[ARM] Add a driver option for +no-neg-immediates

Reviewers: olista01, rengolin, javed.absar, samparker

Reviewed By: samparker

Subscribers: samparker, llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D31197


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@298850 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/Options.td

@@ -1760,6 +1760,8 @@ 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>,
   HelpText<"Disallow use of CRC instructions (ARM only)">;
+def mno_neg_immediates: Flag<["-"], "mno-neg-immediates">, Group<m_arm_Features_Group>,
+  HelpText<"Disallow converting instructions with negative immediates to their negation or inversion.">;
 
 def mgeneral_regs_only : Flag<["-"], "mgeneral-regs-only">, Group<m_aarch64_Features_Group>,
   HelpText<"Generate code which only uses the general purpose registers (AArch64 only)">;

lib/Driver/ToolChains/Arch/AArch64.cpp

@@ -193,4 +193,7 @@ void aarch64::getAArch64TargetFeatures(const Driver &D, const ArgList &Args,
 
   if (Args.hasArg(options::OPT_ffixed_x18))
     Features.push_back("+reserve-x18");
+
+  if (Args.hasArg(options::OPT_mno_neg_immediates))
+    Features.push_back("+no-neg-immediates");
 }

lib/Driver/ToolChains/Arch/ARM.cpp

@@ -449,6 +449,9 @@ void arm::getARMTargetFeatures(const ToolChain &TC,
   // 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");
+
+  if (Args.hasArg(options::OPT_mno_neg_immediates))
+    Features.push_back("+no-neg-immediates");
 }
 
 const std::string arm::getARMArch(StringRef Arch, const llvm::Triple &Triple) {

test/Driver/arm-no-neg-immediates.c

+// RUN: %clang -target arm-none-gnueabi -### %s 2>&1 | FileCheck %s --check-prefix=CHECK-DEFAULT
+// RUN: %clang -target arm-none-gnueabi -mno-neg-immediates -### %s 2>&1 | FileCheck %s
+
+// RUN: %clang -target aarch64-none-gnueabi -### %s 2>&1 | FileCheck %s --check-prefix=CHECK-DEFAULT
+// RUN: %clang -target aarch64-none-gnueabi -mno-neg-immediates -### %s 2>&1 | FileCheck %s
+
+// CHECK: "-target-feature" "+no-neg-immediates"
+// CHECK-DEFAULT-NOT: "+no-neg-immediates"