[clang] Adjust -mlarge-data-threshold handling#77958
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Make it apply to x86-64 medium and large code models since that's what the backend does. Warn if it's used for x86-32. Default to 0, let the driver set it to 65536 for the medium code model if one is not passed. Set it to 0 for the large code model by default to match gcc and since some users make assumptions about the large code model that any small data will break.
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@llvm/pr-subscribers-clang-codegen @llvm/pr-subscribers-clang-driver Author: Arthur Eubanks (aeubanks) ChangesMake it apply to x86-64 medium and large code models since that's what the backend does. Warn if it's used for x86-32. Default to 0, let the driver set it to 65536 for the medium code model Full diff: https://github.com/llvm/llvm-project/pull/77958.diff 6 Files Affected:
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index 0a8a77fadbeb1b..8b5232a6df3958 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -472,7 +472,7 @@ def warn_unsupported_branch_protection: Warning <
def err_sls_hardening_arm_not_supported : Error<
"-mharden-sls is only supported on armv7-a or later">;
def warn_drv_large_data_threshold_invalid_code_model: Warning<
- "'%0' only applies to medium code model">,
+ "'%0' only applies to medium and large code models">,
InGroup<UnusedCommandLineArgument>;
def note_drv_command_failed_diag_msg : Note<
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 7f97d6b6faa398..e8afa1ea4126d8 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4393,7 +4393,7 @@ def mcmodel_EQ : Joined<["-"], "mcmodel=">, Group<m_Group>,
MarshallingInfoString<TargetOpts<"CodeModel">, [{"default"}]>;
def mlarge_data_threshold_EQ : Joined<["-"], "mlarge-data-threshold=">, Group<m_Group>,
Visibility<[ClangOption, CC1Option]>,
- MarshallingInfoInt<TargetOpts<"LargeDataThreshold">, "65535">;
+ MarshallingInfoInt<TargetOpts<"LargeDataThreshold">, "0">;
def mtls_size_EQ : Joined<["-"], "mtls-size=">, Group<m_Group>,
Visibility<[ClangOption, CC1Option]>,
HelpText<"Specify bit size of immediate TLS offsets (AArch64 ELF only): "
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index ad6fc71c1e5038..0cfe7a0133b7e3 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1201,7 +1201,7 @@ void CodeGenModule::Release() {
llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
getModule().setCodeModel(codeModel);
- if (CM == llvm::CodeModel::Medium &&
+ if ((CM == llvm::CodeModel::Medium || CM == llvm::CodeModel::Large) &&
Context.getTargetInfo().getTriple().getArch() ==
llvm::Triple::x86_64) {
getModule().setLargeDataThreshold(getCodeGenOpts().LargeDataThreshold);
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 1ee7ae602f3ce5..27a50b2c32e94d 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5752,20 +5752,29 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
}
}
- if (Arg *A = Args.getLastArg(options::OPT_mlarge_data_threshold_EQ)) {
- if (!Triple.isX86()) {
- D.Diag(diag::err_drv_unsupported_opt_for_target)
- << A->getOption().getName() << TripleStr;
- } else {
- bool IsMediumCM = false;
- if (Arg *A = Args.getLastArg(options::OPT_mcmodel_EQ))
- IsMediumCM = StringRef(A->getValue()) == "medium";
- if (!IsMediumCM) {
+ if (Triple.getArch() == llvm::Triple::x86_64) {
+ bool IsMediumCM = false;
+ bool IsLargeCM = false;
+ if (Arg *A = Args.getLastArg(options::OPT_mcmodel_EQ)) {
+ IsMediumCM = StringRef(A->getValue()) == "medium";
+ IsLargeCM = StringRef(A->getValue()) == "large";
+ }
+ if (Arg *A = Args.getLastArg(options::OPT_mlarge_data_threshold_EQ)) {
+ if (!IsMediumCM && !IsLargeCM) {
D.Diag(diag::warn_drv_large_data_threshold_invalid_code_model)
<< A->getOption().getRenderName();
} else {
A->render(Args, CmdArgs);
}
+ } else if (IsMediumCM) {
+ CmdArgs.push_back("-mlarge-data-threshold=65536");
+ } else if (IsLargeCM) {
+ CmdArgs.push_back("-mlarge-data-threshold=0");
+ }
+ } else {
+ if (Arg *A = Args.getLastArg(options::OPT_mlarge_data_threshold_EQ)) {
+ D.Diag(diag::err_drv_unsupported_opt_for_target)
+ << A->getOption().getName() << TripleStr;
}
}
diff --git a/clang/test/CodeGen/large-data-threshold.c b/clang/test/CodeGen/large-data-threshold.c
index 29ae19e9b71899..d110ad2125c7bc 100644
--- a/clang/test/CodeGen/large-data-threshold.c
+++ b/clang/test/CodeGen/large-data-threshold.c
@@ -2,11 +2,14 @@
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm %s -o - -mcmodel=medium | FileCheck %s --check-prefix=IR-DEFAULT
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm %s -o - -mcmodel=medium -mlarge-data-threshold=200 | FileCheck %s --check-prefix=IR-CUSTOM
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm %s -o - -mcmodel=large -mlarge-data-threshold=200 | FileCheck %s --check-prefix=IR-CUSTOM
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm %s -o - -mcmodel=small -mlarge-data-threshold=200 | FileCheck %s --check-prefix=IR-SMALL
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -S %s -o - -mcmodel=medium -mlarge-data-threshold=200 | FileCheck %s --check-prefix=ASM-SMALL
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -S %s -o - -mcmodel=medium -mlarge-data-threshold=2 | FileCheck %s --check-prefix=ASM-LARGE
-// IR-DEFAULT: !{i32 1, !"Large Data Threshold", i64 65535}
+// IR-DEFAULT: !{i32 1, !"Large Data Threshold", i64 0}
// IR-CUSTOM: !{i32 1, !"Large Data Threshold", i64 200}
+// IR-SMALL-NOT: !"Large Data Threshold"
// ASM-SMALL-NOT: movabsq
// ASM-LARGE: movabsq
diff --git a/clang/test/Driver/large-data-threshold.c b/clang/test/Driver/large-data-threshold.c
index 9914286701c6c1..dfc51349f7bf16 100644
--- a/clang/test/Driver/large-data-threshold.c
+++ b/clang/test/Driver/large-data-threshold.c
@@ -1,8 +1,14 @@
+// RUN: %clang --target=x86_64 -### -c -mcmodel=large -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=ARG %s
// RUN: %clang --target=x86_64 -### -c -mcmodel=medium -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=ARG %s
-// RUN: %clang --target=x86_64 -### -c -mcmodel=small -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=SMALL %s
+// RUN: %clang --target=x86_64 -### -c -mcmodel=large %s 2>&1 | FileCheck --check-prefix=ARG-LARGE-DEFAULT %s
+// RUN: %clang --target=x86_64 -### -c -mcmodel=medium %s 2>&1 | FileCheck --check-prefix=ARG-MEDIUM-DEFAULT %s
+// RUN: %clang --target=x86_64 -### -c -mcmodel=small -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=SMALL --implicit-check-not=mlarge-data-threshold %s
+// RUN: not %clang --target=x86 -### -c -mcmodel=medium -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=ARCH %s
// RUN: not %clang --target=riscv32 -### -c -mcmodel=medium -mlarge-data-threshold=200 %s 2>&1 | FileCheck --check-prefix=ARCH %s
// ARG: "-mlarge-data-threshold=200"
+// ARG-MEDIUM-DEFAULT: "-mlarge-data-threshold=65536"
+// ARG-LARGE-DEFAULT: "-mlarge-data-threshold=0"
-// SMALL: 'mlarge-data-threshold=' only applies to medium code model
-// ARCH: unsupported option 'mlarge-data-threshold=' for target 'riscv32'
+// SMALL: 'mlarge-data-threshold=' only applies to medium and large code models
+// ARCH: unsupported option 'mlarge-data-threshold=' for target
|
MaskRay
reviewed
Jan 12, 2024
| CmdArgs.push_back("-mlarge-data-threshold=0"); | ||
| } | ||
| } else { | ||
| if (Arg *A = Args.getLastArg(options::OPT_mlarge_data_threshold_EQ)) { |
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You can remove err_drv_unsupported_opt_for_target here in favor of TargetSpecific at def mlarge_data_threshold_EQ
MaskRay
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Jan 12, 2024
MaskRay
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Jan 12, 2024
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Jan 28, 2024
Make it apply to x86-64 medium and large code models since that's what the backend does. Limit logic to exclude x86-32. Default to 0, let the driver set it to 65536 for the medium code model if one is not passed. Set it to 0 for the large code model by default to match gcc and since some users make assumptions about the large code model that any small data will break.
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Make it apply to x86-64 medium and large code models since that's what the backend does.
Limit logic to exclude x86-32.
Default to 0, let the driver set it to 65536 for the medium code model
if one is not passed. Set it to 0 for the large code model by default to
match gcc and since some users make assumptions about the large code
model that any small data will break.