Slightly revise iOS additions

driver/main.cpp

@@ -817,7 +817,6 @@ void registerPredefinedTargetVersions() {
     VersionCondition::addPredefinedGlobalIdent("Posix");
     VersionCondition::addPredefinedGlobalIdent("CppRuntime_Clang");
     break;
-  break;
   default:
     if (triple.getEnvironment() == llvm::Triple::Android) {
       VersionCondition::addPredefinedGlobalIdent("Android");

gen/abi-aarch64.cpp

@@ -9,6 +9,7 @@
 //
 // The Procedure Call Standard can be found here:
 // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055b/IHI0055B_aapcs64.pdf
+// https://github.com/ARM-software/software-standards/blob/master/abi/aapcs64/aapcs64.rst
 //
 //===----------------------------------------------------------------------===//
 
@@ -20,7 +21,7 @@
 #include "gen/abi-generic.h"
 
 /**
- * The AACPS64 uses a special native va_list type:
+ * The AAPCS64 uses a special native va_list type:
  *
  * typedef struct __va_list {
  *     void *__stack; // next stack param
@@ -38,19 +39,15 @@
  */
 struct AArch64TargetABI : TargetABI {
 private:
+  const bool isDarwin;
   IndirectByvalRewrite byvalRewrite;
   HFAToArray hfaToArray;
   CompositeToArray64 compositeToArray64;
   IntegerRewrite integerRewrite;
 
-  bool isVaList(Type *t) {
-    if (global.params.targetTriple->isOSDarwin())
-    {
-      return t->ty == Tpointer &&
-        static_cast<TypePointer*>(t)->next->ty == Tchar;
-    }
-    else
-      return t->ty == Tstruct && strcmp(t->toPrettyChars(true),
+  bool isAAPCS64VaList(Type *t) {
+    return !isDarwin && t->ty == Tstruct &&
+           strcmp(t->toPrettyChars(true),
                   "ldc.internal.vararg.std.__va_list") == 0;
   }
 
@@ -61,6 +58,8 @@ private:
   }
 
 public:
+  AArch64TargetABI() : isDarwin(global.params.targetTriple->isOSDarwin()) {}
+
   bool returnInArg(TypeFunction *tf, bool) override {
     if (tf->isref) {
       return false;
@@ -95,7 +94,7 @@ public:
     if (t->ty != Tstruct && t->ty != Tsarray)
       return;
 
-    if (!isReturnVal && isVaList(t)) {
+    if (!isReturnVal && isAAPCS64VaList(t)) {
       // compiler magic: pass va_list args implicitly by reference
       arg.byref = true;
       arg.ltype = arg.ltype->getPointerTo();
@@ -121,16 +120,15 @@ public:
   }
 
   Type *vaListType() override {
-    if (global.params.targetTriple->isOSDarwin())
-      return Type::tchar->pointerTo();
-    else {
+    if (isDarwin)
+      return TargetABI::vaListType(); // char*
+
     // We need to pass the actual va_list type for correct mangling. Simply
     // using TypeIdentifier here is a bit wonky but works, as long as the name
     // is actually available in the scope (this is what DMD does, so if a better
     // solution is found there, this should be adapted).
     return createTypeIdentifier(Loc(), Identifier::idPool("__va_list"));
   }
-  }
 
   const char *objcMsgSendFunc(Type *ret, IrFuncTy &fty) override {
     // see objc/message.h for objc_msgSend selection rules

ir/irtype.cpp

@@ -48,24 +48,27 @@ LLType *IrTypeBasic::getComplexType(llvm::LLVMContext &ctx, LLType *type) {
 
 namespace {
 llvm::Type *getReal80Type(llvm::LLVMContext &ctx) {
-  llvm::Triple::ArchType const a = global.params.targetTriple->getArch();
-  bool const anyX86 = (a == llvm::Triple::x86) || (a == llvm::Triple::x86_64);
-  bool const anyAarch64 =
+  const auto &triple = *global.params.targetTriple;
+  const auto a = triple.getArch();
+  const bool anyX86 = (a == llvm::Triple::x86) || (a == llvm::Triple::x86_64);
+  const bool anyAarch64 =
       (a == llvm::Triple::aarch64) || (a == llvm::Triple::aarch64_be);
-  bool const isAndroid =
-      global.params.targetTriple->getEnvironment() == llvm::Triple::Android;
+  const bool isAndroid = triple.getEnvironment() == llvm::Triple::Android;
 
-  // only x86 has 80bit float - but no support with MS C Runtime!
-  if (anyX86 && !global.params.targetTriple->isWindowsMSVCEnvironment() &&
-      !isAndroid) {
+  // Only x86 has 80-bit extended precision.
+  // MSVC and Android/x86 use double precision, Android/x64 quadruple.
+  if (anyX86 && !triple.isWindowsMSVCEnvironment() && !isAndroid) {
     return llvm::Type::getX86_FP80Ty(ctx);
   }
 
-  if ((anyAarch64 && !global.params.targetTriple->isOSDarwin()) ||
+  // AArch64 targets except Darwin (64-bit) use 128-bit quadruple precision.
+  // FIXME: PowerPC, SystemZ, ...
+  if ((anyAarch64 && !triple.isOSDarwin()) ||
       (isAndroid && a == llvm::Triple::x86_64)) {
     return llvm::Type::getFP128Ty(ctx);
   }
 
+  // 64-bit double precision for all other targets.
   return llvm::Type::getDoubleTy(ctx);
 }
 }