Subzero: Fix a bug in postLower().

In -O2 mode, postLower() is supposed to iterate over just the instructions that were most recently added. Instead, it was iterating all the way to the end of the block, also post-lowering high-level ICE instructions that hadn't yet been lowered. This was basically harmless, given that the spec2k asm code is identical after this patch, but it improves performance. BUG= none R=jvoung@chromium.org Review URL: https://codereview.chromium.org/721333004

Subzero: Fix a bug in postLower().
5d2fa0cf · Jim Stichnoth · 9d801a01 · 5d2fa0cf · 5d2fa0cf
Commit 5d2fa0cf authored Dec 01, 2014 by Jim Stichnoth
Hide whitespace changes
Inline Side-by-side

Showing with 3 additions and 5 deletions

IceTargetLowering.h src/IceTargetLowering.h +1 -3

IceTargetLoweringX8632.cpp src/IceTargetLoweringX8632.cpp +2 -2

No files found.
--- a/src/IceTargetLowering.h
+++ b/src/IceTargetLowering.h
@@ -56,10 +56,8 @@ public:
  CfgNode *getNode() const { return Node; }
  bool atEnd() const { return Cur == End; }
  InstList::iterator getCur() const { return Cur; }
+  InstList::iterator getNext() const { return Next; }
  InstList::iterator getEnd() const { return End; }
-  // Adaptor to enable range-based for loops.
-  InstList::iterator begin() const { return getCur(); }
-  InstList::iterator end() const { return getEnd(); }
  void insert(Inst *Inst);
  Inst *getLastInserted() const;
  void advanceCur() { Cur = Next; }

--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -4299,7 +4299,7 @@ void TargetX8632::lowerPhiAssignments(CfgNode *Node,
  }

  // Add the terminator branch instruction to the end.
-  Context.setInsertPoint(Context.end());
+  Context.setInsertPoint(Context.getEnd());
  _br(Succ);
 }

@@ -4509,7 +4509,7 @@ void TargetX8632::postLower() {
    return;
  // Find two-address non-SSA instructions where Dest==Src0, and set
  // the DestNonKillable flag to keep liveness analysis consistent.
-  for (auto Inst = Context.begin(), E = Context.end(); Inst != E; ++Inst) {
+  for (auto Inst = Context.getCur(), E = Context.getNext(); Inst != E; ++Inst) {
    if (Inst->isDeleted())
      continue;
    if (Variable *Dest = Inst->getDest()) {