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

ahatanaka · ahatanaka · commit 7482d40cd57b · 2015-07-20T23:21:30.000Z
whether register r9 should be reserved. 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: 242737
diff --git 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
@@ -39,10 +39,6 @@ using namespace llvm;
 #define GET_SUBTARGETINFO_CTOR
 #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
@@ -109,8 +109,8 @@ class ARMSubtarget : public ARMGenSubtargetInfo {
   /// 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 @@ class ARMSubtarget : public ARMGenSubtargetInfo {
     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
@@ -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
@@ -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
