From b4e7e32b7bf6e7800ff1e6bc8a245e9c5c654ae6 Mon Sep 17 00:00:00 2001
From: MaartenBrock <MaartenBrock@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Fri, 26 Oct 2007 18:07:27 +0000
Subject: [PATCH] * src/mcs51/peeph.def: moved rules 257.x to 253.x and
 re-enabled 253.b * support/regression/tests/bug1721024.c:new, added

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@4941 4a8a32a2-be11-0410-ad9d-d568d2c75423
---
 ChangeLog                             |  5 +++
 src/mcs51/peeph.def                   | 46 +++++++++++++--------------
 support/regression/tests/bug1721024.c | 27 ++++++++++++++++
 3 files changed, 55 insertions(+), 23 deletions(-)
 create mode 100644 support/regression/tests/bug1721024.c

diff --git a/ChangeLog b/ChangeLog
index 11b0b2bf..285bc22a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-10-26 Maarten Brock <sourceforge.brock AT dse.nl>
+
+	* src/mcs51/peeph.def: moved rules 257.x to 253.x and re-enabled 253.b
+	* support/regression/tests/bug1721024.c:new, added
+
 2007-10-25 Maarten Brock <sourceforge.brock AT dse.nl>
 
 	* support/regression/tests/bug1816470.c: new, added
diff --git a/src/mcs51/peeph.def b/src/mcs51/peeph.def
index 51e25122..66909c94 100644
--- a/src/mcs51/peeph.def
+++ b/src/mcs51/peeph.def
@@ -3734,6 +3734,29 @@ replace {
 	mov	r%3,a
 }
 
+// unsigned char i=8; do{ } while(--i != 0);
+// this applies if i is kept in a register
+replace {
+	dec	%1
+	cjne	%1,#0x00,%2
+} by {
+	;	Peephole 253.a	optimized decrement with compare
+	djnz	%1,%2
+} if notVolatile(%1)
+
+// unsigned char i=8; do{ } while(--i != 0);
+// this applies if i is kept in data memory
+// must come before 256, see bug 1721024
+replace {
+	dec	%1
+	mov	a,%1
+	jnz	%2
+} by {
+	;	Peephole 253.b	optimized decrement with compare
+	djnz	%1,%2
+} if notVolatile(%1), operandsNotRelated(%1 '@r0' '@r1')
+
+
 // applies to f.e. funptrs.c
 // saves one byte if %1 is a register or @register
 replace {
@@ -3852,29 +3875,6 @@ replace {
 } if labelRefCount(%2 0),operandsNotRelated('a' %4 %6 %8)
 
 
-// unsigned char i=8; do{ } while(--i != 0);
-// this applies if i is kept in a register
-replace {
-	dec	%1
-	cjne	%1,#0x00,%2
-} by {
-	;	Peephole 257.a	optimized decrement with compare
-	djnz	%1,%2
-} if notVolatile(%1)
-
-//// unsigned char i=8; do{ } while(--i != 0);
-//// this applies if i is kept in data memory
-// Disabled because together with 256.c it causes bug #1721024
-//replace {
-//	dec	%1
-//	mov	a,%1
-//	jnz	%2
-//} by {
-//	;	Peephole 257.b	optimized decrement with compare
-//	djnz	%1,%2
-//} if notVolatile(%1), operandsNotRelated(%1 '@r0' '@r1')
-
-
 // in_byte<<=1; if(in_bit) in_byte|=1;
 // helps f.e. reading data on a 3-wire (SPI) bus
 replace {
diff --git a/support/regression/tests/bug1721024.c b/support/regression/tests/bug1721024.c
new file mode 100644
index 00000000..1035aa77
--- /dev/null
+++ b/support/regression/tests/bug1721024.c
@@ -0,0 +1,27 @@
+/*
+    bug 1721024
+*/
+
+#include <testfwk.h>
+
+static unsigned char temp1;
+static unsigned char temp2;
+
+void tst(unsigned long acc)
+{
+	UNUSED(acc);
+	temp1--;
+	if (temp1==0)
+	{
+		temp2=0;
+	}
+}
+
+void
+testBug(void)
+{
+	temp1 = 1;
+	temp2 = 2;
+	tst(0xFFFFFFFF);	//make sure acc!=0
+	ASSERT(temp2 == 0);
+}
-- 
2.30.2