replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix bug in LICM that caused the previous big win. :( 

llvm-svn: 3980
This commit is contained in:
Chris Lattner 2002-09-29 22:26:07 +00:00
parent 5b5dd671b2
commit 05e86302f4
1 changed files with 16 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
llvm/lib/Transforms/Scalar/LICM.cpp
View File

@ -14,6 +14,7 @@
#include "llvm/Support/InstVisitor.h"
#include "Support/STLExtras.h"
#include "Support/StatisticReporter.h"
#include "llvm/Assembly/Writer.h"
#include <algorithm>
using std::string;
@ -53,15 +54,15 @@ namespace {
///
void HoistRegion(DominatorTree::Node *N);
/// inCurrentLoop - Little predicate that returns false if the specified
/// basic block is in a subloop of the current one, not the current one
/// itself.
/// inSubLoop - Little predicate that returns true if the specified basic
/// block is in a subloop of the current one, not the current one itself.
///
bool inCurrentLoop(BasicBlock *BB) {
bool inSubLoop(BasicBlock *BB) {
assert(CurLoop->contains(BB) && "Only valid if BB is IN the loop");
for (unsigned i = 0, e = CurLoop->getSubLoops().size(); i != e; ++i)
if (CurLoop->getSubLoops()[i]->contains(BB))
return false; // A subloop actually contains this block!
return true;
return true; // A subloop actually contains this block!
return false;
}
/// hoist - When an instruction is found to only use loop invariant operands
@ -168,11 +169,13 @@ void LICM::visitLoop(Loop *L) {
void LICM::HoistRegion(DominatorTree::Node *N) {
assert(N != 0 && "Null dominator tree node?");
// This subregion is not in the loop, it has already been already been hoisted
if (!inCurrentLoop(N->getNode()))
return;
// If this subregion is not in the top level loop at all, exit.
if (!CurLoop->contains(N->getNode())) return;
visit(*N->getNode());
// Only need to hoist the contents of this block if it is not part of a
// subloop (which would already have been hoisted)
if (!inSubLoop(N->getNode()))
visit(*N->getNode());
const std::vector<DominatorTree::Node*> &Children = N->getChildren();
for (unsigned i = 0, e = Children.size(); i != e; ++i)
@ -184,9 +187,9 @@ void LICM::HoistRegion(DominatorTree::Node *N) {
/// that is safe to hoist, this instruction is called to do the dirty work.
///
void LICM::hoist(Instruction &Inst) {
DEBUG(std::cerr << "LICM hoisting: " << Inst);
BasicBlock *Header = CurLoop->getHeader();
DEBUG(std::cerr << "LICM hoisting to";
WriteAsOperand(std::cerr, Preheader, false);
std::cerr << ": " << Inst);
// Remove the instruction from its current basic block... but don't delete the
// instruction.