Implement eret and deret(return from exception) instructions for Mips. Test examples are given.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186507 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 0 deletions

diff --git a/lib/Target/Mips/MipsInstrFormats.td b/lib/Target/Mips/MipsInstrFormats.td
index c2a5879..0ae93b4 100644
--- a/lib/Target/Mips/MipsInstrFormats.td
+++ b/lib/Target/Mips/MipsInstrFormats.td
@@ -520,6 +520,19 @@ class BRK_FM<bits<6> funct>
 }
 
 //===----------------------------------------------------------------------===//
+//  Exception return format <Cop0|1|0|funct>
+//===----------------------------------------------------------------------===//
+
+class ER_FM<bits<6> funct>
+{
+  bits<32> Inst;
+  let Inst{31-26} = 0x10;
+  let Inst{25}    = 1;
+  let Inst{24-6}  = 0;
+  let Inst{5-0}   = funct;
+}
+
+//===----------------------------------------------------------------------===//
 //
 //  FLOATING POINT INSTRUCTION FORMATS
 //
diff --git a/lib/Target/Mips/MipsInstrInfo.td b/lib/Target/Mips/MipsInstrInfo.td
index 1bc1077..6082a3f 100644
--- a/lib/Target/Mips/MipsInstrInfo.td
+++ b/lib/Target/Mips/MipsInstrInfo.td
@@ -652,6 +652,11 @@ class BRK_FT<string opstr> :
   InstSE<(outs), (ins uimm10:$code_1, uimm10:$code_2),
          !strconcat(opstr, "\t$code_1, $code_2"), [], NoItinerary, FrmOther>;
 
+// (D)Eret
+class ER_FT<string opstr> :
+  InstSE<(outs), (ins),
+         opstr, [], NoItinerary, FrmOther>;
+
 // Sync
 let hasSideEffects = 1 in
 class SYNC_FT :
@@ -958,6 +963,9 @@ def TEQ : TEQ_FT<"teq", CPURegsOpnd>, TEQ_FM<0x34>;
 def BREAK : BRK_FT<"break">, BRK_FM<0xd>;
 def SYSCALL : SYS_FT<"syscall">, SYS_FM<0xc>;
 
+def ERET : ER_FT<"eret">, ER_FM<0x18>;
+def DERET : ER_FT<"deret">, ER_FM<0x1f>;
+
 /// Load-linked, Store-conditional
 let Predicates = [NotN64, HasStdEnc] in {
   def LL : LLBase<"ll", CPURegsOpnd, mem>, LW_FM<0x30>;