add a new OPC_SwitchOpcode which is semantically equivalent
to a scope where every child starts with a CheckOpcode, but
executes more efficiently. Enhance DAGISelMatcherOpt to
form it.
This also fixes a bug in CheckOpcode: apparently the SDNodeInfo
objects are not pointer comparable, we have to compare the
enum name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97438 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 8b25def..1e3550c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1757,6 +1757,36 @@
if (N->getOpcode() != MatcherTable[MatcherIndex++]) break;
continue;
+ case OPC_SwitchOpcode: {
+ unsigned CurNodeOpcode = N.getOpcode();
+
+ unsigned SwitchStart = MatcherIndex-1;
+
+ unsigned CaseSize;
+ while (1) {
+ // Get the size of this case.
+ CaseSize = MatcherTable[MatcherIndex++];
+ if (CaseSize & 128)
+ CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
+ if (CaseSize == 0) break;
+
+ // If the opcode matches, then we will execute this case.
+ if (CurNodeOpcode == MatcherTable[MatcherIndex++])
+ break;
+
+ // Otherwise, skip over this case.
+ MatcherIndex += CaseSize;
+ }
+
+ // If we failed to match, bail out.
+ if (CaseSize == 0) break;
+
+ // Otherwise, execute the case we found.
+ DEBUG(errs() << " OpcodeSwitch from " << SwitchStart
+ << " to " << MatcherIndex << "\n");
+ continue;
+ }
+
case OPC_CheckMultiOpcode: {
unsigned NumOps = MatcherTable[MatcherIndex++];
bool OpcodeEquals = false;