Commit 378df91b authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r229495: 

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r229495 | delena | 2015-02-17 05:10:05 -0800 (Tue, 17 Feb 2015) | 8 lines

Fixed a bug in store sinking.
The problem was in store-sink barrier check.

Store sink barrier should be checked for ModRef (read-write) mode.

http://llvm.org/bugs/show_bug.cgi?id=22613


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llvm-svn: 229564
parent 8add0ee9

llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp

+6 −4
Original line number Diff line number Diff line
@@ -403,7 +403,7 @@ bool MergedLoadStoreMotion::isStoreSinkBarrierInRange(const Instruction& Start, 
                                                      const Instruction& End,

                                                      AliasAnalysis::Location

                                                      Loc) {

  return AA->canInstructionRangeModRef(Start, End, Loc, AliasAnalysis::Ref);

  return AA->canInstructionRangeModRef(Start, End, Loc, AliasAnalysis::ModRef);

}



///
@@ -414,6 +414,7 @@ bool MergedLoadStoreMotion::isStoreSinkBarrierInRange(const Instruction& Start, 
StoreInst *MergedLoadStoreMotion::canSinkFromBlock(BasicBlock *BB1,

                                                   StoreInst *Store0) {

  DEBUG(dbgs() << "can Sink? : "; Store0->dump(); dbgs() << "\n");

  BasicBlock *BB0 = Store0->getParent();

  for (BasicBlock::reverse_iterator RBI = BB1->rbegin(), RBE = BB1->rend();

       RBI != RBE; ++RBI) {

    Instruction *Inst = &*RBI;
@@ -422,13 +423,14 @@ StoreInst *MergedLoadStoreMotion::canSinkFromBlock(BasicBlock *BB1, 
       continue;



    StoreInst *Store1 = cast<StoreInst>(Inst);

    BasicBlock *BB0 = Store0->getParent();



    AliasAnalysis::Location Loc0 = AA->getLocation(Store0);

    AliasAnalysis::Location Loc1 = AA->getLocation(Store1);

    if (AA->isMustAlias(Loc0, Loc1) && Store0->isSameOperationAs(Store1) &&

      !isStoreSinkBarrierInRange(*Store1, BB1->back(), Loc1) &&

      !isStoreSinkBarrierInRange(*Store0, BB0->back(), Loc0)) {

      !isStoreSinkBarrierInRange(*(std::next(BasicBlock::iterator(Store1))),

                                 BB1->back(), Loc1) &&

      !isStoreSinkBarrierInRange(*(std::next(BasicBlock::iterator(Store0))),

                                 BB0->back(), Loc0)) {

      return Store1;

    }

  }

llvm/test/Transforms/InstMerge/st_sink_bugfix_22613.ll

0 → 100644
+114 −0
Original line number Diff line number Diff line 
; ModuleID = 'bug.c'

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

target triple = "x86_64-unknown-linux-gnu"



; RUN: opt -O2 -S < %s | FileCheck %s



; CHECK_LABEL: main

; CHECK: if.end

; CHECK: store

; CHECK: memset

; CHECK: if.then

; CHECK: store

; CHECK: memset



@d = common global i32 0, align 4

@b = common global i32 0, align 4

@f = common global [1 x [3 x i8]] zeroinitializer, align 1

@e = common global i32 0, align 4

@c = common global i32 0, align 4

@a = common global i32 0, align 4



; Function Attrs: nounwind uwtable

define void @fn1() #0 {

entry:

  store i32 0, i32* @d, align 4

  br label %for.cond



for.cond:                                         ; preds = %for.inc8, %entry

  %0 = load i32* @d, align 4

  %cmp = icmp slt i32 %0, 2

  br i1 %cmp, label %for.body, label %for.end10



for.body:                                         ; preds = %for.cond

  %1 = load i32* @d, align 4

  %idxprom = sext i32 %1 to i64

  %2 = load i32* @b, align 4

  %idxprom1 = sext i32 %2 to i64

  %arrayidx = getelementptr inbounds [1 x [3 x i8]]* @f, i32 0, i64 %idxprom1

  %arrayidx2 = getelementptr inbounds [3 x i8]* %arrayidx, i32 0, i64 %idxprom

  store i8 0, i8* %arrayidx2, align 1

  store i32 0, i32* @e, align 4

  br label %for.cond3



for.cond3:                                        ; preds = %for.inc, %for.body

  %3 = load i32* @e, align 4

  %cmp4 = icmp slt i32 %3, 3

  br i1 %cmp4, label %for.body5, label %for.end



for.body5:                                        ; preds = %for.cond3

  %4 = load i32* @c, align 4

  %tobool = icmp ne i32 %4, 0

  br i1 %tobool, label %if.then, label %if.end



if.then:                                          ; preds = %for.body5

  %5 = load i32* @a, align 4

  %dec = add nsw i32 %5, -1

  store i32 %dec, i32* @a, align 4

  br label %if.end



if.end:                                           ; preds = %if.then, %for.body5

  %6 = load i32* @e, align 4

  %idxprom6 = sext i32 %6 to i64

  %arrayidx7 = getelementptr inbounds [3 x i8]* getelementptr inbounds ([1 x [3 x i8]]* @f, i32 0, i64 0), i32 0, i64 %idxprom6

  store i8 1, i8* %arrayidx7, align 1

  br label %for.inc



for.inc:                                          ; preds = %if.end

  %7 = load i32* @e, align 4

  %inc = add nsw i32 %7, 1

  store i32 %inc, i32* @e, align 4

  br label %for.cond3



for.end:                                          ; preds = %for.cond3

  br label %for.inc8



for.inc8:                                         ; preds = %for.end

  %8 = load i32* @d, align 4

  %inc9 = add nsw i32 %8, 1

  store i32 %inc9, i32* @d, align 4

  br label %for.cond



for.end10:                                        ; preds = %for.cond

  ret void

}



; Function Attrs: nounwind uwtable

define i32 @main() #0 {

entry:

  %retval = alloca i32, align 4

  store i32 0, i32* %retval

  call void @fn1()

  %0 = load i8* getelementptr inbounds ([1 x [3 x i8]]* @f, i32 0, i64 0, i64 1), align 1

  %conv = sext i8 %0 to i32

  %cmp = icmp ne i32 %conv, 1

  br i1 %cmp, label %if.then, label %if.end



if.then:                                          ; preds = %entry

  call void @abort() #2

  unreachable



if.end:                                           ; preds = %entry

  ret i32 0

}



; Function Attrs: noreturn nounwind

declare void @abort() #1



attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }

attributes #1 = { noreturn nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }

attributes #2 = { noreturn nounwind }



!llvm.ident = !{!0}



!0 = !{!"clang version 3.7.0 (trunk 229288) (llvm/trunk 229286:229290M)"}