* src/SDCCglobl.h,

[fw/sdcc] / src / mcs51 / rtrack.c

diff --git a/src/mcs51/rtrack.c b/src/mcs51/rtrack.c
index 10882d7fb35b112979b6c95c14a6309f149b38c6..45abfbabf407cea38ec31012e66d3d1e6fde375d 100644 (file)
--- a/src/mcs51/rtrack.c
+++ b/src/mcs51/rtrack.c
@@ -30,6 +30,8 @@
     - a label causes loss of tracking (no handling of information of blocks
       known to follow/preceed the current block)
     - not used in aopGet or genRet
+    - does not track which registers are known to be unchanged within
+      a function (would not have to be saved when calling the function)
 -------------------------------------------------------------------------*/
 
 
@@ -44,7 +46,7 @@
 #define DEBUG(x)
 //#define DEBUG(x) x
 
-#define D(x) x
+#define D(x) do if (!options.noGenComments) {x;} while(0)
 
 #define REGS8051_SET(idx,val) do{ \
                                   regs8051[idx].value = (val) & 0xff; \
@@ -119,6 +121,18 @@ static void invalidateAll()
   regs8051[A_IDX].valueKnown = 0;
 }
 
+static regs * getReg(const char *str)
+{
+  char *s;
+  int regNum;
+
+  regNum = strtol (str, &s, 16);
+  if (s == str+1)
+    {
+      return &regs8051[Rx_NUM_TO_IDX(regNum)];
+    }
+  return NULL;
+}
 
 /* tracking values within registers by looking
    at the line passed to the assembler.
@@ -155,18 +169,11 @@ void rtrackUpdate (const char *line)
       if (!strncmp (line,"mov\ta,r",7))
         {
           /* handle mov from Rx if Rx is known */
-          char *s;
-          int regNum;
-
-          regNum = strtol (line+7, &s, 16);
-          if (s == line+8)
+          regs *r = getReg(line+7);
+          if (r && r->valueKnown)
             {
-              regs *r = &regs8051[Rx_NUM_TO_IDX(regNum)];
-              if (r->valueKnown)
-                {
-                  REGS8051_SET (A_IDX, r->value);
-                  return;
-                }
+              REGS8051_SET (A_IDX, r->value);
+              return;
             }
           REGS8051_UNSET (A_IDX);
           return;
@@ -269,22 +276,23 @@ void rtrackUpdate (const char *line)
 
       if(!strncmp (line,"inc\tr",5))
         {
-          char *s;
-          int regNum;
-
-          regNum = strtol (line+5, &s, 16);
-          if (s == line+6)
+          regs *r = getReg(line+5);
+          if (r && r->valueKnown)
             {
-              regs *r = &regs8051[Rx_NUM_TO_IDX(regNum)];
-              if (r->valueKnown)
-                {
-                  REGS8051_SET (Rx_NUM_TO_IDX(regNum), r->value+1);
-                }
-              return;
+              REGS8051_SET (r->rIdx, r->value+1);
             }
+          return;
         }
     }
 
+  /* some bit in acc is cleared
+     MB: I'm too lazy to find out which right now */
+  if (!strncmp (line,"jbc\tacc",7))
+    {
+      REGS8051_UNSET (A_IDX);
+      return;
+    }
+
   /* unfortunately the label typically following these
      will cause loss of tracking */
   if (!strncmp (line,"jc\t",3) ||
@@ -297,13 +305,39 @@ void rtrackUpdate (const char *line)
   /* if branch not taken in "cjne r2,#0x08,somewhere" 
      r2 is known to be 8 */
   if (!strncmp (line,"cjne",4))
-    return;
+    {
+      if(!strncmp (line,"cjne\ta,#0x",10))
+        {
+          char *s;
+          int value;
+
+          value = strtol (line+8, &s, 16);
+          if (s != line+8)
+              REGS8051_SET (A_IDX, value); /* valid hex found */
+        }
+      if(!strncmp (line,"cjne\tr",6))
+        {
+          char *s;
+          int value;
+          regs *r = getReg(line+6);
+          value = strtol (line+8, &s, 16);
+          if (r && s != line+8)
+              REGS8051_SET (r->rIdx, value); /* valid hex found */
+        }
+      return;
+    }
 
   /* acc eventually known to be zero */
-  if (!strncmp (line,"jz\t",3) ||
-      !strncmp (line,"jnz\t",4))
+  if (!strncmp (line,"jz\t",3))
     return;
 
+  /* acc eventually known to be zero */
+  if (!strncmp (line,"jnz\t",4))
+    {
+      REGS8051_SET (A_IDX, 0x00); // branch not taken
+      return;
+    }
+
   if (!strncmp (line,"djnz\tr",6))
     {
       char *s;
@@ -312,8 +346,8 @@ void rtrackUpdate (const char *line)
       regNum = strtol (line+6, &s, 16);
       if (s == line+7)
         {
-          REGS8051_UNSET (Rx_NUM_TO_IDX(regNum));
-          // REGS8051_SET (Rx_NUM_TO_IDX(regNum), 0x00); // branch not taken
+          //REGS8051_UNSET (Rx_NUM_TO_IDX(regNum));
+          REGS8051_SET (Rx_NUM_TO_IDX(regNum), 0x00); // branch not taken
           return;
         }
     }
@@ -334,7 +368,8 @@ void rtrackUpdate (const char *line)
       !strncmp (line,"rlc\ta,",6) ||
       !strncmp (line,"rrc\ta,",6) ||
       !strncmp (line,"setb\ta",6) ||
-      !strncmp (line,"clrb\ta,",7))
+      !strncmp (line,"clrb\ta,",7)||
+      !strncmp (line,"cpl\tacc",7))
     {
       /* could also handle f.e. "add a,Rx" if a, Rx are known or "xrl a,#0x08" */
       REGS8051_UNSET (A_IDX);
@@ -358,19 +393,12 @@ void rtrackUpdate (const char *line)
 
       if(!strncmp (line,"dec\tr",5))
         {
-          char *s;
-          int regNum;
-
-          regNum = strtol (line+5, &s, 16);
-          if (s == line+6)
+          regs *r = getReg(line+5);
+          if (r && r->valueKnown)
             {
-              regs *r = &regs8051[Rx_NUM_TO_IDX(regNum)];
-              if (r->valueKnown)
-                {
-                  REGS8051_SET (Rx_NUM_TO_IDX(regNum), r->value-1);
-                }
-              return;
+              REGS8051_SET (r->rIdx, r->value-1);
             }
+          return;
         }
     }
 
@@ -424,7 +452,8 @@ void rtrackUpdate (const char *line)
       if (!strcmp (line,"lcall\t__gptrput"))
         {
           /* invalidate R0..R7 because they might have been changed */
-          invalidateAllRx();
+          /* MB: too paranoid ? */
+          //invalidateAllRx();
           return;
         }
       if (!strcmp (line,"lcall\t__gptrget"))
@@ -438,6 +467,24 @@ void rtrackUpdate (const char *line)
         }
      }
 
+  if (!strncmp (line,"xch\ta,r",7))
+    {
+      /* handle xch acc with Rn */
+      regs *r = getReg(line+7);
+      if (r)
+        {
+          unsigned swap;
+          swap = r->valueKnown;
+          r->valueKnown = regs8051[A_IDX].valueKnown;
+          regs8051[A_IDX].valueKnown = swap;
+
+          swap = r->value;
+          r->value = regs8051[A_IDX].value;
+          regs8051[A_IDX].value = swap;
+          return;
+        }
+    }
+
   /* all others unrecognized, invalidate */
   invalidateAll();
 }
@@ -520,6 +567,7 @@ int rtrackMoveALit (const char *x)
                !a->valueKnown))
             {
               /* peepholes convert to clr a */
+              /* MB: why not here ? */
               emitcode ("mov", "a,#0x00");
               return 1;
             }