Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."

Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

llvm-svn: 126481

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

@@ -247,13 +247,11 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB,
     if (PBB->getFirstNonPHIOrDbg() != I)
       return false;
     break;
-  case Instruction::GetElementPtr: {
-    // GEPs are cheap if all indices are constant or if there's only one index.
-    GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
-    if (!GEP->hasAllConstantIndices() && GEP->getNumIndices() > 1)
+  case Instruction::GetElementPtr:
+    // GEPs are cheap if all indices are constant.
+    if (!cast<GetElementPtrInst>(I)->hasAllConstantIndices())
       return false;
     break;
-  }
   case Instruction::Add:
   case Instruction::Sub:
   case Instruction::And:

llvm/test/Transforms/SimplifyCFG/select-gep.ll

@@ -15,7 +15,7 @@ if.end:
   ret i8* %x.addr
 
 ; CHECK: @test1
-; CHECK: %x.addr = select i1 %cmp, i8* %incdec.ptr, i8* %x
+; CHECK-NOT: select
 ; CHECK: ret i8* %x.addr
 }