[ARM] Define subtarget feature "reserve-r9", which is used to decide

whether register r9 should be reserved.

This recommits r242737, which broke bots because the number of subtarget
features went over the limit of 64.

This change is needed because we cannot use a backend option to set
cl::opt "arm-reserve-r9" when doing LTO.

Out-of-tree projects currently using cl::opt option "-arm-reserve-r9" to
reserve r9 should make changes to add subtarget feature "reserve-r9" to
the IR.

rdar://problem/21529937

Differential Revision: http://reviews.llvm.org/D11320

llvm-svn: 242756

5 files changed, 14 insertions, 15 deletions

diff --git a/llvm/lib/Target/ARM/ARM.td b/llvm/lib/Target/ARM/ARM.td
index 1dafff60921..cea97b5fa53 100644
--- a/llvm/lib/Target/ARM/ARM.td
+++ b/llvm/lib/Target/ARM/ARM.td
@@ -154,6 +154,10 @@ def FeatureLongCalls : SubtargetFeature<"long-calls", "GenLongCalls", "true",
                                         "Generate calls via indirect call "
                                         "instructions">;
 
+def FeatureReserveR9 : SubtargetFeature<"reserve-r9", "ReserveR9", "true",
+                                        "Reserve R9, making it unavailable as "
+                                        "GPR">;
+
 def FeatureNoMovt : SubtargetFeature<"no-movt", "NoMovt", "true",
                                      "Don't use movt/movw pairs for 32-bit "
                                      "imms">;
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.cpp b/llvm/lib/Target/ARM/ARMSubtarget.cpp
index 3180480986d..9d2f0291076 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.cpp
+++ b/llvm/lib/Target/ARM/ARMSubtarget.cpp
@@ -40,10 +40,6 @@ using namespace llvm;
 #include "ARMGenSubtargetInfo.inc"
 
 static cl::opt<bool>
-ReserveR9("arm-reserve-r9", cl::Hidden,
-          cl::desc("Reserve R9, making it unavailable as GPR"));
-
-static cl::opt<bool>
 UseFusedMulOps("arm-use-mulops",
                cl::init(true), cl::Hidden);
 
@@ -144,7 +140,7 @@ void ARMSubtarget::initializeEnvironment() {
   UseSoftFloat = false;
   HasThumb2 = false;
   NoARM = false;
-  IsR9Reserved = ReserveR9;
+  ReserveR9 = false;
   NoMovt = false;
   SupportsTailCall = false;
   HasFP16 = false;
@@ -212,13 +208,10 @@ void ARMSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
   if (isTargetNaCl())
     stackAlignment = 16;
 
-  if (isTargetMachO()) {
-    IsR9Reserved = ReserveR9 || !HasV6Ops;
+  if (isTargetMachO())
     SupportsTailCall = !isTargetIOS() || !getTargetTriple().isOSVersionLT(5, 0);
-  } else {
-    IsR9Reserved = ReserveR9;
+  else
     SupportsTailCall = !isThumb1Only();
-  }
 
   if (Align == DefaultAlign) {
     // Assume pre-ARMv6 doesn't support unaligned accesses.
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 4f9bc372e4b..b80dc7051f1 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -109,8 +109,8 @@ protected:
   /// NoARM - True if subtarget does not support ARM mode execution.
   bool NoARM;
 
-  /// IsR9Reserved - True if R9 is a not available as general purpose register.
-  bool IsR9Reserved;
+  /// ReserveR9 - True if R9 is not available as a general purpose register.
+  bool ReserveR9;
 
   /// NoMovt - True if MOVT / MOVW pairs are not used for materialization of
   /// 32-bit imms (including global addresses).
@@ -413,7 +413,9 @@ public:
     return isThumb1Only() && isMClass();
   }
 
-  bool isR9Reserved() const { return IsR9Reserved; }
+  bool isR9Reserved() const {
+    return isTargetMachO() ? (ReserveR9 || !HasV6Ops) : ReserveR9;
+  }
 
   bool useMovt(const MachineFunction &MF) const;
 
diff --git a/llvm/test/CodeGen/ARM/2007-03-13-InstrSched.ll b/llvm/test/CodeGen/ARM/2007-03-13-InstrSched.ll
index 9c0143be06c..81a6bb64971 100644
--- a/llvm/test/CodeGen/ARM/2007-03-13-InstrSched.ll
+++ b/llvm/test/CodeGen/ARM/2007-03-13-InstrSched.ll
@@ -2,7 +2,7 @@
 ; RUN: llc < %s -mtriple=arm-apple-darwin -relocation-model=pic \
 ; RUN:   -mattr=+v6 | grep r9
 ; RUN: llc < %s -mtriple=arm-apple-darwin -relocation-model=pic \
-; RUN:   -mattr=+v6 -arm-reserve-r9 -ifcvt-limit=0 -stats 2>&1 | grep asm-printer
+; RUN:   -mattr=+v6,+reserve-r9 -ifcvt-limit=0 -stats 2>&1 | grep asm-printer
 ; | grep 35
 
 define void @test(i32 %tmp56222, i32 %tmp36224, i32 %tmp46223, i32 %i.0196.0.ph, i32 %tmp8, i32* %tmp1011, i32** %tmp1, i32* %d2.1.out, i32* %d3.1.out, i32* %d0.1.out, i32* %d1.1.out) {
diff --git a/llvm/test/CodeGen/ARM/build-attributes.ll b/llvm/test/CodeGen/ARM/build-attributes.ll
index 29c702304a3..583c96b7444 100644
--- a/llvm/test/CodeGen/ARM/build-attributes.ll
+++ b/llvm/test/CodeGen/ARM/build-attributes.ll
@@ -122,7 +122,7 @@
 ; RUN: llc < %s -mtriple=arm-none-linux-gnueabi -relocation-model=dynamic-no-pic | FileCheck %s --check-prefix=RELOC-OTHER
 ; RUN: llc < %s -mtriple=arm-none-linux-gnueabi | FileCheck %s --check-prefix=RELOC-OTHER
 ; RUN: llc < %s -mtriple=arm-none-linux-gnueabi | FileCheck %s --check-prefix=PCS-R9-USE
-; RUN: llc < %s -mtriple=arm-none-linux-gnueabi -arm-reserve-r9 | FileCheck %s --check-prefix=PCS-R9-RESERVE
+; RUN: llc < %s -mtriple=arm-none-linux-gnueabi -mattr=+reserve-r9 | FileCheck %s --check-prefix=PCS-R9-RESERVE
 
 ; ARMv8.1a (AArch32)
 ; RUN: llc < %s -mtriple=armv8.1a-none-linux-gnueabi -arm-no-strict-align | FileCheck %s --check-prefix=NO-STRICT-ALIGN