Extended the semantics of the critical keyword to include

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

diff --git a/src/mcs51/gen.c b/src/mcs51/gen.c
index aa19b83b1edb3c142e04288ab6b43c00ee5bf1d2..34c178c00454d23ecfe80712a442eb4c09829d61 100644 (file)
--- a/src/mcs51/gen.c
+++ b/src/mcs51/gen.c
@@ -2604,9 +2604,12 @@ genFunction (iCode * ic)
   /* if critical function then turn interrupts off */
   if (IFFUNC_ISCRITICAL (ftype))
     {
-      emitcode ("mov", "c,ea");
+      symbol *tlbl = newiTempLabel (NULL);
+      emitcode ("setb", "c");
+      emitcode ("jbc", "ea,%05d$", (tlbl->key + 100)); /* atomic test & clear */
+      emitcode ("clr", "c");
+      emitcode ("", "%05d$:", (tlbl->key + 100));
       emitcode ("push", "psw"); /* save old ea via c in psw */
-      emitcode ("clr", "ea");
     }
 }
 
@@ -9004,6 +9007,65 @@ release:
   freeAsmop (right, NULL, ic, TRUE);
 }
 
+/*-----------------------------------------------------------------*/
+/* genCritical - generate code for start of a critical sequence    */
+/*-----------------------------------------------------------------*/
+static void
+genCritical (iCode *ic)
+{
+  symbol *tlbl = newiTempLabel (NULL);
+
+  D(emitcode(";     genCritical",""));
+  
+  if (IC_RESULT (ic))
+    aopOp (IC_RESULT (ic), ic, TRUE);
+
+  emitcode ("setb", "c");
+  emitcode ("jbc", "ea,%05d$", (tlbl->key + 100)); /* atomic test & clear */
+  emitcode ("clr", "c");
+  emitcode ("", "%05d$:", (tlbl->key + 100));
+
+  if (IC_RESULT (ic))
+    outBitC (IC_RESULT (ic)); /* save old ea in an operand */
+  else
+    emitcode ("push", "psw"); /* save old ea via c in psw on top of stack*/
+
+  if (IC_RESULT (ic))
+    freeAsmop (IC_RESULT (ic), NULL, ic, TRUE);
+}
+
+/*-----------------------------------------------------------------*/
+/* genEndCritical - generate code for end of a critical sequence   */
+/*-----------------------------------------------------------------*/
+static void
+genEndCritical (iCode *ic)
+{
+  D(emitcode(";     genEndCritical",""));
+  
+  if (IC_RIGHT (ic))
+    {
+      aopOp (IC_RIGHT (ic), ic, FALSE);
+      if (AOP_TYPE (IC_RIGHT (ic)) == AOP_CRY)
+        {
+         emitcode ("mov", "c,%s", IC_RIGHT (ic)->aop->aopu.aop_dir);
+          emitcode ("mov", "ea,c");
+        }
+      else
+        {
+          MOVA (aopGet (AOP (IC_RIGHT (ic)), 0, FALSE, FALSE));
+          emitcode ("rrc", "a");
+          emitcode ("mov", "ea,c");
+        }
+      freeAsmop (IC_RIGHT (ic), NULL, ic, TRUE);
+    }
+  else
+    {
+      emitcode ("pop", "psw"); /* restore ea via c in psw on top of stack */
+      emitcode ("mov", "ea,c");
+    }
+}
+
+
 /*-----------------------------------------------------------------*/
 /* gen51Code - generate code for 8051 based controllers            */
 /*-----------------------------------------------------------------*/
@@ -9262,6 +9324,14 @@ gen51Code (iCode * lic)
          genDummyRead (ic);
          break;
 
+       case CRITICAL:
+         genCritical (ic);
+         break;
+
+       case ENDCRITICAL:
+         genEndCritical (ic);
+         break;
+
        default:
          ic = ic;
        }