[mips] Correct tail call encoding for MIPSR6

r277708 enabled tails calls for MIPS but used the 'jr' instruction when the 
jump target was held in a register. For MIPSR6, 'jalr $zero, $reg' should
have been used. Additionally, add missing patterns for external and global
symbols for tail calls.

Reviewers: dsanders, vkalintiris

Differential Review: https://reviews.llvm.org/D23301

llvm-svn: 279064

9 files changed, 31 insertions, 41 deletions

diff --git a/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td b/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
index 2b636cfe3bf..631789773b2 100644
--- a/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
+++ b/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
@@ -1772,3 +1772,5 @@ let AddedComplexity = 41 in {
   def : LoadRegImmPat<LDC1_D64_MMR6, f64, load>, FGR_64, ISA_MICROMIPS32R6;
   def : StoreRegImmPat<SDC1_D64_MMR6, f64>, FGR_64, ISA_MICROMIPS32R6;
 }
+
+def TAILCALL_MMR6 : TailCall<BC_MMR6, brtarget26_mm>, ISA_MICROMIPS32R6;
diff --git a/llvm/lib/Target/Mips/MicroMipsInstrInfo.td b/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
index 8b9eb36629f..d7d2e5dcd29 100644
--- a/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
@@ -471,18 +471,6 @@ class JumpRegCMM16<string opstr, RegisterOperand RO> :
   let isIndirectBranch = 1;
 }
 
-let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1, hasDelaySlot = 1,
-    hasExtraSrcRegAllocReq = 1, isCTI = 1, Defs = [AT] in {
-  class TailCall_MM<Instruction JumpInst> :
-    PseudoSE<(outs), (ins calltarget:$target), [], II_J>,
-    PseudoInstExpansion<(JumpInst jmptarget_mm:$target)>;
-
-  class TailCallReg_MM<RegisterOperand RO, Instruction JRInst,
-                       RegisterOperand ResRO = RO> :
-    PseudoSE<(outs), (ins RO:$rs), [(MipsTailCall RO:$rs)], II_JR>,
-    PseudoInstExpansion<(JRInst ResRO:$rs)>;
-}
-
 // Break16 and Sdbbp16
 class BrkSdbbp16MM<string opstr> :
   MicroMipsInst16<(outs), (ins uimm4:$code_),
@@ -989,11 +977,7 @@ let DecoderNamespace = "MicroMips", Predicates = [InMicroMips] in {
   def PREFX_MM : PrefetchIndexed<"prefx">, POOL32F_PREFX_FM_MM<0x15, 0x1A0>;
 }
 
-let AdditionalPredicates = [InMicroMips] in {
-  def TAILCALL_MM : TailCall_MM<J_MM>, ISA_MIPS1_NOT_32R6_64R6;
-  def TAILCALLREG_MM : TailCallReg_MM<GPR32Opnd, JR_MM>,
-                       ISA_MIPS1_NOT_32R6_64R6;
-}
+def TAILCALL_MM : TailCall<J_MM, jmptarget_mm>, ISA_MIPS1_NOT_32R6_64R6;
 
 let DecoderNamespace = "MicroMips" in {
   def RDHWR_MM : MMRel, R6MMR6Rel, ReadHardware<GPR32Opnd, HWRegsOpnd>,
@@ -1068,6 +1052,11 @@ let Predicates = [InMicroMips] in {
                 (LW_MM addr:$addr)>;
   def : MipsPat<(subc GPR32:$lhs, GPR32:$rhs),
                 (SUBu_MM GPR32:$lhs, GPR32:$rhs)>;
+
+  def : MipsPat<(MipsTailCall (iPTR tglobaladdr:$dst)),
+                (TAILCALL_MM tglobaladdr:$dst)>, ISA_MIPS1_NOT_32R6_64R6;
+  def : MipsPat<(MipsTailCall (iPTR texternalsym:$dst)),
+                (TAILCALL_MM texternalsym:$dst)>, ISA_MIPS1_NOT_32R6_64R6;
 }
 
 let AddedComplexity = 40 in {
diff --git a/llvm/lib/Target/Mips/Mips32r6InstrInfo.td b/llvm/lib/Target/Mips/Mips32r6InstrInfo.td
index be239b0aa60..f552f8d37af 100644
--- a/llvm/lib/Target/Mips/Mips32r6InstrInfo.td
+++ b/llvm/lib/Target/Mips/Mips32r6InstrInfo.td
@@ -848,8 +848,6 @@ let AdditionalPredicates = [NotInMicroMips] in {
   def SDC2_R6 : SDC2_R6_ENC, SDC2_R6_DESC, ISA_MIPS32R6;
   def SWC2_R6 : SWC2_R6_ENC, SWC2_R6_DESC, ISA_MIPS32R6;
 }
-def TAILCALL_R6 : TailCall<J>, ISA_MIPS32R6;
-def TAILCALLREG_R6 : TailCallReg<GPR32Opnd, JR>, GPR_32, ISA_MIPS32R6;
 
 //===----------------------------------------------------------------------===//
 //
diff --git a/llvm/lib/Target/Mips/Mips64InstrInfo.td b/llvm/lib/Target/Mips/Mips64InstrInfo.td
index c3d8754416a..62b1986e66f 100644
--- a/llvm/lib/Target/Mips/Mips64InstrInfo.td
+++ b/llvm/lib/Target/Mips/Mips64InstrInfo.td
@@ -242,9 +242,9 @@ let isCodeGenOnly = 1 in {
   def BLEZ64 : CBranchZero<"blez", brtarget, setle, GPR64Opnd>, BGEZ_FM<6, 0>;
   def BLTZ64 : CBranchZero<"bltz", brtarget, setlt, GPR64Opnd>, BGEZ_FM<1, 0>;
   def JALR64Pseudo : JumpLinkRegPseudo<GPR64Opnd, JALR, RA, GPR32Opnd>;
-  def TAILCALLREG64 : TailCallReg<GPR64Opnd, JR64>, GPR_64, ISA_MIPS1_NOT_32R6_64R6;
 }
 
+def TAILCALLREG64 : TailCallReg<GPR64Opnd>;
 
 def PseudoReturn64 : PseudoReturnBase<GPR64Opnd>;
 def PseudoIndirectBranch64 : PseudoIndirectBranchBase<GPR64Opnd>;
diff --git a/llvm/lib/Target/Mips/Mips64r6InstrInfo.td b/llvm/lib/Target/Mips/Mips64r6InstrInfo.td
index 0f366608cba..cc01400bb0d 100644
--- a/llvm/lib/Target/Mips/Mips64r6InstrInfo.td
+++ b/llvm/lib/Target/Mips/Mips64r6InstrInfo.td
@@ -165,10 +165,6 @@ def BLTZC64 : BLTZC_ENC, BLTZC64_DESC, ISA_MIPS64R6, GPR_64;
 def BGEZC64 : BGEZC_ENC, BGEZC64_DESC, ISA_MIPS64R6, GPR_64;
 }
 
-def TAILCALL64_R6 : TailCall<J>, ISA_MIPS64R6;
-def TAILCALLREG64_R6 : TailCallReg<GPR64Opnd, JR64>, GPR_64,
-                       ISA_MIPS64R6;
-
 //===----------------------------------------------------------------------===//
 //
 // Instruction Aliases
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
index 3136f504d42..7519c309e44 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -98,6 +98,7 @@ bool MipsAsmPrinter::lowerOperand(const MachineOperand &MO, MCOperand &MCOp) {
 void MipsAsmPrinter::emitPseudoIndirectBranch(MCStreamer &OutStreamer,
                                               const MachineInstr *MI) {
   bool HasLinkReg = false;
+  bool InMicroMipsMode = Subtarget->inMicroMipsMode();
   MCInst TmpInst0;
 
   if (Subtarget->hasMips64r6()) {
@@ -106,8 +107,12 @@ void MipsAsmPrinter::emitPseudoIndirectBranch(MCStreamer &OutStreamer,
     HasLinkReg = true;
   } else if (Subtarget->hasMips32r6()) {
     // MIPS32r6 should use (JALR ZERO, $rs)
-    TmpInst0.setOpcode(Mips::JALR);
-    HasLinkReg = true;
+    if (InMicroMipsMode)
+      TmpInst0.setOpcode(Mips::JRC16_MMR6);
+    else {
+      TmpInst0.setOpcode(Mips::JALR);
+      HasLinkReg = true;
+    }
   } else if (Subtarget->inMicroMipsMode())
     // microMIPS should use (JR_MM $rs)
     TmpInst0.setOpcode(Mips::JR_MM);
@@ -185,7 +190,9 @@ void MipsAsmPrinter::EmitInstruction(const MachineInstr *MI) {
     if (I->getOpcode() == Mips::PseudoReturn ||
         I->getOpcode() == Mips::PseudoReturn64 ||
         I->getOpcode() == Mips::PseudoIndirectBranch ||
-        I->getOpcode() == Mips::PseudoIndirectBranch64) {
+        I->getOpcode() == Mips::PseudoIndirectBranch64 ||
+        I->getOpcode() == Mips::TAILCALLREG ||
+        I->getOpcode() == Mips::TAILCALLREG64) {
       emitPseudoIndirectBranch(*OutStreamer, &*I);
       continue;
     }
diff --git a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
index c473c6ccd06..eb0d3142bec 100644
--- a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
+++ b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
@@ -560,7 +560,7 @@ static int getEquivalentCallShort(int Opcode) {
     return Mips::JALRS16_MM;
   case Mips::TAILCALL_MM:
     llvm_unreachable("Attempting to shorten the TAILCALL_MM pseudo!");
-  case Mips::TAILCALLREG_MM:
+  case Mips::TAILCALLREG:
     return Mips::JR16_MM;
   default:
     llvm_unreachable("Unexpected call instruction for microMIPS.");
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.cpp b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
index aedb8a46c6f..35ddbf221e8 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
@@ -282,7 +282,7 @@ unsigned MipsInstrInfo::getEquivalentCompactForm(
     case Mips::JR:
     case Mips::PseudoReturn:
     case Mips::PseudoIndirectBranch:
-    case Mips::TAILCALLREG_MM:
+    case Mips::TAILCALLREG:
       canUseShortMicroMipsCTI = true;
       break;
     }
@@ -363,8 +363,7 @@ unsigned MipsInstrInfo::getEquivalentCompactForm(
     case Mips::JR:
     case Mips::PseudoReturn:
     case Mips::PseudoIndirectBranch:
-    case Mips::TAILCALLREG_MM:
-    case Mips::TAILCALLREG_R6:
+    case Mips::TAILCALLREG:
       if (canUseShortMicroMipsCTI)
         return Mips::JRC16_MM;
       return Mips::JIC;
@@ -373,7 +372,7 @@ unsigned MipsInstrInfo::getEquivalentCompactForm(
     case Mips::JR64:
     case Mips::PseudoReturn64:
     case Mips::PseudoIndirectBranch64:
-    case Mips::TAILCALLREG64_R6:
+    case Mips::TAILCALLREG64:
       return Mips::JIC64;
     case Mips::JALR64Pseudo:
       return Mips::JIALC64;
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index ff8a5fba732..4dd8a5c719a 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -1370,14 +1370,12 @@ let isCall=1, hasDelaySlot=1, isCTI=1, Defs = [RA] in {
 
 let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1, hasDelaySlot = 1,
     hasExtraSrcRegAllocReq = 1, isCTI = 1, Defs = [AT] in {
-  class TailCall<Instruction JumpInst> :
+  class TailCall<Instruction JumpInst, DAGOperand Opnd> :
     PseudoSE<(outs), (ins calltarget:$target), [], II_J>,
-    PseudoInstExpansion<(JumpInst jmptarget:$target)>;
+    PseudoInstExpansion<(JumpInst Opnd:$target)>;
 
-  class TailCallReg<RegisterOperand RO, Instruction JRInst,
-                    RegisterOperand ResRO = RO> :
-    PseudoSE<(outs), (ins RO:$rs), [(MipsTailCall RO:$rs)], II_JR>,
-    PseudoInstExpansion<(JRInst ResRO:$rs)>;
+  class TailCallReg<RegisterOperand RO> :
+    MipsPseudo<(outs), (ins RO:$rs), [(MipsTailCall RO:$rs)], II_JR>;
 }
 
 class BAL_BR_Pseudo<Instruction RealInst> :
@@ -1919,11 +1917,12 @@ def BLTZALL : MMRel, BGEZAL_FT<"bltzall", brtarget, GPR32Opnd, 0>,
               BGEZAL_FM<0x12>, ISA_MIPS2_NOT_32R6_64R6;
 def BAL_BR : BAL_BR_Pseudo<BGEZAL>;
 
-let AdditionalPredicates = [NotInMicroMips] in {
-def TAILCALL : TailCall<J>, ISA_MIPS1_NOT_32R6_64R6;
-def TAILCALLREG : TailCallReg<GPR32Opnd, JR>, ISA_MIPS1_NOT_32R6_64R6, GPR_32;
+let Predicates = [NotInMicroMips] in { 
+  def TAILCALL : TailCall<J, jmptarget>;
 }
 
+def TAILCALLREG : TailCallReg<GPR32Opnd>;
+
 // Indirect branches are matched as PseudoIndirectBranch/PseudoIndirectBranch64
 // then are expanded to JR, JR64, JALR, or JALR64 depending on the ISA.
 class PseudoIndirectBranchBase<RegisterOperand RO> :