[clang] 9ec7448 - [Clang][AArch64] Add support for -mcpu=grace

[Sjoerd Meijer via cfe-commits]

Author: Sjoerd Meijer
Date: 2022-10-24T17:36:24+05:30
New Revision: 9ec7448857c1bcbc9878e9912167d9453d3be673

URL: https://github.com/llvm/llvm-project/commit/9ec7448857c1bcbc9878e9912167d9453d3be673
DIFF: https://github.com/llvm/llvm-project/commit/9ec7448857c1bcbc9878e9912167d9453d3be673.diff

LOG: [Clang][AArch64] Add support for -mcpu=grace

This adds Clang command line support for the NVIDIA Grace CPU [1], which
we would like to target with -mcpu=grace.

Grace is based on the Arm Neoverse V2 CPU [1], which is why, in the
driver, we pass neoverse-v2 to the compiler when grace is requested.
Thus, for now, it's an alias to Neoverse V2.

This adds support for grace in user-facing tool Clang, but not yet the
developer tools like opt and llc, so we probably want to follow up on
this.

[1] https://www.nvidia.com/en-us/data-center/grace-cpu/

Differential Revision: https://reviews.llvm.org/D136425

Added: 
    

Modified: 
    clang/lib/Driver/ToolChains/Arch/AArch64.cpp
    clang/test/Driver/aarch64-mcpu.c
    llvm/include/llvm/Support/AArch64TargetParser.h

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index cf7e201b4972c..7956a0be46280 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -38,6 +38,8 @@ std::string aarch64::getAArch64TargetCPU(const ArgList &Args,
     CPU = Mcpu.split("+").first.lower();
   }
 
+  CPU = llvm::AArch64::resolveCPUAlias(CPU);
+
   // Handle CPU name is 'native'.
   if (CPU == "native")
     return std::string(llvm::sys::getHostCPUName());
@@ -121,6 +123,8 @@ static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
   CPU = Split.first;
   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::ArchKind::ARMV8A;
 
+  CPU = llvm::AArch64::resolveCPUAlias(CPU);
+
   if (CPU == "native")
     CPU = llvm::sys::getHostCPUName();
 

diff  --git a/clang/test/Driver/aarch64-mcpu.c b/clang/test/Driver/aarch64-mcpu.c
index 8b2701f27a9eb..0433f6a5b3d3f 100644
--- a/clang/test/Driver/aarch64-mcpu.c
+++ b/clang/test/Driver/aarch64-mcpu.c
@@ -61,6 +61,9 @@
 // RUN: %clang -target aarch64 -mcpu=cortex-r82  -### -c %s 2>&1 | FileCheck -check-prefix=CORTEXR82 %s
 // CORTEXR82: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "cortex-r82"
 
+// RUN: %clang -target aarch64 -mcpu=grace -### -c %s 2>&1 | FileCheck -check-prefix=GRACE %s
+// GRACE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "neoverse-v2"
+
 // ================== Check whether -mcpu and -mtune accept mixed-case values.
 // RUN: %clang -target aarch64 -mcpu=Cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=CASE-INSENSITIVE-CA53 %s
 // RUN: %clang -target aarch64 -mtune=Cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=CASE-INSENSITIVE-CA53-TUNE %s

diff  --git a/llvm/include/llvm/Support/AArch64TargetParser.h b/llvm/include/llvm/Support/AArch64TargetParser.h
index f4e157cf80562..3f0981d27427b 100644
--- a/llvm/include/llvm/Support/AArch64TargetParser.h
+++ b/llvm/include/llvm/Support/AArch64TargetParser.h
@@ -139,6 +139,13 @@ StringRef getArchExtName(unsigned ArchExtKind);
 StringRef getArchExtFeature(StringRef ArchExt);
 ArchKind convertV9toV8(ArchKind AK);
 
+// FIXME: We should be able to define CPU aliases in TargetParser.
+inline StringRef resolveCPUAlias(StringRef CPU) {
+  if (CPU == "grace")
+    return "neoverse-v2";
+  return CPU;
+}
+
 // Information by Name
 unsigned getDefaultFPU(StringRef CPU, ArchKind AK);
 uint64_t getDefaultExtensions(StringRef CPU, ArchKind AK);