From 501cc4c6c866ae86475103643c63d3fa984f82ae Mon Sep 17 00:00:00 2001
From: cuz <cuz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Sun, 28 Nov 2004 18:23:16 +0000
Subject: [PATCH] Replace sscanf by an assembler version

git-svn-id: svn://svn.cc65.org/cc65/trunk@3314 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/common/.cvsignore |  1 -
 libsrc/common/Makefile   |  2 +-
 libsrc/common/sscanf.c   | 35 -----------------
 libsrc/common/sscanf.s   | 82 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 83 insertions(+), 37 deletions(-)
 delete mode 100644 libsrc/common/sscanf.c
 create mode 100644 libsrc/common/sscanf.s

diff --git a/libsrc/common/.cvsignore b/libsrc/common/.cvsignore
index 5e71fc4a5..79e0c359a 100644
--- a/libsrc/common/.cvsignore
+++ b/libsrc/common/.cvsignore
@@ -30,7 +30,6 @@ realloc.s
 rewind.s
 scanf.s
 sleep.s
-sscanf.s
 strftime.s
 strtok.s
 strxfrm.s
diff --git a/libsrc/common/Makefile b/libsrc/common/Makefile
index 86cdd7af5..3dcc7ccf8 100644
--- a/libsrc/common/Makefile
+++ b/libsrc/common/Makefile
@@ -60,7 +60,6 @@ C_OBJS =	_afailed.o	\
 		rewind.o	\
                 scanf.o         \
 		sleep.o		\
-		sscanf.o	\
                 strftime.o      \
 		strxfrm.o	\
 		strtok.o	\
@@ -139,6 +138,7 @@ S_OBJS = 	_cwd.o          \
                 signal.o        \
                 sigtable.o      \
 		sprintf.o	\
+		sscanf.o	\
 		strcat.o    	\
 		strchr.o	\
 		strcmp.o	\
diff --git a/libsrc/common/sscanf.c b/libsrc/common/sscanf.c
deleted file mode 100644
index 1a7cd20fc..000000000
--- a/libsrc/common/sscanf.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * sscanf.c
- *
- * (C) Copyright 2001-2002 Ullrich von Bassewitz (uz@cc65.org)
- *
- */
-
-
-
-#include <stdio.h>
-
-
-
-/*****************************************************************************/
-/*     	    	  		     Code				     */
-/*****************************************************************************/
-
-
-
-int sscanf (const char* str, const char* format, ...)
-/* Standard C function */
-{
-    va_list ap;
-
-    /* Setup for variable arguments */
-    va_start (ap, format);
-
-    /* Call vsscanf(). Since we know that va_end won't do anything, we will
-     * save the call and return the value directly.
-     */
-    return vsscanf (str, format, ap);
-}
-
-
-
diff --git a/libsrc/common/sscanf.s b/libsrc/common/sscanf.s
new file mode 100644
index 000000000..025e317a6
--- /dev/null
+++ b/libsrc/common/sscanf.s
@@ -0,0 +1,82 @@
+;
+; int sscanf (const char* str, const char* format, ...);
+;
+; Ullrich von Bassewitz, 2004-11-28
+;
+
+	.export	      	_sscanf
+	.import		addysp, decsp4, _vsscanf
+	.importzp	sp, ptr1
+
+	.macpack     	generic
+
+; ----------------------------------------------------------------------------
+; Data
+
+.bss
+
+ParamSize: 	.res  	1 		; Number of parameter bytes
+
+; ----------------------------------------------------------------------------
+; Code
+; int sscanf (const char* str, const char* format, ...)
+; /* Standard C function */
+; {
+;     va_list ap;
+;
+;     /* Setup for variable arguments */
+;     va_start (ap, format);
+;
+;     /* Call vsscanf(). Since we know that va_end won't do anything, we will
+;      * save the call and return the value directly.
+;      */
+;     return vsscanf (str, format, ap);
+; }
+;
+
+.code
+
+_sscanf:
+  	sty	ParamSize 		; Number of param bytes passed in Y
+
+; We have to push buf and format, both in the order they already have on stack.
+; To make this somewhat more efficient, we will create space on the stack and
+; then do a copy of the complete block instead of pushing each parameter
+; separately. Since the size of the arguments passed is the same as the size
+; of the fixed arguments, this will allow us to calculate the pointer to the
+; fixed size arguments easier (they're just ParamSize bytes away).
+
+	jsr	decsp4
+
+; Calculate a pointer to the fixed parameters
+
+	lda	ParamSize
+	add	sp
+	sta	ptr1
+	ldx	sp+1
+	bcc	@L1
+	inx
+@L1:	stx	ptr1+1
+
+; Now copy both, str and format
+
+	ldy	#4-1
+@L2:	lda	(ptr1),y
+	sta	(sp),y
+	dey
+	bpl	@L2
+
+; Load va_list (last and __fastcall__ parameter to vsscanf)
+
+ 	lda    	ptr1
+ 	ldx    	ptr1+1
+
+; Call vsscanf
+
+	jsr   	_vsscanf
+
+; Cleanup the stack. We will return what we got from vsscanf
+
+	ldy	ParamSize
+	jmp	addysp
+