Merge pull request swiftlang#20474 from tinysun212/pr-swiftc-cygwin-3

Author: swift-ci

lib/IRGen/GenClangType.cpp

@@ -324,7 +324,9 @@ ClangTypeConverter::reverseBuiltinTypeMapping(IRGenModule &IGM,
   // On 64-bit Windows, no C type is imported as an Int or UInt; CLong is
   // imported as an Int32 and CLongLong as an Int64. Therefore, manually
   // add mappings to C for Int and UInt.
-  if (IGM.Triple.isOSWindows() && IGM.Triple.isArch64Bit()) {
+  // On 64-bit Cygwin, no manual mapping is required.
+  if (IGM.Triple.isOSWindows() && !IGM.Triple.isWindowsCygwinEnvironment() &&
+      IGM.Triple.isArch64Bit()) {
     // Map UInt to uintptr_t
     auto swiftUIntType = getNamedSwiftType(stdlib, "UInt");
     auto clangUIntPtrType = ctx.getCanonicalType(ctx.getUIntPtrType());

lib/IRGen/IRGen.cpp

@@ -676,10 +676,17 @@ swift::createTargetMachine(IRGenOptions &Opts, ASTContext &Ctx) {
   }
 
 
+  // On Cygwin 64 bit, dlls are loaded above the max address for 32 bits.
+  // This means that the default CodeModel causes generated code to segfault
+  // when run.
+  Optional<CodeModel::Model> cmodel = None;
+  if (EffectiveTriple.isArch64Bit() && EffectiveTriple.isWindowsCygwinEnvironment())
+    cmodel = CodeModel::Large;
+
   // Create a target machine.
   llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
       EffectiveTriple.str(), CPU, targetFeatures, TargetOpts, Reloc::PIC_,
-      None, OptLevel);
+      cmodel, OptLevel);
   if (!TargetMachine) {
     Ctx.Diags.diagnose(SourceLoc(), diag::no_llvm_target,
                        EffectiveTriple.str(), "no LLVM target machine");