AMDGPU: Avoid emitting "true" predicates

Empty condition strings are considerde always true. This removes a lot
of clutter from the generated matcher tables.

This shrinks the source size of AMDGPUGenDAGISel.inc from 7.3M to
6.1M.

llvm-svn: 367326

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index c8f710d..75890d27 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -1373,8 +1373,10 @@ getPatternComplexity(const CodeGenDAGPatterns &CGP) const {
 ///
 std::string PatternToMatch::getPredicateCheck() const {
   SmallVector<const Predicate*,4> PredList;
-  for (const Predicate &P : Predicates)
-    PredList.push_back(&P);
+  for (const Predicate &P : Predicates) {
+    if (!P.getCondString().empty())
+      PredList.push_back(&P);
+  }
   llvm::sort(PredList, deref<llvm::less>());
 
   std::string Check;