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

[Yeting Kuo via cfe-commits]

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

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

>From 97fe56d808f1752ac4b7d26deecabb857e0a4208 Mon Sep 17 00:00:00 2001
From: Yeting Kuo <yeting.kuo at sifive.com>
Date: Tue, 26 Dec 2023 02:11:30 -0800
Subject: [PATCH] [RISCV][Clang] Remove default feature -save-restore.

It's unnecessary to defaultly pass -save-restore, since riscv backend defaultly
disable save-restore functionality.
---
 clang/lib/Driver/ToolChains/Arch/RISCV.cpp | 6 ++----
 clang/test/Driver/riscv-default-features.c | 2 --
 clang/test/Driver/riscv-features.c         | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

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