diff --git a/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp b/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
index 74f417994a0..cc45c6642ac 100644
--- a/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
+++ b/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
@@ -180,7 +180,7 @@ bool AArch64PostSelectOptimize::runOnMachineFunction(MachineFunction &MF) {
   bool Changed = false;
   for (auto &BB : MF)
     Changed |= optimizeNZCVDefs(BB);
-  return true;
+  return Changed;
 }
 
 char AArch64PostSelectOptimize::ID = 0;
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 8a9d02901dc..8dd013d5a0a 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -6861,12 +6861,10 @@ static SDValue isVMOVModifiedImm(uint64_t SplatBits, uint64_t SplatUndef,
       return SDValue();
     // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
     uint64_t BitMask = 0xff;
-    uint64_t Val = 0;
     unsigned ImmMask = 1;
     Imm = 0;
     for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
       if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
-        Val |= BitMask;
         Imm |= ImmMask;
       } else if ((SplatBits & BitMask) != 0) {
         return SDValue();
diff --git a/lib/Target/ARM/ARMLowOverheadLoops.cpp b/lib/Target/ARM/ARMLowOverheadLoops.cpp
index d40b01927c6..e1d77a585d2 100644
--- a/lib/Target/ARM/ARMLowOverheadLoops.cpp
+++ b/lib/Target/ARM/ARMLowOverheadLoops.cpp
@@ -1227,7 +1227,7 @@ bool ARMLowOverheadLoops::ProcessLoop(MachineLoop *ML) {
   if (LoLoop.Preheader)
     LoLoop.Start = SearchForStart(LoLoop.Preheader);
   else
-    return false;
+    return Changed;
 
   // Find the low-overhead loop components and decide whether or not to fall
   // back to a normal loop. Also look for a vctp instructions and decide
@@ -1261,7 +1261,7 @@ bool ARMLowOverheadLoops::ProcessLoop(MachineLoop *ML) {
   LLVM_DEBUG(LoLoop.dump());
   if (!LoLoop.FoundAllComponents()) {
     LLVM_DEBUG(dbgs() << "ARM Loops: Didn't find loop start, update, end\n");
-    return false;
+    return Changed;
   }
 
   assert(LoLoop.Start->getOpcode() != ARM::t2WhileLoopStart &&
diff --git a/lib/Target/PowerPC/PPCBranchSelector.cpp b/lib/Target/PowerPC/PPCBranchSelector.cpp
index 47b9e97f0d6..fa6713dcca8 100644
--- a/lib/Target/PowerPC/PPCBranchSelector.cpp
+++ b/lib/Target/PowerPC/PPCBranchSelector.cpp
@@ -415,5 +415,5 @@ bool PPCBSel::runOnMachineFunction(MachineFunction &Fn) {
   }
 
   BlockSizes.clear();
-  return true;
+  return EverMadeChange;
 }
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp
index 90c34272cec..1268d15fc33 100644
--- a/lib/Target/X86/X86FloatingPoint.cpp
+++ b/lib/Target/X86/X86FloatingPoint.cpp
@@ -1526,7 +1526,7 @@ void FPS::handleSpecialFP(MachineBasicBlock::iterator &Inst) {
 
     // Scan the assembly for ST registers used, defined and clobbered. We can
     // only tell clobbers from defs by looking at the asm descriptor.
-    unsigned STUses = 0, STDefs = 0, STClobbers = 0, STDeadDefs = 0;
+    unsigned STUses = 0, STDefs = 0, STClobbers = 0;
     unsigned NumOps = 0;
     SmallSet<unsigned, 1> FRegIdx;
     unsigned RCID;
@@ -1559,8 +1559,6 @@ void FPS::handleSpecialFP(MachineBasicBlock::iterator &Inst) {
       case InlineAsm::Kind_RegDef:
       case InlineAsm::Kind_RegDefEarlyClobber:
         STDefs |= (1u << STReg);
-        if (MO.isDead())
-          STDeadDefs |= (1u << STReg);
         break;
       case InlineAsm::Kind_Clobber:
         STClobbers |= (1u << STReg);
diff --git a/utils/benchmark/src/complexity.cc b/utils/benchmark/src/complexity.cc
index 97bf6e09b30..97cb0a88271 100644
--- a/utils/benchmark/src/complexity.cc
+++ b/utils/benchmark/src/complexity.cc
@@ -76,7 +76,6 @@ std::string GetBigOString(BigO complexity) {
 LeastSq MinimalLeastSq(const std::vector<int64_t>& n,
                        const std::vector<double>& time,
                        BigOFunc* fitting_curve) {
-  double sigma_gn = 0.0;
   double sigma_gn_squared = 0.0;
   double sigma_time = 0.0;
   double sigma_time_gn = 0.0;
@@ -84,7 +83,6 @@ LeastSq MinimalLeastSq(const std::vector<int64_t>& n,
   // Calculate least square fitting parameter
   for (size_t i = 0; i < n.size(); ++i) {
     double gn_i = fitting_curve(n[i]);
-    sigma_gn += gn_i;
     sigma_gn_squared += gn_i * gn_i;
     sigma_time += time[i];
     sigma_time_gn += time[i] * gn_i;