[llvm] r367016 - [IR][PatternMatch] introduce m_Unless() matcher

[Roman Lebedev via llvm-commits]

Author: lebedevri
Date: Thu Jul 25 06:34:14 2019
New Revision: 367016

URL: http://llvm.org/viewvc/llvm-project?rev=367016&view=rev
Log:
[IR][PatternMatch] introduce m_Unless() matcher

Summary:
I don't think it already exists? I don't see it at least.
It is important to have it because else we'll do some checks after `match()`,
and that may result in missed folds in commutative nodes.

Reviewers: spatel, craig.topper, RKSimon, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64037

Modified:
    llvm/trunk/include/llvm/IR/PatternMatch.h
    llvm/trunk/unittests/IR/PatternMatch.cpp

Modified: llvm/trunk/include/llvm/IR/PatternMatch.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/PatternMatch.h?rev=367016&r1=367015&r2=367016&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/PatternMatch.h (original)
+++ llvm/trunk/include/llvm/IR/PatternMatch.h Thu Jul 25 06:34:14 2019
@@ -88,6 +88,20 @@ inline class_match<UndefValue> m_Undef()
 /// Match an arbitrary Constant and ignore it.
 inline class_match<Constant> m_Constant() { return class_match<Constant>(); }
 
+/// Inverting matcher
+template <typename Ty> struct match_unless {
+  Ty M;
+
+  match_unless(const Ty &Matcher) : M(Matcher) {}
+
+  template <typename ITy> bool match(ITy *V) { return !M.match(V); }
+};
+
+/// Match if the inner matcher does *NOT* match.
+template <typename Ty> inline match_unless<Ty> m_Unless(const Ty &M) {
+  return match_unless<Ty>(M);
+}
+
 /// Matching combinators
 template <typename LTy, typename RTy> struct match_combine_or {
   LTy L;

Modified: llvm/trunk/unittests/IR/PatternMatch.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/PatternMatch.cpp?rev=367016&r1=367015&r2=367016&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/PatternMatch.cpp (original)
+++ llvm/trunk/unittests/IR/PatternMatch.cpp Thu Jul 25 06:34:14 2019
@@ -454,6 +454,22 @@ TEST_F(PatternMatchTest, SpecificIntSLE)
           .match(NegOne));
 }
 
+TEST_F(PatternMatchTest, Unless) {
+  Value *X = IRB.CreateAdd(IRB.getInt32(1), IRB.getInt32(0));
+
+  EXPECT_TRUE(m_Add(m_One(), m_Zero()).match(X));
+  EXPECT_FALSE(m_Add(m_Zero(), m_One()).match(X));
+
+  EXPECT_FALSE(m_Unless(m_Add(m_One(), m_Zero())).match(X));
+  EXPECT_TRUE(m_Unless(m_Add(m_Zero(), m_One())).match(X));
+
+  EXPECT_TRUE(m_c_Add(m_One(), m_Zero()).match(X));
+  EXPECT_TRUE(m_c_Add(m_Zero(), m_One()).match(X));
+
+  EXPECT_FALSE(m_Unless(m_c_Add(m_One(), m_Zero())).match(X));
+  EXPECT_FALSE(m_Unless(m_c_Add(m_Zero(), m_One())).match(X));
+}
+
 TEST_F(PatternMatchTest, CommutativeDeferredValue) {
   Value *X = IRB.getInt32(1);
   Value *Y = IRB.getInt32(2);