[clang] [RISCV][Clang] Remove default feature -save-restore. (PR #76390)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-backend-risc-v

Author: Yeting Kuo (yetingk)

<details>
<summary>Changes</summary>

It's unnecessary to defaultly pass feature `-save-restore`, since risc-v backend defaultly disables save-restore functionality.

---
Full diff: https://github.com/llvm/llvm-project/pull/76390.diff


3 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Arch/RISCV.cpp (+2-4) 
- (modified) clang/test/Driver/riscv-default-features.c (-2) 
- (modified) clang/test/Driver/riscv-features.c (+1-1) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
index 25b43cefce6b57..f385a97eca991b 100644
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -169,10 +169,8 @@ void riscv::getRISCVTargetFeatures(const Driver &D, const llvm::Triple &Triple,
 
   // GCC Compatibility: -mno-save-restore is default, unless -msave-restore is
   // specified.
-  if (Args.hasFlag(options::OPT_msave_restore, options::OPT_mno_save_restore, false))
-    Features.push_back("+save-restore");
-  else
-    Features.push_back("-save-restore");
+  AddTargetFeature(Args, Features, options::OPT_msave_restore,
+                   options::OPT_mno_save_restore, "save-restore");
 
   // -mno-unaligned-access is default, unless -munaligned-access is specified.
   AddTargetFeature(Args, Features, options::OPT_munaligned_access,
diff --git a/clang/test/Driver/riscv-default-features.c b/clang/test/Driver/riscv-default-features.c
index 6e48f7cc37dcb0..4c3883c1cc1184 100644
--- a/clang/test/Driver/riscv-default-features.c
+++ b/clang/test/Driver/riscv-default-features.c
@@ -2,9 +2,7 @@
 // RUN: %clang --target=riscv64-unknown-elf -S -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64
 
 // RV32: "target-features"="+32bit,+a,+c,+m,+relax,
-// RV32-SAME: -save-restore
 // RV64: "target-features"="+64bit,+a,+c,+m,+relax,
-// RV64-SAME: -save-restore
 
 // Dummy function
 int foo(void){
diff --git a/clang/test/Driver/riscv-features.c b/clang/test/Driver/riscv-features.c
index 716f3f6da57b88..d3700f71aa7e1d 100644
--- a/clang/test/Driver/riscv-features.c
+++ b/clang/test/Driver/riscv-features.c
@@ -24,7 +24,7 @@
 
 // SAVE-RESTORE: "-target-feature" "+save-restore"
 // NO-SAVE-RESTORE: "-target-feature" "-save-restore"
-// DEFAULT: "-target-feature" "-save-restore"
+// DEFAULT-NOT: "-target-feature" "-save-restore"
 // DEFAULT-NOT: "-target-feature" "+save-restore"
 
 // RUN: %clang --target=riscv32-unknown-elf -### %s -munaligned-access 2>&1 | FileCheck %s -check-prefix=FAST-UNALIGNED-ACCESS

``````````

</details>


https://github.com/llvm/llvm-project/pull/76390