From a6d6e6a047c0f429ae043d763dce7080dad8839b Mon Sep 17 00:00:00 2001
From: epetrich <epetrich@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Thu, 12 Aug 2004 04:42:43 +0000
Subject: [PATCH] * src/SDCClrange.c (findPrevUse): fixed bug #1007371

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@3437 4a8a32a2-be11-0410-ad9d-d568d2c75423
---
 ChangeLog        |  4 ++++
 src/SDCClrange.c | 26 +++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6128f494..cb132395 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2004-08-12 Erik Petrich <epetrich AT ivorytower.norman.ok.us>
+
+	* src/SDCClrange.c (findPrevUse): fixed bug #1007371
+
 2004-08-12 Erik Petrich <epetrich AT ivorytower.norman.ok.us>
 
 	* src/SDCCsymt.h,
diff --git a/src/SDCClrange.c b/src/SDCClrange.c
index 31a678b2..d99df74c 100644
--- a/src/SDCClrange.c
+++ b/src/SDCClrange.c
@@ -367,17 +367,33 @@ findPrevUse (eBBlock *ebp, iCode *ic, operand *op, eBBlock **ebbs, int count)
   int i;
   bitVect * succVect;
   bitVect * predVect;
-  
+  eBBlock * pred;
+
   /* If liveness is already known, then a previous call to findNextUse() */
   /* has already taken care of everything. */
   if (ic && bitVectBitValue(ic->rlive, op->key))
     return;
-  
+
+  if (!ic)
+    {
+      /* We are at the start of a block. If the operand is alive at the */
+      /* end of all predecessors, then a previous call to findNextUse() */
+      /* has already taken care of everything. */
+      
+      pred = setFirstItem (ebp->predList);
+      for (; pred; pred = setNextItem (ebp->predList))
+        if (pred->ech && !bitVectBitValue(pred->ech->rlive, op->key))
+          break;
+      
+      if (!pred)
+        return;
+    }
+
   if (op->isaddr)
     OP_SYMBOL (op)->isptr = 1;
 
   OP_SYMBOL (op)->key = op->key;
-  
+
   /* Otherwise, it appears that this symbol was used prior to definition.     */
   /* Just fix the live range; we'll deal with a diagnostic message elsewhere. */
   /* If the symbol use was in a loop, we need to extend the live range to the */
@@ -388,7 +404,7 @@ findPrevUse (eBBlock *ebp, iCode *ic, operand *op, eBBlock **ebbs, int count)
   unvisitBlocks (ebbs, count);
   predVect = newBitVect (count);
   applyToSet (ebp->predList, findRecursivePred, predVect);
-  
+
   /* Blocks that are both recursively predecessors and successors are in */
   /* a loop with the current iCode. Mark the operand as alive in them.   */
   for (i = 0; i < count; i++)
@@ -396,7 +412,7 @@ findPrevUse (eBBlock *ebp, iCode *ic, operand *op, eBBlock **ebbs, int count)
       if (bitVectBitValue(succVect, i) && bitVectBitValue(predVect, i))
         markAlive (ebbs[i]->sch, ebbs[i]->ech, op->key);
     }
-  
+
   freeBitVect (succVect);
   freeBitVect (predVect);
 }
-- 
2.30.2