Completely rewrite support for the Value::use_* list. Now, all operations on

this list (except use_size()) are constant time.  Before the killUse method
(used whenever something stopped using a value) was linear time, and thus
very very slow for large programs.

This speeds GCCAS up _substantially_ on large programs: almost 2x for 176.gcc:

176.gcc:     77.07s -> 37.38s
177.mesa:     7.59s ->  5.57s
252.eon:     21.02s -> 19.52s (*)
253.perlbmk: 11.40s -> 13.05s
254.gap:      7.25s -> 7.42s

252.eon would speed up a whole lot more, but optimization time is being
dominated by the inlining pass, which needs to be fixed.

llvm-svn: 9160
This commit is contained in:
Chris Lattner 2003-10-16 16:53:07 +00:00
parent 0493113344
commit 09ef1749f7

View File

@ -35,7 +35,7 @@ Value::~Value() {
//
if (Uses.begin() != Uses.end()) {
std::cerr << "While deleting: " << *Ty << "%" << Name << "\n";
for (use_const_iterator I = Uses.begin(); I != Uses.end(); ++I)
for (use_const_iterator I = Uses.begin(), E = Uses.end(); I != E; ++I)
std::cerr << "Use still stuck around after Def is destroyed:"
<< **I << "\n";
}
@ -47,25 +47,6 @@ Value::~Value() {
}
void Value::replaceAllUsesWith(Value *New) {
assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
assert(New->getType() == getType() &&
"replaceAllUses of value with new value of different type!");
while (!Uses.empty()) {
User *Use = Uses.back();
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
// constant!
if (Constant *C = dyn_cast<Constant>(Use)) {
C->replaceUsesOfWithOnConstant(this, New);
} else {
Use->replaceUsesOfWith(this, New);
}
}
}
// uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
// except that it doesn't have all of the asserts. The asserts fail because we
// are half-way done resolving types, which causes some types to exist as two
@ -74,31 +55,24 @@ void Value::replaceAllUsesWith(Value *New) {
//
void Value::uncheckedReplaceAllUsesWith(Value *New) {
while (!Uses.empty()) {
User *Use = Uses.back();
Use &U = Uses.back();
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
// constant!
if (Constant *C = dyn_cast<Constant>(Use)) {
C->replaceUsesOfWithOnConstant(this, New, true);
if (Constant *C = dyn_cast<Constant>(U.getUser())) {
C->replaceUsesOfWithOnConstant(this, New);
} else {
Use->replaceUsesOfWith(this, New);
U.set(New);
}
}
}
void Value::replaceAllUsesWith(Value *New) {
assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
assert(New->getType() == getType() &&
"replaceAllUses of value with new value of different type!");
void Value::killUse(User *U) {
assert(U != 0 && "Null users are not allowed!");
unsigned i;
// Scan backwards through the uses list looking for the user. We do this
// because vectors like to be accessed on the end. This is incredibly
// important from a performance perspective.
for (i = Uses.size()-1; Uses[i] != U; --i)
/* empty */;
assert(i < Uses.size() && "Use not in uses list!!");
Uses[i] = Uses.back();
Uses.pop_back();
uncheckedReplaceAllUsesWith(New);
}
//===----------------------------------------------------------------------===//