[llvm] r176408 - recommit r172363 & r171325 (reverted in r172756)
Nuno Lopes
nunoplopes at sapo.pt
Sat Mar 2 03:36:24 PST 2013
Author: nlopes
Date: Sat Mar 2 05:36:24 2013
New Revision: 176408
URL: http://llvm.org/viewvc/llvm-project?rev=176408&view=rev
Log:
recommit r172363 & r171325 (reverted in r172756)
This adds minimalistic support for PHI nodes to llvm.objectsize() evaluation
fingers crossed so that it does break clang boostrap again..
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=176408&r1=176407&r2=176408&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h (original)
+++ llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h Sat Mar 2 05:36:24 2013
@@ -161,12 +161,14 @@ typedef std::pair<APInt, APInt> SizeOffs
class ObjectSizeOffsetVisitor
: public InstVisitor<ObjectSizeOffsetVisitor, SizeOffsetType> {
+ typedef DenseMap<const Value*, SizeOffsetType> CacheMapTy;
+
const DataLayout *TD;
const TargetLibraryInfo *TLI;
bool RoundToAlign;
unsigned IntTyBits;
APInt Zero;
- SmallPtrSet<Instruction *, 8> SeenInsts;
+ CacheMapTy CacheMap;
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=176408&r1=176407&r2=176408&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryBuiltins.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryBuiltins.cpp Sat Mar 2 05:36:24 2013
@@ -405,16 +405,23 @@ ObjectSizeOffsetVisitor::ObjectSizeOffse
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))
- return visitGEPOperator(*GEP);
- return visit(*I);
+ Result = visitGEPOperator(*GEP);
+ else
+ Result = visit(cast<Instruction>(*V));
+ return CacheMap[V] = Result;
}
+
if (Argument *A = dyn_cast<Argument>(V))
return visitArgument(*A);
if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V))
@@ -428,8 +435,6 @@ SizeOffsetType ObjectSizeOffsetVisitor::
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
@@ -563,9 +568,21 @@ SizeOffsetType ObjectSizeOffsetVisitor::
return unknown();
}
-SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode&) {
- // too complex to analyze statically.
- 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::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=176408&r1=176407&r2=176408&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/objsize.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/objsize.ll Sat Mar 2 05:36:24 2013
@@ -256,3 +256,131 @@ 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
+}
+
+ 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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