1 files changed, 108 insertions, 0 deletions
diff --git a/hw/xfree86/os-support/misc/SlowBcopy.S b/hw/xfree86/os-support/misc/SlowBcopy.S
new file mode 100644
index 000000000..9b6af1d69
--- /dev/null
+++ b/hw/xfree86/os-support/misc/SlowBcopy.S
@@ -0,0 +1,108 @@
+/* $XFree86: xc/programs/Xserver/hw/xfree86/os-support/misc/SlowBcopy.S,v 1.1 1999/07/10 07:24:51 dawes Exp $ */
+/*******************************************************************************
+                        Copyright 1994 by Glenn G. Lai
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyr notice appear in all copies and that
+both that copyr notice and this permission notice appear in
+supporting documentation, and that the name of Glenn G. Lai not be
+used in advertising or publicity pertaining to distribution of the
+software without specific, written prior permission.
+
+Glenn G. Lai DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
+ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
+DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
+ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+SOFTWARE.
+
+Glenn G. Lai
+P.O. Box 4314
+Austin, Tx 78765
+glenn@cs.utexas.edu)
+7/21/94
+*******************************************************************************/
+/* $XConsortium: SlowBcopy.s /main/4 1996/02/21 17:40:52 kaleb $ */
+ 
+/* 
+ *   Modified from the output generated by GCC
+ *
+ *   Create a dependency that should be immune from the effect of register
+ *   renaming as is commonly seen in superscalar processors.  This should
+ *   insert a minimum of 100-ns delays between reads/writes at clock rates
+ *   up to 100 MHz---GGL
+ *   
+ *   Slowbcopy(char *src, char *dst, int count)   
+ *   
+ */ 
+
+#include "assyntax.h"
+
+	FILE("SlowBcopy.s")
+
+	AS_BEGIN
+
+gcc2_compiled.:
+___gnu_compiled_c:
+
+	GLOBL	GLNAME(xf86SlowBcopy)
+
+	SEG_TEXT
+	ALIGNTEXT4
+GLNAME(xf86SlowBcopy):
+	PUSH_L	(EBP)
+	MOV_L	(ESP,EBP)
+	PUSH_L	(ESI)
+	PUSH_L	(EBX)
+	MOV_L	(REGOFF(8,EBP),ECX)
+	MOV_L	(REGOFF(12,EBP),EDX)
+	MOV_L	(REGOFF(16,EBP),ESI)
+	XOR_L	(EAX,EAX)
+	CMP_L	(ESI,EAX)
+	JGE	(L3)
+
+	ALIGNTEXT4
+L5:
+	MOV_B	(REGIND(ECX),BL)
+
+	MOV_B	(BL, BH)
+	MOV_B	(BH, BL)
+	MOV_B	(BL, BH)
+	MOV_B	(BH, BL)
+	MOV_B	(BL, BH)
+	MOV_B	(BH, BL)
+	MOV_B	(BL, BH)
+	MOV_B	(BH, BL)
+	MOV_B	(BL, BH)
+	MOV_B	(BH, BL)
+
+	MOV_B	(BL,REGIND(EDX))
+
+	INC_L	(ECX)
+	DEC_L	(ECX)
+	INC_L	(ECX)
+	DEC_L	(ECX)
+	INC_L	(ECX)
+	DEC_L	(ECX)
+	INC_L	(ECX)
+	DEC_L	(ECX)
+	INC_L	(ECX)
+	DEC_L	(ECX)
+
+	INC_L	(ECX)
+	INC_L	(EDX)
+	INC_L	(EAX)
+	CMP_L	(ESI,EAX)
+	JL	(L5)
+L3:
+	LEA_L	(REGOFF(-8,EBP),ESP)
+	POP_L	(EBX)
+	POP_L	(ESI)
+	MOV_L	(EBP,ESP)
+	POP_L	(EBP)
+	RET
+