[Lldb-commits] [lldb] r126144 - in /lldb/trunk/source/Plugins/Instruction/ARM: EmulateInstructionARM.cpp EmulateInstructionARM.h
Johnny Chen
johnny.chen at apple.com
Mon Feb 21 13:24:49 PST 2011
Author: johnny
Date: Mon Feb 21 15:24:49 2011
New Revision: 126144
URL: http://llvm.org/viewvc/llvm-project?rev=126144&view=rev
Log:
Add emulation methods for "TST (immediate)" and "TST (register)".
Plus modified EmulateANDImm/Reg to delegate to TSTImm/Reg for Thumb2
32-bit instructions when Rd == '1111' and setflags is true.
Modified:
lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
Modified: lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp?rev=126144&r1=126143&r2=126144&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp (original)
+++ lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp Mon Feb 21 15:24:49 2011
@@ -4444,9 +4444,9 @@
Rn = Bits32(opcode, 19, 16);
setflags = BitIsSet(opcode, 20);
imm32 = ThumbExpandImm_C(opcode, APSR_C, carry); // (imm32, carry) = ThumbExpandImm(i:imm3:imm8, APSR.C)
- // TODO: Emulate TST (immediate)
+ // if Rd == '1111' && S == '1' then SEE TST (immediate);
if (Rd == 15 && setflags)
- return false;
+ return EmulateTSTImm(eEncodingT1);
if (Rd == 13 || (Rd == 15 && !setflags) || BadReg(Rn))
return false;
break;
@@ -4529,9 +4529,9 @@
Rm = Bits32(opcode, 3, 0);
setflags = BitIsSet(opcode, 20);
shift_n = DecodeImmShift(Bits32(opcode, 5, 4), Bits32(opcode, 14, 12)<<2 | Bits32(opcode, 7, 6), shift_t);
- // TODO: Emulate TST (register)
+ // if Rd == '1111' && S == '1' then SEE TST (register);
if (Rd == 15 && setflags)
- return false;
+ return EmulateTSTReg(eEncodingT2);
if (Rd == 13 || (Rd == 15 && !setflags) || BadReg(Rn) || BadReg(Rm))
return false;
break;
@@ -5470,6 +5470,139 @@
return true;
}
+// Test (immediate) performs a bitwise AND operation on a register value and an immediate value.
+// It updates the condition flags based on the result, and discards the result.
+bool
+EmulateInstructionARM::EmulateTSTImm (ARMEncoding encoding)
+{
+#if 0
+ // ARM pseudo code...
+ if ConditionPassed() then
+ EncodingSpecificOperations();
+ result = R[n] AND imm32;
+ APSR.N = result<31>;
+ APSR.Z = IsZeroBit(result);
+ APSR.C = carry;
+ // APSR.V unchanged
+#endif
+
+ bool success = false;
+ const uint32_t opcode = OpcodeAsUnsigned (&success);
+ if (!success)
+ return false;
+
+ if (ConditionPassed())
+ {
+ uint32_t Rn;
+ uint32_t imm32; // the immediate value to be ANDed to the value obtained from Rn
+ uint32_t carry; // the carry bit after ARM/Thumb Expand operation
+ switch (encoding)
+ {
+ case eEncodingT1:
+ Rn = Bits32(opcode, 19, 16);
+ imm32 = ThumbExpandImm_C(opcode, APSR_C, carry); // (imm32, carry) = ThumbExpandImm(i:imm3:imm8, APSR.C)
+ if (BadReg(Rn))
+ return false;
+ break;
+ case eEncodingA1:
+ Rn = Bits32(opcode, 19, 16);
+ imm32 = ARMExpandImm_C(opcode, APSR_C, carry); // (imm32, carry) = ARMExpandImm(imm12, APSR.C)
+ break;
+ default:
+ return false;
+ }
+
+ // Read the first operand.
+ uint32_t val1 = ReadCoreReg(Rn, &success);
+ if (!success)
+ return false;
+
+ uint32_t result = val1 & imm32;
+
+ EmulateInstruction::Context context;
+ context.type = EmulateInstruction::eContextImmediate;
+ context.SetNoArgs ();
+
+ if (!WriteFlags(context, result, carry))
+ return false;
+ }
+ return true;
+}
+
+// Test (register) performs a bitwise AND operation on a register value and an optionally-shifted register value.
+// It updates the condition flags based on the result, and discards the result.
+bool
+EmulateInstructionARM::EmulateTSTReg (ARMEncoding encoding)
+{
+#if 0
+ // ARM pseudo code...
+ if ConditionPassed() then
+ EncodingSpecificOperations();
+ (shifted, carry) = Shift_C(R[m], shift_t, shift_n, APSR.C);
+ result = R[n] AND shifted;
+ APSR.N = result<31>;
+ APSR.Z = IsZeroBit(result);
+ APSR.C = carry;
+ // APSR.V unchanged
+#endif
+
+ bool success = false;
+ const uint32_t opcode = OpcodeAsUnsigned (&success);
+ if (!success)
+ return false;
+
+ if (ConditionPassed())
+ {
+ uint32_t Rn, Rm;
+ ARM_ShifterType shift_t;
+ uint32_t shift_n; // the shift applied to the value read from Rm
+ uint32_t carry;
+ switch (encoding)
+ {
+ case eEncodingT1:
+ Rn = Bits32(opcode, 2, 0);
+ Rm = Bits32(opcode, 5, 3);
+ shift_t = SRType_LSL;
+ shift_n = 0;
+ case eEncodingT2:
+ Rn = Bits32(opcode, 19, 16);
+ Rm = Bits32(opcode, 3, 0);
+ shift_n = DecodeImmShift(Bits32(opcode, 5, 4), Bits32(opcode, 14, 12)<<2 | Bits32(opcode, 7, 6), shift_t);
+ if (BadReg(Rn) || BadReg(Rm))
+ return false;
+ break;
+ case eEncodingA1:
+ Rn = Bits32(opcode, 19, 16);
+ Rm = Bits32(opcode, 3, 0);
+ shift_n = DecodeImmShift(Bits32(opcode, 6, 5), Bits32(opcode, 11, 7), shift_t);
+ break;
+ default:
+ return false;
+ }
+
+ // Read the first operand.
+ uint32_t val1 = ReadCoreReg(Rn, &success);
+ if (!success)
+ return false;
+
+ // Read the second operand.
+ uint32_t val2 = ReadCoreReg(Rm, &success);
+ if (!success)
+ return false;
+
+ uint32_t shifted = Shift_C(val2, shift_t, shift_n, APSR_C, carry);
+ uint32_t result = val1 & shifted;
+
+ EmulateInstruction::Context context;
+ context.type = EmulateInstruction::eContextImmediate;
+ context.SetNoArgs ();
+
+ if (!WriteFlags(context, result, carry))
+ return false;
+ }
+ return true;
+}
+
EmulateInstructionARM::ARMOpcode*
EmulateInstructionARM::GetARMOpcodeForInstruction (const uint32_t opcode)
{
@@ -5547,6 +5680,12 @@
{ 0x0fe00000, 0x03800000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateORRImm, "orr{s}<c> <Rd>, <Rn>, #const"},
// orr (register)
{ 0x0fe00010, 0x01800000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateORRReg, "orr{s}<c> <Rd>, <Rn>, <Rm> {,<shift>}"},
+ // tst (immediate)
+ { 0x0ff0f000, 0x03100000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateTSTImm, "tst<c> <Rn>, #const"},
+ // tst (register)
+ { 0x0ff0f010, 0x01100000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateTSTReg, "tst<c> <Rn>, <Rm> {,<shift>}"},
+
+
// move bitwise not
{ 0x0fef0000, 0x03e00000, ARMvAll, eEncodingA1, eSize32, &EmulateInstructionARM::EmulateMVNRdImm, "mvn{s}<c> <Rd>, #<const>"},
// asr (immediate)
@@ -5703,6 +5842,12 @@
// orr (register)
{ 0xffffffc0, 0x00004300, ARMvAll, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateORRReg, "orrs|orr<c> <Rdn>, <Rm>"},
{ 0xffe08000, 0xea400000, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateORRReg, "orr{s}<c>.w <Rd>, <Rn>, <Rm> {,<shift>}"},
+ // tst (immediate)
+ { 0xfbf08f00, 0xf0100f00, ARMV6T2_ABOVE, eEncodingT1, eSize32, &EmulateInstructionARM::EmulateTSTImm, "tsts}<c> <Rn>, #<const>"},
+ // tst (register)
+ { 0xffffffc0, 0x00004200, ARMvAll, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateTSTReg, "tst<c> <Rdn>, <Rm>"},
+ { 0xfff08f00, 0xea100f00, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateTSTReg, "tst<c>.w <Rn>, <Rm> {,<shift>}"},
+
// move from high register to high register
{ 0xffffff00, 0x00004600, ARMvAll, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateMOVRdRm, "mov<c> <Rd>, <Rm>"},
Modified: lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h?rev=126144&r1=126143&r2=126144&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h (original)
+++ lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h Mon Feb 21 15:24:49 2011
@@ -707,11 +707,11 @@
// A8.6.230 TST (immediate) - Encoding A1
bool
- EmulateTSTImmediate (ARMEncoding encoding);
+ EmulateTSTImm (ARMEncoding encoding);
// A8.6.231 TST (register) - Encoding T1, A1
bool
- EmulateTSTRegister (ARMEncoding encoding);
+ EmulateTSTReg (ARMEncoding encoding);
// A8.6.262 UXTB - Encoding T1
bool
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