RuntimeLibcalls: Use array initializers for default values

Author: arsenm

llvm/include/llvm/IR/RuntimeLibcalls.h

@@ -103,18 +103,20 @@ struct RuntimeLibcallsInfo {
 
 private:
   /// Stores the name each libcall.
-  const char *LibcallRoutineNames[RTLIB::UNKNOWN_LIBCALL + 1];
+  const char *LibcallRoutineNames[RTLIB::UNKNOWN_LIBCALL + 1] = {nullptr};
 
   /// Stores the CallingConv that should be used for each libcall.
-  CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL];
+  CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL] = {
+      CallingConv::C};
 
   /// The condition type that should be used to test the result of each of the
   /// soft floating-point comparison libcall against integer zero.
   ///
   // FIXME: This is only relevant for the handful of floating-point comparison
   // runtime calls; it's excessive to have a table entry for every single
   // opcode.
-  CmpInst::Predicate SoftFloatCompareLibcallPredicates[RTLIB::UNKNOWN_LIBCALL];
+  CmpInst::Predicate SoftFloatCompareLibcallPredicates[RTLIB::UNKNOWN_LIBCALL] =
+      {CmpInst::BAD_ICMP_PREDICATE};
 
   static bool darwinHasSinCosStret(const Triple &TT) {
     assert(TT.isOSDarwin() && "should be called with darwin triple");

llvm/lib/IR/RuntimeLibcalls.cpp

@@ -12,9 +12,6 @@ using namespace llvm;
 using namespace RTLIB;
 
 void RuntimeLibcallsInfo::initSoftFloatCmpLibcallPredicates() {
-  std::fill(SoftFloatCompareLibcallPredicates,
-            SoftFloatCompareLibcallPredicates + RTLIB::UNKNOWN_LIBCALL,
-            CmpInst::BAD_ICMP_PREDICATE);
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F32] = CmpInst::ICMP_EQ;
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F64] = CmpInst::ICMP_EQ;
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F128] = CmpInst::ICMP_EQ;
@@ -48,19 +45,12 @@ void RuntimeLibcallsInfo::initSoftFloatCmpLibcallPredicates() {
 /// Set default libcall names. If a target wants to opt-out of a libcall it
 /// should be placed here.
 void RuntimeLibcallsInfo::initLibcalls(const Triple &TT) {
-  std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames),
-            nullptr);
-
   initSoftFloatCmpLibcallPredicates();
 
 #define HANDLE_LIBCALL(code, name) setLibcallName(RTLIB::code, name);
 #include "llvm/IR/RuntimeLibcalls.def"
 #undef HANDLE_LIBCALL
 
-  // Initialize calling conventions to their default.
-  for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
-    setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
-
   // Use the f128 variants of math functions on x86
   if (TT.isX86() && TT.isGNUEnvironment()) {
     setLibcallName(RTLIB::REM_F128, "fmodf128");