The code section for an ISR has a specific address.
Currently, whether a function is ISR or not is encoded in the section attribute for that function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96322 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp b/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
index 72f7c16..b015edd 100644
--- a/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
+++ b/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
@@ -106,8 +106,9 @@
   DbgInfo.BeginFunction(MF);
 
   // Now emit the instructions of function in its code section.
-  const MCSection *fCodeSection 
-    = getObjFileLowering().SectionForCode(CurrentFnSym->getName());
+  const MCSection *fCodeSection = 
+    getObjFileLowering().SectionForCode(CurrentFnSym->getName(), 
+                                        PAN::isISR(F->getSection()));
 
   // Start the Code Section.
   O <<  "\n";
diff --git a/lib/Target/PIC16/PIC16ABINames.h b/lib/Target/PIC16/PIC16ABINames.h
index e18ddf1..b0b9318 100644
--- a/lib/Target/PIC16/PIC16ABINames.h
+++ b/lib/Target/PIC16/PIC16ABINames.h
@@ -325,6 +325,19 @@
 
       return o.str();
     } 
+
+    // Return true if the current function is an ISR
+    inline static bool isISR(const std::string SectName) {
+       if (SectName.find("interrupt") != std::string::npos)
+         return true;
+
+       return false;
+    }
+
+    // Return the address for ISR starts in rom.
+    inline static std::string getISRAddr(void) {
+      return "0x4";
+    }
   }; // class PAN.
 } // end namespace llvm;
 
diff --git a/lib/Target/PIC16/PIC16TargetObjectFile.cpp b/lib/Target/PIC16/PIC16TargetObjectFile.cpp
index d7cfe02..b891c18 100644
--- a/lib/Target/PIC16/PIC16TargetObjectFile.cpp
+++ b/lib/Target/PIC16/PIC16TargetObjectFile.cpp
@@ -315,8 +315,12 @@
 
 // Interface used by AsmPrinter to get a code section for a function.
 const PIC16Section *
-PIC16TargetObjectFile::SectionForCode(const std::string &FnName) const {
+PIC16TargetObjectFile::SectionForCode(const std::string &FnName,
+                                      bool isISR) const {
   const std::string &sec_name = PAN::getCodeSectionName(FnName);
+  // If it is ISR, its code section starts at a specific address.
+  if (isISR)
+    return getPIC16Section(sec_name, CODE, PAN::getISRAddr());
   return getPIC16Section(sec_name, CODE);
 }
 
diff --git a/lib/Target/PIC16/PIC16TargetObjectFile.h b/lib/Target/PIC16/PIC16TargetObjectFile.h
index 0b0ad43..cf8bf84 100644
--- a/lib/Target/PIC16/PIC16TargetObjectFile.h
+++ b/lib/Target/PIC16/PIC16TargetObjectFile.h
@@ -137,7 +137,8 @@
 
 
     /// Return a code section for a function.
-    const PIC16Section *SectionForCode (const std::string &FnName) const;
+    const PIC16Section *SectionForCode (const std::string &FnName,
+                                        bool isISR) const;
 
     /// Return a frame section for a function.
     const PIC16Section *SectionForFrame (const std::string &FnName) const;