From: Chris Lattner <sabre@nondot.org>
Date: Wed, 14 Dec 2005 19:25:30 +0000 (+0000)
Subject: When folding loads into ops, immediately replace uses of the op with the
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d4771840fd59654becb989675fbc0d0dc54c6dd4;p=oota-llvm.git

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 8077709c94a..031bf61c746 100644
--- 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();
   }