1 files changed, 76 insertions, 0 deletions
diff --git a/system/mmx/pixel_rand_s16.s b/system/mmx/pixel_rand_s16.s
new file mode 100644
index 0000000..649400b
--- /dev/null
+++ b/system/mmx/pixel_rand_s16.s
@@ -0,0 +1,76 @@
+#    Pure Data Packet mmx routine.
+#    Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org>
+# 
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+# 
+#    This program 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+#
+.globl pixel_rand_s16
+.type  pixel_rand_s16,@function
+
+# mmx rgba pixel gain
+# void pixel_rand_s16(int *dst, nb_4pixel_vectors, short int random_seed[4])
+
+pixel_rand_s16:
+	pushl %ebp
+	movl %esp, %ebp
+	push %esi
+	push %edi
+
+	movl 16(%ebp), %esi	# int16[4] array of random seeds
+	movl 8(%ebp),  %edi	# dst array
+	movl 12(%ebp), %ecx	# pixel count
+
+	movq (%esi), %mm6
+
+
+	pcmpeqw %mm3, %mm3
+	psrlw $15, %mm3		# get bit mask 4 times 0x0001
+	
+	.align 16
+	.loop_rand:	
+
+#	prefetch 128(%esi)	
+
+
+	movq %mm6, %mm4		# get random vector
+	psrlw $15, %mm4		# get first component
+	movq %mm6, %mm5
+	psrlw $14, %mm5		# get second component
+	pxor %mm5, %mm4
+	movq %mm6, %mm5
+	psrlw $12, %mm5		# get third component
+	pxor %mm5, %mm4
+	movq %mm6, %mm5
+	psrlw $3, %mm5		# get forth component
+	pxor %mm5, %mm4
+
+	psllw $1, %mm6		# shift left original random vector
+	pand %mm3, %mm4		# isolate new bit
+	por %mm4, %mm6		# combine into new random vector
+
+	movq %mm6, (%edi)
+	addl $8, %edi
+	decl %ecx
+	jnz .loop_rand	# loop
+
+
+	movq %mm6, (%esi)	# store random seeds
+
+	emms
+	
+	pop %edi
+	pop %esi
+	leave
+	ret
+