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@tomershafir tomershafir commented Jul 3, 2025

This change removes unnecessary tune args to the AArch64 backend. The AArch64 backend automatically handles tune-cpu and adds the necessar
y features based on the models from TableGen.

It follows this fix: #146260 where updating a subtarget feature didn't fail the frontend test because both the toolchain and the test suffered from a coordinated error.

@tomershafir tomershafir force-pushed the clang-aarch64-remove-redundant-backend-tune-args branch from 47da704 to 8179206 Compare July 3, 2025 14:18
@tomershafir tomershafir marked this pull request as ready for review July 3, 2025 16:43
@llvmbot llvmbot added clang Clang issues not falling into any other category backend:AArch64 clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' labels Jul 3, 2025
@tomershafir tomershafir requested a review from fhahn July 3, 2025 16:43
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llvmbot commented Jul 3, 2025

@llvm/pr-subscribers-lld-macho
@llvm/pr-subscribers-llvm-transforms
@llvm/pr-subscribers-lld
@llvm/pr-subscribers-llvm-globalisel

@llvm/pr-subscribers-backend-aarch64

Author: Tomer Shafir (tomershafir)

Changes

This change removes unnecessary tune args to the AArch64 backend. The AArch64 backend automatically handles tune-cpu and adds the necessar
y features based on the models from TableGen.

It follows this fix: #146260 where updating a subtarget feature didn't fail the frontend test because both the toolchain and the test suffered from a coordinated error.


Full diff: https://github.com/llvm/llvm-project/pull/146896.diff

2 Files Affected:

  • (modified) clang/lib/Driver/ToolChains/Arch/AArch64.cpp (-11)
  • (modified) clang/test/Preprocessor/aarch64-target-features.c (+8-8)
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index 343a18b9ca2ea..4f45c369c83db 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -163,17 +163,6 @@ getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
     return false;
 
-  // Handle CPU name is 'native'.
-  if (MtuneLowerCase == "native")
-    MtuneLowerCase = std::string(llvm::sys::getHostCPUName());
-
-  // 'cyclone' and later have zero-cycle register moves and zeroing.
-  if (MtuneLowerCase == "cyclone" ||
-      StringRef(MtuneLowerCase).starts_with("apple")) {
-    Features.push_back("+zcm-gpr64");
-    Features.push_back("+zcz");
-  }
-
   return true;
 }
 
diff --git a/clang/test/Preprocessor/aarch64-target-features.c b/clang/test/Preprocessor/aarch64-target-features.c
index 6700153b79795..d7201207db572 100644
--- a/clang/test/Preprocessor/aarch64-target-features.c
+++ b/clang/test/Preprocessor/aarch64-target-features.c
@@ -316,7 +316,7 @@
 
 // ================== Check whether -mtune accepts mixed-case features.
 // RUN: %clang -target aarch64 -mtune=CYCLONE -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MTUNE-CYCLONE %s
-// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a"
+// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a"
 
 // RUN: %clang -target aarch64 -mcpu=apple-a7 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
 // RUN: %clang -target aarch64 -mcpu=apple-a8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
@@ -342,12 +342,12 @@
 // RUN: %clang -target aarch64 -mcpu=thunderx2t99 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-THUNDERX2T99 %s
 // RUN: %clang -target aarch64 -mcpu=a64fx -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-A64FX %s
 // RUN: %clang -target aarch64 -mcpu=carmel -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-CARMEL %s
-// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
-// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}}"-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
+// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}} "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 // CHECK-MCPU-A34: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
+// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
 // CHECK-MCPU-A35: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A53: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A57: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
@@ -362,10 +362,10 @@
 // CHECK-MCPU-CARMEL: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64 %s
-// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
+// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64_32 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64_32 %s
-// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target aarch64 -march=armv8-a+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s
 // RUN: %clang -target aarch64 -march=armv8-a+nofp+nosimd+nocrc+nocrypto+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s

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llvmbot commented Jul 3, 2025

@llvm/pr-subscribers-clang-driver

Author: Tomer Shafir (tomershafir)

Changes

This change removes unnecessary tune args to the AArch64 backend. The AArch64 backend automatically handles tune-cpu and adds the necessar
y features based on the models from TableGen.

It follows this fix: #146260 where updating a subtarget feature didn't fail the frontend test because both the toolchain and the test suffered from a coordinated error.


Full diff: https://github.com/llvm/llvm-project/pull/146896.diff

2 Files Affected:

  • (modified) clang/lib/Driver/ToolChains/Arch/AArch64.cpp (-11)
  • (modified) clang/test/Preprocessor/aarch64-target-features.c (+8-8)
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index 343a18b9ca2ea..4f45c369c83db 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -163,17 +163,6 @@ getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
     return false;
 
-  // Handle CPU name is 'native'.
-  if (MtuneLowerCase == "native")
-    MtuneLowerCase = std::string(llvm::sys::getHostCPUName());
-
-  // 'cyclone' and later have zero-cycle register moves and zeroing.
-  if (MtuneLowerCase == "cyclone" ||
-      StringRef(MtuneLowerCase).starts_with("apple")) {
-    Features.push_back("+zcm-gpr64");
-    Features.push_back("+zcz");
-  }
-
   return true;
 }
 
diff --git a/clang/test/Preprocessor/aarch64-target-features.c b/clang/test/Preprocessor/aarch64-target-features.c
index 6700153b79795..d7201207db572 100644
--- a/clang/test/Preprocessor/aarch64-target-features.c
+++ b/clang/test/Preprocessor/aarch64-target-features.c
@@ -316,7 +316,7 @@
 
 // ================== Check whether -mtune accepts mixed-case features.
 // RUN: %clang -target aarch64 -mtune=CYCLONE -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MTUNE-CYCLONE %s
-// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a"
+// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a"
 
 // RUN: %clang -target aarch64 -mcpu=apple-a7 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
 // RUN: %clang -target aarch64 -mcpu=apple-a8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
@@ -342,12 +342,12 @@
 // RUN: %clang -target aarch64 -mcpu=thunderx2t99 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-THUNDERX2T99 %s
 // RUN: %clang -target aarch64 -mcpu=a64fx -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-A64FX %s
 // RUN: %clang -target aarch64 -mcpu=carmel -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-CARMEL %s
-// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
-// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}}"-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
+// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}} "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 // CHECK-MCPU-A34: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
+// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
 // CHECK-MCPU-A35: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A53: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A57: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
@@ -362,10 +362,10 @@
 // CHECK-MCPU-CARMEL: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64 %s
-// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
+// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64_32 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64_32 %s
-// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target aarch64 -march=armv8-a+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s
 // RUN: %clang -target aarch64 -march=armv8-a+nofp+nosimd+nocrc+nocrypto+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s

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llvmbot commented Jul 3, 2025

@llvm/pr-subscribers-clang

Author: Tomer Shafir (tomershafir)

Changes

This change removes unnecessary tune args to the AArch64 backend. The AArch64 backend automatically handles tune-cpu and adds the necessar
y features based on the models from TableGen.

It follows this fix: #146260 where updating a subtarget feature didn't fail the frontend test because both the toolchain and the test suffered from a coordinated error.


Full diff: https://github.com/llvm/llvm-project/pull/146896.diff

2 Files Affected:

  • (modified) clang/lib/Driver/ToolChains/Arch/AArch64.cpp (-11)
  • (modified) clang/test/Preprocessor/aarch64-target-features.c (+8-8)
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index 343a18b9ca2ea..4f45c369c83db 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -163,17 +163,6 @@ getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
     return false;
 
-  // Handle CPU name is 'native'.
-  if (MtuneLowerCase == "native")
-    MtuneLowerCase = std::string(llvm::sys::getHostCPUName());
-
-  // 'cyclone' and later have zero-cycle register moves and zeroing.
-  if (MtuneLowerCase == "cyclone" ||
-      StringRef(MtuneLowerCase).starts_with("apple")) {
-    Features.push_back("+zcm-gpr64");
-    Features.push_back("+zcz");
-  }
-
   return true;
 }
 
diff --git a/clang/test/Preprocessor/aarch64-target-features.c b/clang/test/Preprocessor/aarch64-target-features.c
index 6700153b79795..d7201207db572 100644
--- a/clang/test/Preprocessor/aarch64-target-features.c
+++ b/clang/test/Preprocessor/aarch64-target-features.c
@@ -316,7 +316,7 @@
 
 // ================== Check whether -mtune accepts mixed-case features.
 // RUN: %clang -target aarch64 -mtune=CYCLONE -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MTUNE-CYCLONE %s
-// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a"
+// CHECK-MTUNE-CYCLONE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a"
 
 // RUN: %clang -target aarch64 -mcpu=apple-a7 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
 // RUN: %clang -target aarch64 -mcpu=apple-a8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-APPLE-A7 %s
@@ -342,12 +342,12 @@
 // RUN: %clang -target aarch64 -mcpu=thunderx2t99 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-THUNDERX2T99 %s
 // RUN: %clang -target aarch64 -mcpu=a64fx -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-A64FX %s
 // RUN: %clang -target aarch64 -mcpu=carmel -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MCPU-CARMEL %s
-// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
-// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}}"-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A7: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A10: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+lor" "-target-feature" "+neon" "-target-feature" "+pan" "-target-feature" "+perfmon" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+vh"
+// CHECK-MCPU-APPLE-A11: "-cc1"{{.*}} "-triple" "aarch64{{.*}}"{{.*}} "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-MCPU-APPLE-A12: "-cc1"{{.*}} "-triple" "aarch64"{{.*}} "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 // CHECK-MCPU-A34: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
-// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
+// CHECK-MCPU-APPLE-A13: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2" "-target-feature" "+sha3"
 // CHECK-MCPU-A35: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A53: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
 // CHECK-MCPU-A57: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+neon" "-target-feature" "+perfmon" "-target-feature" "+sha2"
@@ -362,10 +362,10 @@
 // CHECK-MCPU-CARMEL: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.2a" "-target-feature" "+aes" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+ras" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64 %s
-// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
+// CHECK-ARCH-ARM64: "-target-cpu" "apple-m1" "-target-feature" "+v8.4a" "-target-feature" "+aes" "-target-feature" "+altnzcv" "-target-feature" "+ccdp" "-target-feature" "+ccpp" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+dotprod" "-target-feature" "+flagm" "-target-feature" "+fp-armv8" "-target-feature" "+fp16fml" "-target-feature" "+fptoint" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+predres" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sb" "-target-feature" "+sha2" "-target-feature" "+sha3" "-target-feature" "+specrestrict" "-target-feature" "+ssbs"
 
 // RUN: %clang -target x86_64-apple-macosx -arch arm64_32 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-ARCH-ARM64_32 %s
-// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+zcm-gpr64" "-target-feature" "+zcz" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
+// CHECK-ARCH-ARM64_32: "-target-cpu" "apple-s4" "-target-feature" "+v8.3a" "-target-feature" "+aes" "-target-feature" "+complxnum" "-target-feature" "+crc" "-target-feature" "+fp-armv8" "-target-feature" "+fullfp16" "-target-feature" "+jsconv" "-target-feature" "+lse" "-target-feature" "+neon" "-target-feature" "+pauth" "-target-feature" "+perfmon" "-target-feature" "+ras" "-target-feature" "+rcpc" "-target-feature" "+rdm" "-target-feature" "+sha2"
 
 // RUN: %clang -target aarch64 -march=armv8-a+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s
 // RUN: %clang -target aarch64 -march=armv8-a+nofp+nosimd+nocrc+nocrypto+fp+simd+crc+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-MARCH-1 %s

This change removes unnecessary tune args to the AArch64 backend. The AArch64 backend automatically handles `tune-cpu` and adds the necessary features based on the models from TableGen.

It follows this fix: llvm#146260 where updating a subtarget feature didn't fail the frontend test because both the toolchain and the test suffered from a coordinated error.
Comment on lines 163 to 165
if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
return false;

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Suggested change
if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
return false;
return DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions);

this can now just become a return I think

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ok, I planned to simplify in a followup patch, but simplified this and a bit more in a new commit

@tomershafir tomershafir force-pushed the clang-aarch64-remove-redundant-backend-tune-args branch 2 times, most recently from 583ce20 to cc1c531 Compare July 4, 2025 11:10
@tomershafir tomershafir force-pushed the clang-aarch64-remove-redundant-backend-tune-args branch from cc1c531 to 2d8120b Compare July 4, 2025 11:34
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Thanks for doing this. LGTM.

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LGTM, thanks

@tomershafir tomershafir merged commit 65e11f6 into llvm:main Jul 5, 2025
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@tomershafir tomershafir deleted the clang-aarch64-remove-redundant-backend-tune-args branch July 5, 2025 06:36
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