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Since LLVM uses structure type equivalence, it isn't useful to keep around

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multiple type names for the same structural type.  Make DTE eliminate all
but one of the type names


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11879 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-02-26 20:02:23 +00:00
parent c230978a82
commit 4f77caaa3d
1 changed files with 11 additions and 10 deletions
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21
lib/Transforms/IPO/DeadTypeElimination.cpp
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@ -49,12 +49,12 @@ Pass *llvm::createDeadTypeEliminationPass() {
// ShouldNukeSymtabEntry - Return true if this module level symbol table entry
// should be eliminated.
//
static inline bool ShouldNukeSymtabEntry(const std::pair<std::string,Value*>&E){
static inline bool ShouldNukeSymtabEntry(const Type *Ty){
// Nuke all names for primitive types!
if (cast<Type>(E.second)->isPrimitiveType()) return true;
if (Ty->isPrimitiveType()) return true;
// Nuke all pointers to primitive types as well...
if (const PointerType *PT = dyn_cast<PointerType>(E.second))
if (const PointerType *PT = dyn_cast<PointerType>(Ty))
if (PT->getElementType()->isPrimitiveType()) return true;
return false;
@ -69,8 +69,7 @@ bool DTE::run(Module &M) {
bool Changed = false;
SymbolTable &ST = M.getSymbolTable();
const std::set<const Type *> &UsedTypes =
getAnalysis<FindUsedTypes>().getTypes();
std::set<const Type *> UsedTypes = getAnalysis<FindUsedTypes>().getTypes();
// Check the symbol table for superfluous type entries...
//
@ -79,18 +78,20 @@ bool DTE::run(Module &M) {
if (STI != ST.end()) {
// Loop over all entries in the type plane...
SymbolTable::VarMap &Plane = STI->second;
for (SymbolTable::VarMap::iterator PI = Plane.begin(); PI != Plane.end();)
for (SymbolTable::VarMap::iterator PI = Plane.begin(); PI != Plane.end();) {
// If this entry should be unconditionally removed, or if we detect that
// the type is not used, remove it.
if (ShouldNukeSymtabEntry(*PI) ||
!UsedTypes.count(cast<Type>(PI->second))) {
SymbolTable::VarMap::iterator PJ = PI++;
Plane.erase(PJ);
const Type *RHS = cast<Type>(PI->second);
if (ShouldNukeSymtabEntry(RHS) || !UsedTypes.count(RHS)) {
Plane.erase(PI++);
++NumKilled;
Changed = true;
} else {
++PI;
// We only need to leave one name for each type.
UsedTypes.erase(RHS);
}
}
}
return Changed;