[llvm-commits] [llvm] r172756 - in /llvm/trunk: include/llvm/Analysis/MemoryBuiltins.h lib/Analysis/MemoryBuiltins.cpp test/Transforms/InstCombine/objsize.ll
Bill Wendling
wendling at apple.com
Thu Jan 17 13:43:26 PST 2013
This is the PR associated with this bug:
http://llvm.org/bugs/show_bug.cgi?id=14988
Nuno,
I had to revert your patches here. Could you please take a look at the PR?
-bw
On Jan 17, 2013, at 1:28 PM, Bill Wendling <isanbard at gmail.com> wrote:
> Author: void
> Date: Thu Jan 17 15:28:46 2013
> New Revision: 172756
>
> URL: http://llvm.org/viewvc/llvm-project?rev=172756&view=rev
> Log:
> Reverting r171325 & r172363. This was causing a mis-compile on the self-hosted LTO build bots.
>
> Okay, here's how to reproduce the problem:
>
> 1) Build a Release (or Release+Asserts) version of clang in the normal way.
>
> 2) Using the clang & clang++ binaries from (1), build a Release (or
> Release+Asserts) version of the same sources, but this time enable LTO ---
> specify the `-flto' flag on the command line.
>
> 3) Run the ARC migrator tests:
>
> $ arcmt-test --args -triple x86_64-apple-darwin10 -fsyntax-only -x objective-c++ ./src/tools/clang/test/ARCMT/cxx-rewrite.mm
>
> You'll see that the output isn't correct (the whitespace is off).
>
> The mis-compile is in the function `RewriteBuffer::RemoveText' in the
> clang/lib/Rewrite/Core/Rewriter.cpp file. When that function and RewriteRope.cpp
> are compiled with LTO and the `arcmt-test' executable is regenerated, you'll see
> the error. When those files are not LTO'ed, then the output of the `arcmt-test'
> is fine.
>
> It is *really* hard to get a testcase out of this. I'll file a PR with what I
> have currently.
>
> --- Reverse-merging r172363 into '.':
> U include/llvm/Analysis/MemoryBuiltins.h
> U lib/Analysis/MemoryBuiltins.cpp
>
> --- Reverse-merging r171325 into '.':
> U test/Transforms/InstCombine/objsize.ll
> G include/llvm/Analysis/MemoryBuiltins.h
> G lib/Analysis/MemoryBuiltins.cpp
>
>
>
> Modified:
> llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
> llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
> llvm/trunk/test/Transforms/InstCombine/objsize.ll
>
> Modified: llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h?rev=172756&r1=172755&r2=172756&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h (original)
> +++ llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h Thu Jan 17 15:28:46 2013
> @@ -153,14 +153,12 @@
> class ObjectSizeOffsetVisitor
> : public InstVisitor<ObjectSizeOffsetVisitor, SizeOffsetType> {
>
> - typedef DenseMap<const Value*, SizeOffsetType> CacheMapTy;
> -
> const DataLayout *TD;
> const TargetLibraryInfo *TLI;
> bool RoundToAlign;
> unsigned IntTyBits;
> APInt Zero;
> - CacheMapTy CacheMap;
> + SmallPtrSet<Instruction *, 8> SeenInsts;
>
> APInt align(APInt Size, uint64_t Align);
>
>
> Modified: llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryBuiltins.cpp?rev=172756&r1=172755&r2=172756&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Analysis/MemoryBuiltins.cpp (original)
> +++ llvm/trunk/lib/Analysis/MemoryBuiltins.cpp Thu Jan 17 15:28:46 2013
> @@ -385,23 +385,16 @@
>
> SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) {
> V = V->stripPointerCasts();
> + if (Instruction *I = dyn_cast<Instruction>(V)) {
> + // If we have already seen this instruction, bail out. Cycles can happen in
> + // unreachable code after constant propagation.
> + if (!SeenInsts.insert(I))
> + return unknown();
>
> - if (isa<Instruction>(V) || isa<GEPOperator>(V)) {
> - // return cached value or insert unknown in cache if size of V was not
> - // computed yet in order to avoid recursions in PHis
> - std::pair<CacheMapTy::iterator, bool> CacheVal =
> - CacheMap.insert(std::make_pair(V, unknown()));
> - if (!CacheVal.second)
> - return CacheVal.first->second;
> -
> - SizeOffsetType Result;
> if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
> - Result = visitGEPOperator(*GEP);
> - else
> - Result = visit(cast<Instruction>(*V));
> - return CacheMap[V] = Result;
> + return visitGEPOperator(*GEP);
> + return visit(*I);
> }
> -
> if (Argument *A = dyn_cast<Argument>(V))
> return visitArgument(*A);
> if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V))
> @@ -415,6 +408,8 @@
> if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
> if (CE->getOpcode() == Instruction::IntToPtr)
> return unknown(); // clueless
> + if (CE->getOpcode() == Instruction::GetElementPtr)
> + return visitGEPOperator(cast<GEPOperator>(*CE));
> }
>
> DEBUG(dbgs() << "ObjectSizeOffsetVisitor::compute() unhandled value: " << *V
> @@ -548,21 +543,9 @@
> return unknown();
> }
>
> -SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode &PHI) {
> - if (PHI.getNumIncomingValues() == 0)
> - return unknown();
> -
> - SizeOffsetType Ret = compute(PHI.getIncomingValue(0));
> - if (!bothKnown(Ret))
> - return unknown();
> -
> - // verify that all PHI incoming pointers have the same size and offset
> - for (unsigned i = 1, e = PHI.getNumIncomingValues(); i != e; ++i) {
> - SizeOffsetType EdgeData = compute(PHI.getIncomingValue(i));
> - if (!bothKnown(EdgeData) || EdgeData != Ret)
> - return unknown();
> - }
> - return Ret;
> +SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode&) {
> + // too complex to analyze statically.
> + return unknown();
> }
>
> SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) {
>
> Modified: llvm/trunk/test/Transforms/InstCombine/objsize.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/objsize.ll?rev=172756&r1=172755&r2=172756&view=diff
> ==============================================================================
> --- llvm/trunk/test/Transforms/InstCombine/objsize.ll (original)
> +++ llvm/trunk/test/Transforms/InstCombine/objsize.ll Thu Jan 17 15:28:46 2013
> @@ -256,131 +256,3 @@
> return:
> ret i32 7
> }
> -
> -declare noalias i8* @valloc(i32) nounwind
> -
> -; CHECK: @test14
> -; CHECK: ret i32 6
> -define i32 @test14(i32 %a) nounwind {
> - switch i32 %a, label %sw.default [
> - i32 1, label %sw.bb
> - i32 2, label %sw.bb1
> - ]
> -
> -sw.bb:
> - %call = tail call noalias i8* @malloc(i32 6) nounwind
> - br label %sw.epilog
> -
> -sw.bb1:
> - %call2 = tail call noalias i8* @calloc(i32 3, i32 2) nounwind
> - br label %sw.epilog
> -
> -sw.default:
> - %call3 = tail call noalias i8* @valloc(i32 6) nounwind
> - br label %sw.epilog
> -
> -sw.epilog:
> - %b.0 = phi i8* [ %call3, %sw.default ], [ %call2, %sw.bb1 ], [ %call, %sw.bb ]
> - %1 = tail call i32 @llvm.objectsize.i32(i8* %b.0, i1 false)
> - ret i32 %1
> -}
> -
> -; CHECK: @test15
> -; CHECK: llvm.objectsize
> -define i32 @test15(i32 %a) nounwind {
> - switch i32 %a, label %sw.default [
> - i32 1, label %sw.bb
> - i32 2, label %sw.bb1
> - ]
> -
> -sw.bb:
> - %call = tail call noalias i8* @malloc(i32 3) nounwind
> - br label %sw.epilog
> -
> -sw.bb1:
> - %call2 = tail call noalias i8* @calloc(i32 2, i32 1) nounwind
> - br label %sw.epilog
> -
> -sw.default:
> - %call3 = tail call noalias i8* @valloc(i32 3) nounwind
> - br label %sw.epilog
> -
> -sw.epilog:
> - %b.0 = phi i8* [ %call3, %sw.default ], [ %call2, %sw.bb1 ], [ %call, %sw.bb ]
> - %1 = tail call i32 @llvm.objectsize.i32(i8* %b.0, i1 false)
> - ret i32 %1
> -}
> -
> -; CHECK: @test16
> -; CHECK: llvm.objectsize
> -define i32 @test16(i8* %a, i32 %n) nounwind {
> - %b = alloca [5 x i8], align 1
> - %c = alloca [5 x i8], align 1
> - switch i32 %n, label %sw.default [
> - i32 1, label %sw.bb
> - i32 2, label %sw.bb1
> - ]
> -
> -sw.bb:
> - %bp = bitcast [5 x i8]* %b to i8*
> - br label %sw.epilog
> -
> -sw.bb1:
> - %cp = bitcast [5 x i8]* %c to i8*
> - br label %sw.epilog
> -
> -sw.default:
> - br label %sw.epilog
> -
> -sw.epilog:
> - %phi = phi i8* [ %a, %sw.default ], [ %cp, %sw.bb1 ], [ %bp, %sw.bb ]
> - %sz = call i32 @llvm.objectsize.i32(i8* %phi, i1 false)
> - ret i32 %sz
> -}
> -
> -; CHECK: @test17
> -; CHECK: ret i32 5
> -define i32 @test17(i32 %n) nounwind {
> - %b = alloca [5 x i8], align 1
> - %c = alloca [5 x i8], align 1
> - %bp = bitcast [5 x i8]* %b to i8*
> - switch i32 %n, label %sw.default [
> - i32 1, label %sw.bb
> - i32 2, label %sw.bb1
> - ]
> -
> -sw.bb:
> - br label %sw.epilog
> -
> -sw.bb1:
> - %cp = bitcast [5 x i8]* %c to i8*
> - br label %sw.epilog
> -
> -sw.default:
> - br label %sw.epilog
> -
> -sw.epilog:
> - %phi = phi i8* [ %bp, %sw.default ], [ %cp, %sw.bb1 ], [ %bp, %sw.bb ]
> - %sz = call i32 @llvm.objectsize.i32(i8* %phi, i1 false)
> - ret i32 %sz
> -}
> -
> - at globalalias = alias internal [60 x i8]* @a
> -
> -; CHECK: @test18
> -; CHECK-NEXT: ret i32 60
> -define i32 @test18() {
> - %bc = bitcast [60 x i8]* @globalalias to i8*
> - %1 = call i32 @llvm.objectsize.i32(i8* %bc, i1 false)
> - ret i32 %1
> -}
> -
> - at globalalias2 = alias weak [60 x i8]* @a
> -
> -; CHECK: @test19
> -; CHECK: llvm.objectsize
> -define i32 @test19() {
> - %bc = bitcast [60 x i8]* @globalalias2 to i8*
> - %1 = call i32 @llvm.objectsize.i32(i8* %bc, i1 false)
> - ret i32 %1
> -}
>
>
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