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




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172756 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2013-01-17 21:28:46 +00:00
parent cb4830cc99
commit 167ede898a
3 changed files with 13 additions and 160 deletions

View File

@ -153,14 +153,12 @@ typedef std::pair<APInt, APInt> SizeOffsetType;
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);

View File

@ -385,23 +385,16 @@ ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const DataLayout *TD,
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 @@ SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) {
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 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitLoadInst(LoadInst&) {
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) {

View File

@ -256,131 +256,3 @@ xpto:
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
}
@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
}
@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
}