Fix PR1975: dag isel emitter produces patterns that isel wrong flag result.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46776 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 11b289b..4b68fb7 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -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");
diff --git a/test/CodeGen/X86/2008-02-05-ISelCrash.ll b/test/CodeGen/X86/2008-02-05-ISelCrash.ll
new file mode 100644
index 0000000..6885cf1
--- /dev/null
+++ b/test/CodeGen/X86/2008-02-05-ISelCrash.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llc -march=x86
+; PR1975
+
+@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
+}
diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index dda56c0..7a1920c 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -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;
}