[llvm-bugs] [Bug 27578] New: SelectInst::Create will crash when give name without giving insert point

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=27578

            Bug ID: 27578
           Summary: SelectInst::Create will crash when give name without
                    giving insert point
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: Core LLVM classes
          Assignee: unassignedbugs at nondot.org
          Reporter: tristan.yim at gmail.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

Code below will get an error, which is unexpected 

  BasicBlock *entry = BasicBlock::Create(Context, "", maxFunction);
  Argument *Arg1 = &*iter;
  iter++;
  Argument *Arg2 = &*iter;
  Value *Compare = Builder.CreateICmpULT(Arg1, Arg2, "c");
  SelectInst *Select  = SelectInst::Create(Compare,
        Arg1, Arg2, "p1.p2");

Error is
While deleting: i1 %c
Use still stuck around after Def is destroyed:  %p1.p2 = select i1 %c, i32 %p1,
i32 %p2
Assertion failed: (use_empty() && "Uses remain when a value is destroyed!"),
function ~Value, file /Users/hyan/code/llvm/llvm/lib/IR/Value.cpp, line 85.
Abort trap: 6

We have two static Create method for SelectInst
static SelectInst *Create(Value *C, Value *S1, Value *S2, const Twine &NameStr
= "", Instruction *InsertBefore = nullptr)
static SelectInst *Create(Value *C, Value *S1, Value *S2, const Twine &NameStr,
BasicBlock *InsertAtEnd)

First Create function should behave as InsertBefore to current insert point
even it's a nullptr. Otherwise this method will be useless.

Workaround for this is using second Create function
  SelectInst *Select  = SelectInst::Create(Compare,
        Arg1, Arg2, "p1.p2", entry);

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