Extending NaplesPU for 64-bit support

nu+ toolchain can be extended to support 64-bit operations. A git branch with full 64-bit support is provided. Consequently, if it is necessary to compile the toolchain supporting this extension, a checkout on llvm-7 branch is required.

Changes are related to both frontend and backend.

nu+ frontend modifications

nu+ frontend abstracts target informations through the TargetInfo class, extending it in the NuPlusTargetInfo implementation.

Target Definition

Since 64-bit operations require to support double-integer and double-floating-point formats, the following changes and additions are required in the target definition:

 class LLVM_LIBRARY_VISIBILITY NuPlusTargetInfo : public TargetInfo {
   ...
 public:
   NuPlusTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
     : TargetInfo(Triple) {
     ...
     resetDataLayout("e-m:e-p:32:32-i64:64:64-i32:32:32-f32:32:32-f64:64:64");
     LongDoubleWidth = 64;
     LongDoubleAlign = 64;
     DoubleWidth = 64;
     DoubleAlign = 64;
     LongWidth = 64;
     LongAlign = 64;
     LongLongWidth = 64;
     LongLongAlign = 64;
   }