[clang] [clang][AArch64] test -cc1 -print-enabled-extensions (PR #143570)
Tomas Matheson via cfe-commits
cfe-commits at lists.llvm.org
Tue Jun 10 09:57:51 PDT 2025
https://github.com/tmatheson-arm created https://github.com/llvm/llvm-project/pull/143570
This adds tests that document how -cc1 and -print-enabled-extensions interact. The current behaviour looks wrong, and is caused by the fact that --print-enabled-extensions uses the MC subtarget feature API to determine the list of extensions to print, whereas the frontend uses the TargetParser API. The latter does no dependency expansion for the -target-feature flags but the MC API does.
This doesn't fix anything but at least it documents the current behaviour, and will serve as a pre-commit test for any future fixes.
>From 4bb35800081983d6a06b6c995d2f93cf5d9fa411 Mon Sep 17 00:00:00 2001
From: Tomas Matheson <tomas.matheson at arm.com>
Date: Tue, 10 Jun 2025 17:52:25 +0100
Subject: [PATCH] [clang][AArch64] test -cc1 -print-enabled-extensions
This adds tests that document how -cc1 and -print-enabled-extensions
interact. The current behaviour looks wrong, and is caused by the fact
that --print-enabled-extensions uses the MC subtarget feature API to
determine the list of extensions to print, whereas the frontend uses
the TargetParser API. The latter does no dependency expansion for the
-target-feature flags but the MC API does.
This doesn't fix anything but at least it documents the current
behaviour, and will serve as a pre-commit test for any future fixes.
---
.../aarch64-print-enabled-extensions-cc1.c | 139 ++++++++++++++++++
1 file changed, 139 insertions(+)
create mode 100644 clang/test/Frontend/aarch64-print-enabled-extensions-cc1.c
diff --git a/clang/test/Frontend/aarch64-print-enabled-extensions-cc1.c b/clang/test/Frontend/aarch64-print-enabled-extensions-cc1.c
new file mode 100644
index 0000000000000..5d65fdafaa251
--- /dev/null
+++ b/clang/test/Frontend/aarch64-print-enabled-extensions-cc1.c
@@ -0,0 +1,139 @@
+// Test how -cc1 -target-feature interacts with -print-enabled-extensions.
+// The current behaviour does not look correct, since dependent features are
+// removed from the printed list when one of their dependencies are disabled,
+// but they are actually still enabled during compilation, and then actually
+// disabled for parsing assembly.
+
+// REQUIRES: aarch64-registered-target
+
+// Behaviour with two positive features.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon -target-feature +sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=POS_ONLY
+
+// Negative -target-feature disables the extension but keeps any dependencies of it (FEAT_FP16).
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon -target-feature +sve -target-feature -sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=POS_NEG
+
+// Disabling then re-enabling a feature is the same as never disabling it.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon -target-feature -sve -target-feature +sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=POS_ONLY
+
+// Disabling then re-enabling a feature is the same as never disabling it.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon -target-feature +sve -target-feature -sve -target-feature +sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=POS_ONLY
+
+// Only disabling it is the same as never having enabled it.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=NEG_ONLY
+
+// Only disabling it is the same as never having enabled it.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +neon -target-feature -sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=NEG_ONLY
+
+// Disabling a dependency (after enabling the dependent) appears to disable the dependent feature.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +sve2 -target-feature -sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=DISABLE_DEP
+
+// Disabling a dependency before enabling the dependent appears to have no effect.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature -sve -target-feature +sve2 \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=DISABLE_DEP2
+
+// Disabling a dependency before enabling the dependent appears to have no effect.
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -print-enabled-extensions \
+// RUN: -target-feature +sve2 \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=DISABLE_DEP2
+
+// Driver --print-enabled-extensions indicates that negative -target-features disable dependent features.
+// RUN: %clang --target=aarch64 -march=armv8-a+sve2 --print-enabled-extensions \
+// RUN: -Xclang -target-feature -Xclang -sve \
+// RUN: | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s --check-prefix=DISABLE_VIA_XCLANG
+
+// However, sve2 is actually enabled in clang but disabled for MC.
+// RUN: %clang --target=aarch64 -march=armv8-a+sve2 -c %s \
+// RUN: -Xclang -target-feature -Xclang -sve \
+// RUN: -Xclang -verify -Xclang -verify-ignore-unexpected=note
+
+
+// POS_ONLY: Extensions enabled for the given AArch64 target
+// POS_ONLY-EMPTY:
+// POS_ONLY-NEXT: Architecture Feature(s) Description
+// POS_ONLY-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// POS_ONLY-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// POS_ONLY-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// POS_ONLY-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// POS_ONLY-NEXT: FEAT_SVE Enable Scalable Vector Extension (SVE) instructions
+// POS_ONLY-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// POS_NEG: Extensions enabled for the given AArch64 target
+// POS_NEG-EMPTY:
+// POS_NEG-NEXT: Architecture Feature(s) Description
+// POS_NEG-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// POS_NEG-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// POS_NEG-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// POS_NEG-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// POS_NEG-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// NEG_POS: Extensions enabled for the given AArch64 target
+// NEG_POS-EMPTY:
+// NEG_POS-NEXT: Architecture Feature(s) Description
+// NEG_POS-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// NEG_POS-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// NEG_POS-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// NEG_POS-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// NEG_POS-NEXT: FEAT_SVE Enable Scalable Vector Extension (SVE) instructions
+// NEG_POS-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// NEG_ONLY: Extensions enabled for the given AArch64 target
+// NEG_ONLY-EMPTY:
+// NEG_ONLY-NEXT: Architecture Feature(s) Description
+// NEG_ONLY-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// NEG_ONLY-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// NEG_ONLY-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// NEG_ONLY-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// DISABLE_DEP: Extensions enabled for the given AArch64 target
+// DISABLE_DEP-EMPTY:
+// DISABLE_DEP-NEXT: Architecture Feature(s) Description
+// DISABLE_DEP-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// DISABLE_DEP-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// DISABLE_DEP-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// DISABLE_DEP-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// DISABLE_DEP-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// DISABLE_DEP2: Extensions enabled for the given AArch64 target
+// DISABLE_DEP2-EMPTY:
+// DISABLE_DEP2-NEXT: Architecture Feature(s) Description
+// DISABLE_DEP2-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// DISABLE_DEP2-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// DISABLE_DEP2-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// DISABLE_DEP2-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// DISABLE_DEP2-NEXT: FEAT_SVE Enable Scalable Vector Extension (SVE) instructions
+// DISABLE_DEP2-NEXT: FEAT_SVE2 Enable Scalable Vector Extension 2 (SVE2) instructions
+// DISABLE_DEP2-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+// DISABLE_VIA_XCLANG: Extensions enabled for the given AArch64 target
+// DISABLE_VIA_XCLANG-EMPTY:
+// DISABLE_VIA_XCLANG-NEXT: Architecture Feature(s) Description
+// DISABLE_VIA_XCLANG-NEXT: FEAT_AdvSIMD Enable Advanced SIMD instructions
+// DISABLE_VIA_XCLANG-NEXT: FEAT_ETE Enable Embedded Trace Extension
+// DISABLE_VIA_XCLANG-NEXT: FEAT_FP Enable Armv8.0-A Floating Point Extensions
+// DISABLE_VIA_XCLANG-NEXT: FEAT_FP16 Enable half-precision floating-point data processing
+// DISABLE_VIA_XCLANG-NEXT: FEAT_TRBE Enable Trace Buffer Extension
+
+#if __ARM_FEATURE_SVE2
+#warning "SVE2 is enabled"
+// expected-warning at -1 {{SVE2 is enabled}}
+#endif
+
+void fn_that_requires_sve2() {
+ __asm__("ldnt1sh z0.s, p0/z, [z1.s]");
+ // expected-error at -1 {{instruction requires: sve2}}
+}
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