For Darwin on ARMv6 and newer, make register r9 available for use as a

caller-saved register.

llvm-svn: 73901

llvm/lib/Target/ARM/ARMInstrInfo.td

@@ -96,6 +96,8 @@ def HasV6     : Predicate<"Subtarget->hasV6Ops()">;
 def IsThumb   : Predicate<"Subtarget->isThumb()">;
 def HasThumb2 : Predicate<"Subtarget->hasThumb2()">;
 def IsARM     : Predicate<"!Subtarget->isThumb()">;
+def IsDarwin    : Predicate<"Subtarget->isTargetDarwin()">;
+def IsNotDarwin : Predicate<"!Subtarget->isTargetDarwin()">;
 
 //===----------------------------------------------------------------------===//
 // ARM Flag Definitions.
@@ -539,21 +541,22 @@ let isReturn = 1, isTerminator = 1 in
                     LdStMulFrm, "ldm${p}${addr:submode} $addr, $dst1",
                     []>;
 
+// On non-Darwin platforms R9 is callee-saved.
 let isCall = 1, Itinerary = IIC_Br,
   Defs = [R0, R1, R2, R3, R12, LR,
           D0, D1, D2, D3, D4, D5, D6, D7, CPSR] in {
   def BL  : ABXI<0b1011, (outs), (ins i32imm:$func, variable_ops),
                 "bl ${func:call}",
-                [(ARMcall tglobaladdr:$func)]>;
+                [(ARMcall tglobaladdr:$func)]>, Requires<[IsNotDarwin]>;
 
   def BL_pred : ABI<0b1011, (outs), (ins i32imm:$func, variable_ops),
                    "bl", " ${func:call}",
-                   [(ARMcall_pred tglobaladdr:$func)]>;
+                   [(ARMcall_pred tglobaladdr:$func)]>, Requires<[IsNotDarwin]>;
 
   // ARMv5T and above
   def BLX : AXI<(outs), (ins GPR:$func, variable_ops), BrMiscFrm,
                 "blx $func",
-                [(ARMcall GPR:$func)]>, Requires<[IsARM, HasV5T]> {
+                [(ARMcall GPR:$func)]>, Requires<[IsARM, HasV5T, IsNotDarwin]> {
     let Inst{7-4}   = 0b0011;
     let Inst{19-8}  = 0b111111111111;
     let Inst{27-20} = 0b00010010;
@@ -563,7 +566,36 @@ let isCall = 1, Itinerary = IIC_Br,
     // ARMv4T
     def BX : ABXIx2<(outs), (ins GPR:$func, variable_ops),
                      "mov lr, pc\n\tbx $func",
-                    [(ARMcall_nolink GPR:$func)]>;
+                    [(ARMcall_nolink GPR:$func)]>, Requires<[IsNotDarwin]>;
+  }
+}
+
+// On Darwin R9 is call-clobbered.
+let isCall = 1, Itinerary = IIC_Br,
+  Defs = [R0, R1, R2, R3, R9, R12, LR,
+          D0, D1, D2, D3, D4, D5, D6, D7, CPSR] in {
+  def BLr9  : ABXI<0b1011, (outs), (ins i32imm:$func, variable_ops),
+                "bl ${func:call}",
+                [(ARMcall tglobaladdr:$func)]>, Requires<[IsDarwin]>;
+
+  def BLr9_pred : ABI<0b1011, (outs), (ins i32imm:$func, variable_ops),
+                   "bl", " ${func:call}",
+                   [(ARMcall_pred tglobaladdr:$func)]>, Requires<[IsDarwin]>;
+
+  // ARMv5T and above
+  def BLXr9 : AXI<(outs), (ins GPR:$func, variable_ops), BrMiscFrm,
+                "blx $func",
+                [(ARMcall GPR:$func)]>, Requires<[IsARM, HasV5T, IsDarwin]> {
+    let Inst{7-4}   = 0b0011;
+    let Inst{19-8}  = 0b111111111111;
+    let Inst{27-20} = 0b00010010;
+  }
+
+  let Uses = [LR] in {
+    // ARMv4T
+    def BXr9 : ABXIx2<(outs), (ins GPR:$func, variable_ops),
+                     "mov lr, pc\n\tbx $func",
+                    [(ARMcall_nolink GPR:$func)]>, Requires<[IsDarwin]>;
   }
 }
 
@@ -1321,7 +1353,10 @@ def : ARMPat<(xor GPR:$LHS, so_imm2part:$RHS),
 
 
 // Direct calls
-def : ARMPat<(ARMcall texternalsym:$func), (BL texternalsym:$func)>;
+def : ARMPat<(ARMcall texternalsym:$func), (BL texternalsym:$func)>,
+      Requires<[IsNotDarwin]>;
+def : ARMPat<(ARMcall texternalsym:$func), (BLr9 texternalsym:$func)>,
+      Requires<[IsDarwin]>;
 
 // zextload i1 -> zextload i8
 def : ARMPat<(zextloadi1 addrmode2:$addr),  (LDRB addrmode2:$addr)>;

llvm/lib/Target/ARM/ARMRegisterInfo.cpp

@@ -235,8 +235,10 @@ ARMRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   };
 
   static const unsigned DarwinCalleeSavedRegs[] = {
+    // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved
+    // register.
     ARM::LR,  ARM::R7,  ARM::R6, ARM::R5, ARM::R4,
-    ARM::R11, ARM::R10, ARM::R9, ARM::R8,
+    ARM::R11, ARM::R10, ARM::R8,
 
     ARM::D15, ARM::D14, ARM::D13, ARM::D12,
     ARM::D11, ARM::D10, ARM::D9,  ARM::D8,
@@ -256,6 +258,7 @@ ARMRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
     &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
     0
   };
+
   static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = {
     &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
     &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass,
@@ -265,7 +268,33 @@ ARMRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
     &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
     0
   };
-  return STI.isThumb() ? ThumbCalleeSavedRegClasses : CalleeSavedRegClasses;
+
+  static const TargetRegisterClass * const DarwinCalleeSavedRegClasses[] = {
+    &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
+    &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
+    &ARM::GPRRegClass, &ARM::GPRRegClass,
+
+    &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
+    &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
+    0
+  };
+
+  static const TargetRegisterClass * const DarwinThumbCalleeSavedRegClasses[] ={
+    &ARM::GPRRegClass,  &ARM::tGPRRegClass, &ARM::tGPRRegClass,
+    &ARM::tGPRRegClass, &ARM::tGPRRegClass, &ARM::GPRRegClass,
+    &ARM::GPRRegClass,  &ARM::GPRRegClass,
+
+    &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
+    &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
+    0
+  };
+
+  if (STI.isThumb()) {
+    return STI.isTargetDarwin()
+      ? DarwinThumbCalleeSavedRegClasses : ThumbCalleeSavedRegClasses;
+  }
+  return STI.isTargetDarwin()
+    ? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses;
 }
 
 BitVector ARMRegisterInfo::getReservedRegs(const MachineFunction &MF) const {

llvm/lib/Target/ARM/ARMRegisterInfo.td

@@ -87,6 +87,7 @@ def CPSR : ARMReg<0, "cpsr">;
 // sp  == Stack Pointer
 // r12 == ip (scratch)
 // r7  == Frame Pointer (thumb-style backtraces)
+// r9  == May be reserved as Thread Register
 // r11 == Frame Pointer (arm-style backtraces)
 // r10 == Stack Limit
 //
@@ -115,13 +116,13 @@ def GPR : RegisterClass<"ARM", [i32], 32, [R0, R1, R2, R3, R4, R5, R6,
       ARM::R4, ARM::R5, ARM::R6, ARM::R7,
       ARM::R8, ARM::R10,
       ARM::R11 };
-    // FP is R7, R9 is available.
+    // FP is R7, R9 is available as non-callee-saved register.
+    // This is used by Darwin.
     static const unsigned ARM_GPR_AO_3[] = {
       ARM::R0, ARM::R1, ARM::R2, ARM::R3,
-      ARM::R12,ARM::LR,
+      ARM::R9, ARM::R12,ARM::LR,
       ARM::R4, ARM::R5, ARM::R6,
-      ARM::R8, ARM::R9, ARM::R10,ARM::R11,
+      ARM::R8, ARM::R10,ARM::R11,ARM::R7 };
-      ARM::R7 };
     // FP is R7, R9 is not available.
     static const unsigned ARM_GPR_AO_4[] = {
       ARM::R0, ARM::R1, ARM::R2, ARM::R3,
@@ -155,17 +156,15 @@ def GPR : RegisterClass<"ARM", [i32], 32, [R0, R1, R2, R3, R4, R5, R6,
       GPRClass::iterator I;
 
       if (Subtarget.isTargetDarwin()) {
-        if (Subtarget.isR9Reserved()) {
+        if (Subtarget.isR9Reserved())
           I = ARM_GPR_AO_4 + (sizeof(ARM_GPR_AO_4)/sizeof(unsigned));
-        } else {
+        else
           I = ARM_GPR_AO_3 + (sizeof(ARM_GPR_AO_3)/sizeof(unsigned));
-        }
       } else {
-        if (Subtarget.isR9Reserved()) {
+        if (Subtarget.isR9Reserved())
           I = ARM_GPR_AO_2 + (sizeof(ARM_GPR_AO_2)/sizeof(unsigned));
-        } else {
+        else
           I = ARM_GPR_AO_1 + (sizeof(ARM_GPR_AO_1)/sizeof(unsigned));
-        }
       }
 
       // Mac OS X requires FP not to be clobbered for backtracing purpose.

llvm/lib/Target/ARM/ARMSubtarget.cpp

@@ -16,15 +16,20 @@
 #include "llvm/Module.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/CommandLine.h"
 using namespace llvm;
 
+static cl::opt<bool>
+ReserveR9("arm-reserve-r9", cl::Hidden,
+          cl::desc("Reserve R9, making it unavailable as GPR"));
+
 ARMSubtarget::ARMSubtarget(const Module &M, const std::string &FS,
                            bool isThumb)
   : ARMArchVersion(V4T)
   , ARMFPUType(None)
   , IsThumb(isThumb)
   , ThumbMode(Thumb1)
-  , IsR9Reserved(false)
+  , IsR9Reserved(ReserveR9)
   , stackAlignment(4)
   , CPUString("generic")
   , TargetType(isELF) // Default to ELF unless otherwise specified.
@@ -83,5 +88,5 @@ ARMSubtarget::ARMSubtarget(const Module &M, const std::string &FS,
     stackAlignment = 8;
 
   if (isTargetDarwin())
-    IsR9Reserved = true;
+    IsR9Reserved = ReserveR9 | (ARMArchVersion < V6);
 }

llvm/test/CodeGen/ARM/2007-03-13-InstrSched.ll

@@ -1,5 +1,8 @@
 ; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin -relocation-model=pic \
-; RUN:   -mattr=+v6 -ifcvt-limit=0 -stats |& grep asm-printer | grep 35
+; RUN:   -mattr=+v6 | grep r9
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin -relocation-model=pic \
+; RUN:   -mattr=+v6 -arm-reserve-r9 -ifcvt-limit=0 -stats |& 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) {
 newFuncRoot: