[llvm-commits] [llvm] r172756 - in /llvm/trunk: include/llvm/Analysis/MemoryBuiltins.h lib/Analysis/MemoryBuiltins.cpp test/Transforms/InstCombine/objsize.ll
Bill Wendling
isanbard at gmail.com
Thu Jan 17 13:28:46 PST 2013
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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