[clang] [MSP430] MSP430X Target CPU selection (PR #232775)
Robin Mueller via cfe-commits
cfe-commits at lists.llvm.org
Sun Oct 25 04:26:41 PDT 2026
https://github.com/robamu updated https://github.com/llvm/llvm-project/pull/232775
>From 57a5269cfa25e50d1afa7e586dc457fb03ccc710 Mon Sep 17 00:00:00 2001
From: Robin Mueller <robin.mueller.m at pm.me>
Date: Thu, 1 Oct 2026 13:52:04 +0200
Subject: [PATCH] [MSP430][Clang] MSP430X Target CPU selection
- Pass -target-cpu to LLVM, taken from `-mcpu` or derived from `-mmcu`.
- Unknown `-mcpu` values for MSP430 are rejected now
- `-mcpu=msp430x` and `-mcpu=msp430xv2` are both mapped to msp430x. The
newer revision does not change the generated code, only CPU cycle
counts
- The information can also be derived from `-mmcu` only using the target
table, which contains the CPU type.
- Added `MSP430X` and `__MSP430X__` defines. The `__MSP430X__` define matches GCC
- Updated GCC Multilib finder to use the GCC root libraries (MSP430X) for
the MSP430X CPU target. Otherwise, it will still use the /430
subdirectory like before.
Based on https://reviews.llvm.org/D109174.
Co-authored-by: Jozef Lawrynowicz <jozefl.opensrc at gmail.com>
Assisted-by: Claude Code (Claude Opus 5.5)
---
clang/lib/Basic/Targets/MSP430.cpp | 2 ++
clang/lib/Basic/Targets/MSP430.h | 18 +++++++++++++-
clang/lib/Driver/ToolChains/CommonArgs.cpp | 3 +++
clang/lib/Driver/ToolChains/Gnu.cpp | 23 +++++++++---------
clang/lib/Driver/ToolChains/MSP430.cpp | 18 ++++++++++++++
clang/lib/Driver/ToolChains/MSP430.h | 2 ++
clang/test/Driver/msp430-cpu.c | 25 +++++++++++++++++++
clang/test/Driver/msp430-toolchain.c | 28 ++++++++++++++++++++++
clang/test/Preprocessor/msp430-defs.c | 9 +++++++
9 files changed, 115 insertions(+), 13 deletions(-)
create mode 100644 clang/test/Driver/msp430-cpu.c
create mode 100644 clang/test/Preprocessor/msp430-defs.c
diff --git a/clang/lib/Basic/Targets/MSP430.cpp b/clang/lib/Basic/Targets/MSP430.cpp
index 844f5d3af70379..989927a8c5ab69 100644
--- a/clang/lib/Basic/Targets/MSP430.cpp
+++ b/clang/lib/Basic/Targets/MSP430.cpp
@@ -29,5 +29,7 @@ void MSP430TargetInfo::getTargetDefines(const LangOptions &Opts,
MacroBuilder &Builder) const {
Builder.defineMacro("MSP430");
Builder.defineMacro("__MSP430__");
+ if (CPU == "msp430x")
+ Builder.defineMacro("__MSP430X__");
// FIXME: defines for different 'flavours' of MCU
}
diff --git a/clang/lib/Basic/Targets/MSP430.h b/clang/lib/Basic/Targets/MSP430.h
index 96a243ef70fae5..fceb7c6e68e201 100644
--- a/clang/lib/Basic/Targets/MSP430.h
+++ b/clang/lib/Basic/Targets/MSP430.h
@@ -23,6 +23,7 @@ namespace targets {
class LLVM_LIBRARY_VISIBILITY MSP430TargetInfo : public TargetInfo {
static const char *const GCCRegNames[];
+ std::string CPU;
public:
MSP430TargetInfo(const llvm::Triple &Triple, const TargetOptions &)
@@ -55,10 +56,25 @@ class LLVM_LIBRARY_VISIBILITY MSP430TargetInfo : public TargetInfo {
return {};
}
+ bool isValidCPUName(StringRef Name) const override {
+ return Name == "msp430" || Name == "msp430x";
+ }
+
+ void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override {
+ Values.append({"msp430", "msp430x"});
+ }
+
+ bool setCPU(StringRef Name) override {
+ if (!isValidCPUName(Name))
+ return false;
+ CPU = Name;
+ return true;
+ }
+
bool allowsLargerPreferedTypeAlignment() const override { return false; }
bool hasFeature(StringRef Feature) const override {
- return Feature == "msp430";
+ return Feature == "msp430" || (Feature == "msp430x" && CPU == "msp430x");
}
ArrayRef<const char *> getGCCRegNames() const override;
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 39dcec2f823bdd..08ae8329433452 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -810,6 +810,9 @@ std::string tools::getCPUName(const Driver &D, const ArgList &Args,
return std::string(CPUName);
}
+ case llvm::Triple::msp430:
+ return msp430::getMSP430TargetCPU(Args);
+
case llvm::Triple::nvptx:
case llvm::Triple::nvptx64:
if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index 90fc71c147364d..0a58b251d0e693 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -1529,20 +1529,19 @@ static bool findMSP430Multilibs(const Driver &D,
StringRef Path, const ArgList &Args,
DetectedMultilibs &Result) {
FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
- MultilibBuilder WithoutExceptions =
- MultilibBuilder("/430").flag("-exceptions", /*Disallow=*/true);
- MultilibBuilder WithExceptions =
- MultilibBuilder("/430/exceptions").flag("-exceptions");
-
- // FIXME: when clang starts to support msp430x ISA additional logic
- // to select between multilib must be implemented
- // MultilibBuilder MSP430xMultilib = MultilibBuilder("/large");
-
- Result.Multilibs.push_back(WithoutExceptions.makeMultilib());
- Result.Multilibs.push_back(WithExceptions.makeMultilib());
- Result.Multilibs.FilterOut(NonExistent);
+ // The MSP430X libraries are in the root, the plain MSP430 ones in /430.
+ // FIXME: Add the /large multilibs once LLVM supports the large memory model.
+ Result.Multilibs =
+ MultilibSetBuilder()
+ .Either(MultilibBuilder().flag("-msp430x"),
+ MultilibBuilder("/430").flag("-msp430x", /*Disallow=*/true))
+ .Maybe(MultilibBuilder("/exceptions").flag("-exceptions"))
+ .makeMultilibSet()
+ .FilterOut(NonExistent);
Multilib::flags_list Flags;
+ std::string CPU = tools::getCPUName(D, Args, TargetTriple);
+ addMultilibFlag(CPU == "msp430x", "-msp430x", Flags);
addMultilibFlag(Args.hasFlag(options::OPT_fexceptions,
options::OPT_fno_exceptions, false),
"-exceptions", Flags);
diff --git a/clang/lib/Driver/ToolChains/MSP430.cpp b/clang/lib/Driver/ToolChains/MSP430.cpp
index 4bd12d1e130e53..5259e0721bdb26 100644
--- a/clang/lib/Driver/ToolChains/MSP430.cpp
+++ b/clang/lib/Driver/ToolChains/MSP430.cpp
@@ -13,6 +13,7 @@
#include "clang/Driver/InputInfo.h"
#include "clang/Driver/Multilib.h"
#include "clang/Options/Options.h"
+#include "llvm/ADT/StringSwitch.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Support/Path.h"
@@ -52,6 +53,23 @@ static StringRef getHWMultLib(const ArgList &Args) {
.Default("-lmul_none");
}
+static bool isMSP430X(StringRef CPU) {
+ return CPU == "msp430x" || CPU == "msp430xv2";
+}
+
+std::string msp430::getMSP430TargetCPU(const ArgList &Args) {
+ if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
+ return isMSP430X(A->getValue()) ? "msp430x" : A->getValue();
+ if (const Arg *A = Args.getLastArg(options::OPT_mmcu_EQ)) {
+ StringRef CPU = llvm::StringSwitch<StringRef>(A->getValue())
+#define MSP430_MCU(NAME, CPU, HWMULT) .Case(NAME, CPU)
+#include "clang/Basic/MSP430Target.def"
+ .Default("");
+ return isMSP430X(CPU) ? "msp430x" : CPU.str();
+ }
+ return "";
+}
+
void msp430::getMSP430TargetFeatures(const Driver &D, const ArgList &Args,
std::vector<StringRef> &Features) {
const Arg *MCU = Args.getLastArg(options::OPT_mmcu_EQ);
diff --git a/clang/lib/Driver/ToolChains/MSP430.h b/clang/lib/Driver/ToolChains/MSP430.h
index 865bcfb7cd3da6..3539c62430f675 100644
--- a/clang/lib/Driver/ToolChains/MSP430.h
+++ b/clang/lib/Driver/ToolChains/MSP430.h
@@ -80,6 +80,8 @@ class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
void getMSP430TargetFeatures(const Driver &D, const llvm::opt::ArgList &Args,
std::vector<llvm::StringRef> &Features);
+std::string getMSP430TargetCPU(const llvm::opt::ArgList &Args);
+
} // end namespace msp430
} // end namespace tools
} // end namespace driver
diff --git a/clang/test/Driver/msp430-cpu.c b/clang/test/Driver/msp430-cpu.c
new file mode 100644
index 00000000000000..d09272436f5700
--- /dev/null
+++ b/clang/test/Driver/msp430-cpu.c
@@ -0,0 +1,25 @@
+// RUN: %clang -### -c %s --target=msp430 2>&1 \
+// RUN: | FileCheck -check-prefix=NO-CPU %s
+// NO-CPU-NOT: "-target-cpu"
+
+// RUN: %clang -### -c %s --target=msp430 -mcpu=msp430 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430 %s
+// RUN: %clang -### -c %s --target=msp430 -mmcu=msp430c111 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430 %s
+// MSP430: "-cc1"{{.*}} "-target-cpu" "msp430"
+
+// msp430xv2 is accepted for GCC compatibility and treated as msp430x.
+// RUN: %clang -### -c %s --target=msp430 -mcpu=msp430x 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430X %s
+// RUN: %clang -### -c %s --target=msp430 -mcpu=msp430xv2 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430X %s
+// RUN: %clang -### -c %s --target=msp430 -mmcu=msp430f2617 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430X %s
+// RUN: %clang -### -c %s --target=msp430 -mmcu=msp430f5529 2>&1 \
+// RUN: | FileCheck -check-prefix=MSP430X %s
+// MSP430X: "-cc1"{{.*}} "-target-cpu" "msp430x"
+
+// RUN: not %clang -c %s --target=msp430 -mcpu=not-a-cpu -o /dev/null 2>&1 \
+// RUN: | FileCheck -check-prefix=INVALID %s
+// INVALID: error: unknown target CPU 'not-a-cpu'
+// INVALID-NEXT: note: valid target CPU values are: msp430, msp430x
diff --git a/clang/test/Driver/msp430-toolchain.c b/clang/test/Driver/msp430-toolchain.c
index 45010deb40a54d..45de069b0aafe9 100644
--- a/clang/test/Driver/msp430-toolchain.c
+++ b/clang/test/Driver/msp430-toolchain.c
@@ -126,6 +126,34 @@
// LIBS-EXC-NEG-NOT: "{{.*}}/430"
// LIBS-EXC-NEG-NOT: "{{.*}}430/crt{{.*}}"
+// The MSP430X multilibs are in the root, not in /430.
+// RUN: %clang -### %s --target=msp430 -mcpu=msp430x -rtlib=libgcc \
+// RUN: --sysroot="%S/Inputs/basic_msp430_tree" > %t 2>&1
+// RUN: FileCheck -check-prefix=LIBS-430X-POS %s < %t
+// RUN: FileCheck -check-prefix=LIBS-430X-NEG %s < %t
+// RUN: %clang -### %s --target=msp430 -mmcu=msp430f5529 -rtlib=libgcc \
+// RUN: --sysroot="%S/Inputs/basic_msp430_tree" > %t 2>&1
+// RUN: FileCheck -check-prefix=LIBS-430X-POS %s < %t
+// RUN: FileCheck -check-prefix=LIBS-430X-NEG %s < %t
+// LIBS-430X-POS: "{{.*}}/Inputs/basic_msp430_tree{{/|\\\\}}msp430-elf{{/|\\\\}}lib{{/|\\\\}}crt0.o"
+// LIBS-430X-POS: "{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1{{/|\\\\}}crtbegin_no_eh.o"
+// LIBS-430X-POS: "-L{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1{{/|\\\\}}"
+// LIBS-430X-POS: "-L{{.*}}/Inputs/basic_msp430_tree{{/|\\\\}}msp430-elf{{/|\\\\}}lib{{/|\\\\}}"
+// LIBS-430X-POS: "{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1{{/|\\\\}}crtend_no_eh.o"
+// LIBS-430X-NEG-NOT: /430
+// LIBS-430X-NEG-NOT: /exceptions
+
+// RUN: %clang -### %s --target=msp430 -mcpu=msp430x -rtlib=libgcc -fexceptions \
+// RUN: --sysroot="%S/Inputs/basic_msp430_tree" > %t 2>&1
+// RUN: FileCheck -check-prefix=LIBS-430X-EXC-POS %s < %t
+// RUN: FileCheck -check-prefix=LIBS-430X-EXC-NEG %s < %t
+// LIBS-430X-EXC-POS: "{{.*}}/Inputs/basic_msp430_tree{{/|\\\\}}msp430-elf{{/|\\\\}}lib/exceptions{{/|\\\\}}crt0.o"
+// LIBS-430X-EXC-POS: "{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1/exceptions{{/|\\\\}}crtbegin.o"
+// LIBS-430X-EXC-POS: "-L{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1/exceptions"
+// LIBS-430X-EXC-POS: "-L{{.*}}/Inputs/basic_msp430_tree{{/|\\\\}}msp430-elf{{/|\\\\}}lib/exceptions"
+// LIBS-430X-EXC-POS: "{{.*}}/Inputs/basic_msp430_tree/lib/gcc/msp430-elf/8.3.1/exceptions{{/|\\\\}}crtend.o"
+// LIBS-430X-EXC-NEG-NOT: /430
+
// RUN: %clang -### %s --target=msp430 -rtlib=libgcc \
// RUN: -fstack-protector --sysroot="%S/Inputs/basic_msp430_tree" 2>&1 \
// RUN: | FileCheck -check-prefix=LIBS-SSP %s
diff --git a/clang/test/Preprocessor/msp430-defs.c b/clang/test/Preprocessor/msp430-defs.c
new file mode 100644
index 00000000000000..6eea5c6e7521cc
--- /dev/null
+++ b/clang/test/Preprocessor/msp430-defs.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple msp430 -E -dM %s -o - \
+// RUN: | FileCheck -check-prefix=MSP430 %s
+// RUN: %clang_cc1 -triple msp430 -target-cpu msp430 -E -dM %s -o - \
+// RUN: | FileCheck -check-prefix=MSP430 %s
+// MSP430-NOT: #define __MSP430X__
+
+// RUN: %clang_cc1 -triple msp430 -target-cpu msp430x -E -dM %s -o - \
+// RUN: | FileCheck -check-prefix=MSP430X %s
+// MSP430X: #define __MSP430X__ 1
More information about the cfe-commits
mailing list