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-rw-r--r--clang/include/clang/Basic/LangOptions.def2
-rw-r--r--clang/include/clang/Driver/CC1Options.td2
-rw-r--r--clang/include/clang/Driver/Options.td5
-rw-r--r--clang/lib/CodeGen/CodeGenModule.cpp4
-rw-r--r--clang/lib/Driver/ToolChains/Clang.cpp7
-rw-r--r--clang/lib/Driver/ToolChains/CommonArgs.cpp34
-rw-r--r--clang/lib/Driver/ToolChains/CommonArgs.h3
-rw-r--r--clang/lib/Frontend/CompilerInvocation.cpp3
-rw-r--r--clang/test/CodeGen/function-alignment.c16
-rw-r--r--clang/test/Driver/clang_f_opts.c4
-rw-r--r--clang/test/Driver/function-alignment.c17
11 files changed, 91 insertions, 6 deletions
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index 029e6516c0a..e7d8302e5c5 100644
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -292,6 +292,8 @@ ENUM_LANGOPT(ClangABICompat, ClangABI, 4, ClangABI::Latest,
"version of Clang that we should attempt to be ABI-compatible "
"with")
+COMPATIBLE_VALUE_LANGOPT(FunctionAlignment, 5, 0, "Default alignment for functions")
+
#undef LANGOPT
#undef COMPATIBLE_LANGOPT
#undef BENIGN_LANGOPT
diff --git a/clang/include/clang/Driver/CC1Options.td b/clang/include/clang/Driver/CC1Options.td
index d6202a25b38..03b43ddd48f 100644
--- a/clang/include/clang/Driver/CC1Options.td
+++ b/clang/include/clang/Driver/CC1Options.td
@@ -645,6 +645,8 @@ def disable_objc_default_synthesize_properties : Flag<["-"], "disable-objc-defau
HelpText<"disable the default synthesis of Objective-C properties">;
def fencode_extended_block_signature : Flag<["-"], "fencode-extended-block-signature">,
HelpText<"enable extended encoding of block type signature">;
+def function_alignment : Separate<["-"], "function-alignment">,
+ HelpText<"default alignment for functions">;
def pic_level : Separate<["-"], "pic-level">,
HelpText<"Value for __PIC__">;
def pic_is_pie : Flag<["-"], "pic-is-pie">,
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index d8e784a8abb..99a438092be 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -611,6 +611,9 @@ def fno_PIC : Flag<["-"], "fno-PIC">, Group<f_Group>;
def fPIE : Flag<["-"], "fPIE">, Group<f_Group>;
def fno_PIE : Flag<["-"], "fno-PIE">, Group<f_Group>;
def faccess_control : Flag<["-"], "faccess-control">, Group<f_Group>;
+def falign_functions : Flag<["-"], "falign-functions">, Group<f_Group>;
+def falign_functions_EQ : Joined<["-"], "falign-functions=">, Group<f_Group>;
+def fno_align_functions: Flag<["-"], "fno-align-functions">, Group<f_Group>;
def fallow_unsupported : Flag<["-"], "fallow-unsupported">, Group<f_Group>;
def fapple_kext : Flag<["-"], "fapple-kext">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Use Apple's kernel extensions ABI">;
@@ -2728,8 +2731,6 @@ def fprofile_dir : Joined<["-"], "fprofile-dir=">, Group<f_Group>;
def fuse_ld_EQ : Joined<["-"], "fuse-ld=">, Group<f_Group>, Flags<[CoreOption]>;
-defm align_functions : BooleanFFlag<"align-functions">, Group<clang_ignored_gcc_optimization_f_Group>;
-def falign_functions_EQ : Joined<["-"], "falign-functions=">, Group<clang_ignored_gcc_optimization_f_Group>;
defm align_labels : BooleanFFlag<"align-labels">, Group<clang_ignored_gcc_optimization_f_Group>;
def falign_labels_EQ : Joined<["-"], "falign-labels=">, Group<clang_ignored_gcc_optimization_f_Group>;
defm align_loops : BooleanFFlag<"align-loops">, Group<clang_ignored_gcc_optimization_f_Group>;
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index a21527abba1..17d9db3399f 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1238,6 +1238,10 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
if (alignment)
F->setAlignment(alignment);
+ if (!D->hasAttr<AlignedAttr>())
+ if (LangOpts.FunctionAlignment)
+ F->setAlignment(1 << LangOpts.FunctionAlignment);
+
// Some C++ ABIs require 2-byte alignment for member functions, in order to
// reserve a bit for differentiating between virtual and non-virtual member
// functions. If the current target's C++ ABI requires this and this is a
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 15e7cf2847c..e96b5b7590f 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3323,6 +3323,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
CheckCodeGenerationOptions(D, Args);
+ unsigned FunctionAlignment = ParseFunctionAlignment(getToolChain(), Args);
+ assert(FunctionAlignment <= 31 && "function alignment will be truncated!");
+ if (FunctionAlignment) {
+ CmdArgs.push_back("-function-alignment");
+ CmdArgs.push_back(Args.MakeArgString(std::to_string(FunctionAlignment)));
+ }
+
llvm::Reloc::Model RelocationModel;
unsigned PICLevel;
bool IsPIE;
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 869cf4c8f2e..1527238c663 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1033,6 +1033,40 @@ tools::ParsePICArgs(const ToolChain &ToolChain, const ArgList &Args) {
return std::make_tuple(RelocM, 0U, false);
}
+// `-falign-functions` indicates that the functions should be aligned to a
+// 16-byte boundary.
+//
+// `-falign-functions=1` is the same as `-fno-align-functions`.
+//
+// The scalar `n` in `-falign-functions=n` must be an integral value between
+// [0, 65536]. If the value is not a power-of-two, it will be rounded up to
+// the nearest power-of-two.
+//
+// If we return `0`, the frontend will default to the backend's preferred
+// alignment.
+//
+// NOTE: icc only allows values between [0, 4096]. icc uses `-falign-functions`
+// to mean `-falign-functions=16`. GCC defaults to the backend's preferred
+// alignment. For unaligned functions, we default to the backend's preferred
+// alignment.
+unsigned tools::ParseFunctionAlignment(const ToolChain &TC,
+ const ArgList &Args) {
+ const Arg *A = Args.getLastArg(options::OPT_falign_functions,
+ options::OPT_falign_functions_EQ,
+ options::OPT_fno_align_functions);
+ if (!A || A->getOption().matches(options::OPT_fno_align_functions))
+ return 0;
+
+ if (A->getOption().matches(options::OPT_falign_functions))
+ return 0;
+
+ unsigned Value = 0;
+ if (StringRef(A->getValue()).getAsInteger(10, Value) || Value > 65536)
+ TC.getDriver().Diag(diag::err_drv_invalid_int_value)
+ << A->getAsString(Args) << A->getValue();
+ return Value ? llvm::Log2_32_Ceil(std::min(Value, 65536u)) : Value;
+}
+
void tools::AddAssemblerKPIC(const ToolChain &ToolChain, const ArgList &Args,
ArgStringList &CmdArgs) {
llvm::Reloc::Model RelocationModel;
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.h b/clang/lib/Driver/ToolChains/CommonArgs.h
index 14db1ea7302..10a03d4a178 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.h
+++ b/clang/lib/Driver/ToolChains/CommonArgs.h
@@ -66,6 +66,9 @@ void AddGoldPlugin(const ToolChain &ToolChain, const llvm::opt::ArgList &Args,
std::tuple<llvm::Reloc::Model, unsigned, bool>
ParsePICArgs(const ToolChain &ToolChain, const llvm::opt::ArgList &Args);
+unsigned ParseFunctionAlignment(const ToolChain &TC,
+ const llvm::opt::ArgList &Args);
+
void AddAssemblerKPIC(const ToolChain &ToolChain,
const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs);
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 9146d2a36df..67e15b41add 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2968,6 +2968,9 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
LangOpts.ObjCExceptions = 1;
}
+ LangOpts.FunctionAlignment =
+ getLastArgIntValue(Args, OPT_function_alignment, 0, Diags);
+
if (LangOpts.CUDA) {
// During CUDA device-side compilation, the aux triple is the
// triple used for host compilation.
diff --git a/clang/test/CodeGen/function-alignment.c b/clang/test/CodeGen/function-alignment.c
new file mode 100644
index 00000000000..9101b2c043f
--- /dev/null
+++ b/clang/test/CodeGen/function-alignment.c
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-NONE
+// RUN: %clang_cc1 -emit-llvm -function-alignment 4 %s -o - | FileCheck %s -check-prefix CHECK-16
+// RUN: %clang_cc1 -emit-llvm -function-alignment 5 %s -o - | FileCheck %s -check-prefix CHECK-32
+
+void f(void) {}
+void __attribute__((__aligned__(64))) g(void) {}
+
+// CHECK-NONE-NOT: define void @f() #0 align
+// CHECK-NONE: define void @g() #0 align 64
+
+// CHECK-16: define void @f() #0 align 16
+// CHECK-16: define void @g() #0 align 64
+
+// CHECK-32: define void @f() #0 align 32
+// CHECK-32: define void @g() #0 align 64
+
diff --git a/clang/test/Driver/clang_f_opts.c b/clang/test/Driver/clang_f_opts.c
index 2b2a7e7b98f..be9ca2c93d6 100644
--- a/clang/test/Driver/clang_f_opts.c
+++ b/clang/test/Driver/clang_f_opts.c
@@ -302,8 +302,6 @@
// RUN: -fkeep-inline-functions \
// RUN: -fno-keep-inline-functions \
// RUN: -freorder-blocks \
-// RUN: -falign-functions \
-// RUN: -falign-functions=1 \
// RUN: -ffloat-store \
// RUN: -fgcse \
// RUN: -fivopts \
@@ -370,8 +368,6 @@
// CHECK-WARNING-DAG: optimization flag '-fkeep-inline-functions' is not supported
// CHECK-WARNING-DAG: optimization flag '-fno-keep-inline-functions' is not supported
// CHECK-WARNING-DAG: optimization flag '-freorder-blocks' is not supported
-// CHECK-WARNING-DAG: optimization flag '-falign-functions' is not supported
-// CHECK-WARNING-DAG: optimization flag '-falign-functions=1' is not supported
// CHECK-WARNING-DAG: optimization flag '-ffloat-store' is not supported
// CHECK-WARNING-DAG: optimization flag '-fgcse' is not supported
// CHECK-WARNING-DAG: optimization flag '-fivopts' is not supported
diff --git a/clang/test/Driver/function-alignment.c b/clang/test/Driver/function-alignment.c
new file mode 100644
index 00000000000..3dd6ad1cbaa
--- /dev/null
+++ b/clang/test/Driver/function-alignment.c
@@ -0,0 +1,17 @@
+// RUN: %clang -### %s 2>&1 | FileCheck %s -check-prefix CHECK-0
+// RUN: %clang -### -falign-functions %s 2>&1 | FileCheck %s -check-prefix CHECK-1
+// RUN: %clang -### -falign-functions=1 %s 2>&1 | FileCheck %s -check-prefix CHECK-1
+// RUN: %clang -### -falign-functions=2 %s 2>&1 | FileCheck %s -check-prefix CHECK-2
+// RUN: %clang -### -falign-functions=3 %s 2>&1 | FileCheck %s -check-prefix CHECK-3
+// RUN: %clang -### -falign-functions=4 %s 2>&1 | FileCheck %s -check-prefix CHECK-4
+// RUN: %clang -### -falign-functions=65537 %s 2>&1 | FileCheck %s -check-prefix CHECK-ERR-65537
+// RUN: %clang -### -falign-functions=a %s 2>&1 | FileCheck %s -check-prefix CHECK-ERR-A
+
+// CHECK-0-NOT: "-function-alignment"
+// CHECK-1-NOT: "-function-alignment"
+// CHECK-2: "-function-alignment" "1"
+// CHECK-3: "-function-alignment" "2"
+// CHECK-4: "-function-alignment" "2"
+// CHECK-ERR-65537: error: invalid integral value '65537' in '-falign-functions=65537'
+// CHECK-ERR-A: error: invalid integral value 'a' in '-falign-functions=a'
+
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