Commit aee68a10 authored by Bill Wendling's avatar Bill Wendling
Browse files

Merging r143437: 

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r143437 | efriedma | 2011-10-31 21:49:29 -0700 (Mon, 31 Oct 2011) | 3 lines

Make sure we use the right insertion point when instcombine replaces a PHI with another instruction.  (Specifically, don't insert an arbitrary instruction before a PHI.)  Fixes PR11275.


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llvm-svn: 143438
parent 3a2254cb

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

+4 −3
Original line number Diff line number Diff line
@@ -2025,9 +2025,10 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { 
        BasicBlock *InstParent = I->getParent();

        BasicBlock::iterator InsertPos = I;



        if (!isa<PHINode>(Result))        // If combining a PHI, don't insert

          while (isa<PHINode>(InsertPos)) // middle of a block of PHIs.

            ++InsertPos;

        // If we replace a PHI with something that isn't a PHI, fix up the

        // insertion point.

        if (!isa<PHINode>(Result) && isa<PHINode>(InsertPos))

          InsertPos = InstParent->getFirstInsertionPt();



        InstParent->getInstList().insert(InsertPos, Result);

llvm/test/Transforms/InstCombine/crash.ll

+25 −0
Original line number Diff line number Diff line
@@ -374,3 +374,28 @@ for.inc: ; preds = %for.cond 
return:                                           ; No predecessors!

  ret void

}



; PR11275

declare void @test18b() noreturn

declare void @test18foo(double**)

declare void @test18a() noreturn

define fastcc void @test18x(i8* %t0, i1 %b) uwtable align 2 {

entry:

  br i1 %b, label %e1, label %e2

e1:

  %t2 = bitcast i8* %t0 to double**

  invoke void @test18b() noreturn

          to label %u unwind label %lpad

e2:

  %t4 = bitcast i8* %t0 to double**

  invoke void @test18a() noreturn

          to label %u unwind label %lpad

lpad:

  %t5 = phi double** [ %t2, %e1 ], [ %t4, %e2 ]

  %lpad.nonloopexit262 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0

          cleanup

  call void @test18foo(double** %t5)

  unreachable

u:

  unreachable

}