[RFA/ARM 02/21] Mark SWP as obsolete.

[Matthew Gretton-Dann <matthew dot gretton-dann at arm dot com>]

ARMv8 obsoletes the SWP{B} instructions.

This patch updates the assembler to error in this case.

gas/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* config/tc-arm.c (check_obsolete): New function.
	(do_rd_rm_rn): Check swp{b} for obsoletion.

gas/testsuite/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* gas/arm/armv8-a-bad.d: New testcase.
	* gas/arm/armv8-a-bad.l: Likewise.
	* gas/arm/armv8-a-bad.s: Likewise.
	* gas/arm/depr-swp.l: Update for change in expected output.
	* gas/arm/depr-swp.s: Add additional test.

include/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* opcode/arm.h (ARM_CPU_IS_ANY): New define.

diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 101f86b..af4a1e5 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -7373,6 +7373,23 @@ do_rn_rd (void)
   inst.instruction |= inst.operands[1].reg << 12;
 }
 
+static bfd_boolean
+check_obsolete (const arm_feature_set *feature, const char *msg)
+{
+  if (ARM_CPU_IS_ANY (cpu_variant))
+    {
+      as_warn ("%s", msg);
+      return TRUE;
+    }
+  else if (ARM_CPU_HAS_FEATURE (cpu_variant, *feature))
+    {
+      as_bad ("%s", msg);
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
 static void
 do_rd_rm_rn (void)
 {
@@ -7383,12 +7400,15 @@ do_rd_rm_rn (void)
       constraint (Rn == inst.operands[0].reg || Rn == inst.operands[1].reg,
 		  _("Rn must not overlap other operands"));
 
-      /* SWP{b} is deprecated for ARMv6* and ARMv7.  */
-      if (warn_on_deprecated
-	  && ARM_CPU_HAS_FEATURE (selected_cpu, arm_ext_v6))
-	as_warn (_("swp{b} use is deprecated for this architecture"));
-
+      /* SWP{b} is obsolete for ARMv8-A, and deprecated for ARMv6* and ARMv7.
+       */
+      if (!check_obsolete (&arm_ext_v8,
+			   _("swp{b} use is obsoleted for ARMv8 and later"))
+	  && warn_on_deprecated
+	  && ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_v6))
+	as_warn (_("swp{b} use is deprecated for ARMv6 and ARMv7"));
     }
+
   inst.instruction |= inst.operands[0].reg << 12;
   inst.instruction |= inst.operands[1].reg;
   inst.instruction |= Rn << 16;
diff --git a/gas/testsuite/gas/arm/armv8-a-bad.d b/gas/testsuite/gas/arm/armv8-a-bad.d
new file mode 100644
index 0000000..94e130c
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8-a-bad.d
@@ -0,0 +1,2 @@
+#name: Invalid v8-a
+#error-output: armv8-a-bad.l
diff --git a/gas/testsuite/gas/arm/armv8-a-bad.l b/gas/testsuite/gas/arm/armv8-a-bad.l
new file mode 100644
index 0000000..2c9a147
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8-a-bad.l
@@ -0,0 +1,2 @@
+.*: Assembler messages:
+.*:7: Error: swp{b} use is obsoleted for ARMv8 and later
diff --git a/gas/testsuite/gas/arm/armv8-a-bad.s b/gas/testsuite/gas/arm/armv8-a-bad.s
new file mode 100644
index 0000000..a6d55c7
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8-a-bad.s
@@ -0,0 +1,7 @@
+	.syntax unified
+	.text
+	.arch armv8-a
+
+	// SWP
+	.arm
+	swp r0, r1, [r2]
diff --git a/gas/testsuite/gas/arm/depr-swp.l b/gas/testsuite/gas/arm/depr-swp.l
index e5052a7..830f13b 100644
--- a/gas/testsuite/gas/arm/depr-swp.l
+++ b/gas/testsuite/gas/arm/depr-swp.l
@@ -1,3 +1,4 @@
 [^:]*: Assembler messages:
-[^:]*:5: Warning: swp{b} use is deprecated for this architecture
-[^:]*:7: Warning: swp{b} use is deprecated for this architecture
+[^:]*:2: Warning: swp{b} use is obsoleted for ARMv8 and later
+[^:]*:6: Warning: swp{b} use is deprecated for ARMv6 and ARMv7
+[^:]*:8: Warning: swp{b} use is deprecated for ARMv6 and ARMv7
diff --git a/gas/testsuite/gas/arm/depr-swp.s b/gas/testsuite/gas/arm/depr-swp.s
index e5c1df3..ceb7d41 100644
--- a/gas/testsuite/gas/arm/depr-swp.s
+++ b/gas/testsuite/gas/arm/depr-swp.s
@@ -1,4 +1,5 @@
 .syntax unified
+swp r0, r1, [r2]
 .arch armv4
 swp r0, r1, [r2]
 .arch armv6
diff --git a/include/opcode/arm.h b/include/opcode/arm.h
index 1c350c8..1ac38a0 100644
--- a/include/opcode/arm.h
+++ b/include/opcode/arm.h
@@ -269,6 +269,9 @@ typedef struct
 #define ARM_CPU_HAS_FEATURE(CPU,FEAT) \
   (((CPU).core & (FEAT).core) != 0 || ((CPU).coproc & (FEAT).coproc) != 0)
 
+#define ARM_CPU_IS_ANY(CPU) \
+  ((CPU).core == ((arm_feature_set)ARM_ANY).core)
+
 #define ARM_MERGE_FEATURE_SETS(TARG,F1,F2)	\
   do {						\
     (TARG).core = (F1).core | (F2).core;	\