driver/main + gen/target: fix environment detection for ppc64 real type

Author: liushuyu

driver/main.cpp

@@ -683,9 +683,13 @@ void registerPredefinedTargetVersions() {
     if (triple.getOS() == llvm::Triple::Linux) {
       VersionCondition::addPredefinedGlobalIdent(
           triple.getArch() == llvm::Triple::ppc64 ? "ELFv1" : "ELFv2");
-      if (opts::mABI == "ieeelongdouble" && triple.isOSGlibc()) {
-        // Only GLibc needs this for IEEELongDouble
-        VersionCondition::addPredefinedGlobalIdent("D_PPCUseIEEE128");
+      if (opts::mABI == "ieeelongdouble") {
+        if (triple.getEnvironment() == llvm::Triple::GNU) {
+          // Only GLibc needs this for IEEELongDouble
+          VersionCondition::addPredefinedGlobalIdent("D_PPCUseIEEE128");
+        } else {
+          warning(Loc(), "float ABI 'ieeelongdouble' is not supported by the target system");
+        }
       }
     }
     break;

gen/target.cpp

@@ -266,10 +266,16 @@ const char *TargetCPP::typeMangle(Type *t) {
                         triple.getArch() == llvm::Triple::x86_64;
     if (triple.getArch() == llvm::Triple::ppc64 ||
         triple.getArch() == llvm::Triple::ppc64le) {
-      if (opts::mABI == "ieeelongdouble") {
+      if (opts::mABI == "ieeelongdouble" &&
+          triple.getEnvironment() == llvm::Triple::GNU) {
         return "u9__ieee128";
       }
-      return "g";
+      if (size(t) == 16) {
+        // IBM long double
+        return "g";
+      }
+      // fall back to 64-bit double type
+      return "e";
     }
     return isAndroidX64 ? "g" : "e";
   }