[clang] [clang][HIP] Apply clang-cl optimization options to device code (PR #228096)
Yaxun Liu via cfe-commits
cfe-commits at lists.llvm.org
Fri Oct 2 07:22:21 PDT 2026
https://github.com/yxsamliu updated https://github.com/llvm/llvm-project/pull/228096
>From f4d578919ca8e4a0c9eebfb27f65ad637e4ffda1 Mon Sep 17 00:00:00 2001
From: "Yaxun (Sam) Liu" <yaxun.liu at amd.com>
Date: Thu, 1 Oct 2026 10:17:45 -0400
Subject: [PATCH 1/2] [clang][HIP] Apply clang-cl optimization options to
device code
clang-cl options such as /O1, /O2, and /Ox currently optimize only
host code in HIP builds, leaving device code unoptimized.
Translate these options before separating host and device arguments so
both compilations receive the requested optimization settings.
---
clang/docs/ReleaseNotes.md | 3 +
clang/include/clang/Driver/Driver.h | 3 +-
clang/lib/Driver/Driver.cpp | 130 +++++++++++++++++++++-
clang/lib/Driver/ToolChains/MSVC.cpp | 130 +---------------------
clang/test/Driver/cl-options.cu | 7 ++
clang/test/Driver/hip-cl-optimization.hip | 106 ++++++++++++++++++
6 files changed, 247 insertions(+), 132 deletions(-)
create mode 100644 clang/test/Driver/hip-cl-optimization.hip
diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md
index d22874d4130eec..4fdefafccea14d 100644
--- a/clang/docs/ReleaseNotes.md
+++ b/clang/docs/ReleaseNotes.md
@@ -815,6 +815,9 @@ features cannot lower the translation-unit ABI level;
#### Miscellaneous Bug Fixes
+- Fixed `clang-cl` optimization options such as `/O1`, `/O2`, and
+ `/Ox` being ignored when compiling HIP device code.
+
#### Miscellaneous Clang Crashes Fixed
- Fixed a crash in CTAD for type alias templates when the aggregate deduction guide could not be resolved. (#GH206994)
diff --git a/clang/include/clang/Driver/Driver.h b/clang/include/clang/Driver/Driver.h
index 15b6fdcb8a5746..914ef62cd62fa9 100644
--- a/clang/include/clang/Driver/Driver.h
+++ b/clang/include/clang/Driver/Driver.h
@@ -360,7 +360,8 @@ class Driver {
/// TranslateInputArgs - Create a new derived argument list from the input
/// arguments, after applying the standard argument translations.
llvm::opt::DerivedArgList *
- TranslateInputArgs(const llvm::opt::InputArgList &Args) const;
+ TranslateInputArgs(const llvm::opt::InputArgList &Args,
+ const llvm::Triple &Triple) const;
// handleArguments - All code related to claiming and printing diagnostics
// related to arguments to the driver are done here.
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 7649941a68b1cc..07f70fbbe0128c 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -459,10 +459,128 @@ Arg *clang::driver::makeInputArg(DerivedArgList &Args, const OptTable &Opts,
return A;
}
-DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args) const {
+static void translateMSVCOptArg(Arg *A, llvm::opt::DerivedArgList &DAL,
+ bool SupportsForcingFramePointer,
+ const char *ExpandChar, const OptTable &Opts) {
+ assert(A->getOption().matches(options::OPT__SLASH_O));
+
+ StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ const char &OptChar = *(OptStr.data() + I);
+ switch (OptChar) {
+ default:
+ break;
+ case '1':
+ case '2':
+ case 'x':
+ case 'd':
+ // Ignore /O[12xd] flags that aren't the last one on the command line.
+ // Only the last one gets expanded.
+ if (&OptChar != ExpandChar) {
+ A->claim();
+ break;
+ }
+ if (OptChar == 'd') {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
+ } else {
+ if (OptChar == '1') {
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ } else if (OptChar == '2' || OptChar == 'x') {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
+ }
+ if (SupportsForcingFramePointer &&
+ !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+ if (OptChar == '1' || OptChar == '2')
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_ffunction_sections));
+ }
+ break;
+ case 'b':
+ if (I + 1 != E && isdigit(OptStr[I + 1])) {
+ switch (OptStr[I + 1]) {
+ case '0':
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_inline));
+ break;
+ case '1':
+ DAL.AddFlagArg(A,
+ Opts.getOption(options::OPT_finline_hint_functions));
+ break;
+ case '2':
+ case '3':
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_finline_functions));
+ break;
+ }
+ ++I;
+ }
+ break;
+ case 'g':
+ A->claim();
+ break;
+ case 'i':
+ if (I + 1 != E && OptStr[I + 1] == '-') {
+ ++I;
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_builtin));
+ } else {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ }
+ break;
+ case 's':
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ break;
+ case 't':
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
+ break;
+ case 'y': {
+ bool OmitFramePointer = true;
+ if (I + 1 != E && OptStr[I + 1] == '-') {
+ OmitFramePointer = false;
+ ++I;
+ }
+ if (SupportsForcingFramePointer) {
+ if (OmitFramePointer)
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+ else
+ DAL.AddFlagArg(A,
+ Opts.getOption(options::OPT_fno_omit_frame_pointer));
+ } else {
+ // Silently accept /Oy- on x86-64 for portable clang-cl build flags.
+ A->claim();
+ }
+ break;
+ }
+ }
+ }
+}
+
+DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args,
+ const llvm::Triple &Triple) const {
const llvm::opt::OptTable &Opts = getOpts();
DerivedArgList *DAL = new DerivedArgList(Args);
+ // Normalize MSVC optimization options before host and device arguments split.
+ bool TranslateMSVCOpts = Triple.isWindowsMSVCEnvironment();
+ // /Oy and /Oy- do not affect the x86-64 host.
+ bool SupportsForcingFramePointer = Triple.getArch() != llvm::Triple::x86_64;
+ // Expand only the last /O[12xd], preserving overrides such as /O2 /Oy-.
+ const char *ExpandChar = nullptr;
+ if (TranslateMSVCOpts) {
+ for (Arg *A : Args.filtered(options::OPT__SLASH_O)) {
+ StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ char OptChar = OptStr[I];
+ char PrevChar = I > 0 ? OptStr[I - 1] : '0';
+ if (PrevChar == 'b') {
+ // OptChar does not expand; it's an argument to the previous char.
+ continue;
+ }
+ if (OptChar == '1' || OptChar == '2' || OptChar == 'x' ||
+ OptChar == 'd')
+ ExpandChar = OptStr.data() + I;
+ }
+ }
+ }
+
bool HasNostdlib = Args.hasArg(options::OPT_nostdlib);
bool HasNostdlibxx = Args.hasArg(options::OPT_nostdlibxx);
bool HasNodefaultlib = Args.hasArg(options::OPT_nodefaultlibs);
@@ -480,6 +598,14 @@ DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args) const {
continue;
}
+ if (TranslateMSVCOpts && A->getOption().matches(options::OPT__SLASH_O)) {
+ // Keep the original argument for unused-option diagnostics.
+ DAL->append(A);
+ translateMSVCOptArg(A, *DAL, SupportsForcingFramePointer, ExpandChar,
+ Opts);
+ continue;
+ }
+
// Unfortunately, we have to parse some forwarding options (-Xassembler,
// -Xlinker, -Xpreprocessor) because we either integrate their functionality
// (assembler and preprocessor), or bypass a previous driver ('collect2').
@@ -1783,7 +1909,7 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
}
// Perform the default argument translations.
- DerivedArgList *TranslatedArgs = TranslateInputArgs(*UArgs);
+ DerivedArgList *TranslatedArgs = TranslateInputArgs(*UArgs, TC.getTriple());
// Check if the environment version is valid except wasm case.
llvm::Triple Triple = TC.getTriple();
diff --git a/clang/lib/Driver/ToolChains/MSVC.cpp b/clang/lib/Driver/ToolChains/MSVC.cpp
index 25ea64a4ba5055..d32d5b9a52fc94 100644
--- a/clang/lib/Driver/ToolChains/MSVC.cpp
+++ b/clang/lib/Driver/ToolChains/MSVC.cpp
@@ -1023,103 +1023,6 @@ SanitizerMask MSVCToolChain::getSupportedSanitizers(
return Res;
}
-static void TranslateOptArg(Arg *A, llvm::opt::DerivedArgList &DAL,
- bool SupportsForcingFramePointer,
- const char *ExpandChar, const OptTable &Opts) {
- assert(A->getOption().matches(options::OPT__SLASH_O));
-
- StringRef OptStr = A->getValue();
- for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
- const char &OptChar = *(OptStr.data() + I);
- switch (OptChar) {
- default:
- break;
- case '1':
- case '2':
- case 'x':
- case 'd':
- // Ignore /O[12xd] flags that aren't the last one on the command line.
- // Only the last one gets expanded.
- if (&OptChar != ExpandChar) {
- A->claim();
- break;
- }
- if (OptChar == 'd') {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
- } else {
- if (OptChar == '1') {
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
- } else if (OptChar == '2' || OptChar == 'x') {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
- }
- if (SupportsForcingFramePointer &&
- !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
- if (OptChar == '1' || OptChar == '2')
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_ffunction_sections));
- }
- break;
- case 'b':
- if (I + 1 != E && isdigit(OptStr[I + 1])) {
- switch (OptStr[I + 1]) {
- case '0':
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_inline));
- break;
- case '1':
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_finline_hint_functions));
- break;
- case '2':
- case '3':
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_finline_functions));
- break;
- }
- ++I;
- }
- break;
- case 'g':
- A->claim();
- break;
- case 'i':
- if (I + 1 != E && OptStr[I + 1] == '-') {
- ++I;
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_builtin));
- } else {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
- }
- break;
- case 's':
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
- break;
- case 't':
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
- break;
- case 'y': {
- bool OmitFramePointer = true;
- if (I + 1 != E && OptStr[I + 1] == '-') {
- OmitFramePointer = false;
- ++I;
- }
- if (SupportsForcingFramePointer) {
- if (OmitFramePointer)
- DAL.AddFlagArg(A,
- Opts.getOption(options::OPT_fomit_frame_pointer));
- else
- DAL.AddFlagArg(
- A, Opts.getOption(options::OPT_fno_omit_frame_pointer));
- } else {
- // Don't warn about /Oy- in x86-64 builds (where
- // SupportsForcingFramePointer is false). The flag having no effect
- // there is a compiler-internal optimization, and people shouldn't have
- // to special-case their build files for x86-64 clang-cl.
- A->claim();
- }
- break;
- }
- }
- }
-}
-
static void TranslateDArg(Arg *A, llvm::opt::DerivedArgList &DAL,
const OptTable &Opts) {
assert(A->getOption().matches(options::OPT_D));
@@ -1154,39 +1057,8 @@ MSVCToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
const OptTable &Opts = getDriver().getOpts();
- // /Oy and /Oy- don't have an effect on X86-64
- bool SupportsForcingFramePointer = getArch() != llvm::Triple::x86_64;
-
- // The -O[12xd] flag actually expands to several flags. We must desugar the
- // flags so that options embedded can be negated. For example, the '-O2' flag
- // enables '-Oy'. Expanding '-O2' into its constituent flags allows us to
- // correctly handle '-O2 -Oy-' where the trailing '-Oy-' disables a single
- // aspect of '-O2'.
- //
- // Note that this expansion logic only applies to the *last* of '[12xd]'.
-
- // First step is to search for the character we'd like to expand.
- const char *ExpandChar = nullptr;
- for (Arg *A : Args.filtered(options::OPT__SLASH_O)) {
- StringRef OptStr = A->getValue();
- for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
- char OptChar = OptStr[I];
- char PrevChar = I > 0 ? OptStr[I - 1] : '0';
- if (PrevChar == 'b') {
- // OptChar does not expand; it's an argument to the previous char.
- continue;
- }
- if (OptChar == '1' || OptChar == '2' || OptChar == 'x' || OptChar == 'd')
- ExpandChar = OptStr.data() + I;
- }
- }
-
for (Arg *A : Args) {
- if (A->getOption().matches(options::OPT__SLASH_O)) {
- // The -O flag actually takes an amalgam of other options. For example,
- // '/Ogyb2' is equivalent to '/Og' '/Oy' '/Ob2'.
- TranslateOptArg(A, *DAL, SupportsForcingFramePointer, ExpandChar, Opts);
- } else if (A->getOption().matches(options::OPT_D)) {
+ if (A->getOption().matches(options::OPT_D)) {
// Translate -Dfoo#bar into -Dfoo=bar.
TranslateDArg(A, *DAL, Opts);
} else if (A->getOption().matches(options::OPT__SLASH_permissive)) {
diff --git a/clang/test/Driver/cl-options.cu b/clang/test/Driver/cl-options.cu
index b241ec6672d851..2517e7d77d4a9e 100644
--- a/clang/test/Driver/cl-options.cu
+++ b/clang/test/Driver/cl-options.cu
@@ -25,3 +25,10 @@
// Gd-NOT: "-fdefault-calling-conv=cdecl"
// Gd: "-cc1" "-triple"
// Gd: "-fdefault-calling-conv=cdecl"
+
+// Optimization options must continue to apply to both CUDA compilation jobs.
+// RUN: not %clang_cl /c /O2 -### -nocudalib -nocudainc -- %s 2>&1 | FileCheck -check-prefix=O2 %s
+// O2: "-cc1" "-triple" "nvptx{{(64)?}}-nvidia-cuda"
+// O2-SAME: "-O3"
+// O2: "-cc1" "-triple"
+// O2-SAME: "-O3"
diff --git a/clang/test/Driver/hip-cl-optimization.hip b/clang/test/Driver/hip-cl-optimization.hip
new file mode 100644
index 00000000000000..3a3720f0a5c67f
--- /dev/null
+++ b/clang/test/Driver/hip-cl-optimization.hip
@@ -0,0 +1,106 @@
+// Check that clang-cl optimization options apply to both host and device.
+// Device-specific options must still override the shared optimization level.
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=OS
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Ox -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Od -- %s 2>&1 | FileCheck %s --check-prefix=O0
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 /Od -- %s 2>&1 | FileCheck %s --check-prefix=O0
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Od /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -clang:-O1 -- %s 2>&1 | FileCheck %s --check-prefix=O1
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -clang:-Xarch_device -clang:-O1 -- %s 2>&1 | FileCheck %s --check-prefix=DEVICE-O1
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 /Ob0 -- %s 2>&1 | FileCheck %s --check-prefix=NOINLINE
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=OS
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Ox -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Od -- %s 2>&1 | FileCheck %s --check-prefix=O0
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 /Od -- %s 2>&1 | FileCheck %s --check-prefix=O0
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /Od /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -clang:-O1 -- %s 2>&1 | FileCheck %s --check-prefix=O1
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 -clang:-Xarch_device -clang:-O1 -- %s 2>&1 | FileCheck %s --check-prefix=DEVICE-O1
+
+// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O2 /Ob0 -- %s 2>&1 | FileCheck %s --check-prefix=NOINLINE
+
+// OS: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// OS-SAME: "-Os"
+// OS: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// OS-SAME: "-Os"
+
+// O3: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// O3-SAME: "-O3"
+// O3: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// O3-SAME: "-O3"
+
+// O0: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// O0-SAME: "-O0"
+// O0: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// O0-SAME: "-O0"
+
+// O1: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// O1-SAME: "-O1"
+// O1: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// O1-SAME: "-O1"
+
+// DEVICE-O1: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// DEVICE-O1-SAME: "-O1"
+// DEVICE-O1: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// DEVICE-O1-SAME: "-O3"
+
+// NOINLINE: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// NOINLINE-SAME: "-O3"
+// NOINLINE-SAME: "-fno-inline"
+// NOINLINE: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
+// NOINLINE-SAME: "-O3"
+// NOINLINE-SAME: "-fno-inline"
>From c437113e897dce7106e7a3fa7ca21dbd8e19b781 Mon Sep 17 00:00:00 2001
From: "Yaxun (Sam) Liu" <yaxun.liu at amd.com>
Date: Fri, 2 Oct 2026 10:21:12 -0400
Subject: [PATCH 2/2] [clang] Extract shared clang-cl optimization translation
Keep clang-cl optimization parsing in an internal helper while the driver
normalizes options before host and device arguments are split.
Select translation by clang-cl mode so Linux and MinGW host toolchains
also receive the canonical optimization options.
---
clang/docs/ReleaseNotes.md | 3 +-
clang/lib/Driver/CMakeLists.txt | 1 +
clang/lib/Driver/ClangCLArgs.cpp | 139 ++++++++++++++++++++++
clang/lib/Driver/ClangCLArgs.h | 41 +++++++
clang/lib/Driver/Driver.cpp | 127 +-------------------
clang/test/Driver/cl-options.c | 9 ++
clang/test/Driver/hip-cl-optimization.hip | 13 ++
7 files changed, 210 insertions(+), 123 deletions(-)
create mode 100644 clang/lib/Driver/ClangCLArgs.cpp
create mode 100644 clang/lib/Driver/ClangCLArgs.h
diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md
index 4fdefafccea14d..4d46ed3b646afc 100644
--- a/clang/docs/ReleaseNotes.md
+++ b/clang/docs/ReleaseNotes.md
@@ -816,7 +816,8 @@ features cannot lower the translation-unit ABI level;
#### Miscellaneous Bug Fixes
- Fixed `clang-cl` optimization options such as `/O1`, `/O2`, and
- `/Ox` being ignored when compiling HIP device code.
+ `/Ox` being ignored when compiling HIP device code or using a non-MSVC
+ host toolchain.
#### Miscellaneous Clang Crashes Fixed
diff --git a/clang/lib/Driver/CMakeLists.txt b/clang/lib/Driver/CMakeLists.txt
index 506536cdc04f5f..c33dfd2471f35a 100644
--- a/clang/lib/Driver/CMakeLists.txt
+++ b/clang/lib/Driver/CMakeLists.txt
@@ -24,6 +24,7 @@ endif()
add_clang_library(clangDriver
Action.cpp
+ ClangCLArgs.cpp
Compilation.cpp
CreateASTUnitFromArgs.cpp
CreateInvocationFromArgs.cpp
diff --git a/clang/lib/Driver/ClangCLArgs.cpp b/clang/lib/Driver/ClangCLArgs.cpp
new file mode 100644
index 00000000000000..64ff6adefd2567
--- /dev/null
+++ b/clang/lib/Driver/ClangCLArgs.cpp
@@ -0,0 +1,139 @@
+//===--- ClangCLArgs.cpp - clang-cl arguments -----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangCLArgs.h"
+#include "clang/Options/Options.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/OptTable.h"
+#include "llvm/Option/Option.h"
+#include "llvm/TargetParser/Triple.h"
+#include <cstddef>
+
+using namespace clang;
+using namespace clang::driver;
+using namespace llvm::opt;
+
+ClangCLArgs::ClangCLArgs(const ArgList &Args, const llvm::Triple &HostTriple)
+ : SupportsForcingFramePointer(HostTriple.getArch() !=
+ llvm::Triple::x86_64) {
+ // Expand only the last /O[12xd], preserving overrides such as /O2 /Oy-.
+ for (Arg *A : Args.filtered(options::OPT__SLASH_O)) {
+ llvm::StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ char OptChar = OptStr[I];
+ char PrevChar = I > 0 ? OptStr[I - 1] : '0';
+ if (PrevChar == 'b') {
+ // OptChar does not expand; it's an argument to the previous char.
+ continue;
+ }
+ if (OptChar == '1' || OptChar == '2' || OptChar == 'x' || OptChar == 'd')
+ ExpandChar = OptStr.data() + I;
+ }
+ }
+}
+
+bool ClangCLArgs::translateArg(Arg *A, DerivedArgList &DAL) const {
+ if (!A->getOption().matches(options::OPT__SLASH_O))
+ return false;
+
+ // Keep the original argument for unused-option diagnostics.
+ DAL.append(A);
+ const OptTable &Opts = getDriverOptTable();
+
+ llvm::StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ const char &OptChar = *(OptStr.data() + I);
+ switch (OptChar) {
+ default:
+ break;
+ case '1':
+ case '2':
+ case 'x':
+ case 'd':
+ // Ignore /O[12xd] flags that aren't the last one on the command line.
+ // Only the last one gets expanded.
+ if (&OptChar != ExpandChar) {
+ A->claim();
+ break;
+ }
+ if (OptChar == 'd') {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
+ } else {
+ if (OptChar == '1') {
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ } else if (OptChar == '2' || OptChar == 'x') {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
+ }
+ if (SupportsForcingFramePointer &&
+ !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+ if (OptChar == '1' || OptChar == '2')
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_ffunction_sections));
+ }
+ break;
+ case 'b':
+ if (I + 1 != E && llvm::isDigit(OptStr[I + 1])) {
+ switch (OptStr[I + 1]) {
+ case '0':
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_inline));
+ break;
+ case '1':
+ DAL.AddFlagArg(A,
+ Opts.getOption(options::OPT_finline_hint_functions));
+ break;
+ case '2':
+ case '3':
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_finline_functions));
+ break;
+ }
+ ++I;
+ }
+ break;
+ case 'g':
+ A->claim();
+ break;
+ case 'i':
+ if (I + 1 != E && OptStr[I + 1] == '-') {
+ ++I;
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_builtin));
+ } else {
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ }
+ break;
+ case 's':
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ break;
+ case 't':
+ DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
+ break;
+ case 'y': {
+ bool OmitFramePointer = true;
+ if (I + 1 != E && OptStr[I + 1] == '-') {
+ OmitFramePointer = false;
+ ++I;
+ }
+ if (SupportsForcingFramePointer) {
+ if (OmitFramePointer)
+ DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+ else
+ DAL.AddFlagArg(A,
+ Opts.getOption(options::OPT_fno_omit_frame_pointer));
+ } else {
+ // Silently accept /Oy- on x86-64 for portable clang-cl build flags.
+ A->claim();
+ }
+ break;
+ }
+ }
+ }
+ return true;
+}
diff --git a/clang/lib/Driver/ClangCLArgs.h b/clang/lib/Driver/ClangCLArgs.h
new file mode 100644
index 00000000000000..fbfd24064fa814
--- /dev/null
+++ b/clang/lib/Driver/ClangCLArgs.h
@@ -0,0 +1,41 @@
+//===--- ClangCLArgs.h - clang-cl arguments ---------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_DRIVER_CLANGCLARGS_H
+#define LLVM_CLANG_LIB_DRIVER_CLANGCLARGS_H
+
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+class Triple;
+namespace opt {
+class Arg;
+class ArgList;
+class DerivedArgList;
+} // namespace opt
+} // namespace llvm
+
+namespace clang::driver {
+
+/// Translate clang-cl options before host and device arguments are split.
+class LLVM_LIBRARY_VISIBILITY ClangCLArgs {
+ const char *ExpandChar = nullptr;
+ bool SupportsForcingFramePointer;
+
+public:
+ /// The argument values must outlive this translator.
+ ClangCLArgs(const llvm::opt::ArgList &Args, const llvm::Triple &HostTriple);
+
+ /// Append A and its canonical expansion to DAL. Return false without
+ /// modifying DAL if A is not handled.
+ bool translateArg(llvm::opt::Arg *A, llvm::opt::DerivedArgList &DAL) const;
+};
+
+} // namespace clang::driver
+
+#endif // LLVM_CLANG_LIB_DRIVER_CLANGCLARGS_H
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 07f70fbbe0128c..20d5520fa03b3d 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "clang/Driver/Driver.h"
+#include "ClangCLArgs.h"
#include "ToolChains/AIX.h"
#include "ToolChains/AMDGPU.h"
#include "ToolChains/AVR.h"
@@ -459,127 +460,14 @@ Arg *clang::driver::makeInputArg(DerivedArgList &Args, const OptTable &Opts,
return A;
}
-static void translateMSVCOptArg(Arg *A, llvm::opt::DerivedArgList &DAL,
- bool SupportsForcingFramePointer,
- const char *ExpandChar, const OptTable &Opts) {
- assert(A->getOption().matches(options::OPT__SLASH_O));
-
- StringRef OptStr = A->getValue();
- for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
- const char &OptChar = *(OptStr.data() + I);
- switch (OptChar) {
- default:
- break;
- case '1':
- case '2':
- case 'x':
- case 'd':
- // Ignore /O[12xd] flags that aren't the last one on the command line.
- // Only the last one gets expanded.
- if (&OptChar != ExpandChar) {
- A->claim();
- break;
- }
- if (OptChar == 'd') {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
- } else {
- if (OptChar == '1') {
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
- } else if (OptChar == '2' || OptChar == 'x') {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
- }
- if (SupportsForcingFramePointer &&
- !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
- if (OptChar == '1' || OptChar == '2')
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_ffunction_sections));
- }
- break;
- case 'b':
- if (I + 1 != E && isdigit(OptStr[I + 1])) {
- switch (OptStr[I + 1]) {
- case '0':
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_inline));
- break;
- case '1':
- DAL.AddFlagArg(A,
- Opts.getOption(options::OPT_finline_hint_functions));
- break;
- case '2':
- case '3':
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_finline_functions));
- break;
- }
- ++I;
- }
- break;
- case 'g':
- A->claim();
- break;
- case 'i':
- if (I + 1 != E && OptStr[I + 1] == '-') {
- ++I;
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_builtin));
- } else {
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
- }
- break;
- case 's':
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
- break;
- case 't':
- DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "3");
- break;
- case 'y': {
- bool OmitFramePointer = true;
- if (I + 1 != E && OptStr[I + 1] == '-') {
- OmitFramePointer = false;
- ++I;
- }
- if (SupportsForcingFramePointer) {
- if (OmitFramePointer)
- DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
- else
- DAL.AddFlagArg(A,
- Opts.getOption(options::OPT_fno_omit_frame_pointer));
- } else {
- // Silently accept /Oy- on x86-64 for portable clang-cl build flags.
- A->claim();
- }
- break;
- }
- }
- }
-}
-
DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args,
const llvm::Triple &Triple) const {
const llvm::opt::OptTable &Opts = getOpts();
DerivedArgList *DAL = new DerivedArgList(Args);
- // Normalize MSVC optimization options before host and device arguments split.
- bool TranslateMSVCOpts = Triple.isWindowsMSVCEnvironment();
- // /Oy and /Oy- do not affect the x86-64 host.
- bool SupportsForcingFramePointer = Triple.getArch() != llvm::Triple::x86_64;
- // Expand only the last /O[12xd], preserving overrides such as /O2 /Oy-.
- const char *ExpandChar = nullptr;
- if (TranslateMSVCOpts) {
- for (Arg *A : Args.filtered(options::OPT__SLASH_O)) {
- StringRef OptStr = A->getValue();
- for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
- char OptChar = OptStr[I];
- char PrevChar = I > 0 ? OptStr[I - 1] : '0';
- if (PrevChar == 'b') {
- // OptChar does not expand; it's an argument to the previous char.
- continue;
- }
- if (OptChar == '1' || OptChar == '2' || OptChar == 'x' ||
- OptChar == 'd')
- ExpandChar = OptStr.data() + I;
- }
- }
- }
+ std::optional<ClangCLArgs> CLArgs;
+ if (IsCLMode())
+ CLArgs.emplace(Args, Triple);
bool HasNostdlib = Args.hasArg(options::OPT_nostdlib);
bool HasNostdlibxx = Args.hasArg(options::OPT_nostdlibxx);
@@ -598,13 +486,8 @@ DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args,
continue;
}
- if (TranslateMSVCOpts && A->getOption().matches(options::OPT__SLASH_O)) {
- // Keep the original argument for unused-option diagnostics.
- DAL->append(A);
- translateMSVCOptArg(A, *DAL, SupportsForcingFramePointer, ExpandChar,
- Opts);
+ if (CLArgs && CLArgs->translateArg(A, *DAL))
continue;
- }
// Unfortunately, we have to parse some forwarding options (-Xassembler,
// -Xlinker, -Xpreprocessor) because we either integrate their functionality
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 57d82622ef4de6..b1d0ccbf60f0de 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -184,6 +184,15 @@
// RUN: %clang_cl /Od -### -- %s 2>&1 | FileCheck -check-prefix=Od %s
// Od: -O0
+// clang-cl optimization options are independent of the host toolchain.
+// RUN: %clang_cl --target=x86_64-unknown-linux-gnu /O1 -### -- %s 2>&1 | FileCheck %s --check-prefix=CL-LINUX-OS
+// CL-LINUX-OS: "-cc1"
+// CL-LINUX-OS-SAME: "-Os"
+
+// RUN: %clang_cl --target=x86_64-w64-windows-gnu /O2 -### -- %s 2>&1 | FileCheck %s --check-prefix=CL-MINGW-O3
+// CL-MINGW-O3: "-cc1"
+// CL-MINGW-O3-SAME: "-O3"
+
// RUN: %clang_cl /Oi- /Oi -### -- %s 2>&1 | FileCheck -check-prefix=Oi %s
// Oi-NOT: -fno-builtin
diff --git a/clang/test/Driver/hip-cl-optimization.hip b/clang/test/Driver/hip-cl-optimization.hip
index 3a3720f0a5c67f..1fa80de854e566 100644
--- a/clang/test/Driver/hip-cl-optimization.hip
+++ b/clang/test/Driver/hip-cl-optimization.hip
@@ -5,6 +5,10 @@
// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=OS
+// RUN: %clang_cl --target=x86_64-unknown-linux-gnu -### /c --offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=LINUX
+
// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --offload-new-driver \
// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
// RUN: /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
@@ -41,6 +45,10 @@
// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=OS
+// RUN: %clang_cl --target=x86_64-unknown-linux-gnu -### /c --no-offload-new-driver \
+// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
+// RUN: /O1 -- %s 2>&1 | FileCheck %s --check-prefix=LINUX
+
// RUN: %clang_cl --target=x86_64-pc-windows-msvc -### /c --no-offload-new-driver \
// RUN: -x hip --offload-arch=gfx1100 -clang:-nogpuinc -clang:-nogpulib \
// RUN: /O2 -- %s 2>&1 | FileCheck %s --check-prefix=O3
@@ -78,6 +86,11 @@
// OS: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
// OS-SAME: "-Os"
+// LINUX: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
+// LINUX-SAME: "-Os"
+// LINUX: "-cc1" "-triple" "x86_64-unknown-linux-gnu"
+// LINUX-SAME: "-Os"
+
// O3: "-cc1" "-triple" "amdgpu11.00-amd-amdhsa"
// O3-SAME: "-O3"
// O3: "-cc1" "-triple" "x86_64-pc-windows-msvc{{[^"]*}}"
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