2S09-08-21 Daniel Gutson <dgutson@codesourcery.com>

	ld/
        * ld-arm/callweak.d: Opcodes updated.
        * ld-arm/callweak.s: Architecture specified.
        * ld-arm/callweak-2.d: New test case.
        * ld-arm/callweak-2.s: New file.

	bfd/
	* elf32-arm.c (arch_has_thumb2_nop): New function.
	(arch_has_arm_nop): New function.
	(elf32_arm_final_link_relocate): NOP opcodes changed.

SVS: ----------------------------------------------------------------------

7 files changed, 91 insertions, 9 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f9c4c6d..47f793f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2009-08-21  Daniel Gutson  <dgutson@codesourcery.com>
+
+	* elf32-arm.c (arch_has_thumb2_nop): New function.
+	(arch_has_arm_nop): New function.
+	(elf32_arm_final_link_relocate): NOP opcodes changed.
+
 2009-08-16  Doug Evans  <dje@google.com>
 
 	* opncls.c (bfd_close): Until BFD_IN_MEMORY has an iovec,
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 49c80ad..5a0d9c3 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -2987,6 +2987,26 @@ using_thumb2 (struct elf32_arm_link_hash_table *globals)
   return arch == TAG_CPU_ARCH_V6T2 || arch >= TAG_CPU_ARCH_V7;
 }
 
+/* Determine what kind of NOPs are available.  */
+
+static bfd_boolean
+arch_has_arm_nop (struct elf32_arm_link_hash_table *globals)
+{
+  const int arch = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
+					     Tag_CPU_arch);
+  return arch == TAG_CPU_ARCH_V6T2
+	 || arch == TAG_CPU_ARCH_V6K
+	 || arch == TAG_CPU_ARCH_V7;
+}
+
+static bfd_boolean
+arch_has_thumb2_nop (struct elf32_arm_link_hash_table *globals)
+{
+  const int arch = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
+					     Tag_CPU_arch);
+  return arch == TAG_CPU_ARCH_V6T2 || arch == TAG_CPU_ARCH_V7;
+}
+
 static bfd_boolean
 arm_stub_is_thumb (enum elf32_arm_stub_type stub_type)
 {
@@ -7073,13 +7093,19 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
 
 	  /* A branch to an undefined weak symbol is turned into a jump to
 	     the next instruction unless a PLT entry will be created.
-	     Do the same for local undefined symbols.  */
+	     Do the same for local undefined symbols.
+	     The jump to the next instruction is optimized as a NOP depending
+	     on the architecture.  */
 	  if (h ? (h->root.type == bfd_link_hash_undefweak
 		   && !(splt != NULL && h->plt.offset != (bfd_vma) -1))
 	      : bfd_is_und_section (sym_sec))
 	    {
-	      value = (bfd_get_32 (input_bfd, hit_data) & 0xf0000000)
-		      | 0x0affffff;
+	      value = (bfd_get_32 (input_bfd, hit_data) & 0xf0000000);
+
+	      if (arch_has_arm_nop (globals))
+		value |= 0x0320f000;
+	      else
+		value |= 0x01a00000; /* Using pre-UAL nop: mov r0, r0.  */
 	    }
 	  else
 	    {
@@ -7324,15 +7350,25 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
 	bfd_vma check;
 	bfd_signed_vma signed_check;
 	int bitsize;
-	int thumb2 = using_thumb2 (globals);
+	const int thumb2 = using_thumb2 (globals);
 
 	/* A branch to an undefined weak symbol is turned into a jump to
-	   the next instruction unless a PLT entry will be created.  */
+	   the next instruction unless a PLT entry will be created.
+	   The jump to the next instruction is optimized as a NOP.W for
+	   Thumb-2 enabled architectures.  */
 	if (h && h->root.type == bfd_link_hash_undefweak
 	    && !(splt != NULL && h->plt.offset != (bfd_vma) -1))
 	  {
-	    bfd_put_16 (input_bfd, 0xe000, hit_data);
-	    bfd_put_16 (input_bfd, 0xbf00, hit_data + 2);
+	    if (arch_has_thumb2_nop (globals))
+	      {
+		bfd_put_16 (input_bfd, 0xf3af, hit_data);
+		bfd_put_16 (input_bfd, 0x8000, hit_data + 2);
+	      }
+	    else
+	      {
+		bfd_put_16 (input_bfd, 0xe000, hit_data);
+		bfd_put_16 (input_bfd, 0xbf00, hit_data + 2);
+	      }
 	    return bfd_reloc_ok;
 	  }
 
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 6f9bc27..040ce8f 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2009-08-21  Daniel Gutson  <dgutson@codesourcery.com>
+
+	* ld-arm/callweak.d: Opcodes updated.
+	* ld-arm/callweak.s: Architecture specified.
+	* ld-arm/callweak-2.d: New test case.
+	* ld-arm/callweak-2.s: New file.
+
 2009-08-17  Nick Clifton  <nickc@redhat.com>
 
 	* ld-elf/linkonce1.d: Accept "UNUSED" as part of the name of an
diff --git a/ld/testsuite/ld-arm/callweak-2.d b/ld/testsuite/ld-arm/callweak-2.d
new file mode 100644
index 0000000..d401479
--- /dev/null
+++ b/ld/testsuite/ld-arm/callweak-2.d
@@ -0,0 +1,15 @@
+
+.*:     file format.*
+
+Disassembly of section .far:
+
+12340000 <[^>]*>:
+12340000:	e320f000 	nop	\{0\}
+12340004:	0320f000 	nopeq	\{0\}
+
+12340008 <[^>]*>:
+12340008:	f3af 8000 	nop.w
+1234000c:	2000      	movs	r0, #0
+1234000e:	f3af 8000 	nop.w
+12340012:	4770      	bx	lr
+
diff --git a/ld/testsuite/ld-arm/callweak-2.s b/ld/testsuite/ld-arm/callweak-2.s
new file mode 100644
index 0000000..af4f026
--- /dev/null
+++ b/ld/testsuite/ld-arm/callweak-2.s
@@ -0,0 +1,17 @@
+	.syntax unified
+	.arch armv6t2
+	.weak bar
+	.section .far, "ax", %progbits
+	.global	_start
+	.type	_start, %function
+_start:
+	bl bar
+	bleq bar
+	.thumb
+	.type foo, %function
+	.thumb_func
+foo:
+	bl bar
+	movs r0, #0
+	bl bar
+	bx lr
diff --git a/ld/testsuite/ld-arm/callweak.d b/ld/testsuite/ld-arm/callweak.d
index 3dffcc4..89cb4a5 100644
--- a/ld/testsuite/ld-arm/callweak.d
+++ b/ld/testsuite/ld-arm/callweak.d
@@ -4,8 +4,8 @@
 Disassembly of section .far:
 
 12340000 <[^>]*>:
-12340000:	eaffffff 	b	12340004 <[^>]*>
-12340004:	0affffff 	beq	12340008 <[^>]*>
+12340000:	e1a00000 	nop			; \(mov r0, r0\)
+12340004:	01a00000 	moveq	r0, r0
 
 12340008 <[^>]*>:
 12340008:	e000      	b.n	1234000c <[^>]*>
diff --git a/ld/testsuite/ld-arm/callweak.s b/ld/testsuite/ld-arm/callweak.s
index 6850da3..b9bcd1b 100644
--- a/ld/testsuite/ld-arm/callweak.s
+++ b/ld/testsuite/ld-arm/callweak.s
@@ -1,4 +1,5 @@
 	.syntax unified
+	.arch armv6
 	.weak bar
 	.section .far, "ax", %progbits
 	.global	_start