[M68k][clang] Enable frame pointer optimization by default

[tclin914]

Enable frame pointer optimization by default to match it with gcc.

Fixes: #75013

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-driver

Author: Jim Lin (tclin914)

Changes

Enable frame pointer optimization by default to match it with gcc.

Fixes: #75013

---

Full diff: https://github.com/llvm/llvm-project/pull/87264.diff

2 Files Affected:

• (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+1)
• (modified) clang/test/Driver/frame-pointer-elim.c (+6)

diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index ace4fb99581e38..ae49f1906053dc 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -114,6 +114,7 @@ static bool useFramePointerForTargetByDefault(const llvm::opt::ArgList &Args,
   case llvm::Triple::csky:
   case llvm::Triple::loongarch32:
   case llvm::Triple::loongarch64:
+  case llvm::Triple::m68k:
     return !clang::driver::tools::areOptimizationsEnabled(Args);
   default:
     break;
diff --git a/clang/test/Driver/frame-pointer-elim.c b/clang/test/Driver/frame-pointer-elim.c
index 847c5b7b0b01f3..e1b0a468ab8259 100644
--- a/clang/test/Driver/frame-pointer-elim.c
+++ b/clang/test/Driver/frame-pointer-elim.c
@@ -125,6 +125,12 @@
 // RUN: %clang -### -target sparc64 -S -O1 %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=KEEP-NONE %s
 
+// M68k targets omit the frame pointer when optimizations are enabled.
+// RUN: %clang -### -target m68k -S %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-ALL %s
+// RUN: %clang -### -target m68k -S -O1 %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=KEEP-NONE %s
+
 // For AAarch32 (A32, T32) linux targets, default omit frame pointer when
 // optimizations are enabled.
 // RUN: %clang -### -target arm-linux-gnueabihf- -marm -S %s 2>&1 | \

[n8pjl]

This is a necessary change to make m68k clang competitive in performance to GCC,
and aligns with #88300.

Reviewed and tested the change. LGTM, but I'm not a maintainer.