Add code to emulate STRH (Register) Arm instruction.
Remove inaccurate comments from EmulateInstruction::Context definition.
Fix contexts in a few arm instruction emulation routines.
git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@127770 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/lldb/Core/EmulateInstruction.h b/include/lldb/Core/EmulateInstruction.h
index bb9047e..b288198 100644
--- a/include/lldb/Core/EmulateInstruction.h
+++ b/include/lldb/Core/EmulateInstruction.h
@@ -95,63 +95,34 @@
// Exclusively used when saving a register to the stack as part of the
// prologue
- // arg0 = register kind
- // arg1 = register number
- // arg2 = signed offset from current SP value where register is being
- // stored
eContextPushRegisterOnStack,
// Exclusively used when restoring a register off the stack as part of
// the epilogue
- // arg0 = register kind
- // arg1 = register number
- // arg2 = signed offset from current SP value where register is being
- // restored
eContextPopRegisterOffStack,
// Add or subtract a value from the stack
- // arg0 = register kind for SP
- // arg1 = register number for SP
- // arg2 = signed offset being applied to the SP value
eContextAdjustStackPointer,
// Add or subtract a value from a base address register (other than SP)
- // arg0 = register kind for base register
- // arg1 = register number of base register
- // arg2 = signed offset being applied to base register
eContextAdjustBaseRegister,
// Used in WriteRegister callbacks to indicate where the
- // arg0 = source register kind
- // arg1 = source register number
- // arg2 = source signed offset
eContextRegisterPlusOffset,
// Used in WriteMemory callback to indicate where the data came from
- // arg0 = register kind
- // arg1 = register number (register being stored)
- // arg2 = address of store
eContextRegisterStore,
eContextRegisterLoad,
// Used when performing a PC-relative branch where the
- // arg0 = don't care
- // arg1 = imm32 (signed offset)
- // arg2 = target instruction set or don't care
eContextRelativeBranchImmediate,
// Used when performing an absolute branch where the
- // arg0 = target register kind
- // arg1 = target register number
- // arg2 = target instruction set or don't care
eContextAbsoluteBranchRegister,
// Used when performing a supervisor call to an operating system to
// provide a service:
- // arg0 = current instruction set or don't care
- // arg1 = immediate data or don't care
- // arg2 = don't care
eContextSupervisorCall,
// Used when performing a MemU operation to read the PC-relative offset
@@ -159,19 +130,15 @@
eContextTableBranchReadMemory,
// Used when random bits are written into a register
- // arg0 = target register kind
- // arg1 = target register number
- // arg2 = don't care
eContextWriteRegisterRandomBits,
// Used when random bits are written to memory
- // arg0 = target memory address
- // arg1 = don't care
- // arg2 = don't care
eContextWriteMemoryRandomBits,
eContextMultiplication,
+
eContextAddition,
+
eContextReturnFromException
};
@@ -179,6 +146,7 @@
eInfoTypeRegisterPlusOffset,
eInfoTypeRegisterPlusIndirectOffset,
eInfoTypeRegisterToRegisterPlusOffset,
+ eInfoTypeRegisterToRegisterPlusIndirectOffset,
eInfoTypeRegisterRegisterOperands,
eInfoTypeOffset,
eInfoTypeRegister,
@@ -230,6 +198,13 @@
int64_t offset; // offset for address calculation
} RegisterToRegisterPlusOffset;
+ struct RegisterToRegisterPlusIndirectOffset
+ {
+ Register base_reg; // base register for address calculation
+ Register offset_reg; // offset register for address calculation
+ Register data_reg; // source/target register for data
+ } RegisterToRegisterPlusIndirectOffset;
+
struct RegisterRegisterOperands
{
Register operand1; // register containing first operand for binary op
@@ -292,6 +267,17 @@
}
void
+ SetRegisterToRegisterPlusIndirectOffset (Register base_reg,
+ Register offset_reg,
+ Register data_reg)
+ {
+ info_type = eInfoTypeRegisterToRegisterPlusIndirectOffset;
+ info.RegisterToRegisterPlusIndirectOffset.base_reg = base_reg;
+ info.RegisterToRegisterPlusIndirectOffset.offset_reg = offset_reg;
+ info.RegisterToRegisterPlusIndirectOffset.data_reg = data_reg;
+ }
+
+ void
SetRegisterRegisterOperands (Register op1_reg,
Register op2_reg)
{
diff --git a/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp b/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
index f45c52f..d68184f 100644
--- a/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
+++ b/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
@@ -412,12 +412,14 @@
context.type = EmulateInstruction::eContextPopRegisterOffStack;
Register dwarf_reg;
dwarf_reg.SetRegister (eRegisterKindDWARF, 0);
+ Register sp_reg;
+ sp_reg.SetRegister (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
for (i=0; i<15; ++i)
{
if (BitIsSet (registers, i))
{
dwarf_reg.num = dwarf_r0 + i;
- context.SetRegisterPlusOffset (dwarf_reg, addr - sp);
+ context.SetRegisterPlusOffset (sp_reg, addr - sp);
data = MemARead(context, addr, 4, 0, &success);
if (!success)
return false;
@@ -430,7 +432,7 @@
if (BitIsSet (registers, 15))
{
dwarf_reg.num = dwarf_pc;
- context.SetRegisterPlusOffset (dwarf_reg, addr - sp);
+ context.SetRegisterPlusOffset (sp_reg, addr - sp);
data = MemARead(context, addr, 4, 0, &success);
if (!success)
return false;
@@ -2509,8 +2511,12 @@
AddWithCarryResult res = AddWithCarry(val1, shifted, 0);
EmulateInstruction::Context context;
- context.type = EmulateInstruction::eContextImmediate;
- context.SetNoArgs ();
+ context.type = EmulateInstruction::eContextAddition;
+ Register op1_reg;
+ Register op2_reg;
+ op1_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + Rn);
+ op2_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + Rm);
+ context.SetRegisterRegisterOperands (op1_reg, op2_reg);
if (!WriteCoreRegOptionalFlags(context, res.result, Rd, setflags, res.carry_out, res.overflow))
return false;
@@ -4834,6 +4840,186 @@
return true;
}
+
+// STRH (register) calculates an address from a base register value and an offset register value, and stores a
+// halfword from a register to memory. The offset register alue can be shifted left by 0, 1, 2, or 3 bits.
+bool
+EmulateInstructionARM::EmulateSTRHRegister (ARMEncoding encoding)
+{
+#if 0
+ if ConditionPassed() then
+ EncodingSpecificOperations(); NullCheckIfThumbEE(n);
+ offset = Shift(R[m], shift_t, shift_n, APSR.C);
+ offset_addr = if add then (R[n] + offset) else (R[n] - offset);
+ address = if index then offset_addr else R[n];
+ if UnalignedSupport() || address<0> == ’0’ then
+ MemU[address,2] = R[t]<15:0>;
+ else // Can only occur before ARMv7
+ MemU[address,2] = bits(16) UNKNOWN;
+ if wback then R[n] = offset_addr;
+#endif
+
+ bool success = false;
+ const uint32_t opcode = OpcodeAsUnsigned (&success);
+ if (!success)
+ return false;
+
+ if (ConditionPassed ())
+ {
+ uint32_t t;
+ uint32_t n;
+ uint32_t m;
+ bool index;
+ bool add;
+ bool wback;
+ ARM_ShifterType shift_t;
+ uint32_t shift_n;
+
+ // EncodingSpecificOperations(); NullCheckIfThumbEE(n);
+ switch (encoding)
+ {
+ case eEncodingT1:
+ // if CurrentInstrSet() == InstrSet_ThumbEE then SEE "Modified operation in ThumbEE";
+ // t = UInt(Rt); n = UInt(Rn); m = UInt(Rm);
+ t = Bits32 (opcode, 2, 0);
+ n = Bits32 (opcode, 5, 3);
+ m = Bits32 (opcode, 8, 6);
+
+ // index = TRUE; add = TRUE; wback = FALSE;
+ index = true;
+ add = true;
+ wback = false;
+
+ // (shift_t, shift_n) = (SRType_LSL, 0);
+ shift_t = SRType_LSL;
+ shift_n = 0;
+
+ break;
+
+ case eEncodingT2:
+ // if Rn == ’1111’ then UNDEFINED;
+ // t = UInt(Rt); n = UInt(Rn); m = UInt(Rm);
+ t = Bits32 (opcode, 15, 12);
+ n = Bits32 (opcode, 19, 16);
+ m = Bits32 (opcode, 3, 0);
+ if (n == 15)
+ return false;
+
+ // index = TRUE; add = TRUE; wback = FALSE;
+ index = true;
+ add = true;
+ wback = false;
+
+ // (shift_t, shift_n) = (SRType_LSL, UInt(imm2));
+ shift_t = SRType_LSL;
+ shift_n = Bits32 (opcode, 5, 4);
+
+ // if BadReg(t) || BadReg(m) then UNPREDICTABLE;
+ if (BadReg (t) || BadReg (m))
+ return false;
+
+ break;
+
+ case eEncodingA1:
+ // if P == ’0’ && W == ’1’ then SEE STRHT;
+ // t = UInt(Rt); n = UInt(Rn); m = UInt(Rm);
+ t = Bits32 (opcode, 15, 12);
+ n = Bits32 (opcode, 19, 16);
+ m = Bits32 (opcode, 3, 0);
+
+ // index = (P == ’1’); add = (U == ’1’); wback = (P == ’0’) || (W == ’1’);
+ index = BitIsSet (opcode, 24);
+ add = BitIsSet (opcode, 23);
+ wback = (BitIsClear (opcode, 24) || BitIsSet (opcode, 21));
+
+ // (shift_t, shift_n) = (SRType_LSL, 0);
+ shift_t = SRType_LSL;
+ shift_n = 0;
+
+ // if t == 15 || m == 15 then UNPREDICTABLE;
+ if ((t == 15) || (m == 15))
+ return false;
+
+ // if wback && (n == 15 || n == t) then UNPREDICTABLE;
+ if (wback && ((n == 15) || (n == t)))
+ return false;
+
+ break;
+
+ default:
+ return false;
+ }
+
+ uint32_t Rm = ReadCoreReg (m, &success);
+ if (!success)
+ return false;
+
+ uint32_t Rn = ReadCoreReg (n, &success);
+ if (!success)
+ return false;
+
+ // offset = Shift(R[m], shift_t, shift_n, APSR.C);
+ uint32_t offset = Shift (Rm, shift_t, shift_n, APSR_C);
+
+ // offset_addr = if add then (R[n] + offset) else (R[n] - offset);
+ addr_t offset_addr;
+ if (add)
+ offset_addr = Rn + offset;
+ else
+ offset_addr = Rn - offset;
+
+ // address = if index then offset_addr else R[n];
+ addr_t address;
+ if (index)
+ address = offset_addr;
+ else
+ address = Rn;
+
+ EmulateInstruction::Context context;
+ context.type = eContextRegisterStore;
+ Register base_reg;
+ base_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + n);
+ Register offset_reg;
+ offset_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + m);
+
+ // if UnalignedSupport() || address<0> == ’0’ then
+ if (UnalignedSupport() || BitIsClear (address, 0))
+ {
+ // MemU[address,2] = R[t]<15:0>;
+ uint32_t Rt = ReadCoreReg (t, &success);
+ if (!success)
+ return false;
+
+ EmulateInstruction::Context context;
+ context.type = eContextRegisterStore;
+ Register base_reg;
+ base_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + n);
+ Register offset_reg;
+ offset_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + m);
+ Register data_reg;
+ data_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + t);
+ context.SetRegisterToRegisterPlusIndirectOffset (base_reg, offset_reg, data_reg);
+
+ if (!MemUWrite (context, address, Bits32 (Rt, 15, 0), 2))
+ return false;
+ }
+ else // Can only occur before ARMv7
+ {
+ // MemU[address,2] = bits(16) UNKNOWN;
+ }
+
+ // if wback then R[n] = offset_addr;
+ if (wback)
+ {
+ context.type = eContextAdjustBaseRegister;
+ context.SetAddress (offset_addr);
+ if (!WriteRegisterUnsigned (context, eRegisterKindDWARF, dwarf_r0 + n, offset_addr))
+ return false;
+ }
+ }
+
+ return true;
+}
// Add with Carry (immediate) adds an immediate value and the carry flag value to a register value,
// and writes the result to the destination register. It can optionally update the condition flags
@@ -9294,6 +9480,7 @@
{ 0x0fd00000, 0x09000000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateSTMDB, "stmdb<c> <Rn>{!} <registers>" },
{ 0x0fd00000, 0x09800000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateSTMIB, "stmib<c> <Rn>{!} <registers>" },
{ 0x0e500010, 0x06000000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateSTRRegister, "str<c> <Rt> [<Rn> +/-<Rm> {<shift>}]{!}" },
+ { 0x0e5000f0, 0x000000b0, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateSTRHRegister, "strh<c> <Rt>,[<Rn>,+/-<Rm>[{!}" },
//----------------------------------------------------------------------
// Other instructions
@@ -9572,6 +9759,8 @@
{ 0xfffff800, 0x00007000, ARMV4T_ABOVE, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateSTRBThumb, "strb<c> <Rt>, [<Rn>, #<imm5>]" },
{ 0xfff00000, 0xf8800000, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateSTRBThumb, "strb<c>.w <Rt>, [<Rn>, #<imm12>]" },
{ 0xfff00800, 0xf8000800, ARMV6T2_ABOVE, eEncodingT3, eSize32, &EmulateInstructionARM::EmulateSTRBThumb, "strb<c> <Rt> ,[<Rn>, #+/-<imm8>]{!}" },
+ { 0xfffffe00, 0x00005200, ARMV4T_ABOVE, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateSTRHRegister, "strh<c> <Rt>,[<Rn>,<Rm>]" },
+ { 0xfff00fc0, 0xf8200000, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateSTRHRegister, "strh<c>.w <Rt>,[<Rn>,<Rm>{,LSL #<imm2>}]" },
//----------------------------------------------------------------------
// Other instructions
diff --git a/source/Plugins/Instruction/ARM/EmulateInstructionARM.h b/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
index 9729974..9e5611a 100644
--- a/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
+++ b/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
@@ -524,6 +524,10 @@
bool
EmulateSTRBThumb (ARMEncoding encoding);
+ // A8.6.207 STRH (register)
+ bool
+ EmulateSTRHRegister (ARMEncoding encoding);
+
// A8.6.1 ADC (immediate)
bool
EmulateADCImm (ARMEncoding encoding);