From 1dd034ed5060fc6078bf56d5656cb1554f750de6 Mon Sep 17 00:00:00 2001
From: Brad Smith <brad@comstyle.com>
Date: Fri, 12 Apr 2019 01:29:18 +0000
Subject: [PATCH] Enable frame pointer elimination for OpenBSD on x86 and
 mips64.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@358245 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/ToolChains/Clang.cpp  | 12 ++++++++++++
 test/Driver/frame-pointer-elim.c |  9 +++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index a5b98aad54..18856650a9 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -534,6 +534,18 @@ static bool useFramePointerForTargetByDefault(const ArgList &Args,
     return !areOptimizationsEnabled(Args);
   }
 
+  if (Triple.isOSOpenBSD()) {
+    switch (Triple.getArch()) {
+    case llvm::Triple::mips64:
+    case llvm::Triple::mips64el:
+    case llvm::Triple::x86:
+    case llvm::Triple::x86_64:
+      return !areOptimizationsEnabled(Args);
+    default:
+      return true;
+    }
+  }
+
   if (Triple.isOSLinux() || Triple.getOS() == llvm::Triple::CloudABI ||
       Triple.isOSHurd()) {
     switch (Triple.getArch()) {
diff --git a/test/Driver/frame-pointer-elim.c b/test/Driver/frame-pointer-elim.c
index 6fcd3eb75a..b050f71611 100644
--- a/test/Driver/frame-pointer-elim.c
+++ b/test/Driver/frame-pointer-elim.c
@@ -26,6 +26,15 @@
 // RUN:   FileCheck --check-prefix=NETBSD %s
 // NETBSD-NOT: "-momit-leaf-frame-pointer"
 
+// OpenBSD follows the same rules as Linux.
+// RUN: %clang -### -target x86_64-unknown-openbsd -S -O1 %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=OPENBSD-OPT %s
+// OPENBSD-OPT: "-momit-leaf-frame-pointer"
+
+// RUN: %clang -### -target x86_64-unknown-openbsd -S %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=OPENBSD %s
+// OPENBSD-NOT: "-momit-leaf-frame-pointer"
+
 // Darwin disables omitting the leaf frame pointer even under optimization
 // unless the command lines are given.
 // RUN: %clang -### -target i386-apple-darwin -S %s 2>&1 | \
-- 
2.40.0