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-rw-r--r--llvm/include/llvm/Analysis/MemoryBuiltins.h2
-rw-r--r--llvm/lib/Analysis/MemoryBuiltins.cpp37
-rw-r--r--llvm/test/Transforms/InstCombine/objsize.ll128
3 files changed, 155 insertions, 12 deletions
diff --git a/llvm/include/llvm/Analysis/MemoryBuiltins.h b/llvm/include/llvm/Analysis/MemoryBuiltins.h
index 9502f621b15..73e0e98cfde 100644
--- a/llvm/include/llvm/Analysis/MemoryBuiltins.h
+++ b/llvm/include/llvm/Analysis/MemoryBuiltins.h
@@ -158,7 +158,7 @@ class ObjectSizeOffsetVisitor
bool RoundToAlign;
unsigned IntTyBits;
APInt Zero;
- SmallPtrSet<Instruction *, 8> SeenInsts;
+ SmallPtrSet<Value*, 8> SeenInsts;
APInt align(APInt Size, uint64_t Align);
diff --git a/llvm/lib/Analysis/MemoryBuiltins.cpp b/llvm/lib/Analysis/MemoryBuiltins.cpp
index 14815801d1e..2eebaad495a 100644
--- a/llvm/lib/Analysis/MemoryBuiltins.cpp
+++ b/llvm/lib/Analysis/MemoryBuiltins.cpp
@@ -385,16 +385,21 @@ 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))
+
+ if (isa<Instruction>(V) || isa<GEPOperator>(V)) {
+ // If we have already seen this instruction, bail out.
+ if (!SeenInsts.insert(V))
return unknown();
+ SizeOffsetType Ret;
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
- return visitGEPOperator(*GEP);
- return visit(*I);
+ Ret = visitGEPOperator(*GEP);
+ else
+ Ret = visit(cast<Instruction>(*V));
+ SeenInsts.erase(V);
+ return Ret;
}
+
if (Argument *A = dyn_cast<Argument>(V))
return visitArgument(*A);
if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V))
@@ -408,8 +413,6 @@ 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
@@ -543,9 +546,21 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitLoadInst(LoadInst&) {
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) {
diff --git a/llvm/test/Transforms/InstCombine/objsize.ll b/llvm/test/Transforms/InstCombine/objsize.ll
index 31a3cb46e45..0ead9d12374 100644
--- a/llvm/test/Transforms/InstCombine/objsize.ll
+++ b/llvm/test/Transforms/InstCombine/objsize.ll
@@ -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
+}
+
+@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
+}
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