[InstCombine] Annotate strdup with deref_or_null
llvm-svn: 372098
diff --git a/llvm/include/llvm/Analysis/MemoryBuiltins.h b/llvm/include/llvm/Analysis/MemoryBuiltins.h
index 5c201f3..a89d76b 100644
--- a/llvm/include/llvm/Analysis/MemoryBuiltins.h
+++ b/llvm/include/llvm/Analysis/MemoryBuiltins.h
@@ -104,6 +104,11 @@
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/llvm/lib/Analysis/MemoryBuiltins.cpp b/llvm/lib/Analysis/MemoryBuiltins.cpp
index 52f3123..5acdeb6 100644
--- a/llvm/lib/Analysis/MemoryBuiltins.cpp
+++ b/llvm/lib/Analysis/MemoryBuiltins.cpp
@@ -307,6 +307,13 @@
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/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index e96e45e..9043818 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -4208,6 +4208,12 @@
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/llvm/test/Transforms/InstCombine/deref-alloc-fns.ll b/llvm/test/Transforms/InstCombine/deref-alloc-fns.ll
index f188510..efaf1cd 100644
--- a/llvm/test/Transforms/InstCombine/deref-alloc-fns.ll
+++ b/llvm/test/Transforms/InstCombine/deref-alloc-fns.ll
@@ -6,6 +6,9 @@
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 @@
%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/llvm/test/Transforms/InstCombine/objsize.ll b/llvm/test/Transforms/InstCombine/objsize.ll
index 7b9dbd2..590fcd6 100644
--- a/llvm/test/Transforms/InstCombine/objsize.ll
+++ b/llvm/test/Transforms/InstCombine/objsize.ll
@@ -141,7 +141,7 @@
; 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 @@
; 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 @@
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
;