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[Analysis] Ignore `nobuiltin` on `allocsize` function calls. 

We currently ignore the `allocsize` attribute on functions calls with
the `nobuiltin` attribute when trying to lower `@llvm.objectsize`. We
shouldn't care about `nobuiltin` here: `allocsize` is explicitly added
by the user, not inferred based on a function's symbol.

llvm-svn: 290588
This commit is contained in:
George Burgess IV 2016-12-27 06:32:14 +00:00
parent f0071ccd08
commit ed16024a9b
2 changed files with 28 additions and 10 deletions
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25
llvm/lib/Analysis/MemoryBuiltins.cpp
View File

@ -77,8 +77,8 @@ static const std::pair<LibFunc::Func, AllocFnsTy> AllocationFnData[] = {
// TODO: Handle "int posix_memalign(void **, size_t, size_t)"
};
static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) {
static Function *getCalledFunction(const Value *V, bool LookThroughBitCast,
bool &IsNoBuiltin) {
// Don't care about intrinsics in this case.
if (isa<IntrinsicInst>(V))
return nullptr;
@ -90,8 +90,7 @@ static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) {
if (!CS.getInstruction())
return nullptr;
if (CS.isNoBuiltin())
return nullptr;
IsNoBuiltin = CS.isNoBuiltin();
Function *Callee = CS.getCalledFunction();
if (!Callee || !Callee->isDeclaration())
@ -143,22 +142,28 @@ getAllocationDataForFunction(const Function *Callee, AllocType AllocTy,
static Optional<AllocFnsTy> getAllocationData(const Value *V, AllocType AllocTy,
const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false) {
if (const Function *Callee = getCalledFunction(V, LookThroughBitCast))
return getAllocationDataForFunction(Callee, AllocTy, TLI);
bool IsNoBuiltinCall;
if (const Function *Callee =
getCalledFunction(V, LookThroughBitCast, IsNoBuiltinCall))
if (!IsNoBuiltinCall)
return getAllocationDataForFunction(Callee, AllocTy, TLI);
return None;
}
static Optional<AllocFnsTy> getAllocationSize(const Value *V,
const TargetLibraryInfo *TLI) {
const Function *Callee = getCalledFunction(V, /*LookThroughBitCast=*/false);
bool IsNoBuiltinCall;
const Function *Callee =
getCalledFunction(V, /*LookThroughBitCast=*/false, IsNoBuiltinCall);
if (!Callee)
return None;
// Prefer to use existing information over allocsize. This will give us an
// accurate AllocTy.
if (Optional<AllocFnsTy> Data =
getAllocationDataForFunction(Callee, AnyAlloc, TLI))
return Data;
if (!IsNoBuiltinCall)
if (Optional<AllocFnsTy> Data =
getAllocationDataForFunction(Callee, AnyAlloc, TLI))
return Data;
Attribute Attr = Callee->getFnAttribute(Attribute::AllocSize);
if (Attr == Attribute())

13
llvm/test/Transforms/InstCombine/allocsize.ll
View File

@ -134,6 +134,19 @@ define void @test_overflow(i8** %p, i32* %r) {
ret void
}
; CHECK-LABEL: define void @test_nobuiltin
; We had a bug where `nobuiltin` would cause `allocsize` to be ignored in
; @llvm.objectsize calculations.
define void @test_nobuiltin(i8** %p, i64* %r) {
%1 = call i8* @my_malloc(i8* null, i32 100) nobuiltin
store i8* %1, i8** %p, align 8
%2 = call i64 @llvm.objectsize.i64.p0i8(i8* %1, i1 false)
; CHECK: store i64 100
store i64 %2, i64* %r, align 8
ret void
}
attributes #0 = { allocsize(1) }
attributes #1 = { allocsize(2, 3) }