From 846dd95f87f62e2faa6092f99b521ecd9790121a Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Thu, 18 Aug 2011 22:31:17 +0000
Subject: [PATCH] Fix the decoding of RFE instruction.  RFEs have the load bit
 set, while SRSs have it unset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138000 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../ARM/Disassembler/ARMDisassembler.cpp      | 50 ++++++++++++++++---
 test/MC/Disassembler/ARM/arm-tests.txt        |  3 ++
 2 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index c5464ceb361..40a7936cfe2 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -1274,31 +1274,65 @@ static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
 
   if (pred == 0xF) {
     switch (Inst.getOpcode()) {
-      case ARM::STMDA:
+      case ARM::LDMDA:
         Inst.setOpcode(ARM::RFEDA);
         break;
-      case ARM::STMDA_UPD:
+      case ARM::LDMDA_UPD:
         Inst.setOpcode(ARM::RFEDA_UPD);
         break;
-      case ARM::STMDB:
+      case ARM::LDMDB:
         Inst.setOpcode(ARM::RFEDB);
         break;
-      case ARM::STMDB_UPD:
+      case ARM::LDMDB_UPD:
         Inst.setOpcode(ARM::RFEDB_UPD);
         break;
-      case ARM::STMIA:
+      case ARM::LDMIA:
         Inst.setOpcode(ARM::RFEIA);
         break;
-      case ARM::STMIA_UPD:
+      case ARM::LDMIA_UPD:
         Inst.setOpcode(ARM::RFEIA_UPD);
         break;
-      case ARM::STMIB:
+      case ARM::LDMIB:
         Inst.setOpcode(ARM::RFEIB);
         break;
-      case ARM::STMIB_UPD:
+      case ARM::LDMIB_UPD:
         Inst.setOpcode(ARM::RFEIB_UPD);
         break;
+      case ARM::STMDA:
+        Inst.setOpcode(ARM::SRSDA);
+        break;
+      case ARM::STMDA_UPD:
+        Inst.setOpcode(ARM::SRSDA_UPD);
+        break;
+      case ARM::STMDB:
+        Inst.setOpcode(ARM::SRSDB);
+        break;
+      case ARM::STMDB_UPD:
+        Inst.setOpcode(ARM::SRSDB_UPD);
+        break;
+      case ARM::STMIA:
+        Inst.setOpcode(ARM::SRSIA);
+        break;
+      case ARM::STMIA_UPD:
+        Inst.setOpcode(ARM::SRSIA_UPD);
+        break;
+      case ARM::STMIB:
+        Inst.setOpcode(ARM::SRSIB);
+        break;
+      case ARM::STMIB_UPD:
+        Inst.setOpcode(ARM::SRSIB_UPD);
+        break;
+      default:
+        CHECK(S, Fail);
     }
+
+    // For stores (which become SRS's, the only operand is the mode.
+    if (fieldFromInstruction32(Insn, 20, 1) == 0) {
+      Inst.addOperand(
+          MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
+      return S;
+    }
+
     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
   }
 
diff --git a/test/MC/Disassembler/ARM/arm-tests.txt b/test/MC/Disassembler/ARM/arm-tests.txt
index 349ad101559..cf258759379 100644
--- a/test/MC/Disassembler/ARM/arm-tests.txt
+++ b/test/MC/Disassembler/ARM/arm-tests.txt
@@ -311,3 +311,6 @@
 
 # CHECK:         strheq  r0, [r0, -r0]
 0xb0 0x00 0x00 0x01
+
+# CHECK: rfedb	#4!
+0x14 0x0 0x32 0xf9