[mips][mips16] Use isUnconditionalBranch() in AnalyzeBranch() and constant island pass.

Summary:
This stops it misidentifying unconditional branches as conditional branches
which fixes a -verify-machineinstrs error about exiting a function via fall through.

Reviewers: sdardis

Subscribers: dsanders, sdardis, llvm-commits

Differential Revision: http://reviews.llvm.org/D19864

llvm-svn: 268731

2 files changed, 4 insertions, 14 deletions

diff --git a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
index a3ea1526629..3b8d3a2ef7d 100644
--- a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
+++ b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
@@ -97,16 +97,6 @@ static unsigned int branchTargetOperand(MachineInstr *MI) {
   llvm_unreachable("Unknown branch type");
 }
 
-static bool isUnconditionalBranch(unsigned int Opcode) {
-  switch (Opcode) {
-  default: return false;
-  case Mips::Bimm16:
-  case Mips::BimmX16:
-  case Mips::JalB16:
-    return true;
-  }
-}
-
 static unsigned int longformBranchOpcode(unsigned int Opcode) {
   switch (Opcode) {
   case Mips::Bimm16:
@@ -1615,7 +1605,7 @@ MipsConstantIslands::fixupConditionalBr(ImmBranch &Br) {
   ++NumCBrFixed;
   if (BMI != MI) {
     if (std::next(MachineBasicBlock::iterator(MI)) == std::prev(MBB->end()) &&
-        isUnconditionalBranch(BMI->getOpcode())) {
+        BMI->isUnconditionalBranch()) {
       // Last MI in the BB is an unconditional branch. Can we simply invert the
       // condition and swap destinations:
       // beqz L1
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.cpp b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
index a1bfba0c354..e5c602f35e6 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
@@ -216,7 +216,7 @@ MipsInstrInfo::BranchType MipsInstrInfo::AnalyzeBranch(
   // If there is only one terminator instruction, process it.
   if (!SecondLastOpc) {
     // Unconditional branch.
-    if (LastOpc == UncondBrOpc) {
+    if (LastInst->isUnconditionalBranch()) {
       TBB = LastInst->getOperand(0).getMBB();
       return BT_Uncond;
     }
@@ -235,7 +235,7 @@ MipsInstrInfo::BranchType MipsInstrInfo::AnalyzeBranch(
 
   // If second to last instruction is an unconditional branch,
   // analyze it and remove the last instruction.
-  if (SecondLastOpc == UncondBrOpc) {
+  if (SecondLastInst->isUnconditionalBranch()) {
     // Return if the last instruction cannot be removed.
     if (!AllowModify)
       return BT_None;
@@ -248,7 +248,7 @@ MipsInstrInfo::BranchType MipsInstrInfo::AnalyzeBranch(
 
   // Conditional branch followed by an unconditional branch.
   // The last one must be unconditional.
-  if (LastOpc != UncondBrOpc)
+  if (!LastInst->isUnconditionalBranch())
     return BT_None;
 
   AnalyzeCondBr(SecondLastInst, SecondLastOpc, TBB, Cond);