[AArch64] Set the minimum alignment on code segments

gas/
2015-03-10  Matthew Wahab  <matthew.wahab@arm.com>

	* config/tc-aarch64.c (mapping_state): Set minimum alignment for
	code sections.

gas/testsuite
2015-03-10  Matthew Wahab  <matthew.wahab@arm.com>

	* gas/aarch64/codealign.d: Add test for code section alignment.
	* gas/aarch64/codealign.s: New file.

gas/ChangeLog

@@ -1,3 +1,8 @@
+2015-03-10  Matthew Wahab  <matthew.wahab@arm.com>
+
+	* config/tc-aarch64.c (mapping_state): Set minimum alignment for
+	code sections.
+
 2015-03-10  Nick Clifton  <nickc@redhat.com>
 
 	PR gas/17852

gas/config/tc-aarch64.c

@@ -1478,7 +1478,14 @@ mapping_state (enum mstate state)
     /* The mapping symbol has already been emitted.
        There is nothing else to do.  */
     return;
-  else if (TRANSITION (MAP_UNDEFINED, MAP_DATA))
+
+  if (state == MAP_INSN)
+    /* AArch64 instructions require 4-byte alignment.  When emitting
+       instructions into any section, record the appropriate section
+       alignment.  */
+    record_alignment (now_seg, 2);
+
+  if (TRANSITION (MAP_UNDEFINED, MAP_DATA))
     /* This case will be evaluated later in the next else.  */
     return;
   else if (TRANSITION (MAP_UNDEFINED, MAP_INSN))

gas/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2015-03-10  Matthew Wahab  <matthew.wahab@arm.com>
+
+	* gas/aarch64/codealign.d: Add test for code section alignment.
+	* gas/aarch64/codealign.s: New file.
+
 2015-03-04  Richard Sandiford  <richard.sandiford@arm.com>
 
 	PR gas/17843

gas/testsuite/gas/aarch64/codealign.d

@@ -0,0 +1,16 @@
+#objdump: --section-headers
+# Minimum code alignment should be set.
+# This test is only valid on ELF based ports.
+#not-target: *-*-*coff *-*-pe *-*-wince *-*-*aout* *-*-netbsd *-*-riscix*
+
+.*: +file format.*aarch64.*
+
+Sections:
+Idx Name          Size      VMA               LMA               File off  Algn
+  0 \.text         .*  .*  .*  .*  2\*\*2
+                  .*CODE.*
+  1 \.data         .*  .*  .* .*  2\*\*0
+                  .*DATA.*
+  2 \.bss          .*  .*  .*  .*  2\*\*0
+.*
+

gas/testsuite/gas/aarch64/codealign.s

@@ -0,0 +1,2 @@
+.text
+  nop