commit e326332acd5fefb9854118603b4d07d4e44b64c5
author Roman Levenstein <romix.llvm@googlemail.com> Wed Mar 26 12:39:26 2008 +0000
committer Roman Levenstein <romix.llvm@googlemail.com> Wed Mar 26 12:39:26 2008 +0000
tree 40c4cfd27294a5496057047830a1f5c4b4fe432c
parent 8dba9afd086f72db920db81a3d73c7297390cda7

Use a linked data structure for the uses lists of an SDNode, just like 
LLVM Value/Use does and MachineRegisterInfo/MachineOperand does.
This allows constant time for all uses list maintenance operations.

The idea was suggested by Chris. Reviewed by Evan and Dan.
Patch is tested and approved by Dan.

On normal use-cases compilation speed is not affected. On very big basic
blocks there are compilation speedups in the range of 15-20% or even better. 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48822 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/DAGCombiner.cpp

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index e24a294..9f44c6a 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -78,7 +78,7 @@
     void AddUsersToWorkList(SDNode *N) {
       for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
            UI != UE; ++UI)
-        AddToWorkList(*UI);
+        AddToWorkList(UI->getUser());
     }
 
     /// visit - call the node-specific routine that knows how to fold each
@@ -2704,7 +2704,7 @@
   bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
   for (SDNode::use_iterator UI = N0.Val->use_begin(), UE = N0.Val->use_end();
        UI != UE; ++UI) {
-    SDNode *User = *UI;
+    SDNode *User = UI->getUser();
     if (User == N)
       continue;
     // FIXME: Only extend SETCC N, N and SETCC N, c for now.
@@ -2743,7 +2743,7 @@
     bool BothLiveOut = false;
     for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
          UI != UE; ++UI) {
-      SDNode *User = *UI;
+      SDNode *User = UI->getUser();
       for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
         SDOperand UseOp = User->getOperand(i);
         if (UseOp.Val == N && UseOp.ResNo == 0) {
@@ -3880,7 +3880,7 @@
   MVT::ValueType VT = N->getValueType(0);
   
   // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
-  if (N->hasOneUse() && (*N->use_begin())->getOpcode() == ISD::FP_ROUND)
+  if (N->hasOneUse() && (N->use_begin())->getOpcode() == ISD::FP_ROUND)
     return SDOperand();
 
   // fold (fp_extend c1fp) -> c1fp
@@ -4101,7 +4101,7 @@
   bool RealUse = false;
   for (SDNode::use_iterator I = Ptr.Val->use_begin(),
          E = Ptr.Val->use_end(); I != E; ++I) {
-    SDNode *Use = *I;
+    SDNode *Use = I->getUser();
     if (Use == N)
       continue;
     if (Use->isPredecessorOf(N))
@@ -4186,7 +4186,7 @@
   
   for (SDNode::use_iterator I = Ptr.Val->use_begin(),
          E = Ptr.Val->use_end(); I != E; ++I) {
-    SDNode *Op = *I;
+    SDNode *Op = I->getUser();
     if (Op == N ||
         (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
       continue;
@@ -4214,7 +4214,7 @@
       bool TryNext = false;
       for (SDNode::use_iterator II = BasePtr.Val->use_begin(),
              EE = BasePtr.Val->use_end(); II != EE; ++II) {
-        SDNode *Use = *II;
+        SDNode *Use = II->getUser();
         if (Use == Ptr.Val)
           continue;
 
@@ -4224,7 +4224,7 @@
           bool RealUse = false;
           for (SDNode::use_iterator III = Use->use_begin(),
                  EEE = Use->use_end(); III != EEE; ++III) {
-            SDNode *UseUse = *III;
+            SDNode *UseUse = III->getUser();
             if (!((UseUse->getOpcode() == ISD::LOAD &&
                    cast<LoadSDNode>(UseUse)->getBasePtr().Val == Use) ||
                   (UseUse->getOpcode() == ISD::STORE &&