Prazek created this revision.
Prazek added reviewers: rsmith, rjmccall, majnemer, nlewycky.
Prazek added a subscriber: cfe-commits.
Keep in mind, that I will not push it untill I will update GVN for using
!invariant.group metadata
http://reviews.llvm.org/D12312
Files:
include/clang/Driver/Options.td
include/clang/Frontend/CodeGenOptions.def
lib/CodeGen/CGClass.cpp
lib/CodeGen/CGExprCXX.cpp
lib/Driver/Tools.cpp
lib/Frontend/CompilerInvocation.cpp
test/CodeGenCXX/virtual-base-ctor.cpp
Index: test/CodeGenCXX/virtual-base-ctor.cpp
===================================================================
--- test/CodeGenCXX/virtual-base-ctor.cpp
+++ test/CodeGenCXX/virtual-base-ctor.cpp
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 %s -emit-llvm -triple %itanium_abi_triple -o - -O2 | FileCheck %s
+// RUN: %clang_cc1 %s -emit-llvm -triple %itanium_abi_triple -o - -O2 -fstrict-vptrs | FileCheck %s
struct B;
extern B x;
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -493,6 +493,7 @@
Opts.NoDwarfDirectoryAsm = Args.hasArg(OPT_fno_dwarf_directory_asm);
Opts.SoftFloat = Args.hasArg(OPT_msoft_float);
Opts.StrictEnums = Args.hasArg(OPT_fstrict_enums);
+ Opts.StrictVPtrs = Args.hasArg(OPT_fstrict_vptrs);
Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
Args.hasArg(OPT_cl_unsafe_math_optimizations) ||
Args.hasArg(OPT_cl_fast_relaxed_math);
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -3368,6 +3368,9 @@
if (Args.hasFlag(options::OPT_fstrict_enums, options::OPT_fno_strict_enums,
false))
CmdArgs.push_back("-fstrict-enums");
+ if (Args.hasFlag(options::OPT_fstrict_vptrs, options::OPT_fno_strict_vptrs,
+ false))
+ CmdArgs.push_back("-fstrict-vptrs");
if (!Args.hasFlag(options::OPT_foptimize_sibling_calls,
options::OPT_fno_optimize_sibling_calls))
CmdArgs.push_back("-mdisable-tail-calls");
Index: lib/CodeGen/CGExprCXX.cpp
===================================================================
--- lib/CodeGen/CGExprCXX.cpp
+++ lib/CodeGen/CGExprCXX.cpp
@@ -1354,6 +1354,11 @@
llvm::Type *elementPtrTy = elementTy->getPointerTo(AS);
llvm::Value *result = Builder.CreateBitCast(allocation, elementPtrTy);
+ // Passing pointer through invariant.group.barrier to avoid propagation of
+ // vptrs information which may be included in previous type.
+ if (CGM.getCodeGenOpts().StrictVPtrs)
+ result = Builder.CreateInvariantGroupBarrier(result);
+
EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
allocSizeWithoutCookie);
if (E->isArray()) {
Index: lib/CodeGen/CGClass.cpp
===================================================================
--- lib/CodeGen/CGClass.cpp
+++ lib/CodeGen/CGClass.cpp
@@ -1253,10 +1253,11 @@
CGM.getCXXABI().EmitCtorCompleteObjectHandler(*this, ClassDecl);
assert(BaseCtorContinueBB);
}
-
+ bool BaseVPtrsInitialized = false;
// Virtual base initializers first.
for (; B != E && (*B)->isBaseInitializer() && (*B)->isBaseVirtual(); B++) {
EmitBaseInitializer(*this, ClassDecl, *B, CtorType);
+ BaseVPtrsInitialized = true;
}
if (BaseCtorContinueBB) {
@@ -1269,8 +1270,14 @@
for (; B != E && (*B)->isBaseInitializer(); B++) {
assert(!(*B)->isBaseVirtual());
EmitBaseInitializer(*this, ClassDecl, *B, CtorType);
+ BaseVPtrsInitialized = true;
}
+ // Pointer to this requires to be passed through invariant.group.barrier
+ // only if we've initilized any base vptrs.
+ if (CGM.getCodeGenOpts().StrictVPtrs && BaseVPtrsInitialized)
+ CXXThisValue = Builder.CreateInvariantGroupBarrier(LoadCXXThis());
+
InitializeVTablePointers(ClassDecl);
// And finally, initialize class members.
@@ -1476,8 +1483,13 @@
EnterDtorCleanups(Dtor, Dtor_Base);
// Initialize the vtable pointers before entering the body.
- if (!CanSkipVTablePointerInitialization(getContext(), Dtor))
- InitializeVTablePointers(Dtor->getParent());
+ if (!CanSkipVTablePointerInitialization(getContext(), Dtor)) {
+ // Inserting llvm.invariant.group.barrier intrinsic before base vptrs
+ // initialization to stop propagating previous vptr value.
+ if (CGM.getCodeGenOpts().StrictVPtrs)
+ CXXThisValue = Builder.CreateInvariantGroupBarrier(LoadCXXThis());
+ InitializeVTablePointers(Dtor->getParent());
+ }
if (isTryBody)
EmitStmt(cast<CXXTryStmt>(Body)->getTryBlock());
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -132,6 +132,7 @@
CODEGENOPT(SimplifyLibCalls , 1, 1) ///< Set when -fbuiltin is enabled.
CODEGENOPT(SoftFloat , 1, 0) ///< -soft-float.
CODEGENOPT(StrictEnums , 1, 0) ///< Optimize based on strict enum definition.
+CODEGENOPT(StrictVPtrs , 1, 0)
CODEGENOPT(TimePasses , 1, 0) ///< Set when -ftime-report is enabled.
CODEGENOPT(UnitAtATime , 1, 1) ///< Unused. For mirroring GCC optimization
///< selection.
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -858,6 +858,7 @@
def fstruct_path_tbaa : Flag<["-"], "fstruct-path-tbaa">, Group<f_Group>;
def fno_struct_path_tbaa : Flag<["-"], "fno-struct-path-tbaa">, Group<f_Group>;
def fno_strict_enums : Flag<["-"], "fno-strict-enums">, Group<f_Group>;
+def fno_strict_vptrs: Flag<["-"], "fno-strict-vptrs">, Group<f_Group>, Flags<[CC1Option]>;
def fno_strict_overflow : Flag<["-"], "fno-strict-overflow">, Group<f_Group>;
def fno_threadsafe_statics : Flag<["-"], "fno-threadsafe-statics">, Group<f_Group>,
Flags<[CC1Option]>, HelpText<"Do not emit code to make initialization of local statics thread safe">;
@@ -986,6 +987,7 @@
def fstrict_enums : Flag<["-"], "fstrict-enums">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Enable optimizations based on the strict definition of an enum's "
"value range">;
+def fstrict_vptrs: Flag<["-"], "fstrict-vptrs">, Group<f_Group>, Flags<[CC1Option]>;
def fstrict_overflow : Flag<["-"], "fstrict-overflow">, Group<f_Group>;
def fsyntax_only : Flag<["-"], "fsyntax-only">,
Flags<[DriverOption,CoreOption,CC1Option]>, Group<Action_Group>;
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