From: sandeep <sandeep@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Wed, 30 Jan 2002 04:09:40 +0000 (+0000)
Subject: added function returnAtEnd - to determine if a basic block terminates with
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=aac4af49be9af5dbbdf36f81aa8e38f369f67456;p=fw%2Fsdcc

added function returnAtEnd - to determine if a basic block terminates with
a RETURN iCode


git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@1861 4a8a32a2-be11-0410-ad9d-d568d2c75423
---

diff --git a/src/SDCCcflow.c b/src/SDCCcflow.c
index 2dc53135..4db70948 100644
--- a/src/SDCCcflow.c
+++ b/src/SDCCcflow.c
@@ -425,3 +425,35 @@ computeControlFlow (eBBlock ** ebbs, int count, int reSort)
   qsort (ebbs, saveCount, sizeof (eBBlock *), dfNumCompare);
 
 }
+
+/*-----------------------------------------------------------------*/
+/* returnAtEnd - returns 1 if Basic Block has a return at the end  */
+/*               of it                                             */
+/*-----------------------------------------------------------------*/
+int returnAtEnd (eBBlock *ebp)
+{
+    /* case 1.
+       This basic block ends in a return statment 
+    */
+    if (ebp->ech && ebp->ech->op == RETURN) return 1;
+
+    /* case 2.
+       This basic block has only one successor and that
+       successor has only one return statement
+    */
+    if (elementsInSet(ebp->succList) == 1) {
+	eBBlock *succ = setFirstItem(ebp->succList);
+	/* could happen for dummy blocks */
+	if (!succ->sch || !succ->ech) return 0;
+
+	/* first iCode is a return */
+	if (succ->sch->op == RETURN) return 2;
+
+	/* or first iCode is a label & the next &
+	   last icode is a return */
+	if (succ->sch->op == LABEL && succ->sch->next == succ->ech &&
+	    succ->ech->op == RETURN ) return 2;
+    }
+
+    return 0;
+}
diff --git a/src/SDCCcflow.h b/src/SDCCcflow.h
index 949c9b5c..4d6af9f5 100644
--- a/src/SDCCcflow.h
+++ b/src/SDCCcflow.h
@@ -40,5 +40,5 @@ void computeControlFlow (eBBlock **, int, int);
 int dfNumCompare (const void *, const void *);
 int bbNumCompare (const void *, const void *);
 void disconBBlock (eBBlock *, eBBlock **, int);
-
+int returnAtEnd (eBBlock *) ;
 #endif