MIPS compact branch support

gcc/
	* config/mips/mips-opts.h (mips_cb_setting): New enum.
	* config/mips/mips-protos.h: Add definitions for
	mips_output_jump and mips_output_equal_conditional_branch
	* gcc/config/mips/mips.c (MIPS_JR): Change to support the
	JIC instruction.
	(mips_emit_compare): Add support for the MIPS R6 conditional
	compact branches.
	(mips_process_sync_loop): Likewise.
	(mips_output_order_conditional_branch): Likewise.
	(mips16_build_call_stub): Change MIPS_CALL to
	mips_output_jump.
	(mips_print_operand_punctuation): Update 's' case to only
	apply to micromips r2.
	(mips_adjust_insn_length): Add support for forbidden slot
	hazards.
	(mips_avoid_hazard): Likewise.
	(mips_reorg_process_insns): Likewise.
	(mips_output_jump): New function.
	(mips_output_equal_conditional_branch): Likewise.
	(mips_output_conditional_branch): Use jrc/bc if compact
	branch support is enabled.  Ensure the forbidden slots
	between the two branch instructions is filled with a nop.
	(mips_option_override): Add support to process the compact
	branch option and set the correct defaults.  Prevent
	non-explict relocs being using for MIPS R6.
	(mips_trampoline_init): Add compact branch support.
	(mips_mult_zero_zero_cost): Allow zero initialisation of
	accumulators with TARGET_DSP.
	* gcc/config/mips/mips.h (TARGET_CB_NEVER): New define.
	(TARGET_CB_MAYBE): New define.
	(TARGET_CB_ALWAYS): New define.
	(ISA_HAS_DELAY_SLOTS): New define.
	(ISA_HAS_COMPACT_BRANCHES): New define.
	(ISA_HAS_JRC): New define.
	(MIPS_BRANCH_C): New define.
	(MIPS_CALL): Removed.
	(MICROMIPS_J): Removed.
	* config/mips/mips.md (compact_form): New attr.
	(hazard): Add support for forbidden slots.
	(define_delay): Add support for compact branches.
	(*branch_order<mode>): Likewise.
	(*branch_order<mode>_inverted): Likewise.
	(*branch_equality<mode>): Likewise.
	(*branch_equality<mode>_inverted): Likewise.
	(*jump_absolute): Likewise.
	(*jump_pic): Likewise.
	(indirect_jump): Use mips_output_jump to produce assembly output.
	(tablejump_<mode>"): Likewise.
	(*<optab>"): Likewise.
	(<optab>_internal): Likewise.
	(sibcall_internal): Likewise.
	(sibcall_value_internal): Likewise.
	(sibcall_value_multiple_internal): Likewise.
	(call_internal): Likewise.
	(call_split): Likewise.
	(call_internal_direct): Likewise.
	(call_direct_split): Likewise.
	(call_value_internal): Likewise.
	(call_value_split): Likewise.
	(call_value_internal_direct): Likewise.
	(call_value_direct_split): Likewise.
	(call_value_multiple_internal): Likewise.
	(call_value_multiple_split): Likewise.
	(mips_get_fcsr_mips16_<mode>): Likewise.
	(mips_set_fcsr_mips16_<mode>): Likewise.
	(tls_get_tp_mips16_<mode>): Likewise.
	* config/mips/mips.opt: Add -mcompact-branches option.
	* config/mips/predicates.md (order_operator): Ensure the
	conditional compact branches are only used if the ISA them.
	* doc/invoke.texi: Document -mcompact-branches option.

gcc/testsuite/
	* gcc.target/mips/mips.exp (mips-dg-options): Handle the
	dependencies between ISA level and compact-branches.
	* gcc.target/mips/branch-10.c: Update expected output to allow
	compact forms of b/bal.
	* gcc.target/mips/branch-11.c: Likewise.
	* gcc.target/mips/branch-12.c: Likewise.
	* gcc.target/mips/branch-13.c: Likewise.
	* gcc.target/mips/branch-3.c: Likewise.
	* gcc.target/mips/branch-4.c: Likewise.
	* gcc.target/mips/branch-5.c: Likewise.
	* gcc.target/mips/branch-6.c: Likewise.
	* gcc.target/mips/branch-7.c: Likewise.
	* gcc.target/mips/branch-8.c: Likewise.
	* gcc.target/mips/branch-9.c: Likewise.
	* gcc.target/mips/branch-cost-1.c: Likewise.
	* gcc.target/mips/call-1.c: Likewise.
	* gcc.target/mips/call-2.c: Likewise.
	* gcc.target/mips/call-3.c: Likewise.
	* gcc.target/mips/call-4.c: Likewise.
	* gcc.target/mips/call-5.c: Likewise.
	* gcc.target/mips/call-6.c: Likewise.
	* gcc.target/mips/lazy-binding-1.c: Likewise.
	* gcc.target/mips/near-far-1.c: Likewise.
	* gcc.target/mips/near-far-2.c: Likewise.
	* gcc.target/mips/near-far-3.c: Likewise.
	* gcc.target/mips/near-far-4.c: Likewise.
	* gcc.target/mips/umips-branch-3.c: Ensure the test is
	run with compact branches allowed.
	* gcc.target/mips/compact-branches-1.c: New file.
	* gcc.target/mips/compact-branches-2.c: Likewise.
	* gcc.target/mips/compact-branches-3.c: Likewise.
	* gcc.target/mips/compact-branches-4.c: Likewise.
	* gcc.target/mips/compact-branches-5.c: Likewise.
	* gcc.target/mips/compact-branches-6.c: Likewise.
	* gcc.target/mips/compact-branches-7.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227385 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 527 insertions, 175 deletions

diff --git a/gcc/config/mips/mips-opts.h b/gcc/config/mips/mips-opts.h
index 79882051595..3c2c6590e3d 100644
--- a/gcc/config/mips/mips-opts.h
+++ b/gcc/config/mips/mips-opts.h
@@ -47,4 +47,10 @@ enum mips_r10k_cache_barrier_setting {
 #define MIPS_ARCH_OPTION_FROM_ABI -1
 #define MIPS_ARCH_OPTION_NATIVE -2
 
+/* Enumerates the setting of the -mcompact-branches= option.  */
+enum mips_cb_setting {
+  MIPS_CB_NEVER,
+  MIPS_CB_OPTIMAL,
+  MIPS_CB_ALWAYS
+};
 #endif
diff --git a/gcc/config/mips/mips-protos.h b/gcc/config/mips/mips-protos.h
index d9ad9100f99..8a9ae0147ed 100644
--- a/gcc/config/mips/mips-protos.h
+++ b/gcc/config/mips/mips-protos.h
@@ -298,6 +298,9 @@ extern const char *mips_output_conditional_branch (rtx_insn *, rtx *,
 						   const char *, const char *);
 extern const char *mips_output_order_conditional_branch (rtx_insn *, rtx *,
 							 bool);
+extern const char *mips_output_equal_conditional_branch (rtx_insn *, rtx *,
+							 bool);
+extern const char *mips_output_jump (rtx *, int, int, bool);
 extern const char *mips_output_sync (void);
 extern const char *mips_output_sync_loop (rtx_insn *, rtx *);
 extern unsigned int mips_sync_loop_insns (rtx_insn *, rtx *);
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index 0b4a5faacdb..0e0ecf232d9 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -176,7 +176,8 @@ along with GCC; see the file COPYING3.  If not see
 /* Return the opcode to jump to register DEST.  When the JR opcode is not
    available use JALR $0, DEST.  */
 #define MIPS_JR(DEST) \
-  (((DEST) << 21) | (ISA_HAS_JR ? 0x8 : 0x9))
+  (TARGET_CB_ALWAYS ? ((0x1b << 27) | ((DEST) << 16)) \
+		    : (((DEST) << 21) | (ISA_HAS_JR ? 0x8 : 0x9)))
 
 /* Return the opcode for:
 
@@ -5181,7 +5182,8 @@ mips_allocate_fcc (machine_mode mode)
    conditions are:
 
       - EQ or NE between two registers.
-      - any comparison between a register and zero.  */
+      - any comparison between a register and zero.
+      - if compact branches are available then any condition is valid.  */
 
 static void
 mips_emit_compare (enum rtx_code *code, rtx *op0, rtx *op1, bool need_eq_ne_p)
@@ -5203,6 +5205,44 @@ mips_emit_compare (enum rtx_code *code, rtx *op0, rtx *op1, bool need_eq_ne_p)
 	  else
 	    *op1 = force_reg (GET_MODE (cmp_op0), cmp_op1);
 	}
+      else if (!need_eq_ne_p && TARGET_CB_MAYBE)
+	{
+	  bool swap = false;
+	  switch (*code)
+	    {
+	    case LE:
+	      swap = true;
+	      *code = GE;
+	      break;
+	    case GT:
+	      swap = true;
+	      *code = LT;
+	      break;
+	    case LEU:
+	      swap = true;
+	      *code = GEU;
+	      break;
+	    case GTU:
+	      swap = true;
+	      *code = LTU;
+	      break;
+	    case GE:
+	    case LT:
+	    case GEU:
+	    case LTU:
+	      /* Do nothing.  */
+	      break;
+	    default:
+	      gcc_unreachable ();
+	    }
+	  *op1 = force_reg (GET_MODE (cmp_op0), cmp_op1);
+	  if (swap)
+	    {
+	      rtx tmp = *op1;
+	      *op1 = *op0;
+	      *op0 = tmp;
+	    }
+	}
       else
 	{
 	  /* The comparison needs a separate scc instruction.  Store the
@@ -7260,7 +7300,7 @@ mips16_build_call_stub (rtx retval, rtx *fn_ptr, rtx args_size, int fp_code)
       if (fp_ret_p)
 	{
 	  /* Now call the non-MIPS16 function.  */
-	  output_asm_insn (MIPS_CALL ("jal", &fn, 0, -1), &fn);
+	  output_asm_insn (mips_output_jump (&fn, 0, -1, true), &fn);
 	  fprintf (asm_out_file, "\t.cfi_register 31,18\n");
 
 	  /* Move the result from floating-point registers to
@@ -8378,7 +8418,7 @@ mips_pop_asm_switch (struct mips_asm_switch *asm_switch)
    '!'  Print "s" to use the short version if the delay slot contains a
 	16-bit instruction.
 
-   See also mips_init_print_operand_pucnt.  */
+   See also mips_init_print_operand_punct.  */
 
 static void
 mips_print_operand_punctuation (FILE *file, int ch)
@@ -8462,7 +8502,8 @@ mips_print_operand_punctuation (FILE *file, int ch)
 
     case ':':
       /* When final_sequence is 0, the delay slot will be a nop.  We can
-	 use the compact version for microMIPS.  */
+	 use the compact version where available.  The %: formatter will
+	 only be present if a compact form of the branch is available.  */
       if (final_sequence == 0)
 	putc ('c', file);
       break;
@@ -8470,8 +8511,9 @@ mips_print_operand_punctuation (FILE *file, int ch)
     case '!':
       /* If the delay slot instruction is short, then use the
 	 compact version.  */
-      if (final_sequence == 0
-	  || get_attr_length (final_sequence->insn (1)) == 2)
+      if (TARGET_MICROMIPS && !TARGET_INTERLINK_COMPRESSED && mips_isa_rev <= 5
+	  && (final_sequence == 0
+	      || get_attr_length (final_sequence->insn (1)) == 2))
 	putc ('s', file);
       break;
 
@@ -12969,6 +13011,7 @@ mips_adjust_insn_length (rtx_insn *insn, int length)
 	break;
 
       case HAZARD_DELAY:
+      case HAZARD_FORBIDDEN_SLOT:
 	length += NOP_INSN_LENGTH;
 	break;
 
@@ -12980,6 +13023,78 @@ mips_adjust_insn_length (rtx_insn *insn, int length)
   return length;
 }
 
+/* Return the asm template for a call.  OPERANDS are the operands, TARGET_OPNO
+   is the operand number of the target.  SIZE_OPNO is the operand number of
+   the argument size operand that can optionally hold the call attributes.  If
+   SIZE_OPNO is not -1 and the call is indirect, use the function symbol from
+   the call attributes to attach a R_MIPS_JALR relocation to the call.  LINK_P
+   indicates whether the jump is a call and needs to set the link register.
+
+   When generating GOT code without explicit relocation operators, all calls
+   should use assembly macros.  Otherwise, all indirect calls should use "jr"
+   or "jalr"; we will arrange to restore $gp afterwards if necessary.  Finally,
+   we can only generate direct calls for -mabicalls by temporarily switching
+   to non-PIC mode.
+
+   For microMIPS jal(r), we try to generate jal(r)s when a 16-bit
+   instruction is in the delay slot of jal(r).
+
+   Where compact branches are available, we try to use them if the delay slot
+   has a NOP (or equivalently delay slots were not enabled for the instruction
+   anyway).  */
+
+const char *
+mips_output_jump (rtx *operands, int target_opno, int size_opno, bool link_p)
+{
+  static char buffer[300];
+  char *s = buffer;
+  bool reg_p = REG_P (operands[target_opno]);
+
+  const char *and_link = link_p ? "al" : "";
+  const char *reg = reg_p ? "r" : "";
+  const char *compact = "";
+  const char *nop = "%/";
+  const char *short_delay = link_p ? "%!" : "";
+  const char *insn_name = TARGET_CB_NEVER || reg_p ? "j" : "b";
+
+  /* Compact branches can only be described when the ISA has support for them
+     as both the compact formatter '%:' and the delay slot NOP formatter '%/'
+     work as a mutually exclusive pair.  I.e. a NOP is never required if a
+     compact form is available.  */
+  if (!final_sequence
+      && (TARGET_CB_MAYBE
+	  || (ISA_HAS_JRC && !link_p && reg_p)))
+    {
+      compact = "c";
+      nop = "";
+    }
+
+  if (TARGET_USE_GOT && !TARGET_EXPLICIT_RELOCS)
+    sprintf (s, "%%*%s%s\t%%%d%%/", insn_name, and_link, target_opno);
+  else
+    {
+      if (!reg_p && TARGET_ABICALLS_PIC2)
+	s += sprintf (s, ".option\tpic0\n\t");
+
+      if (reg_p && mips_get_pic_call_symbol (operands, size_opno))
+	{
+	  s += sprintf (s, "%%*.reloc\t1f,R_MIPS_JALR,%%%d\n1:\t", size_opno);
+	  /* Not sure why this shouldn't permit a short delay but it did not
+	     allow it before so we still don't allow it.  */
+	  short_delay = "";
+	}
+      else
+	s += sprintf (s, "%%*");
+
+      s += sprintf (s, "%s%s%s%s%s\t%%%d%s", insn_name, and_link, reg, compact, short_delay,
+					    target_opno, nop);
+
+      if (!reg_p && TARGET_ABICALLS_PIC2)
+	s += sprintf (s, "\n\t.option\tpic2");
+    }
+  return buffer;
+}
+
 /* Return the assembly code for INSN, which has the operands given by
    OPERANDS, and which branches to OPERANDS[0] if some condition is true.
    BRANCH_IF_TRUE is the asm template that should be used if OPERANDS[0]
@@ -13033,12 +13148,25 @@ mips_output_conditional_branch (rtx_insn *insn, rtx *operands,
     }
 
   /* Output the unconditional branch to TAKEN.  */
-  if (TARGET_ABSOLUTE_JUMPS)
+  if (TARGET_ABSOLUTE_JUMPS && TARGET_CB_MAYBE)
+    {
+      /* Add a hazard nop.  */
+      if (!final_sequence)
+	{
+	  output_asm_insn ("nop\t\t# hazard nop", 0);
+	  fprintf (asm_out_file, "\n");
+	}
+      output_asm_insn (MIPS_ABSOLUTE_JUMP ("bc\t%0"), &taken);
+    }
+  else if (TARGET_ABSOLUTE_JUMPS)
     output_asm_insn (MIPS_ABSOLUTE_JUMP ("j\t%0%/"), &taken);
   else
     {
       mips_output_load_label (taken);
-      output_asm_insn ("jr\t%@%]%/", 0);
+      if (TARGET_CB_MAYBE)
+	output_asm_insn ("jrc\t%@%]", 0);
+      else
+	output_asm_insn ("jr\t%@%]%/", 0);
     }
 
   /* Now deal with its delay slot; see above.  */
@@ -13052,7 +13180,7 @@ mips_output_conditional_branch (rtx_insn *insn, rtx *operands,
 			   asm_out_file, optimize, 1, NULL);
 	  final_sequence->insn (1)->set_deleted ();
 	}
-      else
+      else if (TARGET_CB_NEVER)
 	output_asm_insn ("nop", 0);
       fprintf (asm_out_file, "\n");
     }
@@ -13064,42 +13192,155 @@ mips_output_conditional_branch (rtx_insn *insn, rtx *operands,
 }
 
 /* Return the assembly code for INSN, which branches to OPERANDS[0]
+   if some equality condition is true.  The condition is given by
+   OPERANDS[1] if !INVERTED_P, otherwise it is the inverse of
+   OPERANDS[1].  OPERANDS[2] is the comparison's first operand;
+   OPERANDS[3] is the second operand and may be zero or a register.  */
+
+const char *
+mips_output_equal_conditional_branch (rtx_insn* insn, rtx *operands,
+				      bool inverted_p)
+{
+  const char *branch[2];
+  /* For a simple BNEZ or BEQZ microMIPSr3 branch.  */
+  if (TARGET_MICROMIPS
+      && mips_isa_rev <= 5
+      && operands[3] == const0_rtx
+      && get_attr_length (insn) <= 8)
+    {
+      if (mips_cb == MIPS_CB_OPTIMAL)
+	{
+	  branch[!inverted_p] = "%*b%C1z%:\t%2,%0";
+	  branch[inverted_p] = "%*b%N1z%:\t%2,%0";
+	}
+      else
+	{
+	  branch[!inverted_p] = "%*b%C1z\t%2,%0%/";
+	  branch[inverted_p] = "%*b%N1z\t%2,%0%/";
+	}
+    }
+  else if (TARGET_CB_MAYBE)
+    {
+      if (operands[3] == const0_rtx)
+	{
+	  branch[!inverted_p] = MIPS_BRANCH_C ("b%C1z", "%2,%0");
+	  branch[inverted_p] = MIPS_BRANCH_C ("b%N1z", "%2,%0");
+	}
+      else if (REGNO (operands[2]) != REGNO (operands[3]))
+	{
+	  branch[!inverted_p] = MIPS_BRANCH_C ("b%C1", "%2,%3,%0");
+	  branch[inverted_p] = MIPS_BRANCH_C ("b%N1", "%2,%3,%0");
+	}
+      else
+	{
+	  /* This case is degenerate.  It should not happen, but does.  */
+	  if (GET_CODE (operands[1]) == NE)
+	    inverted_p = !inverted_p;
+
+	  branch[!inverted_p] = MIPS_BRANCH_C ("b", "%0");
+	  branch[inverted_p] = "%*\t\t# branch never";
+	}
+    }
+  else
+    {
+      branch[!inverted_p] = MIPS_BRANCH ("b%C1", "%2,%z3,%0");
+      branch[inverted_p] = MIPS_BRANCH ("b%N1", "%2,%z3,%0");
+    }
+
+  return mips_output_conditional_branch (insn, operands, branch[1], branch[0]);
+}
+
+/* Return the assembly code for INSN, which branches to OPERANDS[0]
    if some ordering condition is true.  The condition is given by
    OPERANDS[1] if !INVERTED_P, otherwise it is the inverse of
    OPERANDS[1].  OPERANDS[2] is the comparison's first operand;
-   its second is always zero.  */
+   OPERANDS[3] is the second operand and may be zero or a register.  */
 
 const char *
-mips_output_order_conditional_branch (rtx_insn *insn, rtx *operands, bool inverted_p)
+mips_output_order_conditional_branch (rtx_insn *insn, rtx *operands,
+				      bool inverted_p)
 {
   const char *branch[2];
 
   /* Make BRANCH[1] branch to OPERANDS[0] when the condition is true.
      Make BRANCH[0] branch on the inverse condition.  */
-  switch (GET_CODE (operands[1]))
+  if (operands[3] != const0_rtx)
     {
-      /* These cases are equivalent to comparisons against zero.  */
-    case LEU:
-      inverted_p = !inverted_p;
-      /* Fall through.  */
-    case GTU:
-      branch[!inverted_p] = MIPS_BRANCH ("bne", "%2,%.,%0");
-      branch[inverted_p] = MIPS_BRANCH ("beq", "%2,%.,%0");
-      break;
+      /* Handle degenerate cases that should not, but do, occur.  */
+      if (REGNO (operands[2]) == REGNO (operands[3]))
+	{
+	  switch (GET_CODE (operands[1]))
+	    {
+	    case LT:
+	    case LTU:
+	      inverted_p = !inverted_p;
+	      /* Fall through.  */
+	    case GE:
+	    case GEU:
+	      branch[!inverted_p] = MIPS_BRANCH_C ("b", "%0");
+	      branch[inverted_p] = "%*\t\t# branch never";
+	      break;
+	   default:
+	      gcc_unreachable ();
+	    }
+	}
+      else
+	{
+	  branch[!inverted_p] = MIPS_BRANCH_C ("b%C1", "%2,%3,%0");
+	  branch[inverted_p] = MIPS_BRANCH_C ("b%N1", "%2,%3,%0");
+	}
+    }
+  else
+    {
+      switch (GET_CODE (operands[1]))
+	{
+	  /* These cases are equivalent to comparisons against zero.  */
+	case LEU:
+	  inverted_p = !inverted_p;
+	  /* Fall through.  */
+	case GTU:
+	  if (TARGET_CB_MAYBE)
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH_C ("bnez", "%2,%0");
+	      branch[inverted_p] = MIPS_BRANCH_C ("beqz", "%2,%0");
+	    }
+	  else
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH ("bne", "%2,%.,%0");
+	      branch[inverted_p] = MIPS_BRANCH ("beq", "%2,%.,%0");
+	    }
+	  break;
 
-      /* These cases are always true or always false.  */
-    case LTU:
-      inverted_p = !inverted_p;
-      /* Fall through.  */
-    case GEU:
-      branch[!inverted_p] = MIPS_BRANCH ("beq", "%.,%.,%0");
-      branch[inverted_p] = MIPS_BRANCH ("bne", "%.,%.,%0");
-      break;
+	  /* These cases are always true or always false.  */
+	case LTU:
+	  inverted_p = !inverted_p;
+	  /* Fall through.  */
+	case GEU:
+	  if (TARGET_CB_MAYBE)
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH_C ("b", "%0");
+	      branch[inverted_p] = "%*\t\t# branch never";
+	    }
+	  else
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH ("beq", "%.,%.,%0");
+	      branch[inverted_p] = MIPS_BRANCH ("bne", "%.,%.,%0");
+	    }
+	  break;
 
-    default:
-      branch[!inverted_p] = MIPS_BRANCH ("b%C1z", "%2,%0");
-      branch[inverted_p] = MIPS_BRANCH ("b%N1z", "%2,%0");
-      break;
+	default:
+	  if (TARGET_CB_MAYBE)
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH_C ("b%C1z", "%2,%0");
+	      branch[inverted_p] = MIPS_BRANCH_C ("b%N1z", "%2,%0");
+	    }
+	  else
+	    {
+	      branch[!inverted_p] = MIPS_BRANCH ("b%C1z", "%2,%0");
+	      branch[inverted_p] = MIPS_BRANCH ("b%N1z", "%2,%0");
+	    }
+	  break;
+	}
     }
   return mips_output_conditional_branch (insn, operands, branch[1], branch[0]);
 }
@@ -13302,11 +13543,18 @@ mips_process_sync_loop (rtx_insn *insn, rtx *operands)
 			       at, oldval, inclusive_mask, NULL);
 	  tmp1 = at;
 	}
-      mips_multi_add_insn ("bne\t%0,%z1,2f", tmp1, required_oldval, NULL);
+      if (TARGET_CB_NEVER)
+	mips_multi_add_insn ("bne\t%0,%z1,2f", tmp1, required_oldval, NULL);
 
       /* CMP = 0 [delay slot].  */
       if (cmp)
         mips_multi_add_insn ("li\t%0,0", cmp, NULL);
+
+      if (TARGET_CB_MAYBE && required_oldval == const0_rtx)
+	mips_multi_add_insn ("bnezc\t%0,2f", tmp1, NULL);
+      else if (TARGET_CB_MAYBE)
+	mips_multi_add_insn ("bnec\t%0,%1,2f", tmp1, required_oldval, NULL);
+
     }
 
   /* $TMP1 = OLDVAL & EXCLUSIVE_MASK.  */
@@ -13369,7 +13617,10 @@ mips_process_sync_loop (rtx_insn *insn, rtx *operands)
      be annulled.  To ensure this behaviour unconditionally use a NOP
      in the delay slot for the branch likely case.  */
 
-  mips_multi_add_insn ("beq%?\t%0,%.,1b%~", at, NULL);
+  if (TARGET_CB_MAYBE)
+    mips_multi_add_insn ("beqzc\t%0,1b", at, NULL);
+  else
+    mips_multi_add_insn ("beq%?\t%0,%.,1b%~", at, NULL);
 
   /* if (INSN1 != MOVE && INSN1 != LI) NEWVAL = $TMP3 [delay slot].  */
   if (insn1 != SYNC_INSN1_MOVE && insn1 != SYNC_INSN1_LI && tmp3 != newval)
@@ -16651,7 +16902,7 @@ mips_orphaned_high_part_p (mips_offset_table *htab, rtx_insn *insn)
 
 static void
 mips_avoid_hazard (rtx_insn *after, rtx_insn *insn, int *hilo_delay,
-		   rtx *delayed_reg, rtx lo_reg)
+		   rtx *delayed_reg, rtx lo_reg, bool *fs_delay)
 {
   rtx pattern, set;
   int nops, ninsns;
@@ -16677,6 +16928,15 @@ mips_avoid_hazard (rtx_insn *after, rtx_insn *insn, int *hilo_delay,
     nops = 2 - *hilo_delay;
   else if (*delayed_reg != 0 && reg_referenced_p (*delayed_reg, pattern))
     nops = 1;
+  /* If processing a forbidden slot hazard then a NOP is required if the
+     branch instruction was not in a sequence (as the sequence would
+     imply it is not actually a compact branch anyway) and the current
+     insn is not an inline asm, and can't go in a delay slot.  */
+  else if (*fs_delay && get_attr_can_delay (insn) == CAN_DELAY_NO
+	   && GET_CODE (PATTERN (after)) != SEQUENCE
+	   && GET_CODE (pattern) != ASM_INPUT
+	   && asm_noperands (pattern) < 0)
+    nops = 1;
   else
     nops = 0;
 
@@ -16689,12 +16949,18 @@ mips_avoid_hazard (rtx_insn *after, rtx_insn *insn, int *hilo_delay,
   /* Set up the state for the next instruction.  */
   *hilo_delay += ninsns;
   *delayed_reg = 0;
+  *fs_delay = false;
   if (INSN_CODE (insn) >= 0)
     switch (get_attr_hazard (insn))
       {
       case HAZARD_NONE:
 	break;
 
+      case HAZARD_FORBIDDEN_SLOT:
+	if (TARGET_CB_MAYBE)
+	  *fs_delay = true;
+	break;
+
       case HAZARD_HILO:
 	*hilo_delay = 0;
 	break;
@@ -16718,6 +16984,7 @@ mips_reorg_process_insns (void)
   rtx_insn *insn, *last_insn, *subinsn, *next_insn;
   rtx lo_reg, delayed_reg;
   int hilo_delay;
+  bool fs_delay;
 
   /* Force all instructions to be split into their final form.  */
   split_all_insns_noflow ();
@@ -16786,6 +17053,7 @@ mips_reorg_process_insns (void)
   hilo_delay = 2;
   delayed_reg = 0;
   lo_reg = gen_rtx_REG (SImode, LO_REGNUM);
+  fs_delay = false;
 
   /* Make a second pass over the instructions.  Delete orphaned
      high-part relocations or turn them into NOPs.  Avoid hazards
@@ -16809,7 +17077,7 @@ mips_reorg_process_insns (void)
 			INSN_CODE (subinsn) = CODE_FOR_nop;
 		      }
 		    mips_avoid_hazard (last_insn, subinsn, &hilo_delay,
-				       &delayed_reg, lo_reg);
+				       &delayed_reg, lo_reg, &fs_delay);
 		  }
 	      last_insn = insn;
 	    }
@@ -16830,7 +17098,7 @@ mips_reorg_process_insns (void)
 	      else
 		{
 		  mips_avoid_hazard (last_insn, insn, &hilo_delay,
-				     &delayed_reg, lo_reg);
+				     &delayed_reg, lo_reg, &fs_delay);
 		  last_insn = insn;
 		}
 	    }
@@ -17695,6 +17963,27 @@ mips_option_override (void)
       target_flags |= MASK_ODD_SPREG;
     }
 
+  if (!ISA_HAS_COMPACT_BRANCHES && mips_cb == MIPS_CB_ALWAYS)
+    {
+      error ("unsupported combination: %qs%s %s",
+	      mips_arch_info->name, TARGET_MICROMIPS ? " -mmicromips" : "",
+	      "-mcompact-branches=always");
+    }
+  else if (!ISA_HAS_DELAY_SLOTS && mips_cb == MIPS_CB_NEVER)
+    {
+      error ("unsupported combination: %qs%s %s",
+	      mips_arch_info->name, TARGET_MICROMIPS ? " -mmicromips" : "",
+	      "-mcompact-branches=never");
+    }
+
+  /* Require explicit relocs for MIPS R6 onwards.  This enables simplification
+     of the compact branch and jump support through the backend.  */
+  if (!TARGET_EXPLICIT_RELOCS && mips_isa_rev >= 6)
+    {
+      error ("unsupported combination: %qs %s",
+	     mips_arch_info->name, "-mno-explicit-relocs");
+    }
+
   /* The effect of -mabicalls isn't defined for the EABI.  */
   if (mips_abi == ABI_EABI && TARGET_ABICALLS)
     {
@@ -18714,6 +19003,18 @@ mips_trampoline_init (rtx m_tramp, tree fndecl, rtx chain_value)
 
 #undef OP
 
+  /* If we are using compact branches we don't have delay slots so
+     place the instruction that was in the delay slot before the JRC
+     instruction.  */
+
+  if (TARGET_CB_ALWAYS)
+    {
+      rtx temp;
+      temp = trampoline[i-2];
+      trampoline[i-2] = trampoline[i-1];
+      trampoline[i-1] = temp;
+    }
+
   /* Copy the trampoline code.  Leave any padding uninitialized.  */
   for (j = 0; j < i; j++)
     {
diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 2d44735e6ca..25a1e0622cd 100644
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -92,6 +92,33 @@ struct mips_cpu_info {
 /* True if we are generating position-independent VxWorks RTP code.  */
 #define TARGET_RTP_PIC (TARGET_VXWORKS_RTP && flag_pic)
 
+/* Compact branches must not be used if the user either selects the
+   'never' policy or the 'optimal' policy on a core that lacks
+   compact branch instructions.  */
+#define TARGET_CB_NEVER (mips_cb == MIPS_CB_NEVER	\
+			 || (mips_cb == MIPS_CB_OPTIMAL \
+			     && !ISA_HAS_COMPACT_BRANCHES))
+
+/* Compact branches may be used if the user either selects the
+   'always' policy or the 'optimal' policy on a core that supports
+   compact branch instructions.  */
+#define TARGET_CB_MAYBE (TARGET_CB_ALWAYS		\
+			 || (mips_cb == MIPS_CB_OPTIMAL \
+			     && ISA_HAS_COMPACT_BRANCHES))
+
+/* Compact branches must always be generated if the user selects
+   the 'always' policy or the 'optimal' policy om a core that
+   lacks delay slot branch instructions.  */
+#define TARGET_CB_ALWAYS (mips_cb == MIPS_CB_ALWAYS	\
+			 || (mips_cb == MIPS_CB_OPTIMAL \
+			     && !ISA_HAS_DELAY_SLOTS))
+
+/* Special handling for JRC that exists in microMIPSR3 as well as R6
+   ISAs with full compact branch support.  */
+#define ISA_HAS_JRC ((ISA_HAS_COMPACT_BRANCHES		\
+		      || TARGET_MICROMIPS)		\
+		     && mips_cb != MIPS_CB_NEVER)
+
 /* True if the output file is marked as ".abicalls; .option pic0"
    (-call_nonpic).  */
 #define TARGET_ABICALLS_PIC0 \
@@ -872,6 +899,10 @@ struct mips_cpu_info {
 
 #define ISA_HAS_JR		(mips_isa_rev <= 5)
 
+#define ISA_HAS_DELAY_SLOTS	1
+
+#define ISA_HAS_COMPACT_BRANCHES (mips_isa_rev >= 6)
+
 /* ISA has branch likely instructions (e.g. mips2).  */
 /* Disable branchlikely for tx39 until compare rewrite.  They haven't
    been generated up to this point.  */
@@ -2645,6 +2676,9 @@ typedef struct mips_args {
 #define MIPS_BRANCH(OPCODE, OPERANDS) \
   "%*" OPCODE "%?\t" OPERANDS "%/"
 
+#define MIPS_BRANCH_C(OPCODE, OPERANDS) \
+  "%*" OPCODE "%:\t" OPERANDS
+
 /* Return an asm string that forces INSN to be treated as an absolute
    J or JAL instruction instead of an assembler macro.  */
 #define MIPS_ABSOLUTE_JUMP(INSN) \
@@ -2652,45 +2686,6 @@ typedef struct mips_args {
    ? ".option\tpic0\n\t" INSN "\n\t.option\tpic2"		\
    : INSN)
 
-/* Return the asm template for a call.  INSN is the instruction's mnemonic
-   ("j" or "jal"), OPERANDS are its operands, TARGET_OPNO is the operand
-   number of the target.  SIZE_OPNO is the operand number of the argument size
-   operand that can optionally hold the call attributes.  If SIZE_OPNO is not
-   -1 and the call is indirect, use the function symbol from the call
-   attributes to attach a R_MIPS_JALR relocation to the call.
-
-   When generating GOT code without explicit relocation operators,
-   all calls should use assembly macros.  Otherwise, all indirect
-   calls should use "jr" or "jalr"; we will arrange to restore $gp
-   afterwards if necessary.  Finally, we can only generate direct
-   calls for -mabicalls by temporarily switching to non-PIC mode.
-
-   For microMIPS jal(r), we try to generate jal(r)s when a 16-bit
-   instruction is in the delay slot of jal(r).  */
-#define MIPS_CALL(INSN, OPERANDS, TARGET_OPNO, SIZE_OPNO)	\
-  (TARGET_USE_GOT && !TARGET_EXPLICIT_RELOCS			\
-   ? "%*" INSN "\t%" #TARGET_OPNO "%/"				\
-   : REG_P (OPERANDS[TARGET_OPNO])				\
-   ? (mips_get_pic_call_symbol (OPERANDS, SIZE_OPNO)		\
-      ? ("%*.reloc\t1f,R_MIPS_JALR,%" #SIZE_OPNO "\n"		\
-	 "1:\t" INSN "r\t%" #TARGET_OPNO "%/")			\
-      : TARGET_MICROMIPS && !TARGET_INTERLINK_COMPRESSED	\
-      ? "%*" INSN "r%!\t%" #TARGET_OPNO "%/"			\
-      : "%*" INSN "r\t%" #TARGET_OPNO "%/")			\
-   : TARGET_MICROMIPS && !TARGET_INTERLINK_COMPRESSED		\
-     ? MIPS_ABSOLUTE_JUMP ("%*" INSN "%!\t%" #TARGET_OPNO "%/")	\
-     : MIPS_ABSOLUTE_JUMP ("%*" INSN "\t%" #TARGET_OPNO "%/"))	\
-
-/* Similar to MIPS_CALL, but this is for MICROMIPS "j" to generate
-   "jrc" when nop is in the delay slot of "jr".  */
-
-#define MICROMIPS_J(INSN, OPERANDS, OPNO)			\
-  (TARGET_USE_GOT && !TARGET_EXPLICIT_RELOCS			\
-   ? "%*j\t%" #OPNO "%/"					\
-   : REG_P (OPERANDS[OPNO])					\
-   ? "%*jr%:\t%" #OPNO						\
-   : MIPS_ABSOLUTE_JUMP ("%*" INSN "\t%" #OPNO "%/"))
-
 
 /* Control the assembler format that we output.  */
 
diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index f4ffd682415..1d1c42bf5f5 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -409,6 +409,15 @@
 	 (eq_attr "sync_mem" "!none") (const_string "syncloop")]
 	(const_string "unknown")))
 
+(define_attr "compact_form" "always,maybe,never"
+  (cond [(eq_attr "jal" "direct")
+	 (const_string "always")
+	 (eq_attr "jal" "indirect")
+	 (const_string "maybe")
+	 (eq_attr "type" "jump")
+	 (const_string "maybe")]
+	(const_string "never")))
+
 ;; Mode for conversion types (fcvt)
 ;; I2S          integer to float single (SI/DI to SF)
 ;; I2D          integer to float double (SI/DI to DF)
@@ -694,7 +703,7 @@
 ;; DELAY means that the next instruction cannot read the result
 ;; of this one.  HILO means that the next two instructions cannot
 ;; write to HI or LO.
-(define_attr "hazard" "none,delay,hilo"
+(define_attr "hazard" "none,delay,hilo,forbidden_slot"
   (cond [(and (eq_attr "type" "load,fpload,fpidxload")
 	      (match_test "ISA_HAS_LOAD_DELAY"))
 	 (const_string "delay")
@@ -1045,21 +1054,37 @@
    (nil)
    (eq_attr "can_delay" "yes")])
 
-;; Branches that don't have likely variants do not annul on false.
+;; Branches that have delay slots and don't have likely variants do
+;; not annul on false.
 (define_delay (and (eq_attr "type" "branch")
 		   (not (match_test "TARGET_MIPS16"))
+		   (ior (match_test "TARGET_CB_NEVER")
+			(and (eq_attr "compact_form" "maybe")
+			     (not (match_test "TARGET_CB_ALWAYS")))
+			(eq_attr "compact_form" "never"))
 		   (eq_attr "branch_likely" "no"))
   [(eq_attr "can_delay" "yes")
    (nil)
    (nil)])
 
-(define_delay (eq_attr "type" "jump")
+(define_delay (and (eq_attr "type" "jump")
+		   (ior (match_test "TARGET_CB_NEVER")
+			(and (eq_attr "compact_form" "maybe")
+			     (not (match_test "TARGET_CB_ALWAYS")))
+			(eq_attr "compact_form" "never")))
   [(eq_attr "can_delay" "yes")
    (nil)
    (nil)])
 
+;; Call type instructions should never have a compact form as the
+;; type is only used for MIPS16 patterns.  For safety put the compact
+;; branch detection condition in anyway.
 (define_delay (and (eq_attr "type" "call")
-		   (eq_attr "jal_macro" "no"))
+		   (eq_attr "jal_macro" "no")
+		   (ior (match_test "TARGET_CB_NEVER")
+			(and (eq_attr "compact_form" "maybe")
+			     (not (match_test "TARGET_CB_ALWAYS")))
+			(eq_attr "compact_form" "never")))
   [(eq_attr "can_delay" "yes")
    (nil)
    (nil)])
@@ -5813,25 +5838,29 @@
   [(set (pc)
 	(if_then_else
 	 (match_operator 1 "order_operator"
-			 [(match_operand:GPR 2 "register_operand" "d")
-			  (const_int 0)])
+			 [(match_operand:GPR 2 "register_operand" "d,d")
+			  (match_operand:GPR 3 "reg_or_0_operand" "J,d")])
 	 (label_ref (match_operand 0 "" ""))
 	 (pc)))]
   "!TARGET_MIPS16"
   { return mips_output_order_conditional_branch (insn, operands, false); }
-  [(set_attr "type" "branch")])
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe,always")
+   (set_attr "hazard" "forbidden_slot")])
 
 (define_insn "*branch_order<mode>_inverted"
   [(set (pc)
 	(if_then_else
 	 (match_operator 1 "order_operator"
-			 [(match_operand:GPR 2 "register_operand" "d")
-			  (const_int 0)])
+			 [(match_operand:GPR 2 "register_operand" "d,d")
+			  (match_operand:GPR 3 "reg_or_0_operand" "J,d")])
 	 (pc)
 	 (label_ref (match_operand 0 "" ""))))]
   "!TARGET_MIPS16"
   { return mips_output_order_conditional_branch (insn, operands, true); }
-  [(set_attr "type" "branch")])
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe,always")
+   (set_attr "hazard" "forbidden_slot")])
 
 ;; Conditional branch on equality comparison.
 
@@ -5844,20 +5873,10 @@
 	 (label_ref (match_operand 0 "" ""))
 	 (pc)))]
   "!TARGET_MIPS16"
-{
-  /* For a simple BNEZ or BEQZ microMIPS branch.  */
-  if (TARGET_MICROMIPS
-      && operands[3] == const0_rtx
-      && get_attr_length (insn) <= 8)
-    return mips_output_conditional_branch (insn, operands,
-					   "%*b%C1z%:\t%2,%0",
-					   "%*b%N1z%:\t%2,%0");
-
-  return mips_output_conditional_branch (insn, operands,
-					 MIPS_BRANCH ("b%C1", "%2,%z3,%0"),
-					 MIPS_BRANCH ("b%N1", "%2,%z3,%0"));
-}
-  [(set_attr "type" "branch")])
+  { return mips_output_equal_conditional_branch (insn, operands, false); }
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe")
+   (set_attr "hazard" "forbidden_slot")])
 
 (define_insn "*branch_equality<mode>_inverted"
   [(set (pc)
@@ -5868,20 +5887,10 @@
 	 (pc)
 	 (label_ref (match_operand 0 "" ""))))]
   "!TARGET_MIPS16"
-{
-  /* For a simple BNEZ or BEQZ microMIPS branch.  */
-  if (TARGET_MICROMIPS
-      && operands[3] == const0_rtx
-      && get_attr_length (insn) <= 8)
-    return mips_output_conditional_branch (insn, operands,
-					   "%*b%N0z%:\t%2,%1",
-					   "%*b%C0z%:\t%2,%1");
-
-  return mips_output_conditional_branch (insn, operands,
-					 MIPS_BRANCH ("b%N1", "%2,%z3,%0"),
-					 MIPS_BRANCH ("b%C1", "%2,%z3,%0"));
-}
-  [(set_attr "type" "branch")])
+  { return mips_output_equal_conditional_branch (insn, operands, true); }
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe")
+   (set_attr "hazard" "forbidden_slot")])
 
 ;; MIPS16 branches
 
@@ -6176,11 +6185,22 @@
   "!TARGET_MIPS16 && TARGET_ABSOLUTE_JUMPS"
 {
   if (get_attr_length (insn) <= 8)
-    return "%*b\t%l0%/";
+    {
+      if (TARGET_CB_MAYBE)
+	return MIPS_ABSOLUTE_JUMP ("%*b%:\t%l0");
+      else
+	return MIPS_ABSOLUTE_JUMP ("%*b\t%l0%/");
+    }
   else
-    return MIPS_ABSOLUTE_JUMP ("%*j\t%l0%/");
+    {
+      if (TARGET_CB_MAYBE && !final_sequence)
+	return MIPS_ABSOLUTE_JUMP ("%*bc\t%l0");
+      else
+	return MIPS_ABSOLUTE_JUMP ("%*j\t%l0%/");
+    }
 }
-  [(set_attr "type" "branch")])
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe")])
 
 (define_insn "*jump_pic"
   [(set (pc)
@@ -6188,14 +6208,23 @@
   "!TARGET_MIPS16 && !TARGET_ABSOLUTE_JUMPS"
 {
   if (get_attr_length (insn) <= 8)
-    return "%*b\t%l0%/";
+    {
+      if (TARGET_CB_MAYBE)
+	return "%*b%:\t%l0";
+      else
+	return "%*b\t%l0%/";
+    }
   else
     {
       mips_output_load_label (operands[0]);
-      return "%*jr\t%@%/%]";
+      if (TARGET_CB_MAYBE)
+	return "%*jr%:\t%@%]";
+      else
+	return "%*jr\t%@%/%]";
     }
 }
-  [(set_attr "type" "branch")])
+  [(set_attr "type" "branch")
+   (set_attr "compact_form" "maybe")])
 
 ;; We need a different insn for the mips16, because a mips16 branch
 ;; does not have a delay slot.
@@ -6242,12 +6271,9 @@
 (define_insn "indirect_jump_<mode>"
   [(set (pc) (match_operand:P 0 "register_operand" "d"))]
   ""
-{
-  if (TARGET_MICROMIPS)
-    return "%*jr%:\t%0";
-  else
-    return "%*j\t%0%/";
-}
+  {
+    return mips_output_jump (operands, 0, -1, false);
+  }
   [(set_attr "type" "jump")
    (set_attr "mode" "none")])
 
@@ -6291,12 +6317,9 @@
 	(match_operand:P 0 "register_operand" "d"))
    (use (label_ref (match_operand 1 "" "")))]
   ""
-{
-  if (TARGET_MICROMIPS)
-    return "%*jr%:\t%0";
-  else
-    return "%*j\t%0%/";
-}
+  {
+    return mips_output_jump (operands, 0, -1, false);
+  }
   [(set_attr "type" "jump")
    (set_attr "mode" "none")])
 
@@ -6508,10 +6531,8 @@
   [(any_return)]
   ""
   {
-    if (TARGET_MICROMIPS)
-      return "%*jr%:\t$31";
-    else
-      return "%*j\t$31%/";
+    operands[0] = gen_rtx_REG (Pmode, RETURN_ADDR_REGNUM);
+    return mips_output_jump (operands, 0, -1, false);
   }
   [(set_attr "type"	"jump")
    (set_attr "mode"	"none")])
@@ -6522,12 +6543,10 @@
   [(any_return)
    (use (match_operand 0 "pmode_register_operand" ""))]
   ""
-{
-  if (TARGET_MICROMIPS)
-    return "%*jr%:\t%0";
-  else
-    return "%*j\t%0%/";
-}
+  {
+    operands[0] = gen_rtx_REG (Pmode, RETURN_ADDR_REGNUM);
+    return mips_output_jump (operands, 0, -1, false);
+  }
   [(set_attr "type"	"jump")
    (set_attr "mode"	"none")])
 
@@ -6783,12 +6802,7 @@
   [(call (mem:SI (match_operand 0 "call_insn_operand" "j,S"))
 	 (match_operand 1 "" ""))]
   "TARGET_SIBCALLS && SIBLING_CALL_P (insn)"
-{
-  if (TARGET_MICROMIPS)
-    return MICROMIPS_J ("j", operands, 0);
-  else
-    return MIPS_CALL ("j", operands, 0, 1);
-}
+  { return mips_output_jump (operands, 0, 1, false); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -6809,12 +6823,7 @@
         (call (mem:SI (match_operand 1 "call_insn_operand" "j,S"))
               (match_operand 2 "" "")))]
   "TARGET_SIBCALLS && SIBLING_CALL_P (insn)"
-{
-  if (TARGET_MICROMIPS)
-    return MICROMIPS_J ("j", operands, 1);
-  else
-    return MIPS_CALL ("j", operands, 1, 2);
-}
+  { return mips_output_jump (operands, 1, 2, false); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -6826,12 +6835,7 @@
 	(call (mem:SI (match_dup 1))
 	      (match_dup 2)))]
   "TARGET_SIBCALLS && SIBLING_CALL_P (insn)"
-{
-  if (TARGET_MICROMIPS)
-    return MICROMIPS_J ("j", operands, 1);
-  else
-    return MIPS_CALL ("j", operands, 1, 2);
-}
+  { return mips_output_jump (operands, 1, 2, false); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -6887,7 +6891,10 @@
 	 (match_operand 1 "" ""))
    (clobber (reg:SI RETURN_ADDR_REGNUM))]
   ""
-  { return TARGET_SPLIT_CALLS ? "#" : MIPS_CALL ("jal", operands, 0, 1); }
+  {
+    return (TARGET_SPLIT_CALLS ? "#"
+	    : mips_output_jump (operands, 0, 1, true));
+  }
   "reload_completed && TARGET_SPLIT_CALLS"
   [(const_int 0)]
 {
@@ -6902,7 +6909,7 @@
    (clobber (reg:SI RETURN_ADDR_REGNUM))
    (clobber (reg:SI 28))]
   "TARGET_SPLIT_CALLS"
-  { return MIPS_CALL ("jal", operands, 0, 1); }
+  { return mips_output_jump (operands, 0, 1, true); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -6916,7 +6923,10 @@
    (const_int 1)
    (clobber (reg:SI RETURN_ADDR_REGNUM))]
   ""
-  { return TARGET_SPLIT_CALLS ? "#" : MIPS_CALL ("jal", operands, 0, -1); }
+  {
+    return (TARGET_SPLIT_CALLS ? "#"
+	    : mips_output_jump (operands, 0, -1, true));
+  }
   "reload_completed && TARGET_SPLIT_CALLS"
   [(const_int 0)]
 {
@@ -6933,7 +6943,7 @@
    (clobber (reg:SI RETURN_ADDR_REGNUM))
    (clobber (reg:SI 28))]
   "TARGET_SPLIT_CALLS"
-  { return MIPS_CALL ("jal", operands, 0, -1); }
+  { return mips_output_jump (operands, 0, -1, true); }
   [(set_attr "jal" "direct")
    (set_attr "jal_macro" "no")])
 
@@ -6956,7 +6966,10 @@
               (match_operand 2 "" "")))
    (clobber (reg:SI RETURN_ADDR_REGNUM))]
   ""
-  { return TARGET_SPLIT_CALLS ? "#" : MIPS_CALL ("jal", operands, 1, 2); }
+  {
+    return (TARGET_SPLIT_CALLS ? "#"
+	    : mips_output_jump (operands, 1, 2, true));
+  }
   "reload_completed && TARGET_SPLIT_CALLS"
   [(const_int 0)]
 {
@@ -6974,7 +6987,7 @@
    (clobber (reg:SI RETURN_ADDR_REGNUM))
    (clobber (reg:SI 28))]
   "TARGET_SPLIT_CALLS"
-  { return MIPS_CALL ("jal", operands, 1, 2); }
+  { return mips_output_jump (operands, 1, 2, true); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -6986,7 +6999,10 @@
    (const_int 1)
    (clobber (reg:SI RETURN_ADDR_REGNUM))]
   ""
-  { return TARGET_SPLIT_CALLS ? "#" : MIPS_CALL ("jal", operands, 1, -1); }
+  {
+    return (TARGET_SPLIT_CALLS ? "#"
+	    : mips_output_jump (operands, 1, -1, true));
+  }
   "reload_completed && TARGET_SPLIT_CALLS"
   [(const_int 0)]
 {
@@ -7005,7 +7021,7 @@
    (clobber (reg:SI RETURN_ADDR_REGNUM))
    (clobber (reg:SI 28))]
   "TARGET_SPLIT_CALLS"
-  { return MIPS_CALL ("jal", operands, 1, -1); }
+  { return mips_output_jump (operands, 1, -1, true); }
   [(set_attr "jal" "direct")
    (set_attr "jal_macro" "no")])
 
@@ -7019,7 +7035,10 @@
 	      (match_dup 2)))
    (clobber (reg:SI RETURN_ADDR_REGNUM))]
   ""
-  { return TARGET_SPLIT_CALLS ? "#" : MIPS_CALL ("jal", operands, 1, 2); }
+  {
+    return (TARGET_SPLIT_CALLS ? "#"
+	    : mips_output_jump (operands, 1, 2, true));
+  }
   "reload_completed && TARGET_SPLIT_CALLS"
   [(const_int 0)]
 {
@@ -7040,7 +7059,7 @@
    (clobber (reg:SI RETURN_ADDR_REGNUM))
    (clobber (reg:SI 28))]
   "TARGET_SPLIT_CALLS"
-  { return MIPS_CALL ("jal", operands, 1, 2); }
+  { return mips_output_jump (operands, 1, 2, true); }
   [(set_attr "jal" "indirect,direct")
    (set_attr "jal_macro" "no")])
 
@@ -7411,7 +7430,7 @@
    (clobber (reg:P PIC_FUNCTION_ADDR_REGNUM))
    (clobber (reg:P RETURN_ADDR_REGNUM))]
   "HAVE_AS_TLS && TARGET_MIPS16"
-  { return MIPS_CALL ("jal", operands, 0, -1); }
+  { return mips_output_jump (operands, 0, -1, true); }
   [(set_attr "type" "call")
    (set_attr "insn_count" "3")
    (set_attr "mode" "<MODE>")])
@@ -7452,7 +7471,7 @@
    (clobber (reg:P PIC_FUNCTION_ADDR_REGNUM))
    (clobber (reg:P RETURN_ADDR_REGNUM))]
   "TARGET_HARD_FLOAT_ABI && TARGET_MIPS16"
-  { return MIPS_CALL ("jal", operands, 0, -1); }
+  { return mips_output_jump (operands, 0, -1, true); }
   [(set_attr "type" "call")
    (set_attr "insn_count" "3")])
 
@@ -7482,7 +7501,7 @@
    (clobber (reg:P PIC_FUNCTION_ADDR_REGNUM))
    (clobber (reg:P RETURN_ADDR_REGNUM))]
   "TARGET_HARD_FLOAT_ABI && TARGET_MIPS16"
-  { return MIPS_CALL ("jal", operands, 0, -1); }
+  { return mips_output_jump (operands, 0, -1, true); }
   [(set_attr "type" "call")
    (set_attr "insn_count" "3")])
 
diff --git a/gcc/config/mips/mips.opt b/gcc/config/mips/mips.opt
index 348c6e03f1e..84887d11623 100644
--- a/gcc/config/mips/mips.opt
+++ b/gcc/config/mips/mips.opt
@@ -418,3 +418,20 @@ Driver
 mload-store-pairs
 Target Report Var(TARGET_LOAD_STORE_PAIRS) Init(1)
 Enable load/store bonding.
+
+mcompact-branches=
+Target RejectNegative JoinedOrMissing Var(mips_cb) Report Enum(mips_cb_setting) Init(MIPS_CB_OPTIMAL)
+Specify the compact branch usage policy
+
+Enum
+Name(mips_cb_setting) Type(enum mips_cb_setting)
+Policies available for use with -mcompact-branches=:
+
+EnumValue
+Enum(mips_cb_setting) String(never) Value(MIPS_CB_NEVER)
+
+EnumValue
+Enum(mips_cb_setting) String(optimal) Value(MIPS_CB_OPTIMAL)
+
+EnumValue
+Enum(mips_cb_setting) String(always) Value(MIPS_CB_ALWAYS)
diff --git a/gcc/config/mips/predicates.md b/gcc/config/mips/predicates.md
index 4929c3dc27e..3259232bb89 100644
--- a/gcc/config/mips/predicates.md
+++ b/gcc/config/mips/predicates.md
@@ -475,7 +475,18 @@
   (match_code "eq,ne,lt,ltu,ge,geu"))
 
 (define_predicate "order_operator"
-  (match_code "lt,ltu,le,leu,ge,geu,gt,gtu"))
+  (match_code "lt,ltu,le,leu,ge,geu,gt,gtu")
+{
+  if (XEXP (op, 1) == const0_rtx)
+    return true;
+
+  if (TARGET_CB_MAYBE
+      && (GET_CODE (op) == LT || GET_CODE (op) == LTU
+	  || GET_CODE (op) == GE || GET_CODE (op) == GEU))
+    return true;
+
+  return false;
+})
 
 ;; For NE, cstore uses sltu instructions in which the first operand is $0.
 ;; This isn't possible in mips16 code.