From a698a472f2fcfb010e17c206b06fe032defe01b6 Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Mon, 1 Dec 2008 08:23:25 +0000
Subject: [PATCH] Reduce copy-and-paste code by splitting out the code into its
 own function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60343 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Scalar/InstructionCombining.cpp           | 108 ++++++++----------
 1 file changed, 50 insertions(+), 58 deletions(-)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 47d9c25d5b6..dac37f07f3a 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -183,6 +183,8 @@ namespace {
     Instruction *FoldAndOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
     Instruction *visitAnd(BinaryOperator &I);
     Instruction *FoldOrOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
+    Instruction *FoldOrWithConstants(BinaryOperator &I,
+                                     Value *A, Value *B, Value *C);
     Instruction *visitOr (BinaryOperator &I);
     Instruction *visitXor(BinaryOperator &I);
     Instruction *visitShl(BinaryOperator &I);
@@ -4445,6 +4447,50 @@ Instruction *InstCombiner::FoldOrOfICmps(Instruction &I,
   return 0;
 }
 
+/// FoldOrWithConstants - This helper function folds:
+///
+///     ((A|B)&1)|(B&-2)
+///
+/// into:
+/// 
+///     (A&1) | B
+Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I,
+                                               Value *A, Value *B, Value *C) {
+  Value *Op1 = I.getOperand(1);
+
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+    if (CI->getValue() == 1) {
+      Value *V1 = 0, *C2 = 0;
+      if (match(Op1, m_And(m_Value(V1), m_Value(C2)))) {
+        ConstantInt *CI2 = dyn_cast<ConstantInt>(C2);
+
+        if (!CI2) {
+          std::swap(V1, C2);
+          CI2 = dyn_cast<ConstantInt>(C2);
+        }
+
+        if (CI2) {
+          APInt NegTwo = -APInt(CI2->getValue().getBitWidth(), 2, true);
+          if (CI2->getValue().eq(NegTwo)) {
+            if (V1 == B) {
+              Instruction *NewOp =
+                InsertNewInstBefore(BinaryOperator::CreateAnd(A, CI), I);
+              return BinaryOperator::CreateOr(NewOp, B);
+            }
+            if (V1 == A) {
+              Instruction *NewOp =
+                InsertNewInstBefore(BinaryOperator::CreateAnd(B, CI), I);
+              return BinaryOperator::CreateOr(NewOp, A);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return 0;
+}
+
 Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   bool Changed = SimplifyCommutative(I);
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -4639,68 +4685,14 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   // ((A|B)&1)|(B&-2) -> (A&1) | B
   if (match(Op0, m_And(m_Or(m_Value(A), m_Value(B)), m_Value(C))) ||
       match(Op0, m_And(m_Value(C), m_Or(m_Value(A), m_Value(B))))) {
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
-      if (CI->getValue() == 1) {
-        Value *V1 = 0, *C2 = 0;
-        if (match(Op1, m_And(m_Value(V1), m_Value(C2)))) {
-          ConstantInt *CI2 = dyn_cast<ConstantInt>(C2);
-
-          if (!CI2) {
-            std::swap(V1, C2);
-            CI2 = dyn_cast<ConstantInt>(C2);
-          }
-
-          if (CI2) {
-            APInt NegTwo = -APInt(CI2->getValue().getBitWidth(), 2, true);
-            if (CI2->getValue().eq(NegTwo)) {
-              if (V1 == B) {
-                Instruction *NewOp =
-                  InsertNewInstBefore(BinaryOperator::CreateAnd(A, CI), I);
-                return BinaryOperator::CreateOr(NewOp, B);
-              }
-              if (V1 == A) {
-                Instruction *NewOp =
-                  InsertNewInstBefore(BinaryOperator::CreateAnd(B, CI), I);
-                return BinaryOperator::CreateOr(NewOp, A);
-              }
-            }
-          }
-        }
-      }
-    }
+    Instruction *Ret = FoldOrWithConstants(I, A, B, C);
+    if (Ret) return Ret;
   }
   // (B&-2)|((A|B)&1) -> (A&1) | B
   if (match(Op1, m_And(m_Or(m_Value(A), m_Value(B)), m_Value(C))) ||
       match(Op1, m_And(m_Value(C), m_Or(m_Value(A), m_Value(B))))) {
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
-      if (CI->getValue() == 1) {
-        Value *V1 = 0, *C2 = 0;
-        if (match(Op0, m_And(m_Value(V1), m_Value(C2)))) {
-          ConstantInt *CI2 = dyn_cast<ConstantInt>(C2);
-
-          if (!CI2) {
-            std::swap(V1, C2);
-            CI2 = dyn_cast<ConstantInt>(C2);
-          }
-
-          if (CI2) {
-            APInt NegTwo = -APInt(CI2->getValue().getBitWidth(), 2, true);
-            if (CI2->getValue().eq(NegTwo)) {
-              if (V1 == B) {
-                Instruction *NewOp =
-                  InsertNewInstBefore(BinaryOperator::CreateAnd(A, CI), I);
-                return BinaryOperator::CreateOr(NewOp, B);
-              }
-              if (V1 == A) {
-                Instruction *NewOp =
-                  InsertNewInstBefore(BinaryOperator::CreateAnd(B, CI), I);
-                return BinaryOperator::CreateOr(NewOp, A);
-              }
-            }
-          }
-        }
-      }
-    }
+    Instruction *Ret = FoldOrWithConstants(I, A, B, C);
+    if (Ret) return Ret;
   }
 
   if (match(Op0, m_Not(m_Value(A)))) {   // ~A | Op1
-- 
2.34.1