Add BLXi to the instruction table for disassembly purpose.

A8.6.23 BLX (immediate)

rdar://problem/9212921

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128644 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index c7960035655ba5910a4ccbdd61c5f19dccead1cb..77068222d6d7729f2e7889b739528178428b4579 100644 (file)
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -1528,6 +1528,16 @@ let isBranch = 1, isTerminator = 1 in {
   }
 }
 
+// BLX (immediate) -- for disassembly only
+def BLXi : AXI<(outs), (ins br_target:$target), BrMiscFrm, NoItinerary,
+               "blx\t$target", [/* pattern left blank */]>,
+           Requires<[IsARM, HasV5T]> {
+  let Inst{31-25} = 0b1111101;
+  bits<25> target;
+  let Inst{23-0} = target{24-1};
+  let Inst{24} = target{0};
+}
+
 // Branch and Exchange Jazelle -- for disassembly only
 def BXJ : ABI<0b0001, (outs), (ins GPR:$func), NoItinerary, "bxj", "\t$func",
               [/* For disassembly only; pattern left blank */]> {

diff --git a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
index cba956311f2f0049a2fdff5183d7bd3b4ae83adb..566485e88c1ae972b7ea86ec07791f5f55a68572 100644 (file)
--- a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
@@ -764,7 +764,7 @@ static bool DisassembleBrFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
           || Opcode == ARM::SMC || Opcode == ARM::SVC) &&
          "Unexpected Opcode");
 
-  assert(NumOps >= 1 && OpInfo[0].RegClass < 0 && "Reg operand expected");
+  assert(NumOps >= 1 && OpInfo[0].RegClass < 0 && "Imm operand expected");
 
   int Imm32 = 0;
   if (Opcode == ARM::SMC) {
@@ -787,7 +787,7 @@ static bool DisassembleBrFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
 }
 
 // Misc. Branch Instructions.
-// BLX, BX
+// BLX, BLXi, BX
 // BX, BX_RET
 static bool DisassembleBrMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
@@ -814,6 +814,17 @@ static bool DisassembleBrMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     return true;
   }
 
+  // BLXi takes imm32 (the PC offset).
+  if (Opcode == ARM::BLXi) {
+    assert(NumOps >= 1 && OpInfo[0].RegClass < 0 && "Imm operand expected");
+    // SignExtend(imm24:H:'0', 32) where imm24 = Inst{23-0} and H = Inst{24}.
+    unsigned Imm26 = slice(insn, 23, 0) << 2 | slice(insn, 24, 24) << 1;
+    int Imm32 = SignExtend32<26>(Imm26);
+    MI.addOperand(MCOperand::CreateImm(Imm32));
+    OpIdx = 1;
+    return true;
+  }
+
   return false;
 }
 

diff --git a/test/MC/Disassembler/ARM/arm-tests.txt b/test/MC/Disassembler/ARM/arm-tests.txt
index d25634ef9df96250f48b73bdf67a766527625f9e..f10dea20227bbb17daa5b312fb94fd665c72dd2f 100644 (file)
--- a/test/MC/Disassembler/ARM/arm-tests.txt
+++ b/test/MC/Disassembler/ARM/arm-tests.txt
@@ -211,3 +211,6 @@
 
 # CHECK:       stc2    p2, cr4, [r9], {157}
 0x9d 0x42 0x89 0xfc
+
+# CHECK:       blx     #60
+0x0f 0x00 0x00 0xfa