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Generate special memcpy code if the target is less than 256 bytes in size and

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located at the stack bottom.


git-svn-id: svn://svn.cc65.org/cc65/trunk@5693 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz 2012-06-07 13:30:21 +00:00
parent 0f7f7796b1
commit b916fae1cc
1 changed files with 40 additions and 2 deletions
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42
src/cc65/stdfunc.c
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@ -202,6 +202,7 @@ static void StdFunc_memcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
ArgDesc Arg1, Arg2, Arg3;
unsigned ParamSize = 0;
unsigned Label;
int Offs;
/* Argument #1 */
ParseArg (&Arg1, Arg1Type);
@ -328,7 +329,7 @@ static void StdFunc_memcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
!(ED_IsLocAbs (&Arg2.Expr) && Arg2.Expr.IVal < 256);
/* Calculate the real stack offset */
int Offs = ED_GetStackOffs (&Arg1.Expr, 0);
Offs = ED_GetStackOffs (&Arg1.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
@ -402,7 +403,7 @@ static void StdFunc_memcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
!(ED_IsLocAbs (&Arg1.Expr) && Arg1.Expr.IVal < 256);
/* Calculate the real stack offset */
int Offs = ED_GetStackOffs (&Arg2.Expr, 0);
Offs = ED_GetStackOffs (&Arg2.Expr, 0);
/* Drop the generated code */
RemoveCode (&Arg1.Expr.Start);
@ -460,6 +461,43 @@ static void StdFunc_memcpy (FuncDesc* F attribute ((unused)), ExprDesc* Expr)
*/
*Expr = Arg1.Expr;
} else 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 <= 127) {
AddCodeLine ("ldy #$%02X", (unsigned char) (Arg3.Expr.IVal - 1));
g_defcodelabel (Label);
AddCodeLine ("lda (ptr1),y");
AddCodeLine ("sta (sp),y");
AddCodeLine ("dey");
AddCodeLine ("bpl %s", LocalLabelName (Label));
} else {
AddCodeLine ("ldy #$00");
g_defcodelabel (Label);
AddCodeLine ("lda (ptr1),y");
AddCodeLine ("sta (sp),y");
AddCodeLine ("iny");
AddCodeLine ("cpy #$%02X", (unsigned char) 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_MakeRValExpr (Expr);
Expr->Type = GetFuncReturn (Expr->Type);
} else {
/* The function result is an rvalue in the primary register */