More optimizations

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

diff --git a/src/cc65/codeinfo.c b/src/cc65/codeinfo.c
index 3430dbeae1d8cf9ed58ca565d12043eb013e166e..982ce4cec1c40544834e73fb68f4364d3df7b1d8 100644 (file)
--- a/src/cc65/codeinfo.c
+++ b/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          },

diff --git a/src/cc65/codeopt.c b/src/cc65/codeopt.c
index fce4c1f34c8215790da78a96a368584502b1b42e..3ec3f12db6e0ac8a70364accd7daca05406350a6 100644 (file)
--- a/src/cc65/codeopt.c
+++ b/src/cc65/codeopt.c
@@ -37,6 +37,7 @@
 
 /* common */
 #include "abend.h"
+#include "chartype.h"
 #include "print.h"
 #include "xsprintf.h"
 
@@ -692,7 +693,7 @@ static unsigned OptAdd2 (CodeSeg* S)
                    strcmp (L[6]->Arg, "addeqysp") == 0 &&
            !CE_HasLabel (L[6])                 &&
            (GetRegInfo (S, I+7) & REG_AX) == 0) {
-               
+
            char Buf [20];
            CodeEntry* X;
            int Offs;
@@ -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                         */
 /*****************************************************************************/
@@ -984,7 +1039,7 @@ static unsigned OptCmp3 (CodeSeg* S)
                CE_ReplaceOPC (L[1], OP65_CMP);
 
                /* Beware: If the first LDA instruction had a label, we have
-                * to move this label to the top of the sequence again.
+                * to move this label to the top of the sequence again.
                 */
                if (CE_HasLabel (E)) {
                    CS_MoveLabels (S, E, L[0]);
@@ -1629,7 +1684,7 @@ static unsigned OptNegAX4 (CodeSeg* S)
 
            /* Insert apropriate test code */
            if (ByteSized) {
-               /* Test bytes */
+               /* Test bytes */
                X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[0]->LI);
                CS_InsertEntry (S, X, I+2);
            } else {
@@ -2017,7 +2072,7 @@ static unsigned OptPtrLoad2 (CodeSeg* S)
            L[7]->OPC == OP65_JSR               &&
                    strcmp (L[7]->Arg, "ldauidx") == 0  &&
            !CE_HasLabel (L[7])) {
-               
+
            CodeEntry* X;
 
                    /* Store the low byte and remove the TAY instead */
@@ -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 */