From d790ae1b42f1a4940d7e8fc4121433716e116fe9 Mon Sep 17 00:00:00 2001
From: cuz <cuz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Mon, 18 Aug 2003 14:40:27 +0000
Subject: [PATCH] More optimizations

git-svn-id: svn://svn.cc65.org/cc65/trunk@2363 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 src/cc65/codeopt.c | 108 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)

diff --git a/src/cc65/codeopt.c b/src/cc65/codeopt.c
index a99b507c6..a3b49ef48 100644
--- a/src/cc65/codeopt.c
+++ b/src/cc65/codeopt.c
@@ -531,6 +531,111 @@ static unsigned OptPtrStore1 (CodeSeg* S)
 
 
 
+static unsigned OptPtrStore2 (CodeSeg* S)
+/* Search for the sequence:
+ *
+ *      lda     #<(label+0)
+ *      ldx     #>(label+0)
+ *      clc
+ *      adc     xxx
+ *      bcc     L
+ *      inx
+ * L:   jsr	pushax
+ *	ldx	#$00
+ *	lda	yyy
+ *	ldy     #$00
+ *      jsr     staspidx
+ *
+ * and replace it by:
+ *
+ *      ldy     xxx
+ *	ldx	#$00
+ *	lda	yyy
+ *      sta	label,y
+ */
+{
+    unsigned Changes = 0;
+
+    /* Walk over the entries */
+    unsigned I = 0;
+    while (I < CS_GetEntryCount (S)) {
+
+	CodeEntry* L[11];
+	unsigned Len;
+
+      	/* Get next entry */
+       	L[0] = CS_GetEntry (S, I);
+
+     	/* Check for the sequence */
+       	if (L[0]->OPC == OP65_LDA      	       	             &&
+	    L[0]->AM == AM65_IMM                             &&
+       	    CS_GetEntries (S, L+1, I+1, 10)                  &&
+       	    L[1]->OPC == OP65_LDX              	             &&
+	    L[1]->AM == AM65_IMM                             &&
+	    L[2]->OPC == OP65_CLC                            &&
+	    L[3]->OPC == OP65_ADC                            &&
+	    (L[3]->AM == AM65_ABS || L[3]->AM == AM65_ZP)    &&
+       	    (L[4]->OPC == OP65_BCC || L[4]->OPC == OP65_JCC) &&
+       	    L[4]->JumpTo != 0                                &&
+       	    L[4]->JumpTo->Owner == L[6]                      &&
+	    L[5]->OPC == OP65_INX                            &&
+            CE_IsCallTo (L[6], "pushax")                     &&
+            L[7]->OPC == OP65_LDX                            &&
+            L[8]->OPC == OP65_LDA                            &&
+       	    L[9]->OPC == OP65_LDY                            &&
+       	    CE_KnownImm (L[9])                               &&
+            L[9]->Num == 0                                   &&
+       	    CE_IsCallTo (L[10], "staspidx")                  &&
+       	    !CS_RangeHasLabel (S, I+1, 5)                    &&
+            !CS_RangeHasLabel (S, I+7, 4)                    &&
+	    /* Check the label last because this is quite costly */
+	    (Len = strlen (L[0]->Arg)) > 3                   &&
+	    L[0]->Arg[0] == '<'                              &&
+	    L[0]->Arg[1] == '('                              &&
+	    strlen (L[1]->Arg) == Len                        &&
+	    L[1]->Arg[0] == '>'                              &&
+       	    memcmp (L[0]->Arg+1, L[1]->Arg+1, Len-1) == 0) {
+
+	    CodeEntry* X;
+	    char* Label;
+
+	    /* We will create all the new stuff behind the current one so
+	     * we keep the line references.
+	     */
+	    X = NewCodeEntry (OP65_LDY,	L[3]->AM, L[3]->Arg, 0, L[0]->LI);
+	    CS_InsertEntry (S, X, I+11);
+
+       	    X = NewCodeEntry (OP65_LDX, L[7]->AM, L[7]->Arg, 0, L[7]->LI);
+	    CS_InsertEntry (S, X, I+12);
+
+            X = NewCodeEntry (OP65_LDA, L[8]->AM, L[8]->Arg, 0, L[8]->LI);
+            CS_InsertEntry (S, X, I+13);
+
+	    Label = memcpy (xmalloc (Len-2), L[0]->Arg+2, Len-3);
+	    Label[Len-3] = '\0';
+       	    X = NewCodeEntry (OP65_STA, AM65_ABSY, Label, 0, L[10]->LI);
+	    CS_InsertEntry (S, X, I+14);
+	    xfree (Label);
+
+	    /* Remove the old code */
+	    CS_DelEntries (S, I, 11);
+
+	    /* Remember, we had changes */
+	    ++Changes;
+
+	}
+
+	/* Next entry */
+	++I;
+
+    }
+
+    /* Return the number of changes made */
+    return Changes;
+}
+
+
+
 /*****************************************************************************/
 /*			Optimize loads through pointers                      */
 /*****************************************************************************/
@@ -1418,6 +1523,7 @@ static OptFunc DOptPtrLoad5    	= { OptPtrLoad5,     "OptPtrLoad5",    	 65, 0,
 static OptFunc DOptPtrLoad6    	= { OptPtrLoad6,     "OptPtrLoad6",    	 86, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrLoad7    	= { OptPtrLoad7,     "OptPtrLoad7",    	100, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrStore1   	= { OptPtrStore1,    "OptPtrStore1",    100, 0, 0, 0, 0, 0 };
+static OptFunc DOptPtrStore2   	= { OptPtrStore2,    "OptPtrStore2",     40, 0, 0, 0, 0, 0 };
 static OptFunc DOptPush1       	= { OptPush1,        "OptPush1",         65, 0, 0, 0, 0, 0 };
 static OptFunc DOptPush2       	= { OptPush2,        "OptPush2",         50, 0, 0, 0, 0, 0 };
 static OptFunc DOptPushPop      = { OptPushPop,      "OptPushPop",        0, 0, 0, 0, 0, 0 };
@@ -1481,6 +1587,7 @@ static OptFunc* OptFuncs[] = {
     &DOptPtrLoad6,
     &DOptPtrLoad7,
     &DOptPtrStore1,
+    &DOptPtrStore2,
     &DOptPush1,
     &DOptPush2,
     &DOptPushPop,
@@ -1738,6 +1845,7 @@ static unsigned RunOptGroup1 (CodeSeg* S)
     unsigned Changes = 0;
 
     Changes += RunOptFunc (S, &DOptPtrStore1, 1);
+    Changes += RunOptFunc (S, &DOptPtrStore2, 1);
     Changes += RunOptFunc (S, &DOptPtrLoad1, 1);
     Changes += RunOptFunc (S, &DOptPtrLoad2, 1);
     Changes += RunOptFunc (S, &DOptPtrLoad3, 1);