Commit: MSP430: GAS: Update NOP generation

[Nick Clifton <nickc at redhat dot com>]

Hi Guys,

  I am checking in the patch below to change the MSP430 port of GAS so
  that it no longer inserts NOP instructions after enabling or disabling
  interrupts.  Instead the user has to specifically request this feature
  via the use of the new command line option -mn.  Also the NOPs, if
  requested, will be inserted for all MCUs, not just the 430Xv2 ones.

Cheers
  Nick

gas/ChangeLog
2013-12-13  Nick Clifton  <nickc@redhat.com>

	* config/tc-msp430.c (mcu_types): Add some more 430X mcu names.
	(OPTION_INTR_NOPS): Define.
	(gen_interrupt_nops): Default to FALSE.
	(md_parse_opton): Add support for OPTION_INTR_NOPS.
	(md_longopts): Add -mn.
	(md_show_usage): Add -mn.
	(msp430_operands): Generate NOPs for all MCUs not just 430Xv2.
	* doc/c-msp430.c: Document -mn.

diff --git a/gas/config/tc-msp430.c b/gas/config/tc-msp430.c
index 67aac43..c2a7b9b 100644
--- a/gas/config/tc-msp430.c
+++ b/gas/config/tc-msp430.c
@@ -528,6 +528,15 @@ static struct mcu_type_s mcu_types[] =
   {"msp430fg4618", MSP_ISA_430X},
   {"msp430fg4619", MSP_ISA_430X},
 
+  {"msp430x241x",  MSP_ISA_430X},
+  {"msp430x26x",   MSP_ISA_430X},
+  {"msp430x461x1", MSP_ISA_430X},
+  {"msp430x46x",   MSP_ISA_430X},
+  {"msp430x471x3", MSP_ISA_430X},
+  {"msp430x471x6", MSP_ISA_430X},
+  {"msp430x471x7", MSP_ISA_430X},
+  {"msp430xg46x",  MSP_ISA_430X},
+
   {"msp430f5418", MSP_ISA_430Xv2},
   {"msp430f5419", MSP_ISA_430Xv2},
   {"msp430f5435", MSP_ISA_430Xv2},
@@ -1124,8 +1133,9 @@ extract_word (char * from, char * to, int limit)
 #define OPTION_POLYMORPHS 'P'
 #define OPTION_LARGE 'l'
 static bfd_boolean large_model = FALSE;
+#define OPTION_INTR_NOPS 'n'
 #define OPTION_NO_INTR_NOPS 'N'
-static bfd_boolean gen_interrupt_nops = TRUE;
+static bfd_boolean gen_interrupt_nops = FALSE;
 #define OPTION_MCPU 'c'
 #define OPTION_MOVE_DATA 'd'
 static bfd_boolean move_data = FALSE;
@@ -1216,6 +1226,9 @@ md_parse_option (int c, char * arg)
     case OPTION_NO_INTR_NOPS:
       gen_interrupt_nops = FALSE;
       return 1;
+    case OPTION_INTR_NOPS:
+      gen_interrupt_nops = TRUE;
+      return 1;
 
     case OPTION_MOVE_DATA:
       move_data = TRUE;
@@ -1267,6 +1280,7 @@ struct option md_longopts[] =
   {"mQ", no_argument, NULL, OPTION_RELAX},
   {"ml", no_argument, NULL, OPTION_LARGE},
   {"mN", no_argument, NULL, OPTION_NO_INTR_NOPS},
+  {"mn", no_argument, NULL, OPTION_INTR_NOPS},
   {"md", no_argument, NULL, OPTION_MOVE_DATA},
   {NULL, no_argument, NULL, 0}
 };
@@ -1288,6 +1302,8 @@ md_show_usage (FILE * stream)
   fprintf (stream,
 	   _("  -mN - disable generation of NOP after changing interrupts\n"));
   fprintf (stream,
+	   _("  -mn - enable generation of NOP after changing interrupts\n"));
+  fprintf (stream,
 	   _("  -md - Force copying of data from ROM to RAM at startup\n"));
 
   show_mcu_list (stream);
@@ -2289,7 +2305,6 @@ msp430_operands (struct msp430_opcode_s * opcode, char * line)
 	  bfd_putl16 ((bfd_vma) bin, frag);
 
 	  if (gen_interrupt_nops
-	      && target_is_430xv2 ()
 	      && (is_opcode ("eint") || is_opcode ("dint")))
 	    {
 	      /* Emit a NOP following interrupt enable/disable.
@@ -2373,7 +2388,6 @@ msp430_operands (struct msp430_opcode_s * opcode, char * line)
 	    }
 
 	  if (gen_interrupt_nops
-	      && target_is_430xv2 ()
 	      && is_opcode ("clr")
 	      && bin == 0x4302 /* CLR R2*/)
 	    {
@@ -3130,7 +3144,6 @@ msp430_operands (struct msp430_opcode_s * opcode, char * line)
 	}
 
       if (gen_interrupt_nops
-	  && target_is_430xv2 ()
 	  && (   (is_opcode ("bic") && bin == 0xc232)
 	      || (is_opcode ("bis") && bin == 0xd232)
 	      || (is_opcode ("mov") && op2.mode == OP_REG && op2.reg == 2)))
diff --git a/gas/doc/c-msp430.texi b/gas/doc/c-msp430.texi
index 2927add..77d6fd1 100644
--- a/gas/doc/c-msp430.texi
+++ b/gas/doc/c-msp430.texi
@@ -46,16 +46,25 @@ enables relaxation at assembly time. DANGEROUS!
 @item -ml
 indicates that the input uses the large code model.
 
+@item -mn
+enables the generation of a NOP instruction following any instruction
+that might change the interrupts enabled/disabled state.  The
+pipelined nature of the MSP430 core means that any instruction that
+changes the interrupt state (@code{EINT}, @code{DINT}, @code{BIC #8,
+SR}, @code{BIS #8, SR} or @code{MOV.W <>, SR}) must be 
+followed by a NOP instruction in order to ensure the correct
+processing of interrupts.  By default it is up to the programmer to
+supply these NOP instructions, but this command line option enables
+the automatic insertion by the assembler.  Note - the assembler does
+not peek ahead to the next instruction so it will insert a NOP even
+one is already present.
+
+@c end-sanitize-msp430
+@c %redact note changed text for mN option
 @item -mN
 disables the generation of a NOP instruction following any instruction
-that might change the interrupts enabled/disabled state.  For the
-430Xv2 architecture the instructions: @code{EINT}, @code{DINT},
-@code{BIC #8, SR}, @code{BIS #8, SR} and @code{MOV.W <>, SR} must be
-followed by a NOP instruction in order to ensure the correct
-processing of interrupts.  By default generation of the NOP
-instruction happens automatically, but this command line option
-disables this behaviour.  It is then up to the programmer to ensure
-that interrupts are enabled and disabled correctly.
+that might change the interrupts enabled/disabled state.  This is the
+default behaviour.
 
 @item -md
 mark the object file as one that requires data to copied from ROM to