[Xtensa] Fix S32C1I instruction encoding and copyPhysReg. (#165174)

Fix S21C1I instruction encoding.Fix special registers parsing for S32C1I
feature. Fix copyPhysReg function for f32 registers copy.

Author: andreisfr

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCCodeEmitter.cpp

@@ -320,7 +320,7 @@ XtensaMCCodeEmitter::getMemRegEncoding(const MCInst &MI, unsigned OpNo,
   case Xtensa::SSIP:
   case Xtensa::LSI:
   case Xtensa::LSIP:
-
+  case Xtensa::S32C1I:
     if (Res & 0x3) {
       report_fatal_error("Unexpected operand value!");
     }

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCTargetDesc.cpp

@@ -202,7 +202,7 @@ bool Xtensa::checkRegister(MCRegister RegNo, const FeatureBitset &FeatureBits,
     return FeatureBits[Xtensa::FeatureWindowed];
   case Xtensa::ATOMCTL:
   case Xtensa::SCOMPARE1:
-    return FeatureBits[Xtensa::FeatureWindowed];
+    return FeatureBits[Xtensa::FeatureS32C1I];
   case Xtensa::NoRegister:
     return false;
   }

llvm/lib/Target/Xtensa/XtensaInstrInfo.cpp

@@ -114,14 +114,31 @@ void XtensaInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                   const DebugLoc &DL, Register DestReg,
                                   Register SrcReg, bool KillSrc,
                                   bool RenamableDest, bool RenamableSrc) const {
-  // The MOV instruction is not present in core ISA,
+  unsigned Opcode;
+
+  // The MOV instruction is not present in core ISA for AR registers,
   // so use OR instruction.
-  if (Xtensa::ARRegClass.contains(DestReg, SrcReg))
+  if (Xtensa::ARRegClass.contains(DestReg, SrcReg)) {
     BuildMI(MBB, MBBI, DL, get(Xtensa::OR), DestReg)
         .addReg(SrcReg, getKillRegState(KillSrc))
         .addReg(SrcReg, getKillRegState(KillSrc));
+    return;
+  }
+
+  if (STI.hasSingleFloat() && Xtensa::FPRRegClass.contains(SrcReg) &&
+      Xtensa::FPRRegClass.contains(DestReg))
+    Opcode = Xtensa::MOV_S;
+  else if (STI.hasSingleFloat() && Xtensa::FPRRegClass.contains(SrcReg) &&
+           Xtensa::ARRegClass.contains(DestReg))
+    Opcode = Xtensa::RFR;
+  else if (STI.hasSingleFloat() && Xtensa::ARRegClass.contains(SrcReg) &&
+           Xtensa::FPRRegClass.contains(DestReg))
+    Opcode = Xtensa::WFR;
   else
     report_fatal_error("Impossible reg-to-reg copy");
+
+  BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
+      .addReg(SrcReg, getKillRegState(KillSrc));
 }
 
 void XtensaInstrInfo::storeRegToStackSlot(

llvm/test/CodeGen/Xtensa/s32c1i.ll

@@ -0,0 +1,7 @@
+; RUN: llc -mtriple=xtensa -mattr=+s32c1i  -filetype=obj %s -o - | llvm-objdump --arch=xtensa --mattr=s32c1i -d - | FileCheck %s -check-prefix=XTENSA
+
+define i32 @constraint_i(i32 %a) {
+; XTENSA: 0: 22 e2 01    s32c1i  a2, a2, 4
+  %res = tail call i32 asm "s32c1i $0, $1, $2", "=r,r,i"(i32 %a, i32 4)
+  ret i32 %res
+}

llvm/test/MC/Xtensa/s32c1i.s

@@ -0,0 +1,13 @@
+# RUN: llvm-mc %s -triple=xtensa -show-encoding --mattr=+s32c1i \
+# RUN:     | FileCheck -check-prefixes=CHECK,CHECK-INST %s
+
+.align	4
+LBL0:
+
+# CHECK-INST: xsr a3, atomctl
+# CHECK: # encoding: [0x30,0x63,0x61]
+xsr a3, atomctl
+
+# CHECK-INST: xsr a3, scompare1
+# CHECK: # encoding: [0x30,0x0c,0x61]
+xsr a3, scompare1