[llvm] [clang] [flang] [AArch64][Driver] Better handling of target feature dependencies (PR #78270)

[Tomas Matheson via cfe-commits]

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@@ -3,8 +3,7 @@
 // FEAT_D128 is optional (off by default) for v9.4a and older, and can be enabled using +d128
 // RUN: %clang -### --target=aarch64-none-elf -march=armv9.4-a        %s 2>&1 | FileCheck %s --check-prefix=NOT_ENABLED
 // RUN: %clang -### --target=aarch64-none-elf -march=armv9.4-a+d128   %s 2>&1 | FileCheck %s --check-prefix=ENABLED
-// RUN: %clang -### --target=aarch64-none-elf -march=armv9.4-a+nod128 %s 2>&1 | FileCheck %s --check-prefix=DISABLED
+// RUN: %clang -### --target=aarch64-none-elf -march=armv9.4-a+nod128 %s 2>&1 | FileCheck %s --check-prefix=NOT_ENABLED
 
 // ENABLED: "-target-feature" "+d128"
 // NOT_ENABLED-NOT: "-target-feature" "+d128"
-// DISABLED: "-target-feature" "-d128"
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tmatheson-arm wrote:

So features that are explicitly disabled with a `+noXYZ` will no longer appear in the `-cc1` command line as `-taget-feature -XYZ`? Is that always the case, what about for features that are on by default?

https://github.com/llvm/llvm-project/pull/78270