Add Intel MCU support to gas

-march=iamcu must be passed to i386 assembler to generate Intel MCU object
file.

gas/

	* config/tc-i386.c (cpu_arch): Add iamcu.
	(i386_align_code): Handle PROCESSOR_IAMCU.
	(i386_arch): Likewise.
	(i386_mach): Likewise.
	(i386_target_format): Likewise.
	(valid_iamcu_cpu_flags): New function.
	(check_cpu_arch_compatible): Only allow Intel MCU instructions
	when targeting Intel MCU.
	(set_cpu_arch): Call valid_iamcu_cpu_flags to check if CPU flags
	are valid for Intel MCU.
	(md_parse_option): Likewise.
	* tc-i386.h (ELF_TARGET_IAMCU_FORMAT): New.
	(processor_type): Add PROCESSOR_IAMCU.
	* doc/c-i386.texi: Document iamcu.

gas/testsuite/

	* gas/i386/i386.exp: Run iamcu-1, iamcu-2, iamcu-3, iamcu-inval-1,
	iamcu-inval-2 and iamcu-inval-3.
	* gas/i386/iamcu-1.d: New file.
	* gas/i386/iamcu-1.s: Likewise.
	* gas/i386/iamcu-2.d: Likewise.
	* gas/i386/iamcu-2.s: Likewise.
	* gas/i386/iamcu-3.d: Likewise.
	* gas/i386/iamcu-3.s: Likewise.
	* gas/i386/iamcu-inval-1.l: Likewise.
	* gas/i386/iamcu-inval-1.s: Likewise.
	* gas/i386/iamcu-inval-2.l: Likewise.
	* gas/i386/iamcu-inval-2.s: Likewise.
	* gas/i386/iamcu-inval-3.l: Likewise.
	* gas/i386/iamcu-inval-3.s: Likewise.

2 files changed, 60 insertions, 3 deletions

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index bbc0969..8a6da64 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -772,6 +772,8 @@ static const arch_entry cpu_arch[] =
     CPU_L1OM_FLAGS, 0, 0 },
   { STRING_COMMA_LEN ("k1om"), PROCESSOR_K1OM,
     CPU_K1OM_FLAGS, 0, 0 },
+  { STRING_COMMA_LEN ("iamcu"), PROCESSOR_IAMCU,
+    CPU_IAMCU_FLAGS, 0, 0 },
   { STRING_COMMA_LEN ("k6"), PROCESSOR_K6,
     CPU_K6_FLAGS, 0, 0 },
   { STRING_COMMA_LEN ("k6_2"), PROCESSOR_K6,
@@ -1218,6 +1220,7 @@ i386_align_code (fragS *fragP, int count)
 	    case PROCESSOR_I486:
 	    case PROCESSOR_PENTIUM:
 	    case PROCESSOR_PENTIUMPRO:
+	    case PROCESSOR_IAMCU:
 	    case PROCESSOR_GENERIC32:
 	      patt = f32_patt;
 	      break;
@@ -1236,6 +1239,7 @@ i386_align_code (fragS *fragP, int count)
 	    case PROCESSOR_I386:
 	    case PROCESSOR_I486:
 	    case PROCESSOR_PENTIUM:
+	    case PROCESSOR_IAMCU:
 	    case PROCESSOR_K6:
 	    case PROCESSOR_ATHLON:
 	    case PROCESSOR_K8:
@@ -1469,6 +1473,20 @@ cpu_flags_and_not (i386_cpu_flags x, i386_cpu_flags y)
   return x;
 }
 
+static int
+valid_iamcu_cpu_flags (const i386_cpu_flags *flags)
+{
+  if (cpu_arch_isa == PROCESSOR_IAMCU)
+    {
+      static const i386_cpu_flags iamcu_flags = CPU_IAMCU_COMPAT_FLAGS;
+      i386_cpu_flags compat_flags;
+      compat_flags = cpu_flags_and_not (*flags, iamcu_flags);
+      return cpu_flags_all_zero (&compat_flags);
+    }
+  else
+    return 1;
+}
+
 #define CPU_FLAGS_ARCH_MATCH		0x1
 #define CPU_FLAGS_64BIT_MATCH		0x2
 #define CPU_FLAGS_AES_MATCH		0x4
@@ -2278,6 +2296,11 @@ check_cpu_arch_compatible (const char *name ATTRIBUTE_UNUSED,
 	arch = default_arch;
     }
 
+  /* If we are targeting Intel MCU, we must enable it.  */
+  if (get_elf_backend_data (stdoutput)->elf_machine_code != EM_IAMCU
+      || new_flag.bitfield.cpuiamcu)
+    return;
+
   /* If we are targeting Intel L1OM, we must enable it.  */
   if (get_elf_backend_data (stdoutput)->elf_machine_code != EM_L1OM
       || new_flag.bitfield.cpul1om)
@@ -2341,7 +2364,11 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED)
 	      else
 		flags = cpu_flags_and_not (cpu_arch_flags,
 					   cpu_arch[j].flags);
-	      if (!cpu_flags_equal (&flags, &cpu_arch_flags))
+
+	      if (!valid_iamcu_cpu_flags (&flags))
+		as_fatal (_("`%s' isn't valid for Intel MCU"),
+			  cpu_arch[j].name);
+	      else if (!cpu_flags_equal (&flags, &cpu_arch_flags))
 		{
 		  if (cpu_sub_arch_name)
 		    {
@@ -2406,6 +2433,13 @@ i386_arch (void)
 	as_fatal (_("Intel K1OM is 64bit ELF only"));
       return bfd_arch_k1om;
     }
+  else if (cpu_arch_isa == PROCESSOR_IAMCU)
+    {
+      if (OUTPUT_FLAVOR != bfd_target_elf_flavour
+	  || flag_code == CODE_64BIT)
+	as_fatal (_("Intel MCU is 32bit ELF only"));
+      return bfd_arch_iamcu;
+    }
   else
     return bfd_arch_i386;
 }
@@ -2435,7 +2469,16 @@ i386_mach (void)
 	return bfd_mach_x64_32;
     }
   else if (!strcmp (default_arch, "i386"))
-    return bfd_mach_i386_i386;
+    {
+      if (cpu_arch_isa == PROCESSOR_IAMCU)
+	{
+	  if (OUTPUT_FLAVOR != bfd_target_elf_flavour)
+	    as_fatal (_("Intel MCU is 32bit ELF only"));
+	  return bfd_mach_i386_iamcu;
+	}
+      else
+	return bfd_mach_i386_i386;
+    }
   else
     as_fatal (_("unknown architecture"));
 }
@@ -9678,7 +9721,10 @@ md_parse_option (int c, char *arg)
 		  else
 		    flags = cpu_flags_and_not (cpu_arch_flags,
 					       cpu_arch[j].flags);
-		  if (!cpu_flags_equal (&flags, &cpu_arch_flags))
+
+		  if (!valid_iamcu_cpu_flags (&flags))
+		    as_fatal (_("`%s' isn't valid for Intel MCU"), arch);
+		  else if (!cpu_flags_equal (&flags, &cpu_arch_flags))
 		    {
 		      if (cpu_sub_arch_name)
 			{
@@ -10088,6 +10134,12 @@ i386_target_format (void)
 	      as_fatal (_("Intel K1OM is 64bit only"));
 	    return ELF_TARGET_K1OM_FORMAT;
 	  }
+	else if (cpu_arch_isa == PROCESSOR_IAMCU)
+	  {
+	    if (x86_elf_abi != I386_ABI)
+	      as_fatal (_("Intel MCU is 32bit only"));
+	    return ELF_TARGET_IAMCU_FORMAT;
+	  }
 	else
 	  return format;
       }
diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h
index deea9c2..40483a1 100644
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -90,6 +90,10 @@ extern unsigned long i386_mach (void);
 #define ELF_TARGET_K1OM_FORMAT	"elf64-k1om"
 #endif
 
+#ifndef ELF_TARGET_IAMCU_FORMAT
+#define ELF_TARGET_IAMCU_FORMAT	"elf32-iamcu"
+#endif
+
 #if ((defined (OBJ_MAYBE_COFF) && defined (OBJ_MAYBE_AOUT)) \
      || defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF) \
      || defined (TE_PE) || defined (TE_PEP) || defined (OBJ_MACH_O))
@@ -233,6 +237,7 @@ enum processor_type
   PROCESSOR_COREI7,
   PROCESSOR_L1OM,
   PROCESSOR_K1OM,
+  PROCESSOR_IAMCU,
   PROCESSOR_K6,
   PROCESSOR_ATHLON,
   PROCESSOR_K8,