Fix Bug 9386 - ARM disassembler failed to disassemble conditional bx

Modified the patch to .td file supplied by Jyun-Yan You.  Add a test case and
modified ARMDisassemblerCore.cpp a little bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131859 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 59a9cd7445e2396d9b16a99c7b0c5bddbd97dec3..e9e11b04652dfd9166f6169bc6d1b36486b5deb2 100644 (file)
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -1313,6 +1313,15 @@ let isBranch = 1, isTerminator = 1, isBarrier = 1, isIndirectBranch = 1 in {
     let Inst{3-0}  = dst;
   }
 
+  // For disassembly only.
+  def BX_pred : AXI<(outs), (ins GPR:$dst, pred:$p), BrMiscFrm, IIC_Br,
+                  "bx$p\t$dst", [/* pattern left blank */]>,
+              Requires<[IsARM, HasV4T]> {
+    bits<4> dst;
+    let Inst{27-4} = 0b000100101111111111110001;
+    let Inst{3-0}  = dst;
+  }
+
   // ARMV4 only
   // FIXME: We would really like to define this as a vanilla ARMPat like:
   // ARMPat<(brind GPR:$dst), (MOVr PC, GPR:$dst)>

diff --git a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
index 642829cdab095008fb6c617ad06b1f9eef953c3b..271ca8c72f08f604defd70ebadf5a95d12472061 100644 (file)
--- a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
@@ -895,8 +895,9 @@ static bool DisassembleBrFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
 }
 
 // Misc. Branch Instructions.
-// BLX, BLXi, BX
-// BX, BX_RET
+// BX_RET, MOVPCLR
+// BLX, BLX_pred, BX, BX_pred
+// BLXi
 static bool DisassembleBrMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
 
@@ -913,7 +914,7 @@ static bool DisassembleBrMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
 
   // BLX and BX take one GPR reg.
   if (Opcode == ARM::BLX || Opcode == ARM::BLX_pred ||
-      Opcode == ARM::BX) {
+      Opcode == ARM::BX || Opcode == ARM::BX_pred) {
     assert(NumOps >= 1 && OpInfo[OpIdx].RegClass == ARM::GPRRegClassID &&
            "Reg operand expected");
     MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::GPRRegClassID,

diff --git a/test/MC/Disassembler/ARM/arm-tests.txt b/test/MC/Disassembler/ARM/arm-tests.txt
index ade29525937dbe5cc3ed4dc978f14b5beddf9e7b..ca072c75beb6f6886b84011042f40dba830d9daa 100644 (file)
--- a/test/MC/Disassembler/ARM/arm-tests.txt
+++ b/test/MC/Disassembler/ARM/arm-tests.txt
@@ -164,6 +164,9 @@
 # CHECK: bx r12
 0x1c 0xff 0x2f 0xe1
 
+# CHECK: bxeq r5
+0x15 0xff 0x2f 0x01
+
 # CHECK:       uqadd16mi       r6, r11, r8
 0x18 0x60 0x6b 0x46