cc65/src/cc65/stdfunc.c

1418 lines
51 KiB
C

/*****************************************************************************/
/* */
/* stdfunc.c */
/* */
/* Handle inlining of known functions for the cc65 compiler */
/* */
/* */
/* */
/* (C) 1998-2010 Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#include <stdlib.h>
#include <string.h>
/* common */
#include "attrib.h"
#include "check.h"
/* cc65 */
#include "asmcode.h"
#include "asmlabel.h"
#include "codegen.h"
#include "error.h"
#include "funcdesc.h"
#include "global.h"
#include "litpool.h"
#include "loadexpr.h"
#include "scanner.h"
#include "stackptr.h"
#include "stdfunc.h"
#include "stdnames.h"
#include "typeconv.h"
/*****************************************************************************/
/* Function forwards */
/*****************************************************************************/
static void StdFunc_memcpy (FuncDesc*, ExprDesc*);
static void StdFunc_memset (FuncDesc*, ExprDesc*);
static void StdFunc_strcmp (FuncDesc*, ExprDesc*);
static void StdFunc_strcpy (FuncDesc*, ExprDesc*);
static void StdFunc_strlen (FuncDesc*, ExprDesc*);
/*****************************************************************************/
/* Data */
/*****************************************************************************/
/* Table with all known functions and their handlers. Must be sorted
** alphabetically!
*/
static struct StdFuncDesc {
const char* Name;
void (*Handler) (FuncDesc*, ExprDesc*);
} StdFuncs[] = {
{ "memcpy", StdFunc_memcpy },
{ "memset", StdFunc_memset },
{ "strcmp", StdFunc_strcmp },
{ "strcpy", StdFunc_strcpy },
{ "strlen", StdFunc_strlen },
};
#define FUNC_COUNT (sizeof (StdFuncs) / sizeof (StdFuncs[0]))
typedef struct ArgDesc ArgDesc;
struct ArgDesc {
const Type* ArgType; /* Required argument type */
ExprDesc Expr; /* Argument expression */
const Type* Type; /* The original type before conversion */
CodeMark Load; /* Start of argument load code */
CodeMark Push; /* Start of argument push code */
CodeMark End; /* End of the code for calculation+push */
unsigned Flags; /* Code generation flags */
};
/*****************************************************************************/
/* Helper functions */
/*****************************************************************************/
static int CmpFunc (const void* Key, const void* Elem)
/* Compare function for bsearch */
{
return strcmp ((const char*) Key, ((const struct StdFuncDesc*) Elem)->Name);
}
static long ArrayElementCount (const ArgDesc* Arg)
/* Check if the type of the given argument is an array. If so, and if the
** element count is known, return it. In all other cases, return UNSPECIFIED.
*/
{
long Count;
if (IsTypeArray (Arg->Type)) {
Count = GetElementCount (Arg->Type);
if (Count == FLEXIBLE) {
/* Treat as unknown */
Count = UNSPECIFIED;
}
} else {
Count = UNSPECIFIED;
}
return Count;
}
static void ParseArg (ArgDesc* Arg, const Type* Type, ExprDesc* Expr)
/* Parse one argument but do not push it onto the stack. Make all fields in
** Arg valid.
*/
{
/* We have a prototype, so chars may be pushed as chars */
Arg->Flags = CF_FORCECHAR;
/* Remember the required argument type */
Arg->ArgType = Type;
/* Init expression */
ED_Init (&Arg->Expr);
Arg->Expr.Flags |= Expr->Flags & E_MASK_KEEP_SUBEXPR;
/* Read the expression we're going to pass to the function */
MarkedExprWithCheck (hie1, &Arg->Expr);
/* Remember the actual argument type */
Arg->Type = Arg->Expr.Type;
/* Convert this expression to the expected type */
TypeConversion (&Arg->Expr, Type);
/* Remember the following code position */
GetCodePos (&Arg->Load);
/* If the value is a constant, set the flag, otherwise load it into the
** primary register.
*/
if (ED_IsConstAbsInt (&Arg->Expr) && ED_CodeRangeIsEmpty (&Arg->Expr)) {
/* Remember that we have a constant value */
Arg->Flags |= CF_CONST;
} else {
/* Load into the primary */
LoadExpr (CF_NONE, &Arg->Expr);
}
/* Remember the following code position */
GetCodePos (&Arg->Push);
GetCodePos (&Arg->End);
/* Use the type of the argument for the push */
Arg->Flags |= TypeOf (Arg->Expr.Type);
/* Propagate from subexpressions */
Expr->Flags |= Arg->Expr.Flags & E_MASK_VIRAL;
}
void AddCmpCodeIfSizeNot256 (const char* Code, long Size)
/* Add a line of Assembly code that compares an index register
** only if it isn't comparing to #<256. (If the next line
** is "bne", then this will avoid a redundant line.)
*/
{
if (Size != 256) {
AddCodeLine (Code, (unsigned int)Size);
}
}
/*****************************************************************************/
/* memcpy */
/*****************************************************************************/
static void StdFunc_memcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
/* Handle the memcpy function */
{
/* Argument types: (void*, const void*, size_t) */
static const Type* Arg1Type = type_void_p;
static const Type* Arg2Type = type_c_void_p;
static const Type* Arg3Type = type_size_t;
ArgDesc Arg1, Arg2, Arg3;
unsigned ParamSize = 0;
unsigned Label;
int Offs;
/* Argument #1 */
ParseArg (&Arg1, Arg1Type, Expr);
g_push (Arg1.Flags, Arg1.Expr.IVal);
GetCodePos (&Arg1.End);
ParamSize += SizeOf (Arg1Type);
ConsumeComma ();
/* Argument #2 */
ParseArg (&Arg2, Arg2Type, Expr);
g_push (Arg2.Flags, Arg2.Expr.IVal);
GetCodePos (&Arg2.End);
ParamSize += SizeOf (Arg2Type);
ConsumeComma ();
/* Argument #3. Since memcpy is a fastcall function, we must load the
** arg into the primary if it is not already there. This parameter is
** also ignored for the calculation of the parameter size, since it is
** not passed via the stack.
*/
ParseArg (&Arg3, Arg3Type, Expr);
if (Arg3.Flags & CF_CONST) {
LoadExpr (CF_NONE, &Arg3.Expr);
}
/* We still need to append deferred inc/dec before calling into the function */
DoDeferred (SQP_KEEP_EAX, &Arg3.Expr);
/* Emit the actual function call. This will also cleanup the stack. */
g_call (CF_FIXARGC, Func_memcpy, ParamSize);
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal == 0) {
/* memcpy has been called with a count argument of zero */
Warning ("Call to memcpy has no effect");
/* Remove all of the generated code but the load of the first
** argument, which is what memcpy returns.
*/
RemoveCode (&Arg1.Push);
/* Set the function result to the first argument */
*Expr = Arg1.Expr;
/* Bail out, no need for further improvements */
goto ExitPoint;
}
if (IS_Get (&InlineStdFuncs)) {
/* We've generated the complete code for the function now and know the
** types of all parameters. Check for situations where better code can
** be generated. If such a situation is detected, throw away the
** generated, and emit better code.
*/
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
((ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr)) ||
(ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr))) &&
((ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) ||
(ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr)))) {
int Reg1 = ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr);
int Reg2 = ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memcpy code */
if (Arg3.Expr.IVal <= 129) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal-1));
g_defcodelabel (Label);
if (Reg2) {
AddCodeLine ("lda (%s),y", ED_GetLabelName (&Arg2.Expr, 0));
} else {
AddCodeLine ("lda %s,y", ED_GetLabelName (&Arg2.Expr, 0));
}
if (Reg1) {
AddCodeLine ("sta (%s),y", ED_GetLabelName (&Arg1.Expr, 0));
} else {
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, 0));
}
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldy #$00");
g_defcodelabel (Label);
if (Reg2) {
AddCodeLine ("lda (%s),y", ED_GetLabelName (&Arg2.Expr, 0));
} else {
AddCodeLine ("lda %s,y", ED_GetLabelName (&Arg2.Expr, 0));
}
if (Reg1) {
AddCodeLine ("sta (%s),y", ED_GetLabelName (&Arg1.Expr, 0));
} else {
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, 0));
}
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
/* memcpy returns the address, so the result is actually identical
** to the first argument.
*/
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr) &&
ED_IsRVal (&Arg1.Expr) && ED_IsLocStack (&Arg1.Expr) &&
(Arg1.Expr.IVal - StackPtr) + Arg3.Expr.IVal < 256) {
/* It is possible to just use one index register even if the stack
** offset is not zero, by adjusting the offset to the constant
** address accordingly. But we cannot do this if the data in
** question is in the register space or at an absolute address less
** than 256. Register space is zero page, which means that the
** address calculation could overflow in the linker.
*/
int AllowOneIndex = !ED_IsLocRegister (&Arg2.Expr) &&
!(ED_IsLocNone (&Arg2.Expr) && Arg2.Expr.IVal < 256);
/* Calculate the real stack offset */
Offs = ED_GetStackOffs (&Arg1.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memcpy code */
if (Arg3.Expr.IVal <= 129 && !AllowOneIndex) {
if (Offs == 0) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs + Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda %s,y", ED_GetLabelName (&Arg2.Expr, -Offs));
AddCodeLine ("sta (sp),y");
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldx #$%02X", (unsigned char) (Arg3.Expr.IVal-1));
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs + Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda %s,x", ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine ("sta (sp),y");
AddCodeLine ("dey");
AddCodeLine ("dex");
AddCodeLine ("bpl %s", LocalLabelName (Label));
}
} else {
if (Offs == 0 || AllowOneIndex) {
AddCodeLine ("ldy #$%02X", (unsigned char) Offs);
g_defcodelabel (Label);
AddCodeLine ("lda %s,y", ED_GetLabelName (&Arg2.Expr, -Offs));
AddCodeLine ("sta (sp),y");
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Offs + Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldx #$00");
AddCodeLine ("ldy #$%02X", (unsigned char) Offs);
g_defcodelabel (Label);
AddCodeLine ("lda %s,x", ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine ("sta (sp),y");
AddCodeLine ("iny");
AddCodeLine ("inx");
AddCmpCodeIfSizeNot256 ("cpx #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
}
/* memcpy returns the address, so the result is actually identical
** to the first argument.
*/
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsRVal (&Arg2.Expr) && ED_IsLocStack (&Arg2.Expr) &&
(Arg2.Expr.IVal - StackPtr) + Arg3.Expr.IVal < 256 &&
ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) {
/* It is possible to just use one index register even if the stack
** offset is not zero, by adjusting the offset to the constant
** address accordingly. But we cannot do this if the data in
** question is in the register space or at an absolute address less
** than 256. Register space is zero page, which means that the
** address calculation could overflow in the linker.
*/
int AllowOneIndex = !ED_IsLocRegister (&Arg1.Expr) &&
!(ED_IsLocNone (&Arg1.Expr) && Arg1.Expr.IVal < 256);
/* Calculate the real stack offset */
Offs = ED_GetStackOffs (&Arg2.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memcpy code */
if (Arg3.Expr.IVal <= 129 && !AllowOneIndex) {
if (Offs == 0) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, 0));
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldx #$%02X", (unsigned char) (Arg3.Expr.IVal-1));
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs + Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,x", ED_GetLabelName (&Arg1.Expr, 0));
AddCodeLine ("dey");
AddCodeLine ("dex");
AddCodeLine ("bpl %s", LocalLabelName (Label));
}
} else {
if (Offs == 0 || AllowOneIndex) {
AddCodeLine ("ldy #$%02X", (unsigned char) Offs);
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, -Offs));
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Offs + Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldx #$00");
AddCodeLine ("ldy #$%02X", (unsigned char) Offs);
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,x", ED_GetLabelName (&Arg1.Expr, 0));
AddCodeLine ("iny");
AddCodeLine ("inx");
AddCmpCodeIfSizeNot256 ("cpx #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
}
/* memcpy returns the address, so the result is actually identical
** to the first argument.
*/
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsRVal (&Arg2.Expr) && ED_IsLocStack (&Arg2.Expr) &&
(Offs = ED_GetStackOffs (&Arg2.Expr, 0)) == 0) {
/* Drop the generated code but leave the load of the first argument*/
RemoveCode (&Arg1.Push);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memcpy code */
AddCodeLine ("sta ptr1");
AddCodeLine ("stx ptr1+1");
if (Arg3.Expr.IVal <= 129) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta (ptr1),y");
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldy #$00");
g_defcodelabel (Label);
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta (ptr1),y");
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
/* Reload result - X hasn't changed by the code above */
AddCodeLine ("lda ptr1");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
/* Bail out, no need for further processing */
goto ExitPoint;
}
}
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
ExitPoint:
/* We expect the closing brace */
ConsumeRParen ();
}
/*****************************************************************************/
/* memset */
/*****************************************************************************/
static void StdFunc_memset (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
/* Handle the memset function */
{
/* Argument types: (void*, int, size_t) */
static const Type* Arg1Type = type_void_p;
static const Type* Arg2Type = type_int;
static const Type* Arg3Type = type_size_t;
ArgDesc Arg1, Arg2, Arg3;
int MemSet = 1; /* Use real memset if true */
unsigned ParamSize = 0;
unsigned Label;
/* Argument #1 */
ParseArg (&Arg1, Arg1Type, Expr);
g_push (Arg1.Flags, Arg1.Expr.IVal);
GetCodePos (&Arg1.End);
ParamSize += SizeOf (Arg1Type);
ConsumeComma ();
/* Argument #2. This argument is special in that we will call another
** function if it is a constant zero.
*/
ParseArg (&Arg2, Arg2Type, Expr);
if ((Arg2.Flags & CF_CONST) != 0 && Arg2.Expr.IVal == 0) {
/* Don't call memset, call bzero instead */
MemSet = 0;
} else {
/* Push the argument */
g_push (Arg2.Flags, Arg2.Expr.IVal);
GetCodePos (&Arg2.End);
ParamSize += SizeOf (Arg2Type);
}
ConsumeComma ();
/* Argument #3. Since memset is a fastcall function, we must load the
** arg into the primary if it is not already there. This parameter is
** also ignored for the calculation of the parameter size, since it is
** not passed via the stack.
*/
ParseArg (&Arg3, Arg3Type, Expr);
if (Arg3.Flags & CF_CONST) {
LoadExpr (CF_NONE, &Arg3.Expr);
}
/* We still need to append deferred inc/dec before calling into the function */
DoDeferred (SQP_KEEP_EAX, &Arg3.Expr);
/* Emit the actual function call. This will also cleanup the stack. */
g_call (CF_FIXARGC, MemSet? Func_memset : Func__bzero, ParamSize);
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal == 0) {
/* memset has been called with a count argument of zero */
Warning ("Call to memset has no effect");
/* Remove all of the generated code but the load of the first
** argument, which is what memset returns.
*/
RemoveCode (&Arg1.Push);
/* Set the function result to the first argument */
*Expr = Arg1.Expr;
/* Bail out, no need for further improvements */
goto ExitPoint;
}
if (IS_Get (&InlineStdFuncs)) {
/* We've generated the complete code for the function now and know the
** types of all parameters. Check for situations where better code can
** be generated. If such a situation is detected, throw away the
** generated, and emit better code.
** Note: Lots of improvements would be possible here, but I will
** concentrate on the most common case: memset with arguments 2 and 3
** being constant numerical values. Some checks have shown that this
** covers nearly 90% of all memset calls.
*/
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsConstAbsInt (&Arg2.Expr) &&
((ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) ||
(ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr)))) {
int Reg = ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memset code */
if (Arg3.Expr.IVal <= 129) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal-1));
AddCodeLine ("lda #$%02X", (unsigned char) Arg2.Expr.IVal);
g_defcodelabel (Label);
if (Reg) {
AddCodeLine ("sta (%s),y", ED_GetLabelName (&Arg1.Expr, 0));
} else {
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, 0));
}
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldy #$00");
AddCodeLine ("lda #$%02X", (unsigned char) Arg2.Expr.IVal);
g_defcodelabel (Label);
if (Reg) {
AddCodeLine ("sta (%s),y", ED_GetLabelName (&Arg1.Expr, 0));
} else {
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, 0));
}
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
/* memset returns the address, so the result is actually identical
** to the first argument.
*/
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsConstAbsInt (&Arg2.Expr) &&
ED_IsRVal (&Arg1.Expr) && ED_IsLocStack (&Arg1.Expr) &&
(Arg1.Expr.IVal - StackPtr) + Arg3.Expr.IVal < 256) {
/* Calculate the real stack offset */
int Offs = ED_GetStackOffs (&Arg1.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need a label */
Label = GetLocalLabel ();
/* Generate memset code */
AddCodeLine ("ldy #$%02X", (unsigned char) Offs);
AddCodeLine ("lda #$%02X", (unsigned char) Arg2.Expr.IVal);
g_defcodelabel (Label);
AddCodeLine ("sta (sp),y");
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Offs + Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
/* memset returns the address, so the result is actually identical
** to the first argument.
*/
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsConstAbsInt (&Arg3.Expr) && Arg3.Expr.IVal <= 256 &&
ED_IsConstAbsInt (&Arg2.Expr) &&
(Arg2.Expr.IVal != 0 || IS_Get (&CodeSizeFactor) > 200)) {
/* Remove all of the generated code but the load of the first
** argument.
*/
RemoveCode (&Arg1.Push);
/* We need a label */
Label = GetLocalLabel ();
/* Generate code */
AddCodeLine ("sta ptr1");
AddCodeLine ("stx ptr1+1");
if (Arg3.Expr.IVal <= 129) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal-1));
AddCodeLine ("lda #$%02X", (unsigned char) Arg2.Expr.IVal);
g_defcodelabel (Label);
AddCodeLine ("sta (ptr1),y");
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldy #$00");
AddCodeLine ("lda #$%02X", (unsigned char) Arg2.Expr.IVal);
g_defcodelabel (Label);
AddCodeLine ("sta (ptr1),y");
AddCodeLine ("iny");
AddCmpCodeIfSizeNot256 ("cpy #$%02X", Arg3.Expr.IVal);
AddCodeLine ("bne %s", LocalLabelName (Label));
}
/* Load the function result pointer into a/x (x is still valid). This
** code will get removed by the optimizer if it is not used later.
*/
AddCodeLine ("lda ptr1");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
/* Bail out, no need for further processing */
goto ExitPoint;
}
}
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
ExitPoint:
/* We expect the closing brace */
ConsumeRParen ();
}
/*****************************************************************************/
/* strcmp */
/*****************************************************************************/
static void StdFunc_strcmp (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
/* Handle the strcmp function */
{
/* Argument types: (const char*, const char*) */
static const Type* Arg1Type = type_c_char_p;
static const Type* Arg2Type = type_c_char_p;
ArgDesc Arg1, Arg2;
unsigned ParamSize = 0;
long ECount1;
long ECount2;
int IsArray;
int Offs;
/* Argument #1 */
ParseArg (&Arg1, Arg1Type, Expr);
g_push (Arg1.Flags, Arg1.Expr.IVal);
ParamSize += SizeOf (Arg1Type);
ConsumeComma ();
/* Argument #2. */
ParseArg (&Arg2, Arg2Type, Expr);
/* Since strcmp is a fastcall function, we must load the
** arg into the primary if it is not already there. This parameter is
** also ignored for the calculation of the parameter size, since it is
** not passed via the stack.
*/
if (Arg2.Flags & CF_CONST) {
LoadExpr (CF_NONE, &Arg2.Expr);
}
/* We still need to append deferred inc/dec before calling into the function */
DoDeferred (SQP_KEEP_EAX, &Arg2.Expr);
/* Emit the actual function call. This will also cleanup the stack. */
g_call (CF_FIXARGC, Func_strcmp, ParamSize);
/* Get the element counts of the arguments. Then get the larger of the
** two into ECount1. This removes FLEXIBLE and UNSPECIFIED automatically
*/
ECount1 = ArrayElementCount (&Arg1);
ECount2 = ArrayElementCount (&Arg2);
if (ECount2 > ECount1) {
ECount1 = ECount2;
}
if (IS_Get (&InlineStdFuncs)) {
/* If the second argument is the empty string literal, we can generate
** more efficient code.
*/
if (ED_IsLocLiteral (&Arg2.Expr) &&
IS_Get (&WritableStrings) == 0 &&
GetLiteralSize (Arg2.Expr.V.LVal) == 1 &&
GetLiteralStr (Arg2.Expr.V.LVal)[0] == '\0') {
/* Drop the generated code so we have the first argument in the
** primary
*/
RemoveCode (&Arg1.Push);
/* We don't need the literal any longer */
ReleaseLiteral (Arg2.Expr.V.LVal);
/* We do now have Arg1 in the primary. Load the first character from
** this string and cast to int. This is the function result.
*/
IsArray = IsTypeArray (Arg1.Type) && ED_IsRVal (&Arg1.Expr);
if (IsArray && ED_IsLocStack (&Arg1.Expr) &&
(Offs = ED_GetStackOffs (&Arg1.Expr, 0) < 256)) {
/* Drop the generated code */
RemoveCode (&Arg1.Load);
/* Generate code */
AddCodeLine ("ldy #$%02X", Offs);
AddCodeLine ("ldx #$00");
AddCodeLine ("lda (sp),y");
} else if (IsArray && ED_IsLocConst (&Arg1.Expr)) {
/* Drop the generated code */
RemoveCode (&Arg1.Load);
/* Generate code */
AddCodeLine ("ldx #$00");
AddCodeLine ("lda %s", ED_GetLabelName (&Arg1.Expr, 0));
} else {
/* Drop part of the generated code so we have the first argument
** in the primary
*/
RemoveCode (&Arg1.Push);
/* Fetch the first char */
g_getind (CF_CHAR | CF_UNSIGNED, 0);
}
} else if ((IS_Get (&CodeSizeFactor) >= 165) &&
((ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr)) ||
(ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr))) &&
((ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) ||
(ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr))) &&
(IS_Get (&EagerlyInlineFuncs) || (ECount1 > 0 && ECount1 < 256))) {
unsigned Entry, Loop, Fin; /* Labels */
const char* Load;
const char* Compare;
if (ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr)) {
Load = "lda (%s),y";
} else {
Load = "lda %s,y";
}
if (ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr)) {
Compare = "cmp (%s),y";
} else {
Compare = "cmp %s,y";
}
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need labels */
Entry = GetLocalLabel ();
Loop = GetLocalLabel ();
Fin = GetLocalLabel ();
/* Generate strcmp code */
AddCodeLine ("ldy #$00");
AddCodeLine ("beq %s", LocalLabelName (Entry));
g_defcodelabel (Loop);
AddCodeLine ("tax");
AddCodeLine ("beq %s", LocalLabelName (Fin));
AddCodeLine ("iny");
g_defcodelabel (Entry);
AddCodeLine (Load, ED_GetLabelName (&Arg1.Expr, 0));
AddCodeLine (Compare, ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine ("beq %s", LocalLabelName (Loop));
AddCodeLine ("ldx #$01");
AddCodeLine ("bcs %s", LocalLabelName (Fin));
AddCodeLine ("ldx #$FF");
g_defcodelabel (Fin);
} else if ((IS_Get (&CodeSizeFactor) > 190) &&
((ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr)) ||
(ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr))) &&
(IS_Get (&EagerlyInlineFuncs) || (ECount1 > 0 && ECount1 < 256))) {
unsigned Entry, Loop, Fin; /* Labels */
const char* Compare;
if (ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr)) {
Compare = "cmp (%s),y";
} else {
Compare = "cmp %s,y";
}
/* Drop the generated code */
RemoveCode (&Arg1.Push);
/* We need labels */
Entry = GetLocalLabel ();
Loop = GetLocalLabel ();
Fin = GetLocalLabel ();
/* Store Arg1 into ptr1 */
AddCodeLine ("sta ptr1");
AddCodeLine ("stx ptr1+1");
/* Generate strcmp code */
AddCodeLine ("ldy #$00");
AddCodeLine ("beq %s", LocalLabelName (Entry));
g_defcodelabel (Loop);
AddCodeLine ("tax");
AddCodeLine ("beq %s", LocalLabelName (Fin));
AddCodeLine ("iny");
g_defcodelabel (Entry);
AddCodeLine ("lda (ptr1),y");
AddCodeLine (Compare, ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine ("beq %s", LocalLabelName (Loop));
AddCodeLine ("ldx #$01");
AddCodeLine ("bcs %s", LocalLabelName (Fin));
AddCodeLine ("ldx #$FF");
g_defcodelabel (Fin);
}
}
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
/* We expect the closing brace */
ConsumeRParen ();
}
/*****************************************************************************/
/* strcpy */
/*****************************************************************************/
static void StdFunc_strcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
/* Handle the strcpy function */
{
/* Argument types: (char*, const char*) */
static const Type* Arg1Type = type_char_p;
static const Type* Arg2Type = type_c_char_p;
ArgDesc Arg1, Arg2;
unsigned ParamSize = 0;
long ECount;
unsigned L1;
/* Argument #1 */
ParseArg (&Arg1, Arg1Type, Expr);
g_push (Arg1.Flags, Arg1.Expr.IVal);
GetCodePos (&Arg1.End);
ParamSize += SizeOf (Arg1Type);
ConsumeComma ();
/* Argument #2. Since strcpy is a fastcall function, we must load the
** arg into the primary if it is not already there. This parameter is
** also ignored for the calculation of the parameter size, since it is
** not passed via the stack.
*/
ParseArg (&Arg2, Arg2Type, Expr);
if (Arg2.Flags & CF_CONST) {
LoadExpr (CF_NONE, &Arg2.Expr);
}
/* We still need to append deferred inc/dec before calling into the function */
DoDeferred (SQP_KEEP_EAX, &Arg2.Expr);
/* Emit the actual function call. This will also cleanup the stack. */
g_call (CF_FIXARGC, Func_strcpy, ParamSize);
/* Get the element count of argument 1 if it is an array */
ECount = ArrayElementCount (&Arg1);
if (IS_Get (&InlineStdFuncs)) {
/* We've generated the complete code for the function now and know the
** types of all parameters. Check for situations where better code can
** be generated. If such a situation is detected, throw away the
** generated, and emit better code.
*/
if (((ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr)) ||
(ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr))) &&
((ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) ||
(ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr))) &&
(IS_Get (&EagerlyInlineFuncs) ||
(ECount != UNSPECIFIED && ECount < 256))) {
const char* Load;
const char* Store;
if (ED_IsLVal (&Arg2.Expr) && ED_IsLocRegister (&Arg2.Expr)) {
Load = "lda (%s),y";
} else {
Load = "lda %s,y";
}
if (ED_IsLVal (&Arg1.Expr) && ED_IsLocRegister (&Arg1.Expr)) {
Store = "sta (%s),y";
} else {
Store = "sta %s,y";
}
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need labels */
L1 = GetLocalLabel ();
/* Generate strcpy code */
AddCodeLine ("ldy #$FF");
g_defcodelabel (L1);
AddCodeLine ("iny");
AddCodeLine (Load, ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine (Store, ED_GetLabelName (&Arg1.Expr, 0));
AddCodeLine ("bne %s", LocalLabelName (L1));
/* strcpy returns argument #1 */
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsRVal (&Arg2.Expr) && ED_IsLocStack (&Arg2.Expr) &&
StackPtr >= -255 &&
ED_IsRVal (&Arg1.Expr) && ED_IsLocConst (&Arg1.Expr)) {
/* It is possible to just use one index register even if the stack
** offset is not zero, by adjusting the offset to the constant
** address accordingly. But we cannot do this if the data in
** question is in the register space or at an absolute address less
** than 256. Register space is zero page, which means that the
** address calculation could overflow in the linker.
*/
int AllowOneIndex = !ED_IsLocRegister (&Arg1.Expr) &&
!(ED_IsLocNone (&Arg1.Expr) && Arg1.Expr.IVal < 256);
/* Calculate the real stack offset */
int Offs = ED_GetStackOffs (&Arg2.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need labels */
L1 = GetLocalLabel ();
/* Generate strcpy code */
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs - 1));
if (Offs == 0 || AllowOneIndex) {
g_defcodelabel (L1);
AddCodeLine ("iny");
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,y", ED_GetLabelName (&Arg1.Expr, -Offs));
} else {
AddCodeLine ("ldx #$FF");
g_defcodelabel (L1);
AddCodeLine ("iny");
AddCodeLine ("inx");
AddCodeLine ("lda (sp),y");
AddCodeLine ("sta %s,x", ED_GetLabelName (&Arg1.Expr, 0));
}
AddCodeLine ("bne %s", LocalLabelName (L1));
/* strcpy returns argument #1 */
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
if (ED_IsRVal (&Arg2.Expr) && ED_IsLocConst (&Arg2.Expr) &&
ED_IsRVal (&Arg1.Expr) && ED_IsLocStack (&Arg1.Expr) &&
StackPtr >= -255) {
/* It is possible to just use one index register even if the stack
** offset is not zero, by adjusting the offset to the constant
** address accordingly. But we cannot do this if the data in
** question is in the register space or at an absolute address less
** than 256. Register space is zero page, which means that the
** address calculation could overflow in the linker.
*/
int AllowOneIndex = !ED_IsLocRegister (&Arg2.Expr) &&
!(ED_IsLocNone (&Arg2.Expr) && Arg2.Expr.IVal < 256);
/* Calculate the real stack offset */
int Offs = ED_GetStackOffs (&Arg1.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
/* We need labels */
L1 = GetLocalLabel ();
/* Generate strcpy code */
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs - 1));
if (Offs == 0 || AllowOneIndex) {
g_defcodelabel (L1);
AddCodeLine ("iny");
AddCodeLine ("lda %s,y", ED_GetLabelName (&Arg2.Expr, -Offs));
AddCodeLine ("sta (sp),y");
} else {
AddCodeLine ("ldx #$FF");
g_defcodelabel (L1);
AddCodeLine ("iny");
AddCodeLine ("inx");
AddCodeLine ("lda %s,x", ED_GetLabelName (&Arg2.Expr, 0));
AddCodeLine ("sta (sp),y");
}
AddCodeLine ("bne %s", LocalLabelName (L1));
/* strcpy returns argument #1 */
*Expr = Arg1.Expr;
/* Bail out, no need for further processing */
goto ExitPoint;
}
}
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
ExitPoint:
/* We expect the closing brace */
ConsumeRParen ();
}
/*****************************************************************************/
/* strlen */
/*****************************************************************************/
static void StdFunc_strlen (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
/* Handle the strlen function */
{
static const Type* ArgType = type_c_char_p;
ExprDesc Arg;
int IsArray;
int IsPtr;
int IsByteIndex;
long ECount;
unsigned L;
ED_Init (&Arg);
Arg.Flags |= Expr->Flags & E_MASK_KEEP_SUBEXPR;
/* Evaluate the parameter */
hie1 (&Arg);
/* We still need to append deferred inc/dec before calling into the function */
DoDeferred (SQP_KEEP_EAX, &Arg);
/* Check if the argument is an array. If so, remember the element count.
** Otherwise set the element count to undefined.
*/
IsArray = IsTypeArray (Arg.Type);
if (IsArray) {
ECount = GetElementCount (Arg.Type);
if (ECount == FLEXIBLE) {
/* Treat as unknown */
ECount = UNSPECIFIED;
}
IsPtr = 0;
} else {
ECount = UNSPECIFIED;
IsPtr = IsTypePtr (Arg.Type);
}
/* Check if the elements of an array can be addressed by a byte sized
** index. This is true if the size of the array is known and less than
** 256.
*/
IsByteIndex = (ECount != UNSPECIFIED && ECount < 256);
/* Do type conversion */
TypeConversion (&Arg, ArgType);
if (IS_Get (&Optimize)) {
/* If the expression is a literal, and if string literals are read
** only, we can calculate the length of the string and remove it
** from the literal pool. Otherwise we have to calculate the length
** at runtime.
*/
if (ED_IsLocLiteral (&Arg) && IS_Get (&WritableStrings) == 0) {
/* Constant string literal */
ED_MakeConstAbs (Expr, GetLiteralSize (Arg.V.LVal) - 1, type_size_t);
/* We don't need the literal any longer */
ReleaseLiteral (Arg.V.LVal);
/* Bail out, no need for further improvements */
goto ExitPoint;
}
}
if (IS_Get (&InlineStdFuncs)) {
/* We will inline strlen for arrays with constant addresses, if either
** requested on the command line, or the array is smaller than 256,
** so the inlining is considered safe.
*/
if (ED_IsLocConst (&Arg) && IsArray &&
(IS_Get (&EagerlyInlineFuncs) || IsByteIndex)) {
/* Generate the strlen code */
L = GetLocalLabel ();
AddCodeLine ("ldy #$FF");
g_defcodelabel (L);
AddCodeLine ("iny");
AddCodeLine ("ldx %s,y", ED_GetLabelName (&Arg, 0));
AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("tya");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = type_size_t;
/* Bail out, no need for further processing */
goto ExitPoint;
}
/* We will inline strlen for arrays on the stack, if the array is
** completely within the reach of a byte sized index register.
*/
if (ED_IsLocStack (&Arg) && IsArray && IsByteIndex &&
(Arg.IVal - StackPtr) + ECount < 256) {
/* Calculate the true stack offset */
int Offs = ED_GetStackOffs (&Arg, 0);
/* Generate the strlen code */
L = GetLocalLabel ();
AddCodeLine ("ldx #$FF");
AddCodeLine ("ldy #$%02X", (unsigned char) (Offs-1));
g_defcodelabel (L);
AddCodeLine ("inx");
AddCodeLine ("iny");
AddCodeLine ("lda (sp),y");
AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("txa");
AddCodeLine ("ldx #$00");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = type_size_t;
/* Bail out, no need for further processing */
goto ExitPoint;
}
/* strlen for a string that is pointed to by a register variable will only
** get inlined if requested on the command line, since we cannot know how
** big the buffer actually is, so inlining is not always safe.
*/
if (ED_IsLocRegister (&Arg) && ED_IsLVal (&Arg) && IsPtr &&
IS_Get (&EagerlyInlineFuncs)) {
/* Generate the strlen code */
L = GetLocalLabel ();
AddCodeLine ("ldy #$FF");
g_defcodelabel (L);
AddCodeLine ("iny");
AddCodeLine ("lda (%s),y", ED_GetLabelName (&Arg, 0));
AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("tax");
AddCodeLine ("tya");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = type_size_t;
/* Bail out, no need for further processing */
goto ExitPoint;
}
/* Last check: We will inline a generic strlen routine if inlining was
** requested on the command line, and the code size factor is more than
** 400 (code is 13 bytes vs. 3 for a jsr call).
*/
if (IS_Get (&CodeSizeFactor) > 400 && IS_Get (&EagerlyInlineFuncs)) {
/* Load the expression into the primary */
LoadExpr (CF_NONE, &Arg);
/* Inline the function */
L = GetLocalLabel ();
AddCodeLine ("sta ptr1");
AddCodeLine ("stx ptr1+1");
AddCodeLine ("ldy #$FF");
g_defcodelabel (L);
AddCodeLine ("iny");
AddCodeLine ("lda (ptr1),y");
AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("tax");
AddCodeLine ("tya");
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = type_size_t;
/* Bail out, no need for further processing */
goto ExitPoint;
}
}
/* Load the expression into the primary */
LoadExpr (CF_NONE, &Arg);
/* Call the strlen function */
AddCodeLine ("jsr _%s", Func_strlen);
/* The function result is an rvalue in the primary register */
ED_FinalizeRValLoad (Expr);
Expr->Type = type_size_t;
ExitPoint:
/* We expect the closing brace */
ConsumeRParen ();
/* Propagate from subexpressions */
Expr->Flags |= Arg.Flags & E_MASK_VIRAL;
}
/*****************************************************************************/
/* Code */
/*****************************************************************************/
int FindStdFunc (const char* Name)
/* Determine if the given function is a known standard function that may be
** called in a special way. If so, return the index, otherwise return -1.
*/
{
/* Look into the table for known names */
struct StdFuncDesc* D =
bsearch (Name, StdFuncs, FUNC_COUNT, sizeof (StdFuncs[0]), CmpFunc);
/* Return the function index or -1 */
if (D == 0) {
return -1;
} else {
return D - StdFuncs;
}
}
void HandleStdFunc (int Index, FuncDesc* F, ExprDesc* lval)
/* Generate code for a known standard function. */
{
struct StdFuncDesc* D;
/* Get a pointer to the table entry */
CHECK (Index >= 0 && Index < (int)FUNC_COUNT);
D = StdFuncs + Index;
/* Call the handler function */
D->Handler (F, lval);
/* We assume all function calls had side effects */
lval->Flags |= E_SIDE_EFFECTS;
}