2, r3, r4 } @ save on the stack tmp10, tmp13, tmp12, tmp11
-	
-	ldrsh r3, [lr, #10]             @ r3 = 'd3'
-	ldrsh r5, [lr, #12]             @ r5 = 'd5'
-	ldrsh r7, [lr, #14]             @ r7 = 'd7'
+__b_evaluation:
+        @@ at this point, R0=block (temp),  R1(free), R2=ROWr32[1], R3=ROWr32[2], R4=ROWr32[3],
+        @@     R5=(temp), R6=ROWr16[0], R7=ROWr16[1], R8-R11 free,
+        @@     R12=__const_ptr_, R14=&block[n]
+        @@ to save some registers/calls, proceed with b0-b3 first, followed by a0-a3
 
-	add r0, r3, r5	                @ r0 = 'z2'
-	add r2, r1, r7                  @ r2 = 'z1'
-	add r4, r3, r7                  @ r4 = 'z3'
-	add r6, r1, r5                  @ r6 = 'z4'
-	ldr r9, [r11, #FIX_1_175875602_ID]
-	add r8, r4, r6                  @ r8 = z3 + z4
-	ldr r10, [r11, #FIX_M_0_899976223_ID]
-	mul r8, r9, r8                  @ r8 = 'z5'
-	ldr r9, [r11, #FIX_M_2_562915447_ID]
-	mul r2, r10, r2                 @ r2 = 'z1'
-	ldr r10, [r11, #FIX_M_1_961570560_ID]
-	mul r0, r9, r0                  @ r0 = 'z2'
-	ldr r9, [r11, #FIX_M_0_390180644_ID]
-	mla r4, r10, r4, r8             @ r4 = 'z3'
-	ldr r10, [r11, #FIX_0_298631336_ID]
-	mla r6, r9, r6, r8              @ r6 = 'z4'
-	ldr r9, [r11, #FIX_2_053119869_ID]
-	mla r7, r10, r7, r2             @ r7 = tmp0 + z1
-	ldr r10, [r11, #FIX_3_072711026_ID]
-	mla r5, r9, r5, r0              @ r5 = tmp1 + z2
-	ldr r9, [r11, #FIX_1_501321110_ID]
-	mla r3, r10, r3, r0             @ r3 = tmp2 + z2
-	add r7, r7, r4                  @ r7 = tmp0
-	mla r1, r9, r1, r2              @ r1 = tmp3 + z1
-	add r5,	r5, r6                  @ r5 = tmp1
-	add r3, r3, r4                  @ r3 = tmp2
-	add r1, r1, r6                  @ r1 = tmp3
+        @@ MUL16(b0, W1, row[1]);
+        @@ MUL16(b1, W3, row[1]);
+        @@ MUL16(b2, W5, row[1]);
+        @@ MUL16(b3, W7, row[1]);
+        @@ MAC16(b0, W3, row[3]);
+        @@ MAC16(b1, -W7, row[3]);
+        @@ MAC16(b2, -W1, row[3]);
+        @@ MAC16(b3, -W5, row[3]);
+        ldr r8, [r12, #offW1]    @ R8=W1
+        mov r2, r2, asr #16      @ R2=ROWr16[3]
+        mul r0, r8, r7           @ R0=W1*ROWr16[1]=b0 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+        ldr r9, [r12, #offW3]    @ R9=W3
+        ldr r10, [r12, #offW5]   @ R10=W5
+        mul r1, r9, r7           @ R1=W3*ROWr16[1]=b1 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+        ldr r11, [r12, #offW7]   @ R11=W7
+        mul r5, r10, r7          @ R5=W5*ROWr16[1]=b2 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+        mul r7, r11, r7          @ R7=W7*ROWr16[1]=b3 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+		teq r2, #0               @ if null avoid muls
+		mlane r0, r9, r2, r0     @ R0+=W3*ROWr16[3]=b0 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+        rsbne r2, r2, #0         @ R2=-ROWr16[3]
+        mlane r1, r11, r2, r1    @ R1-=W7*ROWr16[3]=b1 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+        mlane r5, r8, r2, r5     @ R5-=W1*ROWr16[3]=b2 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+        mlane r7, r10, r2, r7    @ R7-=W5*ROWr16[3]=b3 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
 
-	ldmia sp!, { r0, r2, r4, r6 } @ r0 = tmp10 / r2 = tmp13 / r4 = tmp12 / r6 = tmp11
-	                              @ r1 = tmp3  / r3 = tmp2  / r5 = tmp1  / r7 = tmp0
-	
-	@ Compute DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS)
-	add r8, r0, r1
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, # 0]
-	
-	@ Compute DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS)
-	sub r8, r0, r1
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, #14]
-	
-	@ Compute DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS)
-	add r8, r6, r3
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, # 2]
-	
-	@ Compute DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS)
-	sub r8, r6, r3
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, #12]
-	
-	@ Compute DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS)
-	add r8, r4, r5
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, # 4]
-	
-	@ Compute DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS)
-	sub r8, r4, r5
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, #10]
-	
-	@ Compute DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS)
-	add r8, r2, r7
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, # 6]
-	
-	@ Compute DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS)
-	sub r8, r2, r7
-	add r8, r8, #(1<<10)
-	mov r8, r8, asr #11
-	strh r8, [lr, # 8]
+        @@ at this point, R0=b0,  R1=b1, R2 (free), R3=ROWr32[2], R4=ROWr32[3],
+        @@     R5=b2, R6=ROWr16[0], R7=b3, R8=W1, R9=W3, R10=W5, R11=W7,
+        @@     R12=__const_ptr_, R14=&block[n]
+        @@ temp = ((uint32_t*)row)[2] | ((uint32_t*)row)[3];
+        @@ if (temp != 0) {}
+        orrs r2, r3, r4          @ R2=ROWr32[2] | ROWr32[3]
+        beq __end_b_evaluation
 
-	@ End of row loop
-	add lr, lr, #16
-	subs r12, r12, #1
-	bne row_loop
-	beq start_column_loop
-	
-empty_row:
-	ldr r1, [r11, #FIX_0xFFFF_ID]
-	mov r0, r0, lsl #2
-	and r0, r0, r1
-	add r0, r0, r0, lsl #16
-	str r0, [lr, # 0]
-	str r0, [lr, # 4]
-	str r0, [lr, # 8]
-	str r0, [lr, #12]
+        @@ at this point, R0=b0,  R1=b1, R2 (free), R3=ROWr32[2], R4=ROWr32[3],
+        @@     R5=b2, R6=ROWr16[0], R7=b3, R8=W1, R9=W3, R10=W5, R11=W7,
+        @@     R12=__const_ptr_, R14=&block[n]
+        @@ MAC16(b0, W5, row[5]);
+        @@ MAC16(b2, W7, row[5]);
+        @@ MAC16(b3, W3, row[5]);
+        @@ MAC16(b1, -W1, row[5]);
+        @@ MAC16(b0, W7, row[7]);
+        @@ MAC16(b2, W3, row[7]);
+        @@ MAC16(b3, -W1, row[7]);
+        @@ MAC16(b1, -W5, row[7]);
+        mov r3, r3, asr #16      @ R3=ROWr16[5]
+		teq r3, #0               @ if null avoid muls
+        mlane r0, r10, r3, r0    @ R0+=W5*ROWr16[5]=b0
+        mov r4, r4, asr #16      @ R4=ROWr16[7]
+        mlane r5, r11, r3, r5    @ R5+=W7*ROWr16[5]=b2
+        mlane r7, r9, r3, r7     @ R7+=W3*ROWr16[5]=b3
+        rsbne r3, r3, #0         @ R3=-ROWr16[5]
+        mlane r1, r8, r3, r1     @ R7-=W1*ROWr16[5]=b1
+        @@ R3 is free now
+		teq r4, #0               @ if null avoid muls
+        mlane r0, r11, r4, r0    @ R0+=W7*ROWr16[7]=b0
+        mlane r5, r9, r4, r5     @ R5+=W3*ROWr16[7]=b2
+        rsbne r4, r4, #0         @ R4=-ROWr16[7]
+        mlane r7, r8, r4, r7     @ R7-=W1*ROWr16[7]=b3
+        mlane r1, r10, r4, r1    @ R1-=W5*ROWr16[7]=b1
+        @@ R4 is free now
+__end_b_evaluation:
+        @@ at this point, R0=b0,  R1=b1, R2=ROWr32[2] | ROWr32[3] (tmp), R3 (free), R4 (free),
+        @@     R5=b2, R6=ROWr16[0], R7=b3, R8 (free), R9 (free), R10 (free), R11 (free),
+        @@     R12=__const_ptr_, R14=&block[n]
 
-end_of_row_loop:
-	@ End of loop
-	add lr, lr, #16
-	subs r12, r12, #1
-	bne row_loop
+__a_evaluation:
+        @@ a0 = (W4 * row[0]) + (1 << (ROW_SHIFT - 1));
+        @@ a1 = a0 + W6 * row[2];
+        @@ a2 = a0 - W6 * row[2];
+        @@ a3 = a0 - W2 * row[2];
+        @@ a0 = a0 + W2 * row[2];
+        ldr r9, [r12, #offW4]    @ R9=W4
+        mul r6, r9, r6           @ R6=W4*ROWr16[0]
+        ldr r10, [r12, #offW6]   @ R10=W6
+        ldrsh r4, [r14, #4]      @ R4=ROWr16[2] (a3 not defined yet)
+        add r6, r6, #ROW_SHIFTED_1 @ R6=W4*ROWr16[0] + 1<<(ROW_SHIFT-1) (a0)
 
-start_column_loop:
-	@ Start of column loop
-	ldr lr, [ sp ]
-	mov r12, #8
-column_loop:
-	ldrsh r0, [lr, #( 0*8)]             @ r0 = 'd0'
-	ldrsh r2, [lr, #( 4*8)]             @ r2 = 'd2'
-	ldrsh r4, [lr, #( 8*8)]             @ r4 = 'd4'
-	ldrsh r6, [lr, #(12*8)]             @ r6 = 'd6'
+        mul r11, r10, r4         @ R11=W6*ROWr16[2]
+        ldr r8, [r12, #offW2]    @ R8=W2
+        sub r3, r6, r11          @ R3=a0-W6*ROWr16[2] (a2)
+        @@ temp = ((uint32_t*)row)[2] | ((uint32_t*)row)[3];
+        @@ if (temp != 0) {}
+        teq r2, #0
+        beq __end_bef_a_evaluation
 
-	ldr r3, [r11, #FIX_0_541196100_ID]
-	add r1, r2, r6
-	ldr r5, [r11, #FIX_M_1_847759065_ID]
-	mul r1, r3, r1                      @ r1 = z1
-	ldr r3, [r11, #FIX_0_765366865_ID]
-	mla r6, r5, r6, r1                  @ r6 = tmp2
-	add r5, r0, r4                      @ r5 = tmp0
-	mla r2, r3, r2, r1                  @ r2 = tmp3
-	sub r3, r0, r4                      @ r3 = tmp1
+	add r2, r6, r11          @ R2=a0+W6*ROWr16[2] (a1)
+        mul r11, r8, r4          @ R11=W2*ROWr16[2]
+        sub r4, r6, r11          @ R4=a0-W2*ROWr16[2] (a3)
+        add r6, r6, r11          @ R6=a0+W2*ROWr16[2] (a0)
 
-	add r0, r2, r5, lsl #13             @ r0 = tmp10
-	rsb r2, r2, r5, lsl #13             @ r2 = tmp13
-	add r4, r6, r3, lsl #13             @ r4 = tmp11
-	rsb r6, r6, r3, lsl #13             @ r6 = tmp12
 
-	ldrsh r1, [lr, #( 2*8)]             @ r1 = 'd1'
-	ldrsh r3, [lr, #( 6*8)]             @ r3 = 'd3'
-	ldrsh r5, [lr, #(10*8)]             @ r5 = 'd5'
-	ldrsh r7, [lr, #(14*8)]             @ r7 = 'd7'
+        @@ at this point, R0=b0,  R1=b1, R2=a1, R3=a2, R4=a3,
+        @@     R5=b2, R6=a0, R7=b3, R8=W2, R9=W4, R10=W6, R11 (free),
+        @@     R12=__const_ptr_, R14=&block[n]
 
-	@ Check for empty odd column (happens about 20 to 25 % of the time according to my stats)
-	orr r9, r1, r3
-	orr r10, r5, r7
-	orrs r10, r9, r10
-	beq empty_odd_column
 
-	stmdb   sp!, { r0, r2, r4, r6 } @ save on the stack tmp10, tmp13, tmp12, tmp11
-		
-	add r0, r3, r5	                @ r0 = 'z2'
-	add r2, r1, r7                  @ r2 = 'z1'
-	add r4, r3, r7                  @ r4 = 'z3'
-	add r6, r1, r5                  @ r6 = 'z4'
-	ldr r9, [r11, #FIX_1_175875602_ID]
-	add r8, r4, r6
-	ldr r10, [r11, #FIX_M_0_899976223_ID]
-	mul r8, r9, r8                  @ r8 = 'z5'
-	ldr r9, [r11, #FIX_M_2_562915447_ID]
-	mul r2, r10, r2                 @ r2 = 'z1'
-	ldr r10, [r11, #FIX_M_1_961570560_ID]
-	mul r0, r9, r0                  @ r0 = 'z2'
-	ldr r9, [r11, #FIX_M_0_390180644_ID]
-	mla r4, r10, r4, r8             @ r4 = 'z3'
-	ldr r10, [r11, #FIX_0_298631336_ID]
-	mla r6, r9, r6, r8              @ r6 = 'z4'
-	ldr r9, [r11, #FIX_2_053119869_ID]
-	mla r7, r10, r7, r2             @ r7 = tmp0 + z1
-	ldr r10, [r11, #FIX_3_072711026_ID]
-	mla r5, r9, r5, r0              @ r5 = tmp1 + z2
-	ldr r9, [r11, #FIX_1_501321110_ID]
-	mla r3, r10, r3, r0             @ r3 = tmp2 + z2
-	add r7, r7, r4                  @ r7 = tmp0
-	mla r1, r9, r1, r2              @ r1 = tmp3 + z1
-	add r5,	r5, r6                  @ r5 = tmp1
-	add r3, r3, r4                  @ r3 = tmp2
-	add r1, r1, r6                  @ r1 = tmp3	
-	
-	ldmia sp!, { r0, r2, r4, r6 } @ r0 = tmp10 / r2 = tmp13 / r4 = tmp11 / r6 = tmp12
-	                              @ r1 = tmp3  / r3 = tmp2  / r5 = tmp1  / r7 = tmp0	
+        @@ a0 += W4*row[4]
+        @@ a1 -= W4*row[4]
+        @@ a2 -= W4*row[4]
+        @@ a3 += W4*row[4]
+        ldrsh r11, [r14, #8]     @ R11=ROWr16[4]
+		teq r11, #0              @ if null avoid muls
+        mulne r11, r9, r11       @ R11=W4*ROWr16[4]
+        @@ R9 is free now
+        ldrsh r9, [r14, #12]     @ R9=ROWr16[6]
+        addne r6, r6, r11        @ R6+=W4*ROWr16[4] (a0)
+        subne r2, r2, r11        @ R2-=W4*ROWr16[4] (a1)
+        subne r3, r3, r11        @ R3-=W4*ROWr16[4] (a2)
+        addne r4, r4, r11        @ R4+=W4*ROWr16[4] (a3)
+        @@ W6 alone is no more useful, save W2*ROWr16[6] in it instead
+		teq r9, #0               @ if null avoid muls
+        mulne r11, r10, r9       @ R11=W6*ROWr16[6]
+        addne r6, r6, r11        @ R6+=W6*ROWr16[6] (a0)
+        mulne r10, r8, r9        @ R10=W2*ROWr16[6]
+        @@ a0 += W6*row[6];
+        @@ a3 -= W6*row[6];
+        @@ a1 -= W2*row[6];
+        @@ a2 += W2*row[6];
+        subne r4, r4, r11        @ R4-=W6*ROWr16[6] (a3)
+        subne r2, r2, r10        @ R2-=W2*ROWr16[6] (a1)
+        addne r3, r3, r10        @ R3+=W2*ROWr16[6] (a2)
 
-	@ Compute DESCALE(tmp10 + tmp3, CONST_BITS+PASS1_BITS+3)
-	add r8, r0, r1
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #( 0*8)]
-	
-	@ Compute DESCALE(tmp10 - tmp3, CONST_BITS+PASS1_BITS+3)
-	sub r8, r0, r1
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #(14*8)]
-	
-	@ Compute DESCALE(tmp11 + tmp2, CONST_BITS+PASS1_BITS+3)
-	add r8, r4, r3
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #( 2*8)]
-	
-	@ Compute DESCALE(tmp11 - tmp2, CONST_BITS+PASS1_BITS+3)
-	sub r8, r4, r3
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #(12*8)]
-	
-	@ Compute DESCALE(tmp12 + tmp1, CONST_BITS+PASS1_BITS+3)
-	add r8, r6, r5
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #( 4*8)]
-	
-	@ Compute DESCALE(tmp12 - tmp1, CONST_BITS+PASS1_BITS+3)
-	sub r8, r6, r5
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #(10*8)]
-	
-	@ Compute DESCALE(tmp13 + tmp0, CONST_BITS+PASS1_BITS+3)
-	add r8, r2, r7
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #( 6*8)]
-	
-	@ Compute DESCALE(tmp13 - tmp0, CONST_BITS+PASS1_BITS+3)
-	sub r8, r2, r7
-	add r8, r8, #(1<<17)
-	mov r8, r8, asr #18
-	strh r8, [lr, #( 8*8)]
+__end_a_evaluation:
+        @@ at this point, R0=b0,  R1=b1, R2=a1, R3=a2, R4=a3,
+        @@     R5=b2, R6=a0, R7=b3, R8 (free), R9 (free), R10 (free), R11 (free),
+        @@     R12=__const_ptr_, R14=&block[n]
+        @@ row[0] = (a0 + b0) >> ROW_SHIFT;
+        @@ row[1] = (a1 + b1) >> ROW_SHIFT;
+        @@ row[2] = (a2 + b2) >> ROW_SHIFT;
+        @@ row[3] = (a3 + b3) >> ROW_SHIFT;
+        @@ row[4] = (a3 - b3) >> ROW_SHIFT;
+        @@ row[5] = (a2 - b2) >> ROW_SHIFT;
+        @@ row[6] = (a1 - b1) >> ROW_SHIFT;
+        @@ row[7] = (a0 - b0) >> ROW_SHIFT;
+        add r8, r6, r0           @ R8=a0+b0
+        add r9, r2, r1           @ R9=a1+b1
+        @@ put 2 16 bits half-words in a 32bits word
+        @@ ROWr32[0]=ROWr16[0] | (ROWr16[1]<<16) (only Little Endian compliant then!!!)
+        ldr r10, [r12, #offMASK_MSHW] @ R10=0xFFFF0000
+        and r9, r10, r9, lsl #ROW_SHIFT2MSHW @ R9=0xFFFF0000 & ((a1+b1)<<5)
+        mvn r11, r10             @ R11= NOT R10= 0x0000FFFF
+        and r8, r11, r8, asr #ROW_SHIFT @ R8=0x0000FFFF & ((a0+b0)>>11)
+        orr r8, r8, r9
+        str r8, [r14, #0]
 
-	@ End of row loop
-	add lr, lr, #2
-	subs r12, r12, #1
-	bne column_loop
-	beq the_end
-	
-empty_odd_column:
-	@ Compute DESCALE(tmp10 + tmp3, CONST_BITS+PASS1_BITS+3)
-	@ Compute DESCALE(tmp10 - tmp3, CONST_BITS+PASS1_BITS+3)
-	add r0, r0, #(1<<17)
-	mov r0, r0, asr #18
-	strh r0, [lr, #( 0*8)]
-	strh r0, [lr, #(14*8)]
-	
-	@ Compute DESCALE(tmp11 + tmp2, CONST_BITS+PASS1_BITS+3)
-	@ Compute DESCALE(tmp11 - tmp2, CONST_BITS+PASS1_BITS+3)
-	add r4, r4, #(1<<17)
-	mov r4, r4, asr #18
-	strh r4, [lr, #( 2*8)]
-	strh r4, [lr, #(12*8)]
-	
-	@ Compute DESCALE(tmp12 + tmp1, CONST_BITS+PASS1_BITS+3)
-	@ Compute DESCALE(tmp12 - tmp1, CONST_BITS+PASS1_BITS+3)
-	add r6, r6, #(1<<17)
-	mov r6, r6, asr #18
-	strh r6, [lr, #( 4*8)]
-	strh r6, [lr, #(10*8)]
-	
-	@ Compute DESCALE(tmp13 + tmp0, CONST_BITS+PASS1_BITS+3)
-	@ Compute DESCALE(tmp13 - tmp0, CONST_BITS+PASS1_BITS+3)
-	add r2, r2, #(1<<17)
-	mov r2, r2, asr #18
-	strh r2, [lr, #( 6*8)]
-	strh r2, [lr, #( 8*8)]
+        add r8, r3, r5           @ R8=a2+b2
+        add r9, r4, r7           @ R9=a3+b3
+        and r9, r10, r9, lsl #ROW_SHIFT2MSHW @ R9=0xFFFF0000 & ((a3+b3)<<5)
+        and r8, r11, r8, asr #ROW_SHIFT @ R8=0x0000FFFF & ((a2+b2)>>11)
+        orr r8, r8, r9
+        str r8, [r14, #4]
 
-	@ End of row loop
-	add lr, lr, #2
-	subs r12, r12, #1
-	bne column_loop
-		
-the_end:	
-	@ The end....
-	add sp, sp, #4
-	ldmia   sp!, { r4 - r12, pc }   @ restore callee saved regs and return
+        sub r8, r4, r7           @ R8=a3-b3
+        sub r9, r3, r5           @ R9=a2-b2
+        and r9, r10, r9, lsl #ROW_SHIFT2MSHW @ R9=0xFFFF0000 & ((a2-b2)<<5)
+        and r8, r11, r8, asr #ROW_SHIFT @ R8=0x0000FFFF & ((a3-b3)>>11)
+        orr r8, r8, r9
+        str r8, [r14, #8]
 
-const_array:
+        sub r8, r2, r1           @ R8=a1-b1
+        sub r9, r6, r0           @ R9=a0-b0
+        and r9, r10, r9, lsl #ROW_SHIFT2MSHW @ R9=0xFFFF0000 & ((a0-b0)<<5)
+        and r8, r11, r8, asr #ROW_SHIFT @ R8=0x0000FFFF & ((a1-b1)>>11)
+        orr r8, r8, r9
+        str r8, [r14, #12]
+
+        bal __end_row_loop
+
+__almost_empty_row:
+        @@ the row was empty, except ROWr16[0], now, management of this special case
+        @@ at this point, R0=block, R14=&block[n], R12=__const_ptr_, R1=ROWr32[0], R2=ROWr32[1],
+        @@                R3=ROWr32[2], R4=ROWr32[3], R5=(temp), R6=ROWr16[0], R7=ROWr16[1],
+        @@                R8=0xFFFF (temp), R9-R11 free
+        mov r8, #0x10000         @ R8=0xFFFF (2 steps needed!) it saves a ldr call (because of delay run).
+        sub r8, r8, #1           @ R8 is now ready.
+        and r5, r8, r6, lsl #3   @ R5=R8 & (R6<<3)= (ROWr16[0]<<3) & 0xFFFF
+        orr r5, r5, r5, lsl #16  @ R5=R5 | (R5<<16)
+        str r5, [r14, #0]        @ R14[0]=ROWr32[0]=R5
+        str r5, [r14, #4]        @ R14[4]=ROWr32[1]=R5
+        str r5, [r14, #8]        @ R14[8]=ROWr32[2]=R5
+        str r5, [r14, #12]       @ R14[12]=ROWr32[3]=R5
+
+__end_row_loop:
+        @@ at this point, R0-R11 (free)
+        @@     R12=__const_ptr_, R14=&block[n]
+        ldr r0, [sp, #0]         @ R0=block
+        teq r0, r14              @ compare current &block[8*n] to block, when block is reached, the loop is finished.
+        sub r14, r14, #16
+        bne __row_loop
+
+
+
+	@@ at this point, R0=block, R1-R11 (free)
+	@@     R12=__const_ptr_, R14=&block[n]
+	add r14, r0, #14        @ R14=&block[7], better start from the last col, and decrease the value until col=0, i.e. R14=block.
+__col_loop:
+
+__b_evaluation2:
+	@@ at this point, R0=block (temp),  R1-R11 (free)
+	@@     R12=__const_ptr_, R14=&block[n]
+	@@ proceed with b0-b3 first, followed by a0-a3
+	@@ MUL16(b0, W1, col[8x1]);
+	@@ MUL16(b1, W3, col[8x1]);
+	@@ MUL16(b2, W5, col[8x1]);
+	@@ MUL16(b3, W7, col[8x1]);
+	@@ MAC16(b0, W3, col[8x3]);
+	@@ MAC16(b1, -W7, col[8x3]);
+	@@ MAC16(b2, -W1, col[8x3]);
+	@@ MAC16(b3, -W5, col[8x3]);
+	ldr r8, [r12, #offW1]    @ R8=W1
+	ldrsh r7, [r14, #16]
+	mul r0, r8, r7           @ R0=W1*ROWr16[1]=b0 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+	ldr r9, [r12, #offW3]    @ R9=W3
+	ldr r10, [r12, #offW5]   @ R10=W5
+	mul r1, r9, r7           @ R1=W3*ROWr16[1]=b1 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+	ldr r11, [r12, #offW7]   @ R11=W7
+	mul r5, r10, r7          @ R5=W5*ROWr16[1]=b2 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+	ldrsh r2, [r14, #48]
+	mul r7, r11, r7          @ R7=W7*ROWr16[1]=b3 (ROWr16[1] must be the second arg, to have the possibility to save 1 cycle)
+	teq r2, #0               @ if 0, then avoid muls
+	mlane r0, r9, r2, r0     @ R0+=W3*ROWr16[3]=b0 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+	rsbne r2, r2, #0         @ R2=-ROWr16[3]
+	mlane r1, r11, r2, r1    @ R1-=W7*ROWr16[3]=b1 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+	mlane r5, r8, r2, r5     @ R5-=W1*ROWr16[3]=b2 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+	mlane r7, r10, r2, r7    @ R7-=W5*ROWr16[3]=b3 (ROWr16[3] must be the second arg, to have the possibility to save 1 cycle)
+
+	@@ at this point, R0=b0,  R1=b1, R2 (free), R3 (free), R4 (free),
+	@@     R5=b2, R6 (free), R7=b3, R8=W1, R9=W3, R10=W5, R11=W7,
+	@@     R12=__const_ptr_, R14=&block[n]
+	@@ MAC16(b0, W5, col[5x8]);
+	@@ MAC16(b2, W7, col[5x8]);
+	@@ MAC16(b3, W3, col[5x8]);
+	@@ MAC16(b1, -W1, col[5x8]);
+	@@ MAC16(b0, W7, col[7x8]);
+	@@ MAC16(b2, W3, col[7x8]);
+	@@ MAC16(b3, -W1, col[7x8]);
+	@@ MAC16(b1, -W5, col[7x8]);
+	ldrsh r3, [r14, #80]     @ R3=COLr16[5x8]
+	teq r3, #0               @ if 0 then avoid muls
+	mlane r0, r10, r3, r0    @ R0+=W5*ROWr16[5x8]=b0
+	mlane r5, r11, r3, r5    @ R5+=W7*ROWr16[5x8]=b2
+	mlane r7, r9, r3, r7     @ R7+=W3*ROWr16[5x8]=b3
+	rsbne r3, r3, #0         @ R3=-ROWr16[5x8]
+	ldrsh r4, [r14, #112]    @ R4=COLr16[7x8]
+	mlane r1, r8, r3, r1     @ R7-=W1*ROWr16[5x8]=b1
+	@@ R3 is free now
+	teq r4, #0               @ if 0 then avoid muls
+	mlane r0, r11, r4, r0    @ R0+=W7*ROWr16[7x8]=b0
+	mlane r5, r9, r4, r5     @ R5+=W3*ROWr16[7x8]=b2
+	rsbne r4, r4, #0         @ R4=-ROWr16[7x8]
+	mlane r7, r8, r4, r7     @ R7-=W1*ROWr16[7x8]=b3
+	mlane r1, r10, r4, r1    @ R1-=W5*ROWr16[7x8]=b1
+	@@ R4 is free now
+__end_b_evaluation2:
+	@@ at this point, R0=b0,  R1=b1, R2 (free), R3 (free), R4 (free),
+	@@     R5=b2, R6 (free), R7=b3, R8 (free), R9 (free), R10 (free), R11 (free),
+	@@     R12=__const_ptr_, R14=&block[n]
+
+__a_evaluation2:
+	@@ a0 = (W4 * col[8x0]) + (1 << (COL_SHIFT - 1));
+	@@ a1 = a0 + W6 * row[2];
+	@@ a2 = a0 - W6 * row[2];
+	@@ a3 = a0 - W2 * row[2];
+	@@ a0 = a0 + W2 * row[2];
+	ldrsh r6, [r14, #0]
+	ldr r9, [r12, #offW4]    @ R9=W4
+	mul r6, r9, r6           @ R6=W4*ROWr16[0]
+	ldr r10, [r12, #offW6]   @ R10=W6
+	ldrsh r4, [r14, #32]      @ R4=ROWr16[2] (a3 not defined yet)
+	add r6, r6, #COL_SHIFTED_1 @ R6=W4*ROWr16[0] + 1<<(COL_SHIFT-1) (a0)
+	mul r11, r10, r4         @ R11=W6*ROWr16[2]
+	ldr r8, [r12, #offW2]    @ R8=W2
+	add r2, r6, r11          @ R2=a0+W6*ROWr16[2] (a1)
+	sub r3, r6, r11          @ R3=a0-W6*ROWr16[2] (a2)
+	mul r11, r8, r4          @ R11=W2*ROWr16[2]
+	sub r4, r6, r11          @ R4=a0-W2*ROWr16[2] (a3)
+	add r6, r6, r11          @ R6=a0+W2*ROWr16[2] (a0)
+
+	@@ at this point, R0=b0,  R1=b1, R2=a1, R3=a2, R4=a3,
+	@@     R5=b2, R6=a0, R7=b3, R8=W2, R9=W4, R10=W6, R11 (free),
+	@@     R12=__const_ptr_, R14=&block[n]
+	@@ a0 += W4*row[4]
+	@@ a1 -= W4*row[4]
+	@@ a2 -= W4*row[4]
+	@@ a3 += W4*row[4]
+	ldrsh r11, [r14, #64]     @ R11=ROWr16[4]
+	teq r11, #0              @ if null avoid muls
+	mulne r11, r9, r11       @ R11=W4*ROWr16[4]
+	@@ R9 is free now
+	addne r6, r6, r11        @ R6+=W4*ROWr16[4] (a0)
+	subne r2, r2, r11        @ R2-=W4*ROWr16[4] (a1)
+	subne r3, r3, r11        @ R3-=W4*ROWr16[4] (a2)
+	ldrsh r9, [r14, #96]     @ R9=ROWr16[6]
+	addne r4, r4, r11        @ R4+=W4*ROWr16[4] (a3)
+	@@ W6 alone is no more useful, save W2*ROWr16[6] in it instead
+	teq r9, #0               @ if null avoid muls
+	mulne r11, r10, r9       @ R11=W6*ROWr16[6]
+	addne r6, r6, r11        @ R6+=W6*ROWr16[6] (a0)
+	mulne r10, r8, r9        @ R10=W2*ROWr16[6]
+	@@ a0 += W6*row[6];
+	@@ a3 -= W6*row[6];
+	@@ a1 -= W2*row[6];
+	@@ a2 += W2*row[6];
+	subne r4, r4, r11        @ R4-=W6*ROWr16[6] (a3)
+	subne r2, r2, r10        @ R2-=W2*ROWr16[6] (a1)
+	addne r3, r3, r10        @ R3+=W2*ROWr16[6] (a2)
+__end_a_evaluation2:
+	@@ at this point, R0=b0,  R1=b1, R2=a1, R3=a2, R4=a3,
+	@@     R5=b2, R6=a0, R7=b3, R8 (free), R9 (free), R10 (free), R11 (free),
+	@@     R12=__const_ptr_, R14=&block[n]
+	@@ col[0 ] = ((a0 + b0) >> COL_SHIFT);
+	@@ col[8 ] = ((a1 + b1) >> COL_SHIFT);
+	@@ col[16] = ((a2 + b2) >> COL_SHIFT);
+	@@ col[24] = ((a3 + b3) >> COL_SHIFT);
+	@@ col[32] = ((a3 - b3) >> COL_SHIFT);
+	@@ col[40] = ((a2 - b2) >> COL_SHIFT);
+	@@ col[48] = ((a1 - b1) >> COL_SHIFT);
+	@@ col[56] = ((a0 - b0) >> COL_SHIFT);
+	@@@@@ no optimisation here @@@@@
+	add r8, r6, r0           @ R8=a0+b0
+	add r9, r2, r1           @ R9=a1+b1
+	mov r8, r8, asr #COL_SHIFT
+	mov r9, r9, asr #COL_SHIFT
+	strh r8, [r14, #0]
+	strh r9, [r14, #16]
+	add r8, r3, r5           @ R8=a2+b2
+	add r9, r4, r7           @ R9=a3+b3
+	mov r8, r8, asr #COL_SHIFT
+	mov r9, r9, asr #COL_SHIFT
+	strh r8, [r14, #32]
+	strh r9, [r14, #48]
+	sub r8, r4, r7           @ R8=a3-b3
+	sub r9, r3, r5           @ R9=a2-b2
+	mov r8, r8, asr #COL_SHIFT
+	mov r9, r9, asr #COL_SHIFT
+	strh r8, [r14, #64]
+	strh r9, [r14, #80]
+	sub r8, r2, r1           @ R8=a1-b1
+	sub r9, r6, r0           @ R9=a0-b0
+	mov r8, r8, asr #COL_SHIFT
+	mov r9, r9, asr #COL_SHIFT
+	strh r8, [r14, #96]
+	strh r9, [r14, #112]
+
+__end_col_loop:
+	@@ at this point, R0-R11 (free)
+	@@     R12=__const_ptr_, R14=&block[n]
+	ldr r0, [sp, #0]         @ R0=block
+	teq r0, r14              @ compare current &block[n] to block, when block is reached, the loop is finished.
+	sub r14, r14, #2
+	bne __col_loop
+
+
+
+
+__end_simple_idct_ARM:
+        @@ restore registers to previous status!
+        add sp, sp, #8 @@ the local variables!
+        ldmfd sp!, {r4-r11, r15} @@ update PC with LR content.
+
+
+
+@@ kind of sub-function, here not to overload the common case.
+__end_bef_a_evaluation:
+	add r2, r6, r11          @ R2=a0+W6*ROWr16[2] (a1)
+        mul r11, r8, r4          @ R11=W2*ROWr16[2]
+        sub r4, r6, r11          @ R4=a0-W2*ROWr16[2] (a3)
+        add r6, r6, r11          @ R6=a0+W2*ROWr16[2] (a0)
+	bal __end_a_evaluation
+
+
+__constant_ptr__:  @@ see #defines at the beginning of the source code for values.
 	.align
-	.word FIX_0_298631336
-	.word FIX_0_541196100
-	.word FIX_0_765366865
-	.word FIX_1_175875602
-	.word FIX_1_501321110
-	.word FIX_2_053119869
-	.word FIX_3_072711026
-	.word FIX_M_0_390180644
-	.word FIX_M_0_899976223
-	.word FIX_M_1_847759065
-	.word FIX_M_1_961570560
-	.word FIX_M_2_562915447
-	.word FIX_0xFFFF
+        .word   W1
+        .word   W2
+        .word   W3
+        .word   W4
+        .word   W5
+        .word   W6
+        .word   W7
+        .word   MASK_MSHW
+
+