Author: Kiran Chandramohan Date: 2025-01-15T15:06:57Z New Revision: c593e3d0f77509ce65a6f5bd744f2d1ea9935c47
URL: https://github.com/llvm/llvm-project/commit/c593e3d0f77509ce65a6f5bd744f2d1ea9935c47 DIFF: https://github.com/llvm/llvm-project/commit/c593e3d0f77509ce65a6f5bd744f2d1ea9935c47.diff LOG: [Flang][Driver] Add a flag to control zero initialization of global v… (#122144) …ariables Patch adds a flag to control zero initialization of global variables without default initialization. The default is to zero initialize. Added: flang/test/Driver/fno-zero-init.f90 flang/test/Lower/zero_init.f90 flang/test/Lower/zero_init_default_init.f90 Modified: clang/include/clang/Driver/Options.td clang/lib/Driver/ToolChains/Flang.cpp flang/include/flang/Lower/LoweringOptions.def flang/lib/Frontend/CompilerInvocation.cpp flang/lib/Lower/ConvertVariable.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 2721c1b5d8dc55..dacfca910acc40 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -3505,6 +3505,11 @@ 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]>; +defm init_global_zero : BoolOptionWithoutMarshalling<"f", "init-global-zero", + PosFlag<SetTrue, [], [FlangOption, FC1Option], + "Zero initialize globals without default initialization (default)">, + NegFlag<SetFalse, [], [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 a7d0cc99f27d2d..c46e8222a9631a 100644 --- a/clang/lib/Driver/ToolChains/Flang.cpp +++ b/clang/lib/Driver/ToolChains/Flang.cpp @@ -155,7 +155,9 @@ void Flang::addCodegenOptions(const ArgList &Args, options::OPT_flang_deprecated_no_hlfir, options::OPT_fno_ppc_native_vec_elem_order, options::OPT_fppc_native_vec_elem_order, - options::OPT_ftime_report, options::OPT_ftime_report_EQ}); + options::OPT_finit_global_zero, + options::OPT_fno_init_global_zero, options::OPT_ftime_report, + options::OPT_ftime_report_EQ}); } void Flang::addPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const { diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def index 5a6debfdffe030..396c91948be36b 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(InitGlobalZero, unsigned, 1, 1) #undef LOWERINGOPT #undef ENUM_LOWERINGOPT diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp index 5e7127313c1335..78d1199c19749b 100644 --- a/flang/lib/Frontend/CompilerInvocation.cpp +++ b/flang/lib/Frontend/CompilerInvocation.cpp @@ -1373,6 +1373,14 @@ bool CompilerInvocation::createFromArgs( invoc.loweringOpts.setNoPPCNativeVecElemOrder(true); } + // -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(true); + else + 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 // remarks generated by LLVM in ExecuteCompilerInvocation.cpp. diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp index 9ee42d5cd88002..87236dc293ebbc 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().getInitGlobalZero()) + 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..2ffa10dd040d52 --- /dev/null +++ b/flang/test/Driver/fno-zero-init.f90 @@ -0,0 +1,9 @@ +! 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 new file mode 100644 index 00000000000000..89e6584f410f7c --- /dev/null +++ b/flang/test/Lower/zero_init.f90 @@ -0,0 +1,17 @@ +! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck --check-prefix=CHECK-DEFAULT %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 +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..761052b5b08a0e --- /dev/null +++ b/flang/test/Lower/zero_init_default_init.f90 @@ -0,0 +1,19 @@ +! RUN: %flang_fc1 -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 + +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: } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
