[v4,1/9] MIPS: Add basic support for mips16e2

diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index ca822758b41..585a3682c7b 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -10047,7 +10047,8 @@  mips_file_start (void)
     fputs ("\t.module\tmsa\n", asm_out_file);
   if (TARGET_XPA)
     fputs ("\t.module\txpa\n", asm_out_file);
-  /* FIXME: MIPS16E2 is not supported by GCC? gas does support it */
+  if (TARGET_MIPS16E2)
+    fputs ("\t.module\tmips16e2\n", asm_out_file);
   if (TARGET_CRC)
     fputs ("\t.module\tcrc\n", asm_out_file);
   if (TARGET_GINV)
diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 6daf6d37165..c6781670a54 100644
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -475,6 +475,9 @@  struct mips_cpu_info {
       if (mips_base_compression_flags & MASK_MIPS16)			\
 	builtin_define ("__mips16");					\
 									\
+      if (TARGET_MIPS16E2)						\
+	builtin_define ("__mips_mips16e2");				\
+									\
       if (TARGET_MIPS3D)						\
 	builtin_define ("__mips3d");					\
 									\
@@ -1291,6 +1294,10 @@  struct mips_cpu_info {
 /* The MSA ASE is available.  */
 #define ISA_HAS_MSA		(TARGET_MSA && !TARGET_MIPS16)
 
+/* The MIPS16e V2 instructions are available.  */
+#define ISA_HAS_MIPS16E2       (TARGET_MIPS16 && TARGET_MIPS16E2 \
+				&& !TARGET_64BIT)
+
 /* True if the result of a load is not available to the next instruction.
    A nop will then be needed between instructions like "lw $4,..."
    and "addiu $4,$4,1".  */
@@ -1450,6 +1457,7 @@  struct mips_cpu_info {
 %{msym32} %{mno-sym32} \
 %{mtune=*}" \
 FP_ASM_SPEC "\
+%{mmips16e2} \
 %(subtarget_asm_spec)"
 
 /* Extra switches sometimes passed to the linker.  */
diff --git a/gcc/config/mips/mips.opt b/gcc/config/mips/mips.opt
index 195f5be01cc..4968ed0d544 100644
--- a/gcc/config/mips/mips.opt
+++ b/gcc/config/mips/mips.opt
@@ -380,6 +380,10 @@  msplit-addresses
 Target Mask(SPLIT_ADDRESSES)
 Optimize lui/addiu address loads.
 
+mmips16e2
+Target Var(TARGET_MIPS16E2) Init(0)
+Enable the MIPS16e V2 instructions.
+
 msym32
 Target Var(TARGET_SYM32)
 Assume all symbols have 32-bit values.
diff --git a/gcc/config/mips/predicates.md b/gcc/config/mips/predicates.md
index e34de2937cc..87460a64652 100644
--- a/gcc/config/mips/predicates.md
+++ b/gcc/config/mips/predicates.md
@@ -369,7 +369,7 @@ 
 {
   /* When generating mips16 code, TARGET_LEGITIMATE_CONSTANT_P rejects
      CONST_INTs that can't be loaded using simple insns.  */
-  if (TARGET_MIPS16)
+  if (TARGET_MIPS16 && !TARGET_MIPS16E2)
     return false;
 
   /* Don't handle multi-word moves this way; we don't want to introduce
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index ee78591c73e..1fa00594a91 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -26735,6 +26735,13 @@  MIPS16 code generation can also be controlled on a per-function basis
 by means of @code{mips16} and @code{nomips16} attributes.
 @xref{Function Attributes}, for more information.
 
+@opindex mmips16e2
+@opindex mno-mips16e2
+@item -mmips16e2
+@itemx -mno-mips16e2
+Use (do not use) the MIPS16e2 ASE.  This option modifies the behavior
+of the @option{-mips16} option such that it targets the MIPS16e2 ASE@.
+
 @opindex mflip-mips16
 @item -mflip-mips16
 Generate MIPS16 code on alternating functions.  This option is provided
diff --git a/gcc/testsuite/gcc.target/mips/mips.exp b/gcc/testsuite/gcc.target/mips/mips.exp
index 15d574202d3..e79f685ceb0 100644
--- a/gcc/testsuite/gcc.target/mips/mips.exp
+++ b/gcc/testsuite/gcc.target/mips/mips.exp
@@ -301,6 +301,7 @@  foreach option {
     loongson-mmi
     loongson-ext
     loongson-ext2
+    mips16e2
 } {
     lappend mips_option_groups $option "-m(no-|)$option"
 }
@@ -821,6 +822,12 @@  proc mips-dg-init {} {
 	    "-mno-mips16",
 	    #endif
 
+	    #ifdef __mips_mips16e2
+	    "-mmips16e2",
+	    #else
+	    "-mno-mips16e2",
+	    #endif
+
 	    #ifdef __mips3d
 	    "-mips3d",
 	    #else
@@ -1038,6 +1045,7 @@  proc mips-dg-options { args } {
     # dependency diagram.
     mips_option_dependency options "-mips16" "-mno-micromips"
     mips_option_dependency options "-mmicromips" "-mno-mips16"
+    mips_option_dependency options "-mmicromips" "-mno-mips16e2"
     mips_option_dependency options "-mips3d" "-mpaired-single"
     mips_option_dependency options "-mips3d" "-mno-micromips"
     mips_option_dependency options "-mpaired-single" "-mfp64"
@@ -1417,6 +1425,7 @@  proc mips-dg-options { args } {
 		mips_make_test_option options "-mfp32"
 	    }
 	    mips_make_test_option options "-mno-dsp"
+	    mips_make_test_option options "-mno-mips16e2"
 	    mips_make_test_option options "-mno-synci"
 	    mips_make_test_option options "-mno-micromips"
 	    mips_make_test_option options "-mnan=legacy"
@@ -1449,6 +1458,7 @@  proc mips-dg-options { args } {
 
     # Handle dependencies between options on the right of the diagram.
     mips_option_dependency options "-mno-dsp" "-mno-dspr2"
+    mips_option_dependency options "-mno-mips16" "-mno-mips16e2"
     mips_option_dependency options "-mno-explicit-relocs" "-mgpopt"
     switch -- [mips_test_option options small-data] {
 	"" -