From 2d7fe6a565c073739e01eab012faaf83e1c20b67 Mon Sep 17 00:00:00 2001
From: Jessica Paquette <jpaquette@apple.com>
Date: Thu, 14 Jan 2021 11:09:46 -0800
Subject: [PATCH] [MIPatternMatch] Add m_OneNonDBGUse

Add a matcher that checks if the given subpattern has only one non-debug use.

Also improve existing m_OneUse testcase.

Differential Revision: https://reviews.llvm.org/D94705
---
 .../llvm/CodeGen/GlobalISel/MIPatternMatch.h  | 14 +++++++++++++
 .../CodeGen/GlobalISel/PatternMatchTest.cpp   | 21 ++++++++++++++-----
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h b/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
index ed93dae24c0..55d6d365fbb 100644
--- a/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
+++ b/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
@@ -39,6 +39,20 @@ inline OneUse_match<SubPat> m_OneUse(const SubPat &SP) {
   return SP;
 }
 
+template <typename SubPatternT> struct OneNonDBGUse_match {
+  SubPatternT SubPat;
+  OneNonDBGUse_match(const SubPatternT &SP) : SubPat(SP) {}
+
+  bool match(const MachineRegisterInfo &MRI, Register Reg) {
+    return MRI.hasOneNonDBGUse(Reg) && SubPat.match(MRI, Reg);
+  }
+};
+
+template <typename SubPat>
+inline OneNonDBGUse_match<SubPat> m_OneNonDBGUse(const SubPat &SP) {
+  return SP;
+}
+
 struct ConstantMatch {
   int64_t &CR;
   ConstantMatch(int64_t &C) : CR(C) {}
diff --git a/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp b/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
index a63a34f9154..8a5d8e78339 100644
--- a/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
+++ b/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
@@ -392,13 +392,24 @@ TEST_F(AArch64GISelMITest, MatchMiscellaneous) {
 
   LLT s64 = LLT::scalar(64);
   auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
-  // Make multiple uses of this add.
+  Register Reg = MIBAdd.getReg(0);
+
+  // Only one use of Reg.
   B.buildCast(LLT::pointer(0, 32), MIBAdd);
+  EXPECT_TRUE(mi_match(Reg, *MRI, m_OneUse(m_GAdd(m_Reg(), m_Reg()))));
+  EXPECT_TRUE(mi_match(Reg, *MRI, m_OneNonDBGUse(m_GAdd(m_Reg(), m_Reg()))));
+
+  // Add multiple debug uses of Reg.
+  B.buildInstr(TargetOpcode::DBG_VALUE, {}, {Reg})->getOperand(0).setIsDebug();
+  B.buildInstr(TargetOpcode::DBG_VALUE, {}, {Reg})->getOperand(0).setIsDebug();
+
+  EXPECT_FALSE(mi_match(Reg, *MRI, m_OneUse(m_GAdd(m_Reg(), m_Reg()))));
+  EXPECT_TRUE(mi_match(Reg, *MRI, m_OneNonDBGUse(m_GAdd(m_Reg(), m_Reg()))));
+
+  // Multiple non-debug uses of Reg.
   B.buildCast(LLT::pointer(1, 32), MIBAdd);
-  bool match = mi_match(MIBAdd.getReg(0), *MRI, m_GAdd(m_Reg(), m_Reg()));
-  EXPECT_TRUE(match);
-  match = mi_match(MIBAdd.getReg(0), *MRI, m_OneUse(m_GAdd(m_Reg(), m_Reg())));
-  EXPECT_FALSE(match);
+  EXPECT_FALSE(mi_match(Reg, *MRI, m_OneUse(m_GAdd(m_Reg(), m_Reg()))));
+  EXPECT_FALSE(mi_match(Reg, *MRI, m_OneNonDBGUse(m_GAdd(m_Reg(), m_Reg()))));
 }
 
 TEST_F(AArch64GISelMITest, MatchSpecificConstant) {