Add -fno-movt frontend option, to disable movt/movw on ARM

Summary:
In rL256641, @davide turned off movt generation by default for FreeBSD.
This was because our ld is very old, and did not support the relocations
for it.  However, Ian Lepore added the support very recently, so we
would like to revert rL256641, and replace it with a new `-fno-movt`
frontend option.  This way, it can be turned off when needed.

Reviewers: dexonsmith, echristo, emaste, davide

Subscribers: andrew, aemerson, rengolin, davide, cfe-commits, ahatanak, emaste

Differential Revision: http://reviews.llvm.org/D15899

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@256920 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 7eb4a46db88822af879ac6e619d7ee41615e87c6..796689805caf6a2c996f47650571695d2e8357c7 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -1385,6 +1385,8 @@ def mno_restrict_it: Flag<["-"], "mno-restrict-it">, Group<m_arm_Features_Group>
 def marm : Flag<["-"], "marm">, Alias<mno_thumb>;
 def ffixed_r9 : Flag<["-"], "ffixed-r9">, Group<m_arm_Features_Group>,
   HelpText<"Reserve the r9 register (ARM only)">;
+def mno_movt : Flag<["-"], "mno-movt">, Group<m_arm_Features_Group>,
+  HelpText<"Disallow use of movt/movw pairs (ARM only)">;
 def mcrc : Flag<["-"], "mcrc">, Group<m_arm_Features_Group>,
   HelpText<"Allow use of CRC instructions (ARM only)">;
 def mnocrc : Flag<["-"], "mnocrc">, Group<m_arm_Features_Group>,

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index c61445225767df0fb1008715c0ec2c707899e4b2..ba8d40596126cb135ebc4c8c7464ef90156b4a61 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -938,8 +938,8 @@ static void getARMTargetFeatures(const ToolChain &TC,
   if (Args.hasArg(options::OPT_ffixed_r9))
     Features.push_back("+reserve-r9");
 
-  // The kext and FreeBSD linkers don't know how to deal with movw/movt.
-  if (KernelOrKext || Triple.isOSFreeBSD())
+  // The kext linker doesn't know how to deal with movw/movt.
+  if (KernelOrKext || Args.hasArg(options::OPT_mno_movt))
     Features.push_back("+no-movt");
 }
 

diff --git a/test/Driver/arm-no-movt.c b/test/Driver/arm-no-movt.c
index 1107cf8ff89a4f29825cd653298625a526263979..69085931c3f34e6669ff44b48a3297aa900beda8 100644 (file)
--- a/test/Driver/arm-no-movt.c
+++ b/test/Driver/arm-no-movt.c
@@ -4,11 +4,11 @@
 // RUN: %clang -target armv7-apple-darwin -mkernel -### %s 2>&1 \
 // RUN:    | FileCheck %s -check-prefix CHECK-KERNEL
 
-// RUN: %clang -target armv7-gnueabi-freebsd11 -### %s 2>&1 \
-// RUN:    | FileCheck %s -check-prefix CHECK-FREEBSD
+// RUN: %clang -target armv7-none-gnueabi -mno-movt -### %s 2>&1 \
+// RUN:    | FileCheck %s -check-prefix CHECK-NO-MOVT
 
 // CHECK-DEFAULT-NOT: "-target-feature" "+no-movt"
 
 // CHECK-KERNEL: "-target-feature" "+no-movt"
 
-// CHECK-FREEBSD: "-target-feature" "+no-movt"
+// CHECK-NO-MOVT: "-target-feature" "+no-movt"