From: Chris Lattner <sabre@nondot.org>
Date: Mon, 1 Mar 2010 07:27:07 +0000 (+0000)
Subject: Emit a redundant check for immediates at root context, e.g. (imm 0).
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bd8965a7d9e0ed34bc3a357c2f710de5fbdda36f;p=oota-llvm.git

Emit a redundant check for immediates at root context, e.g. (imm 0).
This allows formation of OpcodeSwitch for top level patterns, in
particular on X86.  This saves about 1K of data space in the x86
table and makes the dispatch much more efficient.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97440 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/utils/TableGen/DAGISelMatcher.h b/utils/TableGen/DAGISelMatcher.h
index 8b6b3229142..1634cd2ecdd 100644
--- a/utils/TableGen/DAGISelMatcher.h
+++ b/utils/TableGen/DAGISelMatcher.h
@@ -55,7 +55,6 @@ public:
     CheckPredicate,       // Fail if node predicate fails.
     CheckOpcode,          // Fail if not opcode.
     SwitchOpcode,         // Dispatch based on opcode.
-    CheckMultiOpcode,     // Fail if not in opcode list.
     CheckType,            // Fail if not correct type.
     CheckChildType,       // Fail if child has wrong type.
     CheckInteger,         // Fail if wrong val.
diff --git a/utils/TableGen/DAGISelMatcherGen.cpp b/utils/TableGen/DAGISelMatcherGen.cpp
index 95cfa5b251c..62442d0c22c 100644
--- a/utils/TableGen/DAGISelMatcherGen.cpp
+++ b/utils/TableGen/DAGISelMatcherGen.cpp
@@ -205,8 +205,17 @@ void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
     AddMatcher(new CheckPredicateMatcher(N->getPredicateFns()[i]));
   
   // Direct match against an integer constant.
-  if (IntInit *II = dynamic_cast<IntInit*>(N->getLeafValue()))
+  if (IntInit *II = dynamic_cast<IntInit*>(N->getLeafValue())) {
+    // If this is the root of the dag we're matching, we emit a redundant opcode
+    // check to ensure that this gets folded into the normal top-level
+    // OpcodeSwitch.
+    if (N == Pattern.getSrcPattern()) {
+      const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("imm"));
+      AddMatcher(new CheckOpcodeMatcher(NI));
+    }
+
     return AddMatcher(new CheckIntegerMatcher(II->getValue()));
+  }
   
   DefInit *DI = dynamic_cast<DefInit*>(N->getLeafValue());
   if (DI == 0) {