Commit 1adbe86d authored by Reid Kleckner's avatar Reid Kleckner
Browse files

[WinEH] Fix inttoptr+phi optimization in presence of catchswitch 

getFirstInsertionPt's return value must be checked for validity before
casting it to Instruction*. Don't attempt to insert casts after a phi in
a catchswitch block.

Fixes PR45033, introduced in D37832.

Reviewed By: davidxl, hfinkel

Differential Revision: https://reviews.llvm.org/D75381
parent 619d7dc3

llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp

+14 −4
Original line number Diff line number Diff line
@@ -218,13 +218,21 @@ Instruction *InstCombiner::FoldIntegerTypedPHI(PHINode &PN) { 
    return nullptr;



  // If any of the operand that requires casting is a terminator

  // instruction, do not do it.

  // instruction, do not do it. Similarly, do not do the transform if the value

  // is PHI in a block with no insertion point, for example, a catchswitch

  // block, since we will not be able to insert a cast after the PHI.

  if (any_of(AvailablePtrVals, [&](Value *V) {

        if (V->getType() == IntToPtr->getType())

          return false;



        auto *Inst = dyn_cast<Instruction>(V);

        return Inst && Inst->isTerminator();

        if (!Inst)

          return false;

        if (Inst->isTerminator())

          return true;

        auto *BB = Inst->getParent();

        if (isa<PHINode>(Inst) && BB->getFirstInsertionPt() == BB->end())

          return true;

        return false;

      }))

    return nullptr;
@@ -264,8 +272,10 @@ Instruction *InstCombiner::FoldIntegerTypedPHI(PHINode &PN) { 
      if (auto *IncomingI = dyn_cast<Instruction>(IncomingVal)) {

        BasicBlock::iterator InsertPos(IncomingI);

        InsertPos++;

        BasicBlock *BB = IncomingI->getParent();

        if (isa<PHINode>(IncomingI))

          InsertPos = IncomingI->getParent()->getFirstInsertionPt();

          InsertPos = BB->getFirstInsertionPt();

        assert(InsertPos != BB->end() && "should have checked above");

        InsertNewInstBefore(CI, *InsertPos);

      } else {

        auto *InsertBB = &IncomingBB->getParent()->getEntryBlock();

llvm/test/Transforms/InstCombine/intptr8.ll

0 → 100644
+77 −0
Original line number Diff line number Diff line 
; RUN: opt < %s  -instcombine -S | FileCheck %s



; PR45033: Don't try to insert a cast into a catchswich block.



target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"

target triple = "x86_64-pc-windows-msvc"



%struct.intrusive_ptr = type { %struct.C* }

%struct.C = type { %struct.intrusive_ref_counter }

%struct.intrusive_ref_counter = type { i32 }



declare dso_local %struct.C* @"?mk@@YAPEAUC@@XZ"() #3

declare dso_local void @"?intrusive_ptr_release@@YAXPEBUintrusive_ref_counter@@@Z"(%struct.intrusive_ref_counter*) #3

declare dso_local void @"?terminate@@YAXXZ"()

declare dso_local i32 @__CxxFrameHandler3(...)



define dso_local void @"?crash@@YAXXZ"() local_unnamed_addr #0 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {

entry:

  %call1 = invoke %struct.C* @"?mk@@YAPEAUC@@XZ"()

          to label %invoke.cont2 unwind label %catch.dispatch



invoke.cont2:                                     ; preds = %entry

  %0 = ptrtoint %struct.C* %call1 to i64

  %call5 = invoke %struct.C* @"?mk@@YAPEAUC@@XZ"()

          to label %try.cont unwind label %catch.dispatch



catch.dispatch:                                   ; preds = %invoke.cont2, %entry

  %a.sroa.0.0 = phi i64 [ %0, %invoke.cont2 ], [ 0, %entry ]

  %1 = catchswitch within none [label %catch] unwind label %ehcleanup



catch:                                            ; preds = %catch.dispatch

  %2 = catchpad within %1 [i8* null, i32 64, i8* null]

  catchret from %2 to label %try.cont



try.cont:                                         ; preds = %invoke.cont2, %catch

  %a.sroa.0.1 = phi i64 [ %0, %invoke.cont2 ], [ %a.sroa.0.0, %catch ]

  %3 = inttoptr i64 %a.sroa.0.1 to %struct.C*

  %tobool.i3 = icmp eq %struct.C* %3, null

  br i1 %tobool.i3, label %"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit6", label %if.then.i4



if.then.i4:                                       ; preds = %try.cont

  %4 = getelementptr %struct.C, %struct.C* %3, i64 0, i32 0

  invoke void @"?intrusive_ptr_release@@YAXPEBUintrusive_ref_counter@@@Z"(%struct.intrusive_ref_counter* %4)

          to label %"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit6" unwind label %terminate.i5



terminate.i5:                                     ; preds = %if.then.i4

  %5 = cleanuppad within none []

  call void @"?terminate@@YAXXZ"() #4 [ "funclet"(token %5) ]

  unreachable



"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit6":         ; preds = %try.cont, %if.then.i4

  ret void



ehcleanup:                                        ; preds = %catch.dispatch

  %6 = cleanuppad within none []

  %7 = inttoptr i64 %a.sroa.0.0 to %struct.C*

  %tobool.i = icmp eq %struct.C* %7, null

  br i1 %tobool.i, label %"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit", label %if.then.i



if.then.i:                                        ; preds = %ehcleanup

  %8 = getelementptr %struct.C, %struct.C* %7, i64 0, i32 0

  invoke void @"?intrusive_ptr_release@@YAXPEBUintrusive_ref_counter@@@Z"(%struct.intrusive_ref_counter* %8) [ "funclet"(token %6) ]

          to label %"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit" unwind label %terminate.i



terminate.i:                                      ; preds = %if.then.i

  %9 = cleanuppad within %6 []

  call void @"?terminate@@YAXXZ"() #4 [ "funclet"(token %9) ]

  unreachable



"??1?$intrusive_ptr@UC@@@@QEAA@XZ.exit":          ; preds = %ehcleanup, %if.then.i

  cleanupret from %6 unwind to caller

}



; CHECK-LABEL: define dso_local void @"?crash@@YAXXZ"

; CHECK: catch.dispatch:

; CHECK-NEXT: %a.sroa.0.0 = phi i64

; CHECK-NEXT: catchswitch within none [label %catch] unwind label %ehcleanup