MIPS: Sort out mm_isBranchInstr.

mm_isBranchInstr() did reside in the math emu code even though it logically
is separate and also is used outside the math emu code.  In addition GCC 4.9.0
leaves the following unnnecessarily bloated function body for a non-microMIPS
configuration:

<mm_isBranchInstr>:
    105c:       afa50004        sw      a1,4(sp)
    1060:       afa60008        sw      a2,8(sp)
    1064:       afa7000c        sw      a3,12(sp)
    1068:       03e00008        jr      ra
    106c:       00001021        move    v0,zero

which stores arguments that are never going to be used on the stack frame.

Move mm_isBranchInstr() from cp1emu.c to branch.c, then split mm_isBranchInstr()
into a __mm_isBranchInstr() core and a mm_isBranchInstr() wrapper inline function
which only invokes __mm_isBranchInstr() on microMIPS configurations.

This shaves off 112 bytes off the kernel and improves code flow a bit.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/branch.h b/arch/mips/include/asm/branch.h
index d109e34..de781cf 100644
--- a/arch/mips/include/asm/branch.h
+++ b/arch/mips/include/asm/branch.h
@@ -20,6 +20,24 @@
 extern int __microMIPS_compute_return_epc(struct pt_regs *regs);
 extern int __MIPS16e_compute_return_epc(struct pt_regs *regs);
 
+/*
+ * microMIPS bitfields
+ */
+#define MM_POOL32A_MINOR_MASK	0x3f
+#define MM_POOL32A_MINOR_SHIFT	0x6
+#define MM_MIPS32_COND_FC	0x30
+
+extern int __mm_isBranchInstr(struct pt_regs *regs,
+	struct mm_decoded_insn dec_insn, unsigned long *contpc);
+
+static inline int mm_isBranchInstr(struct pt_regs *regs,
+	struct mm_decoded_insn dec_insn, unsigned long *contpc)
+{
+	if (!cpu_has_mmips)
+		return 0;
+
+	return __mm_isBranchInstr(regs, dec_insn, contpc);
+}
 
 static inline int delay_slot(struct pt_regs *regs)
 {