Commit 2a8b38be authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r296698: 

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r296698 | rnk | 2017-03-01 17:41:12 -0500 (Wed, 01 Mar 2017) | 10 lines

[Constant Hoisting] Avoid inserting instructions before EH pads

Now that terminators can be EH pads, this code needs to iterate over the
immediate dominators of the EH pad to find a valid insertion point.

Fix for PR32107

Patch by Robert Olliff!

Differential Revision: https://reviews.llvm.org/D30511
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llvm-svn: 299670
parent d70b75e8

llvm/lib/Transforms/Scalar/ConstantHoisting.cpp

+10 −2
Original line number Diff line number Diff line
@@ -136,8 +136,16 @@ Instruction *ConstantHoistingPass::findMatInsertPt(Instruction *Inst, 
  if (Idx != ~0U && isa<PHINode>(Inst))

    return cast<PHINode>(Inst)->getIncomingBlock(Idx)->getTerminator();



  BasicBlock *IDom = DT->getNode(Inst->getParent())->getIDom()->getBlock();

  return IDom->getTerminator();

  // This must be an EH pad. Iterate over immediate dominators until we find a

  // non-EH pad. We need to skip over catchswitch blocks, which are both EH pads

  // and terminators.

  auto IDom = DT->getNode(Inst->getParent())->getIDom();

  while (IDom->getBlock()->isEHPad()) {

    assert(Entry != IDom->getBlock() && "eh pad in entry block");

    IDom = IDom->getIDom();

  }



  return IDom->getBlock()->getTerminator();

}



/// \brief Find an insertion point that dominates all uses.

llvm/test/Transforms/ConstantHoisting/X86/ehpad.ll

0 → 100644
+62 −0
Original line number Diff line number Diff line 
; RUN: opt -S -consthoist < %s | FileCheck %s



; FIXME: The catchpad doesn't even use the constant, so a better fix would be to

; insert the bitcast in the catchpad block.



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

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



; CHECK-LABEL: define i32 @main

; CHECK: %tobool = icmp eq i32 %argc, 0

; CHECK-NEXT: bitcast i64 9209618997431186100 to i64

; CHECK-NEXT: br i1 %tobool



; Function Attrs: norecurse

define i32 @main(i32 %argc, i8** nocapture readnone %argv) local_unnamed_addr #0 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {

  %call = tail call i64 @fn(i64 0)

  %call1 = tail call i64 @fn(i64 1)

  %tobool = icmp eq i32 %argc, 0

  br i1 %tobool, label %2, label %1



; <label>:1:                                      ; preds = %0

  %call2 = invoke i64 @fn(i64 %call)

          to label %6 unwind label %catch.dispatch



; <label>:2:                                      ; preds = %0

  %call3 = invoke i64 @fn(i64 %call1)

          to label %6 unwind label %catch.dispatch



catch.dispatch:                                   ; preds = %2, %1

  %z.0 = phi i64 [ %call, %1 ], [ %call1, %2 ]

  %3 = catchswitch within none [label %4] unwind to caller



; <label>:4:                                      ; preds = %catch.dispatch

  %5 = catchpad within %3 [i8* null, i32 64, i8* null]

  br i1 %tobool, label %then, label %else



then:

  %call4 = tail call i64 @fn(i64 %z.0) [ "funclet"(token %5) ]

  %add = add i64 %call4, 9209618997431186100

  br label %endif



else:

  %call5 = tail call i64 @fn(i64 0) [ "funclet"(token %5) ]

  %add6 = add i64 %call5, 9209618997431186100

  br label %endif



endif:

  %v = phi i64 [ %add, %then ], [ %add6, %else ]

  %call7 = tail call i64 @fn(i64 %v) [ "funclet"(token %5) ]

  %call8 = tail call i64 @fn(i64 %call7) [ "funclet"(token %5) ]

  catchret from %5 to label %6



; <label>:6:                                      ; preds = %1, %2, %4

  ret i32 0

}



declare i64 @fn(i64) local_unnamed_addr #1



declare i32 @__CxxFrameHandler3(...)



attributes #0 = { norecurse "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "stack-protector-buffer-size"="8" "target-features"="+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

attributes #1 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "stack-protector-buffer-size"="8" "target-features"="+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }