Pull in r200963 from upstream llvm trunk (by Venkatraman Govindaraju):

  [Sparc] Emit correct encoding for atomic instructions. Also, add support for parsing CAS instructions to test the CAS encoding.

Introduced here: http://svnweb.freebsd.org/changeset/base/262261

Index: test/MC/Sparc/sparc-atomic-instructions.s
===================================================================
--- test/MC/Sparc/sparc-atomic-instructions.s
+++ test/MC/Sparc/sparc-atomic-instructions.s
@@ -0,0 +1,19 @@
+! RUN: llvm-mc %s -arch=sparcv9 -show-encoding | FileCheck %s
+
+        ! CHECK: membar 15             ! encoding: [0x81,0x43,0xe0,0x0f]
+        membar 15
+
+        ! CHECK: stbar                 ! encoding: [0x81,0x43,0xc0,0x00]
+        stbar
+
+        ! CHECK: swap [%i0+%l6], %o2   ! encoding: [0xd4,0x7e,0x00,0x16]
+        swap [%i0+%l6], %o2
+
+        ! CHECK: swap [%i0+32], %o2    ! encoding: [0xd4,0x7e,0x20,0x20]
+        swap [%i0+32], %o2
+
+        ! CHECK: cas [%i0], %l6, %o2   ! encoding: [0xd5,0xe6,0x10,0x16]
+        cas [%i0], %l6, %o2
+
+        ! CHECK: casx [%i0], %l6, %o2  ! encoding: [0xd5,0xf6,0x10,0x16]
+        casx [%i0], %l6, %o2
Index: lib/Target/Sparc/SparcInstrInfo.td
===================================================================
--- lib/Target/Sparc/SparcInstrInfo.td
+++ lib/Target/Sparc/SparcInstrInfo.td
@@ -935,19 +935,19 @@ let Predicates = [HasV9], hasSideEffects = 1, rd =
  def MEMBARi : F3_2<2, 0b101000, (outs), (ins i32imm:$simm13),
                     "membar $simm13", []>;
 
-let Constraints = "$val = $rd" in {
+let Constraints = "$val = $dst" in {
   def SWAPrr : F3_1<3, 0b001111,
-                 (outs IntRegs:$rd), (ins IntRegs:$val, MEMrr:$addr),
-                 "swap [$addr], $rd",
-                 [(set i32:$rd, (atomic_swap_32 ADDRrr:$addr, i32:$val))]>;
+                 (outs IntRegs:$dst), (ins MEMrr:$addr, IntRegs:$val),
+                 "swap [$addr], $dst",
+                 [(set i32:$dst, (atomic_swap_32 ADDRrr:$addr, i32:$val))]>;
   def SWAPri : F3_2<3, 0b001111,
-                 (outs IntRegs:$rd), (ins IntRegs:$val, MEMri:$addr),
-                 "swap [$addr], $rd",
-                 [(set i32:$rd, (atomic_swap_32 ADDRri:$addr, i32:$val))]>;
+                 (outs IntRegs:$dst), (ins MEMri:$addr, IntRegs:$val),
+                 "swap [$addr], $dst",
+                 [(set i32:$dst, (atomic_swap_32 ADDRri:$addr, i32:$val))]>;
 }
 
 let Predicates = [HasV9], Constraints = "$swap = $rd" in
-  def CASrr: F3_1<3, 0b111100,
+  def CASrr: F3_1_asi<3, 0b111100, 0b10000000,
                 (outs IntRegs:$rd), (ins IntRegs:$rs1, IntRegs:$rs2,
                                      IntRegs:$swap),
                  "cas [$rs1], $rs2, $rd",
Index: lib/Target/Sparc/SparcInstrFormats.td
===================================================================
--- lib/Target/Sparc/SparcInstrFormats.td
+++ lib/Target/Sparc/SparcInstrFormats.td
@@ -100,9 +100,8 @@ class F3<dag outs, dag ins, string asmstr, list<da
 
 // Specific F3 classes: SparcV8 manual, page 44
 //
-class F3_1<bits<2> opVal, bits<6> op3val, dag outs, dag ins,
+class F3_1_asi<bits<2> opVal, bits<6> op3val, bits<8> asi, dag outs, dag ins,
            string asmstr, list<dag> pattern> : F3<outs, ins, asmstr, pattern> {
-  bits<8> asi = 0; // asi not currently used
   bits<5> rs2;
 
   let op         = opVal;
@@ -113,6 +112,10 @@ class F3<dag outs, dag ins, string asmstr, list<da
   let Inst{4-0}  = rs2;
 }
 
+class F3_1<bits<2> opVal, bits<6> op3val, dag outs, dag ins, string asmstr,
+       list<dag> pattern> : F3_1_asi<opVal, op3val, 0, outs, ins,
+                                                     asmstr, pattern>;
+
 class F3_2<bits<2> opVal, bits<6> op3val, dag outs, dag ins,
            string asmstr, list<dag> pattern> : F3<outs, ins, asmstr, pattern> {
   bits<13> simm13;
Index: lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
===================================================================
--- lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
+++ lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
@@ -546,7 +546,24 @@ parseOperand(SmallVectorImpl<MCParsedAsmOperand*>
                                                  Parser.getTok().getLoc()));
     Parser.Lex(); // Eat the [
 
-    ResTy = parseMEMOperand(Operands);
+    if (Mnemonic == "cas" || Mnemonic == "casx") {
+      SMLoc S = Parser.getTok().getLoc();
+      if (getLexer().getKind() != AsmToken::Percent)
+        return MatchOperand_NoMatch;
+      Parser.Lex(); // eat %
+
+      unsigned RegNo, RegKind;
+      if (!matchRegisterName(Parser.getTok(), RegNo, RegKind))
+        return MatchOperand_NoMatch;
+
+      Parser.Lex(); // Eat the identifier token.
+      SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer()-1);
+      Operands.push_back(SparcOperand::CreateReg(RegNo, RegKind, S, E));
+      ResTy = MatchOperand_Success;
+    } else {
+      ResTy = parseMEMOperand(Operands);
+    }
+
     if (ResTy != MatchOperand_Success)
       return ResTy;
 
Index: lib/Target/Sparc/SparcInstr64Bit.td
===================================================================
--- lib/Target/Sparc/SparcInstr64Bit.td
+++ lib/Target/Sparc/SparcInstr64Bit.td
@@ -415,7 +415,7 @@ def SETHIXi : F2_1<0b100,
 
 // ATOMICS.
 let Predicates = [Is64Bit], Constraints = "$swap = $rd" in {
-  def CASXrr: F3_1<3, 0b111110,
+  def CASXrr: F3_1_asi<3, 0b111110, 0b10000000,
                 (outs I64Regs:$rd), (ins I64Regs:$rs1, I64Regs:$rs2,
                                      I64Regs:$swap),
                  "casx [$rs1], $rs2, $rd",