Fix h8300 relaxation.

7 files changed, 149 insertions, 32 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 8b096bc..479674b 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2002-11-15  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* coff-h8300.c (h8300_reloc16_estimate): Do not optimize away
+	jsr after a short jump.
+	* elf32-h8300.c (elf32_h8_relax_section): Likewise.
+
 2002-11-15  Klee Dienes  <kdienes@apple.com>
 
 	* pef.c (bfd_pef_convert_architecture): Move declaration of
diff --git a/bfd/coff-h8300.c b/bfd/coff-h8300.c
index 4aab46b..c83015e 100644
--- a/bfd/coff-h8300.c
+++ b/bfd/coff-h8300.c
@@ -4,21 +4,21 @@
    Free Software Foundation, Inc.
    Written by Steve Chamberlain, <sac@cygnus.com>.
 
-This file is part of BFD, the Binary File Descriptor library.
+   This file is part of BFD, the Binary File Descriptor library.
 
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
 
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 #include "bfd.h"
 #include "sysdep.h"
@@ -483,6 +483,13 @@ h8300_reloc16_estimate (abfd, input_section, reloc, shrink, link_info)
 	 closer if we do relax this branch.  */
       if ((int) gap >= -128 && (int) gap <= 128)
 	{
+	  bfd_byte code;
+
+	  if (!bfd_get_section_contents (abfd, input_section, & code,
+					 reloc->address, 1))
+	    break;
+	  code = bfd_get_8 (abfd, & code);
+
 	  /* It's possible we may be able to eliminate this branch entirely;
 	     if the previous instruction is a branch around this instruction,
 	     and there's no label at this instruction, then we can reverse
@@ -494,9 +501,25 @@ h8300_reloc16_estimate (abfd, input_section, reloc, shrink, link_info)
 		lab1:				lab1:
 
 	     This saves 4 bytes instead of two, and should be relatively
-	     common.  */
-
-	  if (gap <= 126
+	     common.
+
+	     Only perform this optimisation for jumps (code 0x5a) not
+	     subroutine calls, as otherwise it could transform:
+	     
+	     	             mov.w   r0,r0
+	     	             beq     .L1
+	           	     jsr     @_bar
+	              .L1:   rts
+	              _bar:  rts
+	     into:
+	     	             mov.w   r0,r0
+	     	             bne     _bar
+	     	             rts
+	     	      _bar:  rts
+	     
+	     which changes the call (jsr) into a branch (bne).  */
+	  if (code == 0x5a
+	      && gap <= 126
 	      && last_reloc
 	      && last_reloc->howto->type == R_PCRBYTE)
 	    {
diff --git a/bfd/elf32-h8300.c b/bfd/elf32-h8300.c
index 1d643cb..9cb900b 100644
--- a/bfd/elf32-h8300.c
+++ b/bfd/elf32-h8300.c
@@ -2,21 +2,21 @@
    Copyright 1993, 1995, 1998, 1999, 2001, 2002
    Free Software Foundation, Inc.
 
-This file is part of BFD, the Binary File Descriptor library.
+   This file is part of BFD, the Binary File Descriptor library.
 
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
 
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 #include "bfd.h"
 #include "sysdep.h"
@@ -827,14 +827,34 @@ elf32_h8_relax_section (abfd, sec, link_info, again)
 		elf_section_data (sec)->this_hdr.contents = contents;
 		symtab_hdr->contents = (unsigned char *) isymbuf;
 
+		/* Get the instruction code being relaxed.  */
+		code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
+
 		/* If the previous instruction conditionally jumped around
 		   this instruction, we may be able to reverse the condition
 		   and redirect the previous instruction to the target of
 		   this instruction.
 
 		   Such sequences are used by the compiler to deal with
-		   long conditional branches.  */
-		if ((int) gap <= 130
+		   long conditional branches.
+
+		   Only perform this optimisation for jumps (code 0x5a) not
+		   subroutine calls, as otherwise it could transform:
+		   
+		   	             mov.w   r0,r0
+		   	             beq     .L1
+		         	     jsr     @_bar
+		              .L1:   rts
+		              _bar:  rts
+		   into:
+		   	             mov.w   r0,r0
+			             bne     _bar
+			             rts
+			      _bar:  rts
+
+		   which changes the call (jsr) into a branch (bne).  */
+		if (code == 0x5a
+		    && (int) gap <= 130
 		    && (int) gap >= -128
 		    && last_reloc
 		    && ELF32_R_TYPE (last_reloc->r_info) == R_H8_PCREL8
@@ -890,9 +910,6 @@ elf32_h8_relax_section (abfd, sec, link_info, again)
 		      }
 		  }
 
-		/* We could not eliminate this jump, so just shorten it.  */
-		code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
-
 		if (code == 0x5e)
 		  bfd_put_8 (abfd, 0x55, contents + irel->r_offset - 1);
 		else if (code == 0x5a)
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 118c6e1..5460327 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2002-11-15  Nick Clifton  <nickc@redhat.com>
+
+	* ld-h8300: New directory.
+	* ld-h8300/h8300.exp: New expect script.  Only run tests for h8300
+	targets.
+	* ld-h8300/relax.s: New assembler source file.
+	* ld-h8300/relax.d: New expected output file.
+
 2002-11-11  Hans-Peter Nilsson  <hp@axis.com>
 
 	* ld-elf/sec64k.exp: New test.
diff --git a/ld/testsuite/ld-h8300/h8300.exp b/ld/testsuite/ld-h8300/h8300.exp
new file mode 100644
index 0000000..99542f4
--- /dev/null
+++ b/ld/testsuite/ld-h8300/h8300.exp
@@ -0,0 +1,32 @@
+# Expect script for ld-h8300 tests
+# Copyright 2002 Free Software Foundation, Inc.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+#
+# Written by Nick Clifton  <nickc@redhat.com>
+#
+
+# Test h8300
+
+if ![istarget h8300-*-*] {
+    return
+}
+
+set test_list [lsort [glob -nocomplain $srcdir/$subdir/*.d]]
+foreach test $test_list {
+    # We need to strip the ".d", but can leave the dirname.
+    verbose [file rootname $test]
+    run_dump_test [file rootname $test]
+}
diff --git a/ld/testsuite/ld-h8300/relax.d b/ld/testsuite/ld-h8300/relax.d
new file mode 100644
index 0000000..a5672a5
--- /dev/null
+++ b/ld/testsuite/ld-h8300/relax.d
@@ -0,0 +1,21 @@
+# name: H8300 Relxation Test
+# ld: --relax
+# objdump: -d --no-show-raw-insn
+
+# Based on the test case reported by Kazu Hirata:
+# http://sources.redhat.com/ml/binutils/2002-11/msg00301.html
+
+.*:     file format .*-h8300
+
+Disassembly of section .text:
+
+00000100 <_start>:
+ 100:	0d 00             mov.w	r0,r0
+ 102:	47 02             beq	.+2 \(106\)
+ 104:	55 02             bsr	.+2 \(108\)
+
+00000106 <.L1>:
+ 106:	54 70             rts	
+
+00000108 <_bar>:
+ 108:	54 70             rts	
diff --git a/ld/testsuite/ld-h8300/relax.s b/ld/testsuite/ld-h8300/relax.s
new file mode 100644
index 0000000..b06f3a9
--- /dev/null
+++ b/ld/testsuite/ld-h8300/relax.s
@@ -0,0 +1,10 @@
+	.text
+	.global _start
+_start:
+        mov.w   r0,r0
+        beq     .L1
+        jsr     @_bar
+.L1:
+        rts
+_bar:
+        rts