More optimizations

git-svn-id: svn://svn.cc65.org/cc65/trunk@842 b7a2c559-68d2-44c3-8de9-860c34a00d81

src/cc65/codeinfo.c

@@ -67,6 +67,10 @@ struct FuncInfo {
 
 static const FuncInfo FuncInfoTable[] = {
     { "addysp",	       	REG_Y, 	       	REG_NONE	},
+    { "aslax1",         REG_AX,		REG_AX          },
+    { "aslax2",         REG_AX,		REG_AX          },
+    { "aslax3",         REG_AX,		REG_AX          },
+    { "aslax4",         REG_AX,		REG_AX          },
     { "bnega",          REG_A,          REG_AX          },
     { "bnegax",         REG_AX,         REG_AX          },
     { "bnegeax",        REG_AX,         REG_AX          },
@@ -122,6 +126,10 @@ static const FuncInfo FuncInfoTable[] = {
     { "pusheax",        REG_AX,         REG_Y           },
     { "pushw0sp",  	REG_NONE,	REG_AXY	    	},
     { "pushwysp",  	REG_Y,		REG_AXY	    	},
+    { "shlax1",         REG_AX,		REG_AX          },
+    { "shlax2",         REG_AX,		REG_AX          },
+    { "shlax3",         REG_AX,		REG_AX          },
+    { "shlax4",         REG_AX,		REG_AX          },
     { "shrax1",         REG_AX,         REG_AX          },
     { "shrax2",         REG_AX,         REG_AX          },
     { "shrax3",         REG_AX,         REG_AX          },

src/cc65/codeopt.c

@@ -37,6 +37,7 @@
 
 /* common */
 #include "abend.h"
+#include "chartype.h"
 #include "print.h"
 #include "xsprintf.h"
 
@@ -809,6 +810,60 @@ static unsigned OptAdd3 (CodeSeg* S)
 
 
 
+/*****************************************************************************/
+/*				Optimize shifts                              */
+/*****************************************************************************/
+
+
+
+static unsigned OptShift1 (CodeSeg* S)
+/* A call to the shlaxN routine may get replaced by one or more asl insns
+ * if the value of X is not used later.
+ */
+{
+    unsigned Changes = 0;
+
+    /* Walk over the entries */
+    unsigned I = 0;
+    while (I < CS_GetEntryCount (S)) {
+
+      	/* Get next entry */
+       	CodeEntry* E = CS_GetEntry (S, I);
+
+     	/* Check for the sequence */
+	if (E->OPC == OP65_JSR                       &&
+       	    (strncmp (E->Arg, "shlax", 5) == 0 ||
+	     strncmp (E->Arg, "aslax", 5) == 0)	     &&
+	    strlen (E->Arg) == 6                     &&
+	    IsDigit (E->Arg[5])                      &&
+	    !RegXUsed (S, I+1)) {
+
+	    /* Insert shift insns */
+	    unsigned Count = E->Arg[5] - '0';
+	    while (Count--) {
+	    	CodeEntry* X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
+	    	CS_InsertEntry (S, X, I+1);
+	    }
+
+	    /* Delete the call to shlax */
+	    CS_DelEntry (S, I);
+
+	    /* Remember, we had changes */
+	    ++Changes;
+
+	}
+
+	/* Next entry */
+	++I;
+
+    }
+
+    /* Return the number of changes made */
+    return Changes;
+}
+
+
+
 /*****************************************************************************/
 /*		  	  Optimizations for compares                         */
 /*****************************************************************************/
@@ -2278,6 +2333,8 @@ static OptFunc OptFuncs [] = {
     OptEntry (OptAdd1, optPre),
     OptEntry (OptAdd2, optPre),
     OptEntry (OptAdd3, optMain),
+    /* Optimize shifts */
+    OptEntry (OptShift1, optPre),
     /* Optimize jump cascades */
     OptEntry (OptJumpCascades, optMain),
     /* Remove dead jumps */