From: Craig Topper <craig.topper@gmail.com>
Date: Thu, 6 Apr 2017 18:59:08 +0000 (+0000)
Subject: [InstSimplify] Remove unreachable default from SimplifyBinOp.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f8e400cffa8bed8dfc01aba1e9e1ad3505ee5d4e;p=llvm

[InstSimplify] Remove unreachable default from SimplifyBinOp.

We have dedicated handlers for every opcode so nothing can get here anymore. The switch doesn't get detected as fully covered because Opcode is an unsigned. Casting to Instruction::BinaryOps still doesn't detect it because BinaryOpsEnd is in the enum and 1 past the last opcode.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299687 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index da0495c340b..ed67ea3fb36 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -4169,28 +4169,7 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
   case Instruction::Xor:
     return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
   default:
-    if (Constant *CLHS = dyn_cast<Constant>(LHS))
-      if (Constant *CRHS = dyn_cast<Constant>(RHS))
-        return ConstantFoldBinaryOpOperands(Opcode, CLHS, CRHS, Q.DL);
-
-    // If the operation is associative, try some generic simplifications.
-    if (Instruction::isAssociative(Opcode))
-      if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
-        return V;
-
-    // If the operation is with the result of a select instruction check whether
-    // operating on either branch of the select always yields the same value.
-    if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
-      if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
-        return V;
-
-    // If the operation is with the result of a phi instruction, check whether
-    // operating on all incoming values of the phi always yields the same value.
-    if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
-      if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
-        return V;
-
-    return nullptr;
+    llvm_unreachable("Unexpected opcode");
   }
 }