Index: lib/CodeGen/MachineVerifier.cpp
===================================================================
--- lib/CodeGen/MachineVerifier.cpp
+++ lib/CodeGen/MachineVerifier.cpp
@@ -739,7 +739,7 @@
   if (!isUInt<5>(MI->getOperand(1).getImm()))
     report("Unknown asm flags", &MI->getOperand(1), 1);
 
-  assert(InlineAsm::MIOp_FirstOperand == 2 && "Asm format changed");
+  static_assert(InlineAsm::MIOp_FirstOperand == 2, "Asm format changed");
 
   unsigned OpNo = InlineAsm::MIOp_FirstOperand;
   unsigned NumOps;
Index: lib/CodeGen/SlotIndexes.cpp
===================================================================
--- lib/CodeGen/SlotIndexes.cpp
+++ lib/CodeGen/SlotIndexes.cpp
@@ -127,7 +127,7 @@
 void SlotIndexes::renumberIndexes(IndexList::iterator curItr) {
   // Number indexes with half the default spacing so we can catch up quickly.
   const unsigned Space = SlotIndex::InstrDist/2;
-  assert((Space & 3) == 0 && "InstrDist must be a multiple of 2*NUM");
+  static_assert((Space & 3) == 0, "InstrDist must be a multiple of 2*NUM");
 
   IndexList::iterator startItr = std::prev(curItr);
   unsigned index = startItr->getIndex();
Index: lib/MC/MCDwarf.cpp
===================================================================
--- lib/MC/MCDwarf.cpp
+++ lib/MC/MCDwarf.cpp
@@ -243,7 +243,9 @@
       0, // length of DW_LNS_set_epilogue_begin
       1  // DW_LNS_set_isa
   };
-  assert(array_lengthof(StandardOpcodeLengths) == (DWARF2_LINE_OPCODE_BASE - 1));
+  static_assert(array_lengthof(StandardOpcodeLengths) ==
+                    (DWARF2_LINE_OPCODE_BASE - 1),
+                "");
   return Emit(MCOS, StandardOpcodeLengths);
 }
 
Index: lib/Support/FoldingSet.cpp
===================================================================
--- lib/Support/FoldingSet.cpp
+++ lib/Support/FoldingSet.cpp
@@ -101,6 +101,8 @@
     // Otherwise do it the hard way.
     // To be compatible with above bulk transfer, we need to take endianness
     // into account.
+    static_assert(sys::IsBigEndianHost || sys::IsLittleEndianHost,
+                  "Unexpected host endianness");
     if (sys::IsBigEndianHost) {
       for (Pos += 4; Pos <= Size; Pos += 4) {
         unsigned V = ((unsigned char)String[Pos - 4] << 24) |
@@ -109,8 +111,7 @@
                       (unsigned char)String[Pos - 1];
         Bits.push_back(V);
       }
-    } else {
-      assert(sys::IsLittleEndianHost && "Unexpected host endianness");
+    } else {  // Little-endian host
       for (Pos += 4; Pos <= Size; Pos += 4) {
         unsigned V = ((unsigned char)String[Pos - 1] << 24) |
                      ((unsigned char)String[Pos - 2] << 16) |
Index: lib/Target/X86/X86FloatingPoint.cpp
===================================================================
--- lib/Target/X86/X86FloatingPoint.cpp
+++ lib/Target/X86/X86FloatingPoint.cpp
@@ -300,7 +300,7 @@
   // function.  If it is all integer, there is nothing for us to do!
   bool FPIsUsed = false;
 
-  assert(X86::FP6 == X86::FP0+6 && "Register enums aren't sorted right!");
+  static_assert(X86::FP6 == X86::FP0+6, "Register enums aren't sorted right!");
   for (unsigned i = 0; i <= 6; ++i)
     if (MF.getRegInfo().isPhysRegUsed(X86::FP0+i)) {
       FPIsUsed = true;
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -17843,7 +17843,8 @@
   // 9  ) EFLAGS (implicit-def)
 
   assert(MI->getNumOperands() == 10 && "VAARG_64 should have 10 operands!");
-  assert(X86::AddrNumOperands == 5 && "VAARG_64 assumes 5 address operands");
+  static_assert(X86::AddrNumOperands == 5,
+                "VAARG_64 assumes 5 address operands");
 
   unsigned DestReg = MI->getOperand(0).getReg();
   MachineOperand &Base = MI->getOperand(1);
Index: lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1621,7 +1621,11 @@
 void FunctionStackPoisoner::SetShadowToStackAfterReturnInlined(
     IRBuilder<> &IRB, Value *ShadowBase, int Size) {
   assert(!(Size % 8));
-  assert(kAsanStackAfterReturnMagic == 0xf5);
+
+  #ifndef NDEBUG
+  static_assert(kAsanStackAfterReturnMagic == 0xf5, "");
+  #endif
+
   for (int i = 0; i < Size; i += 8) {
     Value *p = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
     IRB.CreateStore(ConstantInt::get(IRB.getInt64Ty(), 0xf5f5f5f5f5f5f5f5ULL),
Index: unittests/ADT/SCCIteratorTest.cpp
===================================================================
--- unittests/ADT/SCCIteratorTest.cpp
+++ unittests/ADT/SCCIteratorTest.cpp
@@ -250,7 +250,7 @@
   typedef Graph<NUM_NODES> GT;
 
   /// Enumerate all graphs using NUM_GRAPHS bits.
-  assert(NUM_GRAPHS < sizeof(unsigned) * CHAR_BIT && "Too many graphs!");
+  static_assert(NUM_GRAPHS < sizeof(unsigned) * CHAR_BIT, "Too many graphs!");
   for (unsigned GraphDescriptor = 0; GraphDescriptor < (1U << NUM_GRAPHS);
        ++GraphDescriptor) {
     GT G;