[Lldb-commits] [lldb] r125524 - in /lldb/trunk/source/Plugins/Instruction/ARM: EmulateInstructionARM.cpp EmulateInstructionARM.h
Johnny Chen
johnny.chen at apple.com
Mon Feb 14 14:04:26 PST 2011
Author: johnny
Date: Mon Feb 14 16:04:25 2011
New Revision: 125524
URL: http://llvm.org/viewvc/llvm-project?rev=125524&view=rev
Log:
Add entries for EmulateMovRdImm() -- "MOV (immediate)" -- Encodings T1 & T2 into g_thumb_opcodes
table. Modify EmulateInstructionARM::EvaluateInstruction() so that if the cpsr has changed
during evaluate instruction, we flush out the change into m_inst_cpsr in preparation for the next
instruction.
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=125524&r1=125523&r2=125524&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp (original)
+++ lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp Mon Feb 14 16:04:25 2011
@@ -647,6 +647,91 @@
return true;
}
+// Move (immediate) writes an immediate value to the destination register. It
+// can optionally update the condition flags based on the value.
+// MOV (immediate)
+bool
+EmulateInstructionARM::EmulateMovRdImm (ARMEncoding encoding)
+{
+#if 0
+ // ARM pseudo code...
+ if (ConditionPassed())
+ {
+ EncodingSpecificOperations();
+ result = imm32;
+ if d == 15 then // Can only occur for ARM encoding
+ ALUWritePC(result); // setflags is always FALSE here
+ else
+ R[d] = result;
+ if setflags then
+ 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 Rd; // the destination register
+ uint32_t imm12; // some intermediate result
+ uint32_t imm32; // the immediate value to be written to Rd
+ uint32_t carry; // the carry bit after ThumbExpandImm_C or ARMExpandImm_C.
+ bool setflags;
+ switch (encoding) {
+ case eEncodingT1:
+ Rd = Bits32(opcode, 11, 8);
+ setflags = !InITBlock();
+ imm32 = Bits32(opcode, 7, 0); // imm32 = ZeroExtend(imm8, 32)
+ carry = Bit32(m_inst_cpsr, CPSR_C);
+ break;
+ case eEncodingT2:
+ Rd = Bits32(opcode, 15, 12);
+ setflags = BitIsSet(opcode, 20);
+ imm12 = Bit32(opcode, 26) << 11 | Bits32(opcode, 14, 12) << 8 | Bits32(opcode, 7, 0);
+ imm32 = ThumbExpandImm_C(imm12, Bit32(m_inst_cpsr, CPSR_C), carry);
+ break;
+ default:
+ return false;
+ }
+ uint32_t result = imm32;
+
+ // The context specifies that an immediate is to be moved into Rd.
+ EmulateInstruction::Context context = { EmulateInstruction::eContextImmediate,
+ 0,
+ 0,
+ 0 };
+
+ if (Rd == 15)
+ {
+ if (!ALUWritePC (context, result))
+ return false;
+ }
+ else
+ {
+ if (!WriteRegisterUnsigned (context, eRegisterKindDWARF, dwarf_r0 + Rd, result))
+ return false;
+ if (setflags)
+ {
+ m_new_inst_cpsr = m_inst_cpsr;
+ SetBit32(m_new_inst_cpsr, CPSR_N, Bit32(result, CPSR_N));
+ SetBit32(m_new_inst_cpsr, CPSR_Z, result == 0 ? 1 : 0);
+ SetBit32(m_new_inst_cpsr, CPSR_C, carry);
+ if (m_new_inst_cpsr != m_inst_cpsr)
+ {
+ if (!WriteRegisterUnsigned (context, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FLAGS, m_new_inst_cpsr))
+ return false;
+ }
+ }
+ }
+ }
+ return true;
+}
+
// Bitwise NOT (immediate) writes the bitwise inverse of an immediate value to
// the destination register. It can optionally update the condition flags based
// on the value.
@@ -679,21 +764,21 @@
if (ConditionPassed())
{
uint32_t Rd; // the destination register
- uint32_t imm12; // the first operand to ThumbExpandImm_C or ARMExpandImm_C.
- uint32_t imm32; // the output after ThumbExpandImm_C or ARMExpandImm_C.
- uint32_t carry; // the carry bit after ThumbExpandImm_C or ARMExpandImm_C.
+ uint32_t imm12; // the first operand to ThumbExpandImm_C or ARMExpandImm_C
+ uint32_t imm32; // the output after ThumbExpandImm_C or ARMExpandImm_C
+ uint32_t carry; // the carry bit after ThumbExpandImm_C or ARMExpandImm_C
bool setflags;
switch (encoding) {
case eEncodingT1:
Rd = Bits32(opcode, 11, 8);
- imm12 = Bit32(opcode, 26) << 11 | Bits32(opcode, 14, 12) << 8 | Bits32(opcode, 7, 0);
setflags = BitIsSet(opcode, 20);
+ imm12 = Bit32(opcode, 26) << 11 | Bits32(opcode, 14, 12) << 8 | Bits32(opcode, 7, 0);
imm32 = ThumbExpandImm_C(imm12, Bit32(m_inst_cpsr, CPSR_C), carry);
break;
case eEncodingA1:
Rd = Bits32(opcode, 15, 12);
- imm12 = Bits32(opcode, 11, 0);
setflags = BitIsSet(opcode, 20);
+ imm12 = Bits32(opcode, 11, 0);
imm32 = ARMExpandImm_C(imm12, Bit32(m_inst_cpsr, CPSR_C), carry);
break;
default:
@@ -2935,6 +3020,9 @@
{ 0xffffff00, 0x00004600, ARMvAll, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateMovRdRm, "mov<c> <Rd>, <Rm>"},
// move from low register to low register
{ 0xffffffc0, 0x00000000, ARMvAll, eEncodingT2, eSize16, &EmulateInstructionARM::EmulateMovRdRm, "movs <Rd>, <Rm>"},
+ // move immediate
+ { 0xfffff800, 0x00002000, ARMvAll, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateMovRdImm, "movs|mov<c> <Rd>, #imm8"},
+ { 0xfbef8000, 0xf04f0000, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateMovRdImm, "mov{s}<c>.w <Rd>, #<const>"},
// move bitwise not
{ 0xfbef8000, 0xf06f0000, ARMV6T2_ABOVE, eEncodingT1, eSize32, &EmulateInstructionARM::EmulateMvnRdImm, "mvn{s} <Rd>, #<const>"},
// compare a register with immediate
@@ -3298,5 +3386,9 @@
if (m_inst_mode == eModeThumb && m_it_session.InITBlock())
m_it_session.ITAdvance();
+ // If the flags have changed, flush it out.
+ if (m_new_inst_cpsr != m_inst_cpsr)
+ m_inst_cpsr = m_new_inst_cpsr;
+
return false;
}
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=125524&r1=125523&r2=125524&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h (original)
+++ lldb/trunk/source/Plugins/Instruction/ARM/EmulateInstructionARM.h Mon Feb 14 16:04:25 2011
@@ -290,6 +290,10 @@
bool
EmulateMovRdRm (ARMEncoding encoding);
+ // MOV (immediate)
+ bool
+ EmulateMovRdImm (ARMEncoding encoding);
+
// MVN (immediate)
bool
EmulateMvnRdImm (ARMEncoding encoding);
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