Emit banksel and movlp instructions.

Split large global data (both initialized and un-initialized) into multiple sections of <= 80 bytes.
Provide routines to manage PIC16 ABI naming conventions.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71073 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 203 insertions, 0 deletions

diff --git a/lib/Target/PIC16/PIC16TargetAsmInfo.cpp b/lib/Target/PIC16/PIC16TargetAsmInfo.cpp
index 6b0a0d0..ac4039b 100644
--- a/lib/Target/PIC16/PIC16TargetAsmInfo.cpp
+++ b/lib/Target/PIC16/PIC16TargetAsmInfo.cpp
@@ -14,6 +14,8 @@
 #include "PIC16TargetAsmInfo.h"
 #include "PIC16TargetMachine.h"
 #include "llvm/GlobalValue.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/DerivedTypes.h"
 
 using namespace llvm;
 
@@ -61,3 +63,204 @@ const char *PIC16TargetAsmInfo::getASDirective(unsigned size,
     return NULL;
 }
 
+const Section *
+PIC16TargetAsmInfo::getBSSSectionForGlobal(const GlobalVariable *GV) const {
+  assert (GV->hasInitializer() && "This global doesn't need space");
+  Constant *C = GV->getInitializer();
+  assert (C->isNullValue() && "Unitialized globals has non-zero initializer");
+
+  // Find how much space this global needs.
+  const TargetData *TD = TM.getTargetData();
+  const Type *Ty = C->getType(); 
+  unsigned ValSize = TD->getTypePaddedSize(Ty);
+ 
+  // Go through all BSS Sections and assign this variable
+  // to the first available section having enough space.
+  PIC16Section *FoundBSS = NULL;
+  for (unsigned i = 0; i < BSSSections.size(); i++) {
+    if (DataBankSize - BSSSections[i]->Size >= ValSize) {
+      FoundBSS = BSSSections[i];
+      break;
+    }
+  }
+
+  // No BSS section spacious enough was found. Crate a new one.
+  if (! FoundBSS) {
+    char *name = new char[32];
+    sprintf (name, "udata.%d.# UDATA", BSSSections.size());
+    const Section *NewSection = getNamedSection (name);
+
+    FoundBSS = new PIC16Section(NewSection);
+
+    // Add this newly created BSS section to the list of BSSSections.
+    BSSSections.push_back(FoundBSS);
+  }
+  
+  // Insert the GV into this BSS.
+  FoundBSS->Items.push_back(GV);
+  FoundBSS->Size += ValSize;
+
+  // We can't do this here because GV is const .
+  // const std::string SName = FoundBSS->S_->getName();
+  // GV->setSection(SName);
+
+  return FoundBSS->S_;
+} 
+
+const Section *
+PIC16TargetAsmInfo::getIDATASectionForGlobal(const GlobalVariable *GV) const {
+  assert (GV->hasInitializer() && "This global doesn't need space");
+  Constant *C = GV->getInitializer();
+  assert (!C->isNullValue() && "initialized globals has zero initializer");
+  assert (GV->getType()->getAddressSpace() == PIC16ISD::RAM_SPACE &&
+          "can split initialized RAM data only");
+
+  // Find how much space this global needs.
+  const TargetData *TD = TM.getTargetData();
+  const Type *Ty = C->getType(); 
+  unsigned ValSize = TD->getTypePaddedSize(Ty);
+ 
+  // Go through all IDATA Sections and assign this variable
+  // to the first available section having enough space.
+  PIC16Section *FoundIDATA = NULL;
+  for (unsigned i = 0; i < IDATASections.size(); i++) {
+    if ( DataBankSize - IDATASections[i]->Size >= ValSize) {
+      FoundIDATA = IDATASections[i]; 
+      break;
+    }
+  }
+
+  // No IDATA section spacious enough was found. Crate a new one.
+  if (! FoundIDATA) {
+    char *name = new char[32];
+    sprintf (name, "idata.%d.# IDATA", IDATASections.size());
+    const Section *NewSection = getNamedSection (name);
+
+    FoundIDATA = new PIC16Section(NewSection);
+
+    // Add this newly created IDATA section to the list of IDATASections.
+    IDATASections.push_back(FoundIDATA);
+  }
+  
+  // Insert the GV into this IDATA.
+  FoundIDATA->Items.push_back(GV);
+  FoundIDATA->Size += ValSize;
+
+  // We can't do this here because GV is const .
+  // GV->setSection(FoundIDATA->S->getName());
+
+  return FoundIDATA->S_;
+} 
+
+// Override default implementation to put the true globals into
+// multiple data sections if required.
+const Section*
+PIC16TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV1) const {
+  // We select the section based on the initializer here, so it really
+  // has to be a GlobalVariable.
+  if (!isa<GlobalVariable>(GV1))
+    return TargetAsmInfo::SelectSectionForGlobal(GV1);
+
+  const GlobalVariable *GV = dyn_cast<GlobalVariable>(GV1); 
+  // We are only dealing with true globals here. So names with a "."
+  // are local globals. Also declarations are not entertained.
+  std::string name = GV->getName();
+  if (name.find(".auto.") != std::string::npos
+      || name.find(".arg.") != std::string::npos || !GV->hasInitializer())
+    return TargetAsmInfo::SelectSectionForGlobal(GV);
+
+  const Constant *C = GV->getInitializer();
+  // See if this is an uninitialized global.
+  if (C->isNullValue()) 
+    return getBSSSectionForGlobal(GV); 
+
+  // This is initialized data. We only deal with initialized data in RAM.
+  if (GV->getType()->getAddressSpace() == PIC16ISD::RAM_SPACE) 
+    return getIDATASectionForGlobal(GV);
+
+  // Else let the default implementation take care of it.
+  return TargetAsmInfo::SelectSectionForGlobal(GV);
+}
+
+void PIC16TargetAsmInfo::SetSectionForGVs(Module &M) {
+  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I) {
+    if (!I->hasInitializer())   // External global require no code.
+      continue;
+
+    // Any variables reaching here with "." in its name is a local scope
+    // variable and should not be printed in global data section.
+    std::string name = I->getName();
+    if (name.find(".auto.") != std::string::npos
+      || name.find(".arg.") != std::string::npos)
+      continue;
+    int AddrSpace = I->getType()->getAddressSpace();
+
+    if (AddrSpace == PIC16ISD::RAM_SPACE)
+      I->setSection(SectionForGlobal(I)->getName());
+  }
+}
+
+
+// Helper routine.
+// Func name starts after prefix and followed by a .
+static std::string getFuncNameForSym(const std::string &Sym, 
+                                      PIC16ABINames::IDs PrefixType) {
+
+  const char *prefix = getIDName (PIC16ABINames::PREFIX_SYMBOL);
+
+  // This name may or may not start with prefix;
+  // Func names start after prfix in that case.
+  size_t func_name_start = 0;
+  if (Sym.find(prefix, 0, strlen(prefix)) != std::string::npos)
+    func_name_start = strlen(prefix);
+
+  // Position of the . after func name.
+  size_t func_name_end = Sym.find ('.', func_name_start);
+
+  return Sym.substr (func_name_start, func_name_end);
+}
+
+// Helper routine to create a section name given the section prefix
+// and func name.
+static std::string
+getSectionNameForFunc (const std::string &Fname,
+                       const PIC16ABINames::IDs sec_id) {
+  std::string sec_id_string = getIDName (sec_id);
+  return sec_id_string + "." + Fname + ".#";
+}
+
+
+// Get the section for the given external symbol names.
+// This function is meant for only mangled external symbol names.
+std::string 
+llvm::getSectionNameForSym(const std::string &Sym) {
+  std::string SectionName;
+
+  PIC16ABINames::IDs id = getID (Sym);
+  std::string Fname = getFuncNameForSym (Sym, id);
+
+  switch (id) {
+    default : assert (0 && "Could not determine external symbol type");
+    case PIC16ABINames::FUNC_FRAME: 
+    case PIC16ABINames::FUNC_RET: 
+    case PIC16ABINames::FUNC_TEMPS: 
+    case PIC16ABINames::FUNC_ARGS:  {
+      return getSectionNameForFunc (Fname, PIC16ABINames::FRAME_SECTION);
+    }
+    case PIC16ABINames::FUNC_AUTOS: { 
+      return getSectionNameForFunc (Fname, PIC16ABINames::AUTOS_SECTION);
+    }
+  }
+}
+
+PIC16TargetAsmInfo::~PIC16TargetAsmInfo() {
+  
+  for (unsigned i = 0; i < BSSSections.size(); i++) {
+      delete BSSSections[i]; 
+  }
+
+  for (unsigned i = 0; i < IDATASections.size(); i++) {
+      delete IDATASections[i]; 
+  }
+}