Eliminate iOS-specific tail call instructions.

After register masks were introdruced to represent the call clobbers, it
is no longer necessary to have duplicate instruction for iOS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154209 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 27 insertions, 75 deletions

diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp
index bd4b2a9da9..402ecb0c5f 100644
--- a/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/lib/Target/ARM/ARMFrameLowering.cpp
@@ -422,17 +422,16 @@ void ARMFrameLowering::emitEpilogue(MachineFunction &MF,
     if (AFI->getGPRCalleeSavedArea1Size()) MBBI++;
   }
 
-  if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND ||
-      RetOpcode == ARM::TCRETURNri || RetOpcode == ARM::TCRETURNriND) {
+  if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNri) {
     // Tail call return: adjust the stack pointer and jump to callee.
     MBBI = MBB.getLastNonDebugInstr();
     MachineOperand &JumpTarget = MBBI->getOperand(0);
 
     // Jump to label or value in register.
-    if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND) {
-      unsigned TCOpcode = (RetOpcode == ARM::TCRETURNdi)
-        ? (STI.isThumb() ? ARM::tTAILJMPd : ARM::TAILJMPd)
-        : (STI.isThumb() ? ARM::tTAILJMPdND : ARM::TAILJMPdND);
+    if (RetOpcode == ARM::TCRETURNdi) {
+      unsigned TCOpcode = STI.isThumb() ?
+               (STI.isTargetIOS() ? ARM::tTAILJMPd : ARM::tTAILJMPdND) :
+               ARM::TAILJMPd;
       MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(TCOpcode));
       if (JumpTarget.isGlobal())
         MIB.addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
@@ -449,10 +448,6 @@ void ARMFrameLowering::emitEpilogue(MachineFunction &MF,
       BuildMI(MBB, MBBI, dl,
               TII.get(STI.isThumb() ? ARM::tTAILJMPr : ARM::TAILJMPr)).
         addReg(JumpTarget.getReg(), RegState::Kill);
-    } else if (RetOpcode == ARM::TCRETURNriND) {
-      BuildMI(MBB, MBBI, dl,
-              TII.get(STI.isThumb() ? ARM::tTAILJMPrND : ARM::TAILJMPrND)).
-        addReg(JumpTarget.getReg(), RegState::Kill);
     }
 
     MachineInstr *NewMI = prior(MBBI);
@@ -648,9 +643,7 @@ void ARMFrameLowering::emitPopInst(MachineBasicBlock &MBB,
   DebugLoc DL = MI->getDebugLoc();
   unsigned RetOpcode = MI->getOpcode();
   bool isTailCall = (RetOpcode == ARM::TCRETURNdi ||
-                     RetOpcode == ARM::TCRETURNdiND ||
-                     RetOpcode == ARM::TCRETURNri ||
-                     RetOpcode == ARM::TCRETURNriND);
+                     RetOpcode == ARM::TCRETURNri);
 
   SmallVector<unsigned, 4> Regs;
   unsigned i = CSI.size();
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index e771693590..d453b2c20b 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -2026,45 +2026,22 @@ def BXJ : ABI<0b0001, (outs), (ins GPR:$func), NoItinerary, "bxj", "\t$func",
 
 // Tail calls.
 
-let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1 in {
-  // IOS versions.
-  let Uses = [SP] in {
-    def TCRETURNdi : PseudoInst<(outs), (ins i32imm:$dst, variable_ops),
-                       IIC_Br, []>, Requires<[IsIOS]>;
+let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1, Uses = [SP] in {
+  def TCRETURNdi : PseudoInst<(outs), (ins i32imm:$dst, variable_ops),
+                              IIC_Br, []>;
 
-    def TCRETURNri : PseudoInst<(outs), (ins tcGPR:$dst, variable_ops),
-                       IIC_Br, []>, Requires<[IsIOS]>;
+  def TCRETURNri : PseudoInst<(outs), (ins tcGPR:$dst, variable_ops),
+                              IIC_Br, []>;
 
-    def TAILJMPd : ARMPseudoExpand<(outs), (ins br_target:$dst, variable_ops),
-                   4, IIC_Br, [],
-                   (Bcc br_target:$dst, (ops 14, zero_reg))>,
-                   Requires<[IsARM, IsIOS]>;
+  def TAILJMPd : ARMPseudoExpand<(outs), (ins br_target:$dst, variable_ops),
+                                 4, IIC_Br, [],
+                                 (Bcc br_target:$dst, (ops 14, zero_reg))>,
+                                 Requires<[IsARM]>;
 
-    def TAILJMPr : ARMPseudoExpand<(outs), (ins tcGPR:$dst, variable_ops),
-                   4, IIC_Br, [],
-                   (BX GPR:$dst)>,
-                   Requires<[IsARM, IsIOS]>;
-
-  }
-
-  // Non-IOS versions (the difference is R9).
-  let Uses = [SP] in {
-    def TCRETURNdiND : PseudoInst<(outs), (ins i32imm:$dst, variable_ops),
-                       IIC_Br, []>, Requires<[IsNotIOS]>;
-
-    def TCRETURNriND : PseudoInst<(outs), (ins tcGPR:$dst, variable_ops),
-                       IIC_Br, []>, Requires<[IsNotIOS]>;
-
-    def TAILJMPdND : ARMPseudoExpand<(outs), (ins brtarget:$dst, variable_ops),
-                   4, IIC_Br, [],
-                   (Bcc br_target:$dst, (ops 14, zero_reg))>,
-                   Requires<[IsARM, IsNotIOS]>;
-
-    def TAILJMPrND : ARMPseudoExpand<(outs), (ins tcGPR:$dst, variable_ops),
-                     4, IIC_Br, [],
-                     (BX GPR:$dst)>,
-                     Requires<[IsARM, IsNotIOS]>;
-  }
+  def TAILJMPr : ARMPseudoExpand<(outs), (ins tcGPR:$dst, variable_ops),
+                                 4, IIC_Br, [],
+                                 (BX GPR:$dst)>,
+                                 Requires<[IsARM]>;
 }
 
 // Secure Monitor Call is a system instruction.
@@ -4829,24 +4806,10 @@ def : ARMPat<(ARMWrapperJT tjumptable:$dst, imm:$id),
 
 // TODO: add,sub,and, 3-instr forms?
 
-// Tail calls
-def : ARMPat<(ARMtcret tcGPR:$dst),
-          (TCRETURNri tcGPR:$dst)>, Requires<[IsIOS]>;
-
-def : ARMPat<(ARMtcret (i32 tglobaladdr:$dst)),
-          (TCRETURNdi texternalsym:$dst)>, Requires<[IsIOS]>;
-
-def : ARMPat<(ARMtcret (i32 texternalsym:$dst)),
-          (TCRETURNdi texternalsym:$dst)>, Requires<[IsIOS]>;
-
-def : ARMPat<(ARMtcret tcGPR:$dst),
-          (TCRETURNriND tcGPR:$dst)>, Requires<[IsNotIOS]>;
-
-def : ARMPat<(ARMtcret (i32 tglobaladdr:$dst)),
-          (TCRETURNdiND texternalsym:$dst)>, Requires<[IsNotIOS]>;
-
-def : ARMPat<(ARMtcret (i32 texternalsym:$dst)),
-          (TCRETURNdiND texternalsym:$dst)>, Requires<[IsNotIOS]>;
+// Tail calls. These patterns also apply to Thumb mode.
+def : Pat<(ARMtcret tcGPR:$dst), (TCRETURNri tcGPR:$dst)>;
+def : Pat<(ARMtcret (i32 tglobaladdr:$dst)), (TCRETURNdi texternalsym:$dst)>;
+def : Pat<(ARMtcret (i32 texternalsym:$dst)), (TCRETURNdi texternalsym:$dst)>;
 
 // Direct calls
 def : ARMPat<(ARMcall texternalsym:$func), (BL texternalsym:$func)>,
diff --git a/lib/Target/ARM/ARMInstrThumb.td b/lib/Target/ARM/ARMInstrThumb.td
index 6c45ccc5ae..b9ef6925b5 100644
--- a/lib/Target/ARM/ARMInstrThumb.td
+++ b/lib/Target/ARM/ARMInstrThumb.td
@@ -504,24 +504,20 @@ let isBranch = 1, isTerminator = 1 in
 let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1 in {
   // IOS versions.
   let Uses = [SP] in {
-    // tTAILJMPd: IOS version uses a Thumb2 branch (no Thumb1 tail calls
-    // on IOS), so it's in ARMInstrThumb2.td.
     def tTAILJMPr : tPseudoExpand<(outs), (ins tcGPR:$dst, variable_ops),
                      4, IIC_Br, [],
                      (tBX GPR:$dst, (ops 14, zero_reg))>,
-                     Requires<[IsThumb, IsIOS]>;
+                     Requires<[IsThumb]>;
   }
-  // Non-IOS versions (the difference is R9).
+  // tTAILJMPd: IOS version uses a Thumb2 branch (no Thumb1 tail calls
+  // on IOS), so it's in ARMInstrThumb2.td.
+  // Non-IOS version:
   let Uses = [SP] in {
     def tTAILJMPdND : tPseudoExpand<(outs),
                    (ins t_brtarget:$dst, pred:$p, variable_ops),
                    4, IIC_Br, [],
                    (tB t_brtarget:$dst, pred:$p)>,
                  Requires<[IsThumb, IsNotIOS]>;
-    def tTAILJMPrND : tPseudoExpand<(outs), (ins tcGPR:$dst, variable_ops),
-                     4, IIC_Br, [],
-                     (tBX GPR:$dst, (ops 14, zero_reg))>,
-                     Requires<[IsThumb, IsNotIOS]>;
   }
 }