When folding loads into ops, immediately replace uses of the op with the

load.  This reduces number of worklist iterations and avoid missing optimizations
depending on folding of things into sext_inreg nodes (which aren't supported by
all targets).
Tested by Regression/CodeGen/X86/extend.ll:test2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24712 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8077709c94abadfe26be8bd5fc5d70d879e7faaf..031bf61c746eb9e4233336dca7913708ce5e1265 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1554,7 +1554,7 @@ SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
     SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
                                        N0.getOperand(1), N0.getOperand(2),
                                        N0.getValueType());
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
               ExtLoad.getValue(1));
     return SDOperand();
@@ -1567,7 +1567,7 @@ SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
     SDOperand ExtLoad = DAG.getNode(ISD::SEXTLOAD, VT, N0.getOperand(0),
                                     N0.getOperand(1), N0.getOperand(2),
                                     N0.getOperand(3));
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
               ExtLoad.getValue(1));
     return SDOperand();
@@ -1596,7 +1596,7 @@ SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
     SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
                                        N0.getOperand(1), N0.getOperand(2),
                                        N0.getValueType());
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
               ExtLoad.getValue(1));
     return SDOperand();
@@ -1609,7 +1609,7 @@ SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
     SDOperand ExtLoad = DAG.getNode(ISD::ZEXTLOAD, VT, N0.getOperand(0),
                                     N0.getOperand(1), N0.getOperand(2),
                                     N0.getOperand(3));
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
               ExtLoad.getValue(1));
     return SDOperand();
@@ -1673,7 +1673,7 @@ SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
     SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
                                        N0.getOperand(1), N0.getOperand(2),
                                        EVT);
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
     return SDOperand();
   }
@@ -1684,7 +1684,7 @@ SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
     SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
                                        N0.getOperand(1), N0.getOperand(2),
                                        EVT);
-    WorkList.push_back(N);
+    CombineTo(N, ExtLoad);
     CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
     return SDOperand();
   }