[flang-commits] [clang] [flang] [Flang][Driver] Add a flag to control zero initialization of global v… (PR #122144)
Kiran Chandramohan via flang-commits
flang-commits at lists.llvm.org
Mon Jan 13 10:10:09 PST 2025
https://github.com/kiranchandramohan updated https://github.com/llvm/llvm-project/pull/122144
>From 483501549b910d1e91dab05cce65793c44aaa6f6 Mon Sep 17 00:00:00 2001
From: Kiran Chandramohan <kiran.chandramohan at arm.com>
Date: Wed, 8 Jan 2025 17:26:24 +0000
Subject: [PATCH 1/2] [Flang][Driver] Add a flag to control zero initialization
of global variables
Patch adds a flag to control zero initialization of global variables
without default initialization. The default is to zero initialize.
---
clang/include/clang/Driver/Options.td | 3 +++
clang/lib/Driver/ToolChains/Flang.cpp | 1 +
flang/include/flang/Lower/LoweringOptions.def | 3 +++
flang/lib/Frontend/CompilerInvocation.cpp | 6 ++++++
flang/lib/Lower/ConvertVariable.cpp | 6 +++++-
flang/test/Driver/fno-zero-init.f90 | 5 +++++
flang/test/Lower/zero_init.f90 | 16 ++++++++++++++++
flang/test/Lower/zero_init_default_init.f90 | 18 ++++++++++++++++++
8 files changed, 57 insertions(+), 1 deletion(-)
create mode 100644 flang/test/Driver/fno-zero-init.f90
create mode 100644 flang/test/Lower/zero_init.f90
create mode 100644 flang/test/Lower/zero_init_default_init.f90
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 52823430919de4..e8d18cf78e985a 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3494,6 +3494,9 @@ 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_overflow : Flag<["-"], "fno-strict-overflow">, Group<f_Group>,
Visibility<[ClangOption, FlangOption]>;
+def fno_zero_init_global_without_init : Flag<["-"], "fno-zero-init-global-without-init">, Group<f_Group>,
+ Visibility<[FlangOption, FC1Option]>,
+ HelpText<"Do not zero initialize globals without default initialization">;
def fno_pointer_tbaa : Flag<["-"], "fno-pointer-tbaa">, Group<f_Group>;
def fno_temp_file : Flag<["-"], "fno-temp-file">, Group<f_Group>,
Visibility<[ClangOption, CC1Option, CLOption, DXCOption]>, HelpText<
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 75b10e88371ae7..609f5315426977 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -153,6 +153,7 @@ void Flang::addCodegenOptions(const ArgList &Args,
Args.addAllArgs(CmdArgs, {options::OPT_flang_experimental_hlfir,
options::OPT_flang_deprecated_no_hlfir,
options::OPT_fno_ppc_native_vec_elem_order,
+ options::OPT_fno_zero_init_global_without_init,
options::OPT_fppc_native_vec_elem_order});
}
diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def
index 5a6debfdffe030..acce21f5faab8b 100644
--- a/flang/include/flang/Lower/LoweringOptions.def
+++ b/flang/include/flang/Lower/LoweringOptions.def
@@ -44,5 +44,8 @@ ENUM_LOWERINGOPT(IntegerWrapAround, unsigned, 1, 0)
/// If false, assume that the shapes/types/allocation-status match.
ENUM_LOWERINGOPT(ReallocateLHS, unsigned, 1, 1)
+/// If true, initialize globals without initialization to zero.
+/// On by default.
+ENUM_LOWERINGOPT(ZeroInitGlobalsWithoutInit, unsigned, 1, 1)
#undef LOWERINGOPT
#undef ENUM_LOWERINGOPT
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 340efb1c63a5e5..fa91a0e2642bc8 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1373,6 +1373,12 @@ bool CompilerInvocation::createFromArgs(
invoc.loweringOpts.setNoPPCNativeVecElemOrder(true);
}
+ // -fno-zero-init-global-without-init
+ if (args.hasArg(
+ clang::driver::options::OPT_fno_zero_init_global_without_init)) {
+ invoc.loweringOpts.setZeroInitGlobalsWithoutInit(false);
+ }
+
// Preserve all the remark options requested, i.e. -Rpass, -Rpass-missed or
// -Rpass-analysis. This will be used later when processing and outputting the
// remarks generated by LLVM in ExecuteCompilerInvocation.cpp.
diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index 9ee42d5cd88002..db8a57d416274c 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -635,7 +635,11 @@ static fir::GlobalOp defineGlobal(Fortran::lower::AbstractConverter &converter,
global.setLinkName(builder.createCommonLinkage());
Fortran::lower::createGlobalInitialization(
builder, global, [&](fir::FirOpBuilder &builder) {
- mlir::Value initValue = builder.create<fir::ZeroOp>(loc, symTy);
+ mlir::Value initValue;
+ if (converter.getLoweringOptions().getZeroInitGlobalsWithoutInit())
+ initValue = builder.create<fir::ZeroOp>(loc, symTy);
+ else
+ initValue = builder.create<fir::UndefOp>(loc, symTy);
builder.create<fir::HasValueOp>(loc, initValue);
});
}
diff --git a/flang/test/Driver/fno-zero-init.f90 b/flang/test/Driver/fno-zero-init.f90
new file mode 100644
index 00000000000000..faa757b32a8dab
--- /dev/null
+++ b/flang/test/Driver/fno-zero-init.f90
@@ -0,0 +1,5 @@
+! Check that the driver passes through -fno-zero-init-global-without-init:
+! RUN: %flang -### -S -fno-zero-init-global-without-init %s -o - 2>&1 | FileCheck %s
+! Check that the compiler accepts -fno-zero-init-global-without-init:
+! RUN: %flang_fc1 -emit-hlfir -fno-zero-init-global-without-init %s -o -
+! CHECK: "-fc1"{{.*}}"-fno-zero-init-global-without-init"
diff --git a/flang/test/Lower/zero_init.f90 b/flang/test/Lower/zero_init.f90
new file mode 100644
index 00000000000000..76201eb0f0cbd0
--- /dev/null
+++ b/flang/test/Lower/zero_init.f90
@@ -0,0 +1,16 @@
+! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-DEFAULT %s
+! RUN: %flang_fc1 -fno-zero-init-global-without-init -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-NO-ZERO-INIT %s
+
+module m1
+ real :: x
+end module m1
+
+!CHECK-DEFAULT: fir.global @_QMm1Ex : f32 {
+!CHECK-DEFAULT: %[[UNDEF:.*]] = fir.zero_bits f32
+!CHECK-DEFAULT: fir.has_value %[[UNDEF]] : f32
+!CHECK-DEFAULT: }
+
+!CHECK-NO-ZERO-INIT: fir.global @_QMm1Ex : f32 {
+!CHECK-NO-ZERO-INIT: %[[UNDEF:.*]] = fir.undefined f32
+!CHECK-NO-ZERO-INIT: fir.has_value %[[UNDEF]] : f32
+!CHECK-NO-ZERO-INIT: }
diff --git a/flang/test/Lower/zero_init_default_init.f90 b/flang/test/Lower/zero_init_default_init.f90
new file mode 100644
index 00000000000000..ac6faf37e8d1bf
--- /dev/null
+++ b/flang/test/Lower/zero_init_default_init.f90
@@ -0,0 +1,18 @@
+! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck %s
+! RUN: %flang_fc1 -fno-zero-init-global-without-init -emit-hlfir -o - %s | FileCheck %s
+
+! Test that the flag does not affect globals with default init
+
+module m2
+ type val
+ integer :: my_val = 1
+ end type val
+ type(val) :: v1
+end module m2
+
+!CHECK: fir.global @_QMm2Ev1 : !fir.type<_QMm2Tval{my_val:i32}> {
+!CHECK: %[[V1:.*]] = fir.undefined !fir.type<_QMm2Tval{my_val:i32}>
+!CHECK: %[[ONE:.*]] = arith.constant 1 : i32
+!CHECK: %[[V1_INIT:.*]] = fir.insert_value %[[V1]], %[[ONE]], ["my_val", !fir.type<_QMm2Tval{my_val:i32}>] : (!fir.type<_QMm2Tval{my_val:i32}>, i32) -> !fir.type<_QMm2Tval{my_val:i32}>
+!CHECK: fir.has_value %[[V1_INIT]] : !fir.type<_QMm2Tval{my_val:i32}>
+!CHECK: }
>From 0887ccae49760f8ea93d6c3fffdc247855f861f1 Mon Sep 17 00:00:00 2001
From: Kiran Chandramohan <kiran.chandramohan at arm.com>
Date: Mon, 13 Jan 2025 18:06:07 +0000
Subject: [PATCH 2/2] Change name to init-global-zero and add positive flag as
well
---
clang/include/clang/Driver/Options.td | 9 ++++++---
clang/lib/Driver/ToolChains/Flang.cpp | 3 ++-
flang/include/flang/Lower/LoweringOptions.def | 2 +-
flang/lib/Frontend/CompilerInvocation.cpp | 10 +++++-----
flang/lib/Lower/ConvertVariable.cpp | 2 +-
flang/test/Driver/fno-zero-init.f90 | 14 +++++++++-----
flang/test/Lower/zero_init.f90 | 3 ++-
flang/test/Lower/zero_init_default_init.f90 | 3 ++-
8 files changed, 28 insertions(+), 18 deletions(-)
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index e8d18cf78e985a..854449bcab6364 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3494,9 +3494,12 @@ 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_overflow : Flag<["-"], "fno-strict-overflow">, Group<f_Group>,
Visibility<[ClangOption, FlangOption]>;
-def fno_zero_init_global_without_init : Flag<["-"], "fno-zero-init-global-without-init">, Group<f_Group>,
- Visibility<[FlangOption, FC1Option]>,
- HelpText<"Do not zero initialize globals without default initialization">;
+defm init_global_zero : BoolFOption<"init-global-zero",
+ CodeGenOpts<"InitGlobalZero">, DefaultTrue,
+ NegFlag<SetFalse, [], [FlangOption, FC1Option],
+ "Zero initialize globals without default initialization">,
+ PosFlag<SetTrue, [], [FlangOption, FC1Option],
+ "Do not zero initialize globals without default initialization">>;
def fno_pointer_tbaa : Flag<["-"], "fno-pointer-tbaa">, Group<f_Group>;
def fno_temp_file : Flag<["-"], "fno-temp-file">, Group<f_Group>,
Visibility<[ClangOption, CC1Option, CLOption, DXCOption]>, HelpText<
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 609f5315426977..cdce51a93bad21 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -153,7 +153,8 @@ void Flang::addCodegenOptions(const ArgList &Args,
Args.addAllArgs(CmdArgs, {options::OPT_flang_experimental_hlfir,
options::OPT_flang_deprecated_no_hlfir,
options::OPT_fno_ppc_native_vec_elem_order,
- options::OPT_fno_zero_init_global_without_init,
+ options::OPT_finit_global_zero,
+ options::OPT_fno_init_global_zero,
options::OPT_fppc_native_vec_elem_order});
}
diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def
index acce21f5faab8b..396c91948be36b 100644
--- a/flang/include/flang/Lower/LoweringOptions.def
+++ b/flang/include/flang/Lower/LoweringOptions.def
@@ -46,6 +46,6 @@ ENUM_LOWERINGOPT(ReallocateLHS, unsigned, 1, 1)
/// If true, initialize globals without initialization to zero.
/// On by default.
-ENUM_LOWERINGOPT(ZeroInitGlobalsWithoutInit, unsigned, 1, 1)
+ENUM_LOWERINGOPT(InitGlobalZero, unsigned, 1, 1)
#undef LOWERINGOPT
#undef ENUM_LOWERINGOPT
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index fa91a0e2642bc8..f9661d1bd3a229 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1373,11 +1373,11 @@ bool CompilerInvocation::createFromArgs(
invoc.loweringOpts.setNoPPCNativeVecElemOrder(true);
}
- // -fno-zero-init-global-without-init
- if (args.hasArg(
- clang::driver::options::OPT_fno_zero_init_global_without_init)) {
- invoc.loweringOpts.setZeroInitGlobalsWithoutInit(false);
- }
+ // -f[no-]init-global-zero
+ if (!args.hasFlag(clang::driver::options::OPT_finit_global_zero,
+ clang::driver::options::OPT_fno_init_global_zero,
+ /*default=*/true))
+ invoc.loweringOpts.setInitGlobalZero(false);
// Preserve all the remark options requested, i.e. -Rpass, -Rpass-missed or
// -Rpass-analysis. This will be used later when processing and outputting the
diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index db8a57d416274c..87236dc293ebbc 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -636,7 +636,7 @@ static fir::GlobalOp defineGlobal(Fortran::lower::AbstractConverter &converter,
Fortran::lower::createGlobalInitialization(
builder, global, [&](fir::FirOpBuilder &builder) {
mlir::Value initValue;
- if (converter.getLoweringOptions().getZeroInitGlobalsWithoutInit())
+ if (converter.getLoweringOptions().getInitGlobalZero())
initValue = builder.create<fir::ZeroOp>(loc, symTy);
else
initValue = builder.create<fir::UndefOp>(loc, symTy);
diff --git a/flang/test/Driver/fno-zero-init.f90 b/flang/test/Driver/fno-zero-init.f90
index faa757b32a8dab..2ffa10dd040d52 100644
--- a/flang/test/Driver/fno-zero-init.f90
+++ b/flang/test/Driver/fno-zero-init.f90
@@ -1,5 +1,9 @@
-! Check that the driver passes through -fno-zero-init-global-without-init:
-! RUN: %flang -### -S -fno-zero-init-global-without-init %s -o - 2>&1 | FileCheck %s
-! Check that the compiler accepts -fno-zero-init-global-without-init:
-! RUN: %flang_fc1 -emit-hlfir -fno-zero-init-global-without-init %s -o -
-! CHECK: "-fc1"{{.*}}"-fno-zero-init-global-without-init"
+! Check that the driver passes through -f[no-]init-global-zero:
+! RUN: %flang -### -S -finit-global-zero %s -o - 2>&1 | FileCheck --check-prefix=CHECK-POS %s
+! RUN: %flang -### -S -fno-init-global-zero %s -o - 2>&1 | FileCheck --check-prefix=CHECK-NEG %s
+! Check that the compiler accepts -f[no-]init-global-zero:
+! RUN: %flang_fc1 -emit-hlfir -finit-global-zero %s -o -
+! RUN: %flang_fc1 -emit-hlfir -fno-init-global-zero %s -o -
+
+! CHECK-POS: "-fc1"{{.*}}"-finit-global-zero"
+! CHECK-NEG: "-fc1"{{.*}}"-fno-init-global-zero"
diff --git a/flang/test/Lower/zero_init.f90 b/flang/test/Lower/zero_init.f90
index 76201eb0f0cbd0..89e6584f410f7c 100644
--- a/flang/test/Lower/zero_init.f90
+++ b/flang/test/Lower/zero_init.f90
@@ -1,5 +1,6 @@
! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-DEFAULT %s
-! RUN: %flang_fc1 -fno-zero-init-global-without-init -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-NO-ZERO-INIT %s
+! RUN: %flang_fc1 -finit-global-zero -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-DEFAULT %s
+! RUN: %flang_fc1 -fno-init-global-zero -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-NO-ZERO-INIT %s
module m1
real :: x
diff --git a/flang/test/Lower/zero_init_default_init.f90 b/flang/test/Lower/zero_init_default_init.f90
index ac6faf37e8d1bf..761052b5b08a0e 100644
--- a/flang/test/Lower/zero_init_default_init.f90
+++ b/flang/test/Lower/zero_init_default_init.f90
@@ -1,5 +1,6 @@
! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck %s
-! RUN: %flang_fc1 -fno-zero-init-global-without-init -emit-hlfir -o - %s | FileCheck %s
+! RUN: %flang_fc1 -finit-global-zero -emit-hlfir -o - %s | FileCheck %s
+! RUN: %flang_fc1 -fno-init-global-zero -emit-hlfir -o - %s | FileCheck %s
! Test that the flag does not affect globals with default init
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