[llvm] [MIPatternMatch] Add m_GUMin and m_GUMax (PR #121068)

[Min-Yih Hsu via llvm-commits]

https://github.com/mshockwave created https://github.com/llvm/llvm-project/pull/121068

And make all unsigned and signed versions of min/max matchers commutative, since we already made a precedent of m_GAdd that is commutative by default.

>From 7082cce5852b0ebe49537db46427e54c1a6d588d Mon Sep 17 00:00:00 2001
From: Min Hsu <min.hsu at sifive.com>
Date: Tue, 24 Dec 2024 12:27:53 -0800
Subject: [PATCH] [MIPatternMatch] Add m_GUMin and m_GUMax

And make all unsigned and signed versions of min/max matchers
commutative, since we already made a precedent of m_GAdd that is
commutative by default.
---
 .../llvm/CodeGen/GlobalISel/MIPatternMatch.h  | 20 +++++++++++---
 .../CodeGen/GlobalISel/PatternMatchTest.cpp   | 26 +++++++++++++++++++
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h b/llvm/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
index ea6ed322e9b192..95d28834900e00 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h
@@ -538,15 +538,27 @@ m_GAShr(const LHS &L, const RHS &R) {
 }
 
 template <typename LHS, typename RHS>
-inline BinaryOp_match<LHS, RHS, TargetOpcode::G_SMAX, false>
+inline BinaryOp_match<LHS, RHS, TargetOpcode::G_SMAX, true>
 m_GSMax(const LHS &L, const RHS &R) {
-  return BinaryOp_match<LHS, RHS, TargetOpcode::G_SMAX, false>(L, R);
+  return BinaryOp_match<LHS, RHS, TargetOpcode::G_SMAX, true>(L, R);
 }
 
 template <typename LHS, typename RHS>
-inline BinaryOp_match<LHS, RHS, TargetOpcode::G_SMIN, false>
+inline BinaryOp_match<LHS, RHS, TargetOpcode::G_SMIN, true>
 m_GSMin(const LHS &L, const RHS &R) {
-  return BinaryOp_match<LHS, RHS, TargetOpcode::G_SMIN, false>(L, R);
+  return BinaryOp_match<LHS, RHS, TargetOpcode::G_SMIN, true>(L, R);
+}
+
+template <typename LHS, typename RHS>
+inline BinaryOp_match<LHS, RHS, TargetOpcode::G_UMAX, true>
+m_GUMax(const LHS &L, const RHS &R) {
+  return BinaryOp_match<LHS, RHS, TargetOpcode::G_UMAX, true>(L, R);
+}
+
+template <typename LHS, typename RHS>
+inline BinaryOp_match<LHS, RHS, TargetOpcode::G_UMIN, true>
+m_GUMin(const LHS &L, const RHS &R) {
+  return BinaryOp_match<LHS, RHS, TargetOpcode::G_UMIN, true>(L, R);
 }
 
 // Helper for unary instructions (G_[ZSA]EXT/G_TRUNC) etc
diff --git a/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp b/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
index 59a86fa5646f36..2088a3f81ed57a 100644
--- a/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
@@ -224,6 +224,32 @@ TEST_F(AArch64GISelMITest, MatchBinaryOp) {
   auto MIBAddCst = B.buildAdd(s64, MIBCst, Copies[0]);
   auto MIBUnmerge = B.buildUnmerge({s32, s32}, B.buildConstant(s64, 42));
 
+  // Match min/max, and make sure they're commutative.
+  auto SMin = B.buildSMin(s64, Copies[2], MIBAdd);
+  EXPECT_TRUE(mi_match(SMin.getReg(0), *MRI,
+                       m_GSMin(m_GAdd(m_Reg(Src1), m_Reg(Src2)), m_Reg(Src0))));
+  EXPECT_EQ(Src0, Copies[2]);
+  EXPECT_EQ(Src1, Copies[0]);
+  EXPECT_EQ(Src2, Copies[1]);
+  auto SMax = B.buildSMax(s64, Copies[2], MIBAdd);
+  EXPECT_TRUE(mi_match(SMax.getReg(0), *MRI,
+                       m_GSMax(m_GAdd(m_Reg(Src1), m_Reg(Src2)), m_Reg(Src0))));
+  EXPECT_EQ(Src0, Copies[2]);
+  EXPECT_EQ(Src1, Copies[0]);
+  EXPECT_EQ(Src2, Copies[1]);
+  auto UMin = B.buildUMin(s64, Copies[2], MIBAdd);
+  EXPECT_TRUE(mi_match(UMin.getReg(0), *MRI,
+                       m_GUMin(m_GAdd(m_Reg(Src1), m_Reg(Src2)), m_Reg(Src0))));
+  EXPECT_EQ(Src0, Copies[2]);
+  EXPECT_EQ(Src1, Copies[0]);
+  EXPECT_EQ(Src2, Copies[1]);
+  auto UMax = B.buildUMax(s64, Copies[2], MIBAdd);
+  EXPECT_TRUE(mi_match(UMax.getReg(0), *MRI,
+                       m_GUMax(m_GAdd(m_Reg(Src1), m_Reg(Src2)), m_Reg(Src0))));
+  EXPECT_EQ(Src0, Copies[2]);
+  EXPECT_EQ(Src1, Copies[0]);
+  EXPECT_EQ(Src2, Copies[1]);
+
   // m_BinOp with opcode.
   // Match binary instruction, opcode and its non-commutative operands.
   match = mi_match(MIBAddCst, *MRI,