[llvm-commits] [llvm] r46776 - in /llvm/trunk: lib/CodeGen/SelectionDAG/SelectionDAG.cpp test/CodeGen/X86/2008-02-05-ISelCrash.ll utils/TableGen/DAGISelEmitter.cpp

[Evan Cheng]

Author: evancheng
Date: Tue Feb  5 16:50:29 2008
New Revision: 46776

URL: http://llvm.org/viewvc/llvm-project?rev=46776&view=rev
Log:
Fix PR1975: dag isel emitter produces patterns that isel wrong flag result.

Added:
    llvm/trunk/test/CodeGen/X86/2008-02-05-ISelCrash.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/trunk/utils/TableGen/DAGISelEmitter.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=46776&r1=46775&r2=46776&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Tue Feb  5 16:50:29 2008
@@ -3183,10 +3183,6 @@
 void SelectionDAG::ReplaceAllUsesWith(SDOperand FromN, SDOperand To,
                                       DAGUpdateListener *UpdateListener) {
   SDNode *From = FromN.Val;
-  // FIXME: This works around a dag isel emitter bug.
-  if (From->getNumValues() == 1 && FromN.ResNo != 0)
-    return;  // FIXME: THIS IS BOGUS
-  
   assert(From->getNumValues() == 1 && FromN.ResNo == 0 && 
          "Cannot replace with this method!");
   assert(From != To.Val && "Cannot replace uses of with self");

Added: llvm/trunk/test/CodeGen/X86/2008-02-05-ISelCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-02-05-ISelCrash.ll?rev=46776&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-02-05-ISelCrash.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2008-02-05-ISelCrash.ll Tue Feb  5 16:50:29 2008
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llc -march=x86
+; PR1975
+
+ at nodes = external global i64		; <i64*> [#uses=2]
+
+define fastcc i32 @ab(i32 %alpha, i32 %beta) nounwind  {
+entry:
+	%tmp1 = load i64* @nodes, align 8		; <i64> [#uses=1]
+	%tmp2 = add i64 %tmp1, 1		; <i64> [#uses=1]
+	store i64 %tmp2, i64* @nodes, align 8
+	ret i32 0
+}

Modified: llvm/trunk/utils/TableGen/DAGISelEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/DAGISelEmitter.cpp?rev=46776&r1=46775&r2=46776&view=diff

==============================================================================
--- llvm/trunk/utils/TableGen/DAGISelEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/DAGISelEmitter.cpp Tue Feb  5 16:50:29 2008
@@ -305,6 +305,8 @@
   std::map<std::string, std::string> VariableMap;
   // Node to operator mapping
   std::map<std::string, Record*> OperatorMap;
+  // Name of the folded node which produces a flag.
+  std::pair<std::string, unsigned> FoldedFlag;
   // Names of all the folded nodes which produce chains.
   std::vector<std::pair<std::string, unsigned> > FoldedChains;
   // Original input chain(s).
@@ -587,8 +589,17 @@
       emitCheck(RootName + ".getOpcode() == " +
                 CInfo.getEnumName());
       EmitMatchCode(Child, Parent, RootName, ChainSuffix, FoundChain);
-      if (NodeHasProperty(Child, SDNPHasChain, CGP))
+      bool HasChain = false;
+      if (NodeHasProperty(Child, SDNPHasChain, CGP)) {
+        HasChain = true;
         FoldedChains.push_back(std::make_pair(RootName, CInfo.getNumResults()));
+      }
+      if (NodeHasProperty(Child, SDNPOutFlag, CGP)) {
+        assert(FoldedFlag.first == "" && FoldedFlag.second == 0 &&
+               "Pattern folded multiple nodes which produce flags?");
+        FoldedFlag = std::make_pair(RootName,
+                                    CInfo.getNumResults() + (unsigned)HasChain);
+      }
     } else {
       // If this child has a name associated with it, capture it in VarMap. If
       // we already saw this in the pattern, emit code to verify dagness.
@@ -1105,9 +1116,15 @@
         }
 
         if (NodeHasOutFlag) {
-          emitCode("ReplaceUses(SDOperand(N.Val, " +
-                   utostr(NumPatResults + (unsigned)InputHasChain)
-                   +"), InFlag);");
+          if (FoldedFlag.first != "") {
+            emitCode("ReplaceUses(SDOperand(" + FoldedFlag.first + ".Val, " +
+                     utostr(FoldedFlag.second) + "), InFlag);");
+          } else {
+            assert(NodeHasProperty(Pattern, SDNPOutFlag, CGP));
+            emitCode("ReplaceUses(SDOperand(N.Val, " +
+                     utostr(NumPatResults + (unsigned)InputHasChain)
+                     +"), InFlag);");
+          }
           NeedReplace = true;
         }