[ARM] No IT usage deprecation for ARMv8-M

Deprecations related to the use of the IT instruction introduced in
Armv8-A do not apply to Armv8-M Baseline and mainline. However the
warning logic do not distinguish between the various profiles and warn
whenever the architecture version is 8.

This patch adds a check to exclude M profile architectures from this
warning. This works as expected when -march is specified on the
command-line or a .arch/.cpu directive exist. However, in autodetection
mode the CPU/architecture targeted is only known once the instructions
have been all processed but this code is run when IT instruction is
processed. It is therefore not possible to distinguish between Armv8-M
and Armv8-A in that mode.

The approach chosen here is not to warn in autodetection mode. The udf.d
testcase that relied on that behavior to test deprecation warning for
Armv8-A is therefore updated to explicitely pass -march=armv8-a.

2018-01-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>

gas/
	* config/tc-arm.c (it_fsm_post_encode): Do not warn if targeting M
	profile architecture or if in autodetection mode.  Clarify that
	deprecation is for performance reason and concerns Armv8-A and Armv8-R.
	* testsuite/gas/arm/armv8-ar-bad.l: Adapt to new IT deprecation warning
	message.
	* testsuite/gas/arm/armv8-ar-it-bad.l: Likewise.
	* testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l: Likewise.
	* testsuite/gas/arm/udf.l: Likewise.
	* testsuite/gas/arm/udf.d: Assemble for Armv8-A explicitely.

7 files changed, 70 insertions, 54 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 4166359..391912c 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,15 @@
+2018-01-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	* config/tc-arm.c (it_fsm_post_encode): Do not warn if targeting M
+	profile architecture or if in autodetection mode.  Clarify that
+	deprecation is for performance reason and concerns Armv8-A and Armv8-R.
+	* testsuite/gas/arm/armv8-ar-bad.l: Adapt to new IT deprecation warning
+	message.
+	* testsuite/gas/arm/armv8-ar-it-bad.l: Likewise.
+	* testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l: Likewise.
+	* testsuite/gas/arm/udf.l: Likewise.
+	* testsuite/gas/arm/udf.d: Assemble for Armv8-A explicitely.
+
 2018-01-15  Nick Clifton  <nickc@redhat.com>
 
 	* po/uk.po: Updated Ukranian translation.
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 0e16688..c07362a 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -18559,12 +18559,13 @@ it_fsm_post_encode (void)
   if (now_it.insn_cond
       && !now_it.warn_deprecated
       && warn_on_deprecated
-      && ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_v8))
+      && ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_v8)
+      && !ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_m))
     {
       if (inst.instruction >= 0x10000)
 	{
 	  as_tsktsk (_("IT blocks containing 32-bit Thumb instructions are "
-		     "deprecated in ARMv8"));
+		     "performance deprecated in ARMv8-A and ARMv8-R"));
 	  now_it.warn_deprecated = TRUE;
 	}
       else
@@ -18575,9 +18576,10 @@ it_fsm_post_encode (void)
 	    {
 	      if ((inst.instruction & p->mask) == p->pattern)
 		{
-		  as_tsktsk (_("IT blocks containing 16-bit Thumb instructions "
-			     "of the following class are deprecated in ARMv8: "
-			     "%s"), p->description);
+		  as_tsktsk (_("IT blocks containing 16-bit Thumb "
+			       "instructions of the following class are "
+			       "performance deprecated in ARMv8-A and "
+			       "ARMv8-R: %s"), p->description);
 		  now_it.warn_deprecated = TRUE;
 		  break;
 		}
@@ -18589,7 +18591,8 @@ it_fsm_post_encode (void)
       if (now_it.block_length > 1)
 	{
 	  as_tsktsk (_("IT blocks containing more than one conditional "
-		     "instruction are deprecated in ARMv8"));
+		     "instruction are performance deprecated in ARMv8-A and "
+		     "ARMv8-R"));
 	  now_it.warn_deprecated = TRUE;
 	}
     }
diff --git a/gas/testsuite/gas/arm/armv8-ar-bad.l b/gas/testsuite/gas/arm/armv8-ar-bad.l
index ae9a3d1..f70de35 100644
--- a/gas/testsuite/gas/arm/armv8-ar-bad.l
+++ b/gas/testsuite/gas/arm/armv8-ar-bad.l
@@ -10,7 +10,7 @@
 .*:23: Error: immediate value out of range -- `hlt 0x10000'
 .*:24: Error: instruction cannot be conditional -- `hltne 0x1'
 .*:28: Error: immediate value out of range -- `hlt 64'
-.*:30: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Miscellaneous 16-bit instructions
+.*:30: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Miscellaneous 16-bit instructions
 .*:30: Error: instruction is always unconditional -- `hltne 0'
 .*:34: Error: r15 not allowed here -- `stlb pc,\[r0\]'
 .*:35: Error: r15 not allowed here -- `stlb r0,\[pc\]'
diff --git a/gas/testsuite/gas/arm/armv8-ar-it-bad.l b/gas/testsuite/gas/arm/armv8-ar-it-bad.l
index a69938d..de3ed97 100644
--- a/gas/testsuite/gas/arm/armv8-ar-it-bad.l
+++ b/gas/testsuite/gas/arm/armv8-ar-it-bad.l
@@ -1,18 +1,18 @@
 .*: Assembler messages:
-.*:6: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8
-.*:14: IT blocks containing more than one conditional instruction are deprecated in ARMv8
-.*:19: IT blocks containing more than one conditional instruction are deprecated in ARMv8
-.*:29: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8
-.*:35: IT blocks containing more than one conditional instruction are deprecated in ARMv8
-.*:39: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-.*:42: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Miscellaneous 16-bit instructions
-.*:48: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Literal loads
-.*:51: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Hi-register ADD, MOV, CMP, BX, BLX using pc
-.*:54: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
+.*:6: IT blocks containing 32-bit Thumb instructions are performance deprecated in ARMv8-A and ARMv8-R
+.*:14: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
+.*:19: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
+.*:29: IT blocks containing 32-bit Thumb instructions are performance deprecated in ARMv8-A and ARMv8-R
+.*:35: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
+.*:39: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+.*:42: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Miscellaneous 16-bit instructions
+.*:48: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Literal loads
+.*:51: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Hi-register ADD, MOV, CMP, BX, BLX using pc
+.*:54: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
 .*:54: Error: r15 not allowed here -- `addeq r0,pc,pc'
-.*:57: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
+.*:57: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
 .*:57: Error: r15 not allowed here -- `addeq pc,r0,r0'
-.*:60: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: ADD/SUB sp, sp #imm
-.*:64: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: ADD/SUB sp, sp #imm
-.*:67: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: ADD/SUB sp, sp #imm
-.*:71: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: ADD/SUB sp, sp #imm
+.*:60: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: ADD/SUB sp, sp #imm
+.*:64: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: ADD/SUB sp, sp #imm
+.*:67: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: ADD/SUB sp, sp #imm
+.*:71: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: ADD/SUB sp, sp #imm
diff --git a/gas/testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l b/gas/testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l
index 0da4701..0726100 100644
--- a/gas/testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l
+++ b/gas/testsuite/gas/arm/sp-pc-validations-bad-t-v8a.l
@@ -1,48 +1,48 @@
 [^:]*: Assembler messages:
-[^:]*:27: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:27: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:27: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:27: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:27: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0\]'
-[^:]*:28: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:28: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:28: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:28: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:28: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0,#0\]'
-[^:]*:29: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:29: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:29: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:29: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:29: Error: branch must be last instruction in IT block -- `ldreq r15,\[sp\]'
-[^:]*:30: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:30: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:30: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:30: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:30: Error: branch must be last instruction in IT block -- `ldreq r15,\[sp,#0\]'
-[^:]*:31: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:31: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:31: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:31: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:31: Error: branch must be last instruction in IT block -- `ldreq.w r15,\[r0\]'
-[^:]*:32: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:32: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:32: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:32: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:32: Error: branch must be last instruction in IT block -- `ldreq.w r15,\[r0,#0\]'
-[^:]*:33: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:33: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:33: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:33: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:33: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0,#-4\]'
-[^:]*:34: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:34: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:34: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:34: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:34: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0\],#4'
-[^:]*:35: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:35: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:35: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:35: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:35: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0,#0\]!'
-[^:]*:38: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:38: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:38: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:38: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:38: Error: branch must be last instruction in IT block -- `ldreq r15,label'
-[^:]*:39: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:39: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:39: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:39: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:39: Error: branch must be last instruction in IT block -- `ldreq.w r15,label'
-[^:]*:40: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:40: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:40: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:40: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:40: Error: branch must be last instruction in IT block -- `ldreq.w r15,\[pc,#-0\]'
-[^:]*:43: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:43: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:43: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:43: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:43: Error: branch must be last instruction in IT block -- `ldreq r15,\[r0,r1\]'
-[^:]*:44: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:44: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:44: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:44: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:44: Error: branch must be last instruction in IT block -- `ldreq.w r15,\[r0,r1\]'
-[^:]*:45: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-[^:]*:45: IT blocks containing more than one conditional instruction are deprecated in ARMv8
+[^:]*:45: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+[^:]*:45: IT blocks containing more than one conditional instruction are performance deprecated in ARMv8-A and ARMv8-R
 [^:]*:45: Error: branch must be last instruction in IT block -- `ldreq.w r15,\[r0,r1,LSL#2\]'
 [^:]*:48: Error: r15 not allowed here -- `ldrb pc,\[r0,#4\]'
 [^:]*:51: Error: r15 not allowed here -- `ldrb.w pc,\[r0,#4\]'
diff --git a/gas/testsuite/gas/arm/udf.d b/gas/testsuite/gas/arm/udf.d
index db41080..04e3145 100644
--- a/gas/testsuite/gas/arm/udf.d
+++ b/gas/testsuite/gas/arm/udf.d
@@ -1,5 +1,6 @@
 #objdump: -dr --prefix-addresses --show-raw-insn
 #name: UDF
+#as: -march=armv8-a
 #error-output: udf.l
 
 .*: +file format .*arm.*
diff --git a/gas/testsuite/gas/arm/udf.l b/gas/testsuite/gas/arm/udf.l
index 2e154b6..21aff94 100644
--- a/gas/testsuite/gas/arm/udf.l
+++ b/gas/testsuite/gas/arm/udf.l
@@ -1,3 +1,3 @@
 ^[^:]*: Assembler messages:
-^[^:]*:16: IT blocks containing 16-bit Thumb instructions of the following class are deprecated in ARMv8: Short branches, Undefined, SVC, LDM/STM
-^[^:]*:21: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8
+^[^:]*:16: IT blocks containing 16-bit Thumb instructions of the following class are performance deprecated in ARMv8-A and ARMv8-R: Short branches, Undefined, SVC, LDM/STM
+^[^:]*:21: IT blocks containing 32-bit Thumb instructions are performance deprecated in ARMv8-A and ARMv8-R