From: tecodev <tecodev@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Sat, 22 Jan 2005 13:22:07 +0000 (+0000)
Subject: * src/SDCCopt.c (killDeadCode): do not throw iCodes away if one
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=5a55bd5eca262ce15fa89b7825c74042f89168ae;p=fw%2Fsdcc

* src/SDCCopt.c (killDeadCode): do not throw iCodes away if one
  of the operands is volatile. Fixes #1020220


git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@3646 4a8a32a2-be11-0410-ad9d-d568d2c75423
---

diff --git a/ChangeLog b/ChangeLog
index 75a82ee5..2d4c75d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2005-01-22 Daniel Winkler <post AT danielwinkler.de>
+
+	* src/SDCCopt.c (killDeadCode): do not throw iCodes away if one
+	  of the operands is volatile. Fixes #1020220
+
 2005-01-22 Daniel Winkler <post AT danielwinkler.de>
 
 	* src/pic16/pcoderegs.c (pCodeOptime2pCodes): reenabled optimization
diff --git a/src/SDCCopt.c b/src/SDCCopt.c
index f7e67ce6..1377a58e 100644
--- a/src/SDCCopt.c
+++ b/src/SDCCopt.c
@@ -879,6 +879,18 @@ killDeadCode (eBBlock ** ebbs, int count)
 	      if (IC_RESULT (ic) && isOperandVolatile (IC_RESULT (ic), FALSE))
 		continue;
 
+	      /* We also cannot remove the iCode, when an operand is volatile.       */
+	      /* Even read access can cause side effects on some hardware registers! */
+
+	      /* if the left operand is volatile then continue */
+	      if (IC_LEFT(ic) && isOperandVolatile (IC_LEFT (ic), TRUE))
+		continue;
+
+	      /* if the right operand is volatile then continue */
+	      if (IC_RIGHT(ic) && isOperandVolatile (IC_RIGHT (ic), TRUE))
+		continue;
+
+
 	      /* if the result is a temp & isaddr then skip */
 	      if (IC_RESULT (ic) && POINTER_SET (ic))
 		continue;