From dbb003c9acd078d90a458ba3a579fb9dbb876e87 Mon Sep 17 00:00:00 2001 From: cuz Date: Sat, 27 Nov 2004 14:45:49 +0000 Subject: [PATCH] Added assembler include function for _scanf git-svn-id: svn://svn.cc65.org/cc65/trunk@3304 b7a2c559-68d2-44c3-8de9-860c34a00d81 --- libsrc/common/_scanf.c | 173 +++++++++++++++++++++++++++------------ libsrc/common/_scanf.h | 7 +- libsrc/common/_scanf.inc | 21 +++++ 3 files changed, 144 insertions(+), 57 deletions(-) create mode 100644 libsrc/common/_scanf.inc diff --git a/libsrc/common/_scanf.c b/libsrc/common/_scanf.c index 53d65694e..367c09af7 100644 --- a/libsrc/common/_scanf.c +++ b/libsrc/common/_scanf.c @@ -12,6 +12,7 @@ #include #include +#include #include #include #include @@ -39,9 +40,10 @@ -static struct scanfdata* D; /* Copy of function argument */ -static va_list ap; /* Copy of function argument */ +static struct scanfdata* D_; /* Copy of function argument */ +static va_list ap; /* Copy of function argument */ static jmp_buf JumpBuf; /* Label that is used in case of EOF */ +static unsigned CharCount; /* Characters read so far */ static int C; /* Character from input */ static unsigned Width; /* Maximum field width */ static long IntVal; /* Converted int value */ @@ -57,6 +59,15 @@ static const unsigned char Bits[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 }; +/* We need C to be 16 bits since we cannot check for EOF otherwise. + * Unfortunately, this causes the code to be quite larger, even if for most + * purposes, checking the low byte would be enough, since if C is EOF, the + * low byte will not match any useful character anyway (at least for the + * supported platforms - I know that this is not portable). So the following + * macro is used to access just the low byte of C. + */ +#define CHAR(c) (*((unsigned char*)&(c))) + /*****************************************************************************/ @@ -124,13 +135,57 @@ static void InvertCharSet (void) +static void __fastcall__ Error (unsigned char Code) +/* Does a longjmp using the given code */ +{ + longjmp (JumpBuf, Code); +} + + + static void ReadChar (void) /* Get an input character, count characters */ { - C = D->get (D->data); - if (C != EOF) { - ++D->ccount; - } + /* Move D to ptr1 */ + asm ("lda %v", D_); + asm ("ldx %v+1", D_); + asm ("sta ptr1"); + asm ("stx ptr1+1"); + + /* Copy the get vector to jmpvec */ + asm ("ldy #%b", offsetof (struct scanfdata, get)); + asm ("lda (ptr1),y"); + asm ("sta jmpvec+1"); + asm ("iny"); + asm ("lda (ptr1),y"); + asm ("sta jmpvec+2"); + + /* Load D->data into __AX__ */ + asm ("ldy #%b", offsetof (struct scanfdata, data)+1); + asm ("lda (ptr1),y"); + asm ("tax"); + asm ("dey"); + asm ("lda (ptr1),y"); + + /* Call the get routine */ + asm ("jsr jmpvec"); + + /* Assign the result to C */ + asm ("sta %v", C); + asm ("stx %v+1", C); + + /* If C is not EOF, bump the character counter. */ + asm ("inx"); + asm ("bne %g", Done); + asm ("cmp #$FF"); + asm ("bne %g", Done); + + /* Must bump CharCount. */ + asm ("inc %v", CharCount); + asm ("bne %g", Done); + asm ("inc %v+1", CharCount); + +Done: } @@ -140,7 +195,7 @@ static void ReadCharWithCheck (void) { ReadChar (); if (C == EOF) { - longjmp (JumpBuf, RC_EOF); + Error (RC_EOF); } } @@ -161,17 +216,27 @@ static void ReadSign (void) * positive, store 0 otherwise. */ { - switch (C) { - case '-': - ReadChar (); - Positive = 0; - break; - case '+': - ReadChar (); - /* FALLTHROUGH */ - default: - Positive = 1; - } + /* We can ignore the high byte of C here, since if it is EOF, the lower + * byte won't match anyway. + */ + asm ("lda %v", C); + asm ("cmp #'-'"); + asm ("bne %g", NotNeg); + + /* Negative value */ + asm ("jsr %v", ReadChar); + asm ("lda #$00"); /* Flag as negative */ + asm ("beq %g", Store); + + /* Positive value */ +NotNeg: + asm ("cmp #'+'"); + asm ("bne %g", Pos); + asm ("jsr %v", ReadChar); /* Skip the + sign */ +Pos: + asm ("lda #$01"); /* Flag as positive */ +Store: + asm ("sta %v", Positive); } @@ -210,10 +275,10 @@ static void AssignInt (void) asm ("ldy %v", IntBytes); /* Assign the integer value */ - asm ("L1: lda %v,y", IntVal); +Loop: asm ("lda %v,y", IntVal); asm ("sta (ptr1),y"); asm ("dey"); - asm ("bpl L1"); + asm ("bpl %g", Loop); } } @@ -238,7 +303,7 @@ static unsigned char ReadInt (unsigned char Base) /* If we didn't convert anything, it's an error */ if (CharCount == 0) { - longjmp (JumpBuf, RC_NOCONV); + Error (RC_NOCONV); } /* Return the number of characters converted */ @@ -247,7 +312,7 @@ static unsigned char ReadInt (unsigned char Base) -static void ScanInt (unsigned char Base) +static void __fastcall__ ScanInt (unsigned char Base) /* Scan an integer including white space, sign and optional base spec, * and store it into IntVal. */ @@ -260,9 +325,9 @@ static void ScanInt (unsigned char Base) /* If Base is unknown (zero), figure it out */ if (Base == 0) { - if (C == '0') { + if (CHAR (C) == '0') { ReadChar (); - switch (C) { + switch (CHAR (C)) { case 'x': case 'X': Base = 16; @@ -293,14 +358,15 @@ static void ScanInt (unsigned char Base) -int _scanf (struct scanfdata* D_, register const char* format, va_list ap_) +int __fastcall__ _scanf (register struct scanfdata* D, + register const char* format, va_list ap_) /* This is the routine used to do the actual work. It is called from several * types of wrappers to implement the actual ISO xxscanf functions. */ { - char F; /* Character from format string */ + register char F; /* Character from format string */ unsigned char Result; /* setjmp result */ - char* S; + char* S; unsigned char HaveWidth; /* True if a width was given */ char Start; /* Start of range */ @@ -308,12 +374,12 @@ int _scanf (struct scanfdata* D_, register const char* format, va_list ap_) * nice, but on a 6502 platform it gives better code, since the values * do not have to be passed as parameters. */ - D = D_; + D_ = D; ap = ap_; /* Initialize variables */ Conversions = 0; - D->ccount = 0; + CharCount = 0; /* Set up the jump label. The get() routine will use this label when EOF * is reached. @@ -429,7 +495,7 @@ Again: case 'i': /* Optionally signed integer with a base */ - ScanInt (0); + ScanInt (0); break; case 'o': @@ -448,13 +514,13 @@ Again: case 'f': case 'g': /* Optionally signed float */ - longjmp (JumpBuf, RC_NOCONV); + Error (RC_NOCONV); break; case 's': /* Whitespace terminated string */ SkipWhite (); - if (!NoAssign) { + if (!NoAssign) { S = va_arg (ap, char*); } while (!isspace (C) && Width--) { @@ -465,34 +531,34 @@ Again: } /* Terminate the string just read */ if (!NoAssign) { - *S = '\0'; - } + *S = '\0'; + } ++Conversions; - break; + break; case 'c': - /* Fixed length string, NOT zero terminated */ - if (!HaveWidth) { - /* No width given, default is 1 */ - Width = 1; - } - if (!NoAssign) { - S = va_arg (ap, char*); + /* Fixed length string, NOT zero terminated */ + if (!HaveWidth) { + /* No width given, default is 1 */ + Width = 1; + } + if (!NoAssign) { + S = va_arg (ap, char*); while (Width--) { *S++ = C; ReadCharWithCheck (); } - } else { + } else { /* Just skip as many chars as given */ while (Width--) { ReadCharWithCheck (); } } - ++Conversions; + ++Conversions; break; case '[': - /* String using characters from a set */ + /* String using characters from a set */ Invert = 0; /* Clear the set */ memset (CharSet, 0, sizeof (CharSet)); @@ -563,16 +629,16 @@ Again: case 'p': /* Pointer, format is 0xABCD */ SkipWhite (); - if (C != '0') { - longjmp (JumpBuf, RC_NOCONV); + if (CHAR (C) != '0') { + Error (RC_NOCONV); } ReadChar (); - if (C != 'x' && C != 'X') { - longjmp (JumpBuf, RC_NOCONV); + if (CHAR (C) != 'x' && CHAR (C) != 'X') { + Error (RC_NOCONV); } ReadChar (); if (ReadInt (16) != 4) { /* 4 chars expected */ - longjmp (JumpBuf, RC_NOCONV); + Error (RC_NOCONV); } AssignInt (); ++Conversions; @@ -580,13 +646,13 @@ Again: case 'n': /* Store characters consumed so far */ - IntVal = D->ccount; + IntVal = CharCount; AssignInt (); break; default: /* Invalid conversion */ - longjmp (JumpBuf, RC_NOCONV); + Error (RC_NOCONV); break; } @@ -604,7 +670,7 @@ Again: * conversions, it is considered an error, otherwise the number * of conversions is returned (the default behaviour). */ - if (C == EOF && D->ccount == 0) { + if (C == EOF && CharCount == 0) { /* Special case: error */ Conversions = EOF; } @@ -617,3 +683,4 @@ Again: + diff --git a/libsrc/common/_scanf.h b/libsrc/common/_scanf.h index e477c37da..0dbf0e01b 100644 --- a/libsrc/common/_scanf.h +++ b/libsrc/common/_scanf.h @@ -21,13 +21,12 @@ typedef int __fastcall__ (*ungetfunc) (int c, void* data); /* Control structure passed to the low level worker function. - * Beware: The low level functions will access the structure on the assembly - * level, so check this when altering the structure. + * Beware: This structure is mirrored in the _scanf.inc assembler include + * file, so check this when altering the structure. */ struct scanfdata { getfunc get; /* Pointer to input routine */ ungetfunc unget; /* Pointer to pushback routine */ - unsigned ccount; /* Number of chars read */ /* Fields used outside of _scanf */ void* data; /* Caller data */ @@ -36,7 +35,7 @@ struct scanfdata { /* Internal scanning routine */ -int _scanf (struct scanfdata* d, const char* format, va_list ap); +int __fastcall__ _scanf (struct scanfdata* d, const char* format, va_list ap); diff --git a/libsrc/common/_scanf.inc b/libsrc/common/_scanf.inc new file mode 100644 index 000000000..48ae5b08a --- /dev/null +++ b/libsrc/common/_scanf.inc @@ -0,0 +1,21 @@ +; +; Ullrich von Bassewitz, 2004-11-27 +; + +;---------------------------------------------------------------------------- +; Structure passed to _scanf + +.struct SCANFDATA + GET .addr + UNGET .addr + DATA .addr +.endstruct + +;---------------------------------------------------------------------------- +; Global data + +.global _scanf + + + + -- 2.39.5