From 95a440b936c26b97eb47d691df551d21ce8c13d3 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Thu, 1 Oct 2020 14:36:42 +0100
Subject: [PATCH] [IR] PatternMatch - add m_FShl/m_FShr funnel shift intrinsic
 matchers. NFCI.

---
 llvm/include/llvm/IR/PatternMatch.h       | 12 ++++++++++++
 llvm/lib/Analysis/InstructionSimplify.cpp | 15 +++++----------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/llvm/include/llvm/IR/PatternMatch.h b/llvm/include/llvm/IR/PatternMatch.h
index 78a311d..000a3af 100644
--- a/llvm/include/llvm/IR/PatternMatch.h
+++ b/llvm/include/llvm/IR/PatternMatch.h
@@ -2015,6 +2015,18 @@ inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_FMax(const Opnd0 &Op0,
   return m_Intrinsic<Intrinsic::maxnum>(Op0, Op1);
 }
 
+template <typename Opnd0, typename Opnd1, typename Opnd2>
+inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
+m_FShl(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
+  return m_Intrinsic<Intrinsic::fshl>(Op0, Op1, Op2);
+}
+
+template <typename Opnd0, typename Opnd1, typename Opnd2>
+inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
+m_FShr(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
+  return m_Intrinsic<Intrinsic::fshr>(Op0, Op1, Op2);
+}
+
 //===----------------------------------------------------------------------===//
 // Matchers for two-operands operators with the operators in either order
 //
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 7645cc9..c139661 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -3963,10 +3963,8 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
 
     // Test for a bogus zero-shift-guard-op around funnel-shift or rotate.
     Value *ShAmt;
-    auto isFsh = m_CombineOr(m_Intrinsic<Intrinsic::fshl>(m_Value(X), m_Value(),
-                                                          m_Value(ShAmt)),
-                             m_Intrinsic<Intrinsic::fshr>(m_Value(), m_Value(X),
-                                                          m_Value(ShAmt)));
+    auto isFsh = m_CombineOr(m_FShl(m_Value(X), m_Value(), m_Value(ShAmt)),
+                             m_FShr(m_Value(), m_Value(X), m_Value(ShAmt)));
     // (ShAmt == 0) ? fshl(X, *, ShAmt) : X --> X
     // (ShAmt == 0) ? fshr(*, X, ShAmt) : X --> X
     if (match(TrueVal, isFsh) && FalseVal == X && CmpLHS == ShAmt)
@@ -3977,12 +3975,9 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
     // intrinsics do not have that problem.
     // We do not allow this transform for the general funnel shift case because
     // that would not preserve the poison safety of the original code.
-    auto isRotate = m_CombineOr(m_Intrinsic<Intrinsic::fshl>(m_Value(X),
-                                                             m_Deferred(X),
-                                                             m_Value(ShAmt)),
-                                m_Intrinsic<Intrinsic::fshr>(m_Value(X),
-                                                             m_Deferred(X),
-                                                             m_Value(ShAmt)));
+    auto isRotate =
+        m_CombineOr(m_FShl(m_Value(X), m_Deferred(X), m_Value(ShAmt)),
+                    m_FShr(m_Value(X), m_Deferred(X), m_Value(ShAmt)));
     // (ShAmt == 0) ? X : fshl(X, X, ShAmt) --> fshl(X, X, ShAmt)
     // (ShAmt == 0) ? X : fshr(X, X, ShAmt) --> fshr(X, X, ShAmt)
     if (match(FalseVal, isRotate) && TrueVal == X && CmpLHS == ShAmt &&
-- 
2.7.4