From: Nick Clifton <nickc@redhat.com>
Date: Thu, 2 May 2002 09:11:14 +0000 (+0000)
Subject: Do not convert a subtract of zero into an add of zero.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=358b94bdb1b02dbc21a19719fbaa9fbe9c93c61a;p=binutils-gdb.git

Do not convert a subtract of zero into an add of zero.
---

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 76b97adf60d..6244a875175 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2002-05-02  Nick Clifton  <nickc@cambridge.redhat.com>
+
+	* config/tc-arm.c (thumb_add_sub): Do not convert a subtract of
+	zero into an add of zero - it is not the same.
+
 2002-05-01  Arati Dikey <aratid@kpit.com>
 
 	* tc-sh.c (get_specific): Generate warning if the same
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 162553f6436..1370f13e5ae 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -7433,11 +7433,11 @@ thumb_add_sub (str, subtract)
 	  int offset = inst.reloc.exp.X_add_number;
 
 	  if (subtract)
-	    offset = -offset;
+	    offset = - offset;
 
 	  if (offset < 0)
 	    {
-	      offset = -offset;
+	      offset = - offset;
 	      subtract = 1;
 
 	      /* Quick check, in case offset is MIN_INT.  */
@@ -7447,7 +7447,9 @@ thumb_add_sub (str, subtract)
 		  return;
 		}
 	    }
-	  else
+	  /* Note - you cannot convert a subtract of 0 into an
+	     add of 0 because the carry flag is set differently.  */
+	  else if (offset > 0)
 	    subtract = 0;
 
 	  if (Rd == REG_SP)
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 428b6a20457..6e552b7e11f 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2002-05-02  Nick Clifton  <nickc@cambridge.redhat.com>
+
+	* gas/arm/arm7t.s: Add thumb mode "sub r?, #0" and "add r?, #0".
+	* gas/arm/arm7t.d: Add expected results.  (Make sure that the
+	subtract is not converted into an add).
+
 2002-04-23  H.J. Lu <hjl@gnu.org>
 
 	* gas/mips/elempic.d: Use empic.l.
diff --git a/gas/testsuite/gas/arm/arm7t.d b/gas/testsuite/gas/arm/arm7t.d
index dc4993a0b52..87b388f5e63 100644
--- a/gas/testsuite/gas/arm/arm7t.d
+++ b/gas/testsuite/gas/arm/arm7t.d
@@ -66,3 +66,5 @@ Disassembly of section .text:
 [		]*dc:.*fred
 0+e0 <[^>]*> 0000c0de ?	.*
 0+e4 <[^>]*> 0000dead ?	.*
+0+e8 <[^>]*> 3800      	sub	r0, #0
+0+ea <[^>]*> 3000      	add	r0, #0
diff --git a/gas/testsuite/gas/arm/arm7t.s b/gas/testsuite/gas/arm/arm7t.s
index d155752eedd..f3251117d18 100644
--- a/gas/testsuite/gas/arm/arm7t.s
+++ b/gas/testsuite/gas/arm/arm7t.s
@@ -72,3 +72,11 @@ misc:
 	.align
 .L2:
 	.word	fred
+	
+	.ltorg
+	.thumb
+	.global thumb_tests
+	.thumb_func
+thumb_tests:	
+	sub	r0, #0
+	add	r0, #0