[Hexagon] Remove C6 and C7 as separate registers

These are M0 and M1. Removing duplicated registers reduces the number
of explicit register aliasing.

llvm-svn: 302306

3 files changed, 6 insertions, 20 deletions

diff --git a/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp b/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
index 3396ddbe4fa..87c212b6163 100644
--- a/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
+++ b/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
@@ -553,7 +553,7 @@ static DecodeStatus DecodeCtrRegsRegisterClass(MCInst &Inst, unsigned RegNo,
   using namespace Hexagon;
   static const MCPhysReg CtrlRegDecoderTable[] = {
     /*  0 */  SA0,        LC0,        SA1,        LC1,
-    /*  4 */  P3_0,       C5,         C6,         C7,
+    /*  4 */  P3_0,       C5,         M0,         M1,
     /*  8 */  USR,        PC,         UGP,        GP,
     /* 12 */  CS0,        CS1,        UPCYCLELO,  UPCYCLEHI,
     /* 16 */  FRAMELIMIT, FRAMEKEY,   PKTCOUNTLO, PKTCOUNTHI,
diff --git a/llvm/lib/Target/Hexagon/HexagonRegisterInfo.td b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.td
index 2519b7c4006..45dbb3a6d21 100644
--- a/llvm/lib/Target/Hexagon/HexagonRegisterInfo.td
+++ b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.td
@@ -122,12 +122,6 @@ let Namespace = "Hexagon" in {
   def P2 : Rp<2, "p2">, DwarfRegNum<[65]>;
   def P3 : Rp<3, "p3">, DwarfRegNum<[66]>;
 
-  // Modifier registers.
-  // C6 and C7 can also be M0 and M1, but register names must be unique, even
-  // if belonging to different register classes.
-  def M0 : Mx<0, "m0">, DwarfRegNum<[72]>;
-  def M1 : Mx<1, "m1">, DwarfRegNum<[73]>;
-
   // Fake register to represent USR.OVF bit. Artihmetic/saturating instruc-
   // tions modify this bit, and multiple such instructions are allowed in the
   // same packet. We need to ignore output dependencies on this bit, but not
@@ -149,8 +143,8 @@ let Namespace = "Hexagon" in {
   // When defining more Cn registers, make sure to explicitly mark them
   // as reserved in HexagonRegisterInfo.cpp.
   def C5:         Rc<5,  "c5",         ["c5"]>,    DwarfRegNum<[72]>;
-  def C6:         Rc<6,  "c6",         [], [M0]>,  DwarfRegNum<[73]>;
-  def C7:         Rc<7,  "c7",         [], [M1]>,  DwarfRegNum<[74]>;
+  def M0:         Rc<6,  "m0",         ["c6"]>,    DwarfRegNum<[73]>;
+  def M1:         Rc<7,  "m1",         ["c7"]>,    DwarfRegNum<[74]>;
   // Define C8 separately and make it aliased with USR.
   // The problem is that USR has subregisters (e.g. overflow). If USR was
   // specified as a subregister of C9_8, it would imply that subreg_overflow
@@ -177,7 +171,7 @@ let Namespace = "Hexagon" in {
     def C1_0:     Rcc<0,  "c1:0",   [SA0, LC0], ["lc0:sa0"]>, DwarfRegNum<[67]>;
     def C3_2:     Rcc<2,  "c3:2",   [SA1, LC1], ["lc1:sa1"]>, DwarfRegNum<[69]>;
     def C5_4:     Rcc<4,  "c5:4",   [P3_0, C5]>,              DwarfRegNum<[71]>;
-    def C7_6:     Rcc<6,  "c7:6",   [C6, C7],   ["m1:0"]>,    DwarfRegNum<[72]>;
+    def C7_6:     Rcc<6,  "c7:6",   [M0, M1],   ["m1:0"]>,    DwarfRegNum<[72]>;
     // Use C8 instead of USR as a subregister of C9_8.
     def C9_8:     Rcc<8,  "c9:8",   [C8, PC]>,                DwarfRegNum<[74]>;
     def C11_10:   Rcc<10, "c11:10", [UGP, GP]>,               DwarfRegNum<[76]>;
@@ -280,8 +274,8 @@ def ModRegs : RegisterClass<"Hexagon", [i32], 32, (add M0, M1)>;
 
 let Size = 32, isAllocatable = 0 in
 def CtrRegs : RegisterClass<"Hexagon", [i32], 32,
-  (add LC0, SA0, LC1, SA1, P3_0, C5, C6, C7,
-       C8, PC, UGP, GP, CS0, CS1, UPCYCLELO, UPCYCLEHI,
+  (add LC0, SA0, LC1, SA1, P3_0, C5, C8, PC, UGP, GP, CS0, CS1,
+       UPCYCLELO, UPCYCLEHI,
        FRAMELIMIT, FRAMEKEY, PKTCOUNTLO, PKTCOUNTHI, UTIMERLO, UTIMERHI,
        M0, M1, USR)>;
 
diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
index dfb5f4cc826..70410ff03a6 100644
--- a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
@@ -788,14 +788,6 @@ HexagonMCCodeEmitter::getMachineOpValue(MCInst const &MI, MCOperand const &MO,
     if (HexagonMCInstrInfo::isSubInstruction(MI) ||
         llvm::HexagonMCInstrInfo::getType(MCII, MI) == HexagonII::TypeCJ)
       return HexagonMCInstrInfo::getDuplexRegisterNumbering(Reg);
-    switch(MI.getOpcode()){
-    case Hexagon::A2_tfrrcr:
-    case Hexagon::A2_tfrcrr:
-      if(Reg == Hexagon::M0)
-        Reg = Hexagon::C6;
-      if(Reg == Hexagon::M1)
-        Reg = Hexagon::C7;
-    }
     return MCT.getRegisterInfo()->getEncodingValue(Reg);
   }