[clang] [llvm] [clang][driver] Set TLSDESC as the default for Android on RISC-V (PR #81198)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: Paul Kirth (ilovepi)

<details>
<summary>Changes</summary>

Sets TLSDESC as the default on Android versions newer than 29, or if its
Android on RISC-V.


---
Full diff: https://github.com/llvm/llvm-project/pull/81198.diff


2 Files Affected:

- (modified) clang/test/Driver/tls-dialect.c (+5) 
- (modified) llvm/include/llvm/TargetParser/Triple.h (+1-2) 


``````````diff
diff --git a/clang/test/Driver/tls-dialect.c b/clang/test/Driver/tls-dialect.c
index 4e105ce3cea5d9..f309f4a44fbc3f 100644
--- a/clang/test/Driver/tls-dialect.c
+++ b/clang/test/Driver/tls-dialect.c
@@ -3,6 +3,11 @@
 // RUN: %clang -### --target=riscv64-linux %s 2>&1 | FileCheck --check-prefix=NODESC %s
 // RUN: %clang -### --target=x86_64-linux -mtls-dialect=gnu %s 2>&1 | FileCheck --check-prefix=NODESC %s
 
+/// Android supports TLSDESC by default after Android version 29 and all RISC-V
+/// TLSDESC is not on by default in Linux, even on RISC-V
+// RUN: %clang -### --target=riscv64-android %s 2>&1 | FileCheck --check-prefix=DESC %s
+// RUN: %clang -### --target=riscv64-linux %s 2>&1 | FileCheck --check-prefix=NODESC %s
+
 /// LTO
 // RUN: %clang -### --target=riscv64-linux -flto -mtls-dialect=desc %s 2>&1 | FileCheck --check-prefix=LTO-DESC %s
 // RUN: %clang -### --target=riscv64-linux -flto %s 2>&1 | FileCheck --check-prefix=LTO-NODESC %s
diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index 98d8490cc9f7a2..0382d97d3fe38b 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -1036,8 +1036,7 @@ class Triple {
   /// True if the target supports both general-dynamic and TLSDESC, and TLSDESC
   /// is enabled by default.
   bool hasDefaultTLSDESC() const {
-    // TODO: Improve check for other platforms, like Android, and RISC-V
-    return false;
+    return isAndroid() && (!isAndroidVersionLT(29) || isRISCV64());
   }
 
   /// Tests whether the target uses -data-sections as default.

``````````

</details>


https://github.com/llvm/llvm-project/pull/81198