From: David Bolvansky Date: Tue, 17 Sep 2019 10:12:48 +0000 (+0000) Subject: [InstCombine] Annotate strdup with deref_or_null X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d4e3b6ef79b9abbb7e9016a7ef59882ff5e51404;p=llvm [InstCombine] Annotate strdup with deref_or_null git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372098 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/Analysis/MemoryBuiltins.h b/include/llvm/Analysis/MemoryBuiltins.h index 5c201f35916..a89d76b9e5b 100644 --- a/include/llvm/Analysis/MemoryBuiltins.h +++ b/include/llvm/Analysis/MemoryBuiltins.h @@ -104,6 +104,11 @@ bool isReallocLikeFn(const Function *F, const TargetLibraryInfo *TLI); bool isOpNewLikeFn(const Value *V, const TargetLibraryInfo *TLI, bool LookThroughBitCast = false); +/// Tests if a value is a call or invoke to a library function that +/// allocates memory (strdup, strndup). +bool isStrdupLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast = false); + //===----------------------------------------------------------------------===// // malloc Call Utility Functions. // diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp index 52f31238227..5acdeb64a40 100644 --- a/lib/Analysis/MemoryBuiltins.cpp +++ b/lib/Analysis/MemoryBuiltins.cpp @@ -307,6 +307,13 @@ bool llvm::isOpNewLikeFn(const Value *V, const TargetLibraryInfo *TLI, return getAllocationData(V, OpNewLike, TLI, LookThroughBitCast).hasValue(); } +/// Tests if a value is a call or invoke to a library function that +/// allocates memory (strdup, strndup). +bool llvm::isStrdupLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, StrDupLike, TLI, LookThroughBitCast).hasValue(); +} + /// extractMallocCall - Returns the corresponding CallInst if the instruction /// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we /// ignore InvokeInst here. diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index e96e45e802a..90438189f89 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -4208,6 +4208,12 @@ static void annotateAnyAllocSite(CallBase &Call, const TargetLibraryInfo *TLI) { Call.addAttribute(AttributeList::ReturnIndex, Attribute::getWithDereferenceableOrNullBytes( Call.getContext(), Size.getZExtValue())); + } else if (isStrdupLikeFn(&Call, TLI) && Call.getNumArgOperands() == 1) { + // TODO: handle strndup + if (uint64_t Len = GetStringLength(Call.getOperand(0))) + Call.addAttribute( + AttributeList::ReturnIndex, + Attribute::getWithDereferenceableOrNullBytes(Call.getContext(), Len)); } } diff --git a/test/Transforms/InstCombine/deref-alloc-fns.ll b/test/Transforms/InstCombine/deref-alloc-fns.ll index f188510dfdf..efaf1cd1604 100644 --- a/test/Transforms/InstCombine/deref-alloc-fns.ll +++ b/test/Transforms/InstCombine/deref-alloc-fns.ll @@ -6,6 +6,9 @@ declare noalias i8* @calloc(i64, i64) declare noalias i8* @realloc(i8* nocapture, i64) declare noalias nonnull i8* @_Znam(i64) ; throwing version of 'new' declare noalias nonnull i8* @_Znwm(i64) ; throwing version of 'new' +declare noalias i8* @strdup(i8*) + +@.str = private unnamed_addr constant [6 x i8] c"hello\00", align 1 define noalias i8* @malloc_nonconstant_size(i64 %n) { ; CHECK-LABEL: @malloc_nonconstant_size( @@ -206,3 +209,21 @@ define noalias i8* @op_new_constant_zero_size() { %call = tail call i8* @_Znam(i64 0) ret i8* %call } + +define noalias i8* @strdup_constant_str() { +; CHECK-LABEL: @strdup_constant_str( +; CHECK-NEXT: [[CALL:%.*]] = tail call noalias dereferenceable_or_null(6) i8* @strdup(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0)) +; CHECK-NEXT: ret i8* [[CALL]] +; + %call = tail call noalias i8* @strdup(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0)) + ret i8* %call +} + +define noalias i8* @strdup_notconstant_str(i8 * %str) { +; CHECK-LABEL: @strdup_notconstant_str( +; CHECK-NEXT: [[CALL:%.*]] = tail call noalias i8* @strdup(i8* [[STR:%.*]]) +; CHECK-NEXT: ret i8* [[CALL]] +; + %call = tail call noalias i8* @strdup(i8* %str) + ret i8* %call +} diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll index 7b9dbd24ff9..590fcd60f48 100644 --- a/test/Transforms/InstCombine/objsize.ll +++ b/test/Transforms/InstCombine/objsize.ll @@ -141,7 +141,7 @@ define i32 @test4(i8** %esc) nounwind ssp { ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TMP0:%.*]] = alloca [[STRUCT_DATA:%.*]], align 8 ; CHECK-NEXT: [[TMP1:%.*]] = bitcast %struct.data* [[TMP0]] to i8* -; CHECK-NEXT: call void @llvm.memset.p0i8.i32(i8* nonnull align 8 dereferenceable(1824) [[TMP1]], i8 0, i32 1824, i1 false) +; CHECK-NEXT: call void @llvm.memset.p0i8.i32(i8* nonnull align 8 dereferenceable(1824) [[TMP1]], i8 0, i32 1824, i1 false) #0 ; CHECK-NEXT: [[TMP2:%.*]] = bitcast i8** [[ESC:%.*]] to %struct.data** ; CHECK-NEXT: store %struct.data* [[TMP0]], %struct.data** [[TMP2]], align 4 ; CHECK-NEXT: ret i32 0 @@ -163,7 +163,7 @@ define i8* @test5(i32 %n) nounwind ssp { ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TMP0:%.*]] = tail call noalias dereferenceable_or_null(20) i8* @malloc(i32 20) #0 ; CHECK-NEXT: [[TMP1:%.*]] = load i8*, i8** @s, align 8 -; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* nonnull align 1 dereferenceable(10) [[TMP0]], i8* nonnull align 1 dereferenceable(10) [[TMP1]], i32 10, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* nonnull align 1 dereferenceable(10) [[TMP0]], i8* nonnull align 1 dereferenceable(10) [[TMP1]], i32 10, i1 false) #0 ; CHECK-NEXT: ret i8* [[TMP0]] ; entry: @@ -227,7 +227,7 @@ declare noalias i8* @strndup(i8* nocapture, i32) nounwind define i32 @test9(i8** %esc) { ; CHECK-LABEL: @test9( -; CHECK-NEXT: [[CALL:%.*]] = tail call i8* @strdup(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i32 0, i32 0)) #0 +; CHECK-NEXT: [[CALL:%.*]] = tail call dereferenceable_or_null(8) i8* @strdup(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i32 0, i32 0)) #0 ; CHECK-NEXT: store i8* [[CALL]], i8** [[ESC:%.*]], align 8 ; CHECK-NEXT: ret i32 8 ;