Commit e5e9018d authored by Bill Wendling's avatar Bill Wendling
Browse files

Merging r182485: 

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r182485 | arnolds | 2013-05-22 09:54:56 -0700 (Wed, 22 May 2013) | 7 lines

LoopVectorize: Make Value pointers that could be RAUW'ed a VH

The Value pointers we store in the induction variable list can be RAUW'ed by a
call to SCEVExpander::expandCodeFor, use a TrackingVH instead. Do the same thing
in some other places where we store pointers that could potentially be RAUW'ed.

Fixes PR16073.
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llvm-svn: 182492
parent e4c54e3d

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

+4 −3
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ 
#include "llvm/Support/Debug.h"

#include "llvm/Support/PatternMatch.h"

#include "llvm/Support/raw_ostream.h"

#include "llvm/Support/ValueHandle.h"

#include "llvm/Target/TargetLibraryInfo.h"

#include "llvm/Transforms/Scalar.h"

#include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -382,7 +383,7 @@ public: 


    // The starting value of the reduction.

    // It does not have to be zero!

    Value *StartValue;

    TrackingVH<Value> StartValue;

    // The instruction who's value is used outside the loop.

    Instruction *LoopExitInstr;

    // The kind of the reduction.
@@ -427,7 +428,7 @@ public: 
    /// This flag indicates if we need to add the runtime check.

    bool Need;

    /// Holds the pointers that we need to check.

    SmallVector<Value*, 2> Pointers;

    SmallVector<TrackingVH<Value>, 2> Pointers;

    /// Holds the pointer value at the beginning of the loop.

    SmallVector<const SCEV*, 2> Starts;

    /// Holds the pointer value at the end of the loop.
@@ -441,7 +442,7 @@ public: 
    InductionInfo(Value *Start, InductionKind K) : StartValue(Start), IK(K) {}

    InductionInfo() : StartValue(0), IK(IK_NoInduction) {}

    /// Start value.

    Value *StartValue;

    TrackingVH<Value> StartValue;

    /// Induction kind.

    InductionKind IK;

  };

llvm/test/Transforms/LoopVectorize/value-ptr-bug.ll

0 → 100644
+50 −0
Original line number Diff line number Diff line 
; RUN: opt -S -loop-vectorize -force-vector-width=4 -force-vector-unroll=1 -dce -instcombine < %s | FileCheck %s



target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"



; PR16073



; Because we were caching value pointers accross a function call that could RAUW

; we would generate an undefined value store below:

; SCEVExpander::expandCodeFor would change a value (the start value of an

; induction) that we cached in the induction variable list.



; CHECK: test_vh

; CHECK-NOT: store <4 x i8> undef



define void @test_vh(i32* %ptr265, i32* %ptr266, i32 %sub267) {

entry:

  br label %loop



loop:

  %inc = phi i32 [ %sub267, %entry ], [ %add, %loop]

  %ext.inc = sext i32 %inc to i64

  %add.ptr265 = getelementptr inbounds i32* %ptr265, i64 %ext.inc

  %add.ptr266 = getelementptr inbounds i32* %ptr266, i64 %ext.inc

  %add = add i32 %inc, 9

  %cmp = icmp slt i32 %add, 140

  br i1 %cmp, label %block1, label %loop



block1:

  %sub267.lcssa = phi i32 [ %add, %loop ]

  %add.ptr266.lcssa = phi i32* [ %add.ptr266, %loop ]

  %add.ptr265.lcssa = phi i32* [ %add.ptr265, %loop ]

  %tmp29 = bitcast i32* %add.ptr265.lcssa to i8*

  %tmp30 = bitcast i32* %add.ptr266.lcssa to i8*

  br label %do.body272



do.body272:

  %row_width.5 = phi i32 [ %sub267.lcssa, %block1 ], [ %dec, %do.body272 ]

  %sp.4 = phi i8* [ %tmp30, %block1 ], [ %incdec.ptr273, %do.body272 ]

  %dp.addr.4 = phi i8* [ %tmp29, %block1 ], [ %incdec.ptr274, %do.body272 ]

  %incdec.ptr273 = getelementptr inbounds i8* %sp.4, i64 1

  %tmp31 = load i8* %sp.4, align 1

  %incdec.ptr274 = getelementptr inbounds i8* %dp.addr.4, i64 1

  store i8 %tmp31, i8* %dp.addr.4, align 1

  %dec = add i32 %row_width.5, -1

  %cmp276 = icmp eq i32 %dec, 0

  br i1 %cmp276, label %loop.exit, label %do.body272



loop.exit:

  ret void

}