MIPS/BFD: Consistently mark the LSI CW4010 as a MIPS II processor

Make BFD agree with GAS and mark the LSI MiniRISC CW4010 processor core
(for an odd reason referred to as LSI R4010 across our code base) as a
MIPS II processor in BFD as well, fixing a bug that has been there since
forever and addressing linker warnings like:

$ as -m4010 empty.s -o 4010.o
$ ld -r 4010.o -o 4010-r.o
ld: 4010.o: warning: Inconsistent ISA between e_flags and .MIPS.abiflags
$

due to the ISA level being recorded as MIPS III in ELF file header's
`e_flags' vs MIPS II in the MIPS ABI Flags section:

$ readelf -Ah 4010.o
ELF Header:
  Magic:   7f 45 4c 46 01 02 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              REL (Relocatable file)
  Machine:                           MIPS R3000
  Version:                           0x1
  Entry point address:               0x0
  Start of program headers:          0 (bytes into file)
  Start of section headers:          348 (bytes into file)
  Flags:                             0x20821000, 4010, o32, mips3
  Size of this header:               52 (bytes)
  Size of program headers:           0 (bytes)
  Number of program headers:         0
  Size of section headers:           40 (bytes)
  Number of section headers:         11
  Section header string table index: 10
Attribute Section: gnu
File Attributes
  Tag_GNU_MIPS_ABI_FP: Hard float (double precision)

MIPS ABI Flags Version: 0

ISA: MIPS2
GPR size: 32
CPR1 size: 32
CPR2 size: 0
FP ABI: Hard float (double precision)
ISA Extension: LSI R4010
ASEs:
	None
FLAGS 1: 00000000
FLAGS 2: 00000000
$

Available documentation[1][2] clearly indicates the LSI CW4010 processor
is only backwards compatible with the MIPS R4000 processor as far as the
latter's 32-bit instructions are concerned and consequently can only be
considered a MIPS II ISA implementation (with vendor extensions).

This fixes an LD testsuite failure:

FAIL: MIPS incompatible objects:  "-march=r4010 -32"      "-march=r4650 -32"

triggered for the `mips-sgi-irix5' and `mips-sgi-irix6' targets.

References:

[1] Paul Cobb, Bob Caulk, Joe Cesana, "The MiniRISC CW4010: A
    Superscalar MIPS Processor ASIC Core", LSI Logic, July 1995,
    presented at Hot Chips VII, Stanford University, Stanford,
    California, August 1995

[2] "MiniRISC MR4010 Superscalar Microprocessor Reference Device", LSI
    Logic, November 1996, Doc. No. DB09-000028-00, Order No. C15017

	bfd/
	* cpu-mips.c (arch_info_struct): Mark the 4010 32-bit.
	* elfxx-mips.c (mips_set_isa_flags) <bfd_mach_mips4010>: Set
	E_MIPS_ARCH_2 rather than E_MIPS_ARCH_3 in `e_flags'.
	(mips_mach_extensions): Mark `bfd_mach_mips4010' as extending
	`bfd_mach_mips6000' rather than `bfd_mach_mips4000'.

	ld/
	* testsuite/ld-mips-elf/lsi-4010-isa.d: New test.
	* ld/testsuite/ld-mips-elf/mips-elf.exp: Run the new test.

3 files changed, 14 insertions, 6 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index e088cdc..cd5cb57 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2017-06-26  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* cpu-mips.c (arch_info_struct): Mark the 4010 32-bit.
+	* elfxx-mips.c (mips_set_isa_flags) <bfd_mach_mips4010>: Set
+	E_MIPS_ARCH_2 rather than E_MIPS_ARCH_3 in `e_flags'.
+	(mips_mach_extensions): Mark `bfd_mach_mips4010' as extending
+	`bfd_mach_mips6000' rather than `bfd_mach_mips4000'.
+
 2017-06-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR binutils/21665
diff --git a/bfd/cpu-mips.c b/bfd/cpu-mips.c
index b9ecdd6..70a8aa7 100644
--- a/bfd/cpu-mips.c
+++ b/bfd/cpu-mips.c
@@ -114,7 +114,7 @@ static const bfd_arch_info_type arch_info_struct[] =
   N (32, 32, bfd_mach_mips3000, "mips:3000",      FALSE, NN(I_mips3000)),
   N (32, 32, bfd_mach_mips3900, "mips:3900",      FALSE, NN(I_mips3900)),
   N (64, 64, bfd_mach_mips4000, "mips:4000",      FALSE, NN(I_mips4000)),
-  N (64, 64, bfd_mach_mips4010, "mips:4010",      FALSE, NN(I_mips4010)),
+  N (32, 32, bfd_mach_mips4010, "mips:4010",      FALSE, NN(I_mips4010)),
   N (64, 64, bfd_mach_mips4100, "mips:4100",      FALSE, NN(I_mips4100)),
   N (64, 64, bfd_mach_mips4111, "mips:4111",      FALSE, NN(I_mips4111)),
   N (64, 64, bfd_mach_mips4120, "mips:4120",      FALSE, NN(I_mips4120)),
diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
index 830207a..e326edd 100644
--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -11863,6 +11863,10 @@ mips_set_isa_flags (bfd *abfd)
       val = E_MIPS_ARCH_2;
       break;
 
+    case bfd_mach_mips4010:
+      val = E_MIPS_ARCH_2 | E_MIPS_MACH_4010;
+      break;
+
     case bfd_mach_mips4000:
     case bfd_mach_mips4300:
     case bfd_mach_mips4400:
@@ -11870,10 +11874,6 @@ mips_set_isa_flags (bfd *abfd)
       val = E_MIPS_ARCH_3;
       break;
 
-    case bfd_mach_mips4010:
-      val = E_MIPS_ARCH_3 | E_MIPS_MACH_4010;
-      break;
-
     case bfd_mach_mips4100:
       val = E_MIPS_ARCH_3 | E_MIPS_MACH_4100;
       break;
@@ -14024,7 +14024,6 @@ static const struct mips_mach_extension mips_mach_extensions[] =
   { bfd_mach_mips4400, bfd_mach_mips4000 },
   { bfd_mach_mips4300, bfd_mach_mips4000 },
   { bfd_mach_mips4100, bfd_mach_mips4000 },
-  { bfd_mach_mips4010, bfd_mach_mips4000 },
   { bfd_mach_mips5900, bfd_mach_mips4000 },
 
   /* MIPS32 extensions.  */
@@ -14033,6 +14032,7 @@ static const struct mips_mach_extension mips_mach_extensions[] =
   /* MIPS II extensions.  */
   { bfd_mach_mips4000, bfd_mach_mips6000 },
   { bfd_mach_mipsisa32, bfd_mach_mips6000 },
+  { bfd_mach_mips4010, bfd_mach_mips6000 },
 
   /* MIPS I extensions.  */
   { bfd_mach_mips6000, bfd_mach_mips3000 },