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-rw-r--r--JavaScriptCore/assembler/ARMv7Assembler.h168
-rw-r--r--JavaScriptCore/assembler/MacroAssemblerARM.h9
-rw-r--r--JavaScriptCore/assembler/MacroAssemblerARMv7.h8
-rw-r--r--JavaScriptCore/assembler/MacroAssemblerCodeRef.h6
4 files changed, 136 insertions, 55 deletions
diff --git a/JavaScriptCore/assembler/ARMv7Assembler.h b/JavaScriptCore/assembler/ARMv7Assembler.h
index 078de44..02ce2e9 100644
--- a/JavaScriptCore/assembler/ARMv7Assembler.h
+++ b/JavaScriptCore/assembler/ARMv7Assembler.h
@@ -407,6 +407,11 @@ register writeback
class ARMv7Assembler {
public:
+ ~ARMv7Assembler()
+ {
+ ASSERT(m_jumpsToLink.isEmpty());
+ }
+
typedef ARMRegisters::RegisterID RegisterID;
typedef ARMRegisters::FPRegisterID FPRegisterID;
@@ -477,6 +482,17 @@ public:
private:
+ struct LinkRecord {
+ LinkRecord(intptr_t from, intptr_t to)
+ : from(from)
+ , to(to)
+ {
+ }
+
+ intptr_t from;
+ intptr_t to;
+ };
+
// ARMv7, Appx-A.6.3
bool BadReg(RegisterID reg)
{
@@ -574,6 +590,7 @@ private:
OP_SUB_SP_imm_T1 = 0xB080,
OP_BKPT = 0xBE00,
OP_IT = 0xBF00,
+ OP_NOP_T1 = 0xBF00,
} OpcodeID;
typedef enum {
@@ -608,6 +625,7 @@ private:
OP_MOV_imm_T3 = 0xF240,
OP_SUB_imm_T4 = 0xF2A0,
OP_MOVT = 0xF2C0,
+ OP_NOP_T2a = 0xF3AF,
OP_LDRH_reg_T2 = 0xF830,
OP_LDRH_imm_T3 = 0xF830,
OP_STR_imm_T4 = 0xF840,
@@ -626,6 +644,7 @@ private:
typedef enum {
OP_B_T4b = 0x9000,
+ OP_NOP_T2b = 0x8000,
} OpcodeID2;
struct FourFours {
@@ -1481,6 +1500,15 @@ public:
void* executableCopy(ExecutablePool* allocator)
{
void* copy = m_formatter.executableCopy(allocator);
+
+ unsigned jumpCount = m_jumpsToLink.size();
+ for (unsigned i = 0; i < jumpCount; ++i) {
+ uint16_t* location = reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(copy) + m_jumpsToLink[i].from);
+ uint16_t* target = reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(copy) + m_jumpsToLink[i].to);
+ linkJumpAbsolute(location, target);
+ }
+ m_jumpsToLink.clear();
+
ASSERT(copy);
return copy;
}
@@ -1503,11 +1531,7 @@ public:
{
ASSERT(to.m_offset != -1);
ASSERT(from.m_offset != -1);
-
- uint16_t* location = reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(m_formatter.data()) + from.m_offset);
- intptr_t relative = to.m_offset - from.m_offset;
-
- linkWithOffset(location, relative);
+ m_jumpsToLink.append(LinkRecord(from.m_offset, to.m_offset));
}
static void linkJump(void* code, JmpSrc from, void* to)
@@ -1515,9 +1539,7 @@ public:
ASSERT(from.m_offset != -1);
uint16_t* location = reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset);
- intptr_t relative = reinterpret_cast<intptr_t>(to) - reinterpret_cast<intptr_t>(location);
-
- linkWithOffset(location, relative);
+ linkJumpAbsolute(location, to);
}
// bah, this mathod should really be static, since it is used by the LinkBuffer.
@@ -1541,10 +1563,9 @@ public:
ASSERT(!(reinterpret_cast<intptr_t>(from) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(to) & 1));
- intptr_t relative = reinterpret_cast<intptr_t>(to) - reinterpret_cast<intptr_t>(from);
- linkWithOffset(reinterpret_cast<uint16_t*>(from), relative);
+ linkJumpAbsolute(reinterpret_cast<uint16_t*>(from), to);
- ExecutableAllocator::cacheFlush(reinterpret_cast<uint16_t*>(from) - 2, 2 * sizeof(uint16_t));
+ ExecutableAllocator::cacheFlush(reinterpret_cast<uint16_t*>(from) - 5, 5 * sizeof(uint16_t));
}
static void relinkCall(void* from, void* to)
@@ -1613,14 +1634,14 @@ private:
static void setInt32(void* code, uint32_t value)
{
uint16_t* location = reinterpret_cast<uint16_t*>(code);
+ ASSERT(isMOV_imm_T3(location - 4) && isMOVT(location - 2));
- uint16_t lo16 = value;
- uint16_t hi16 = value >> 16;
-
- spliceHi5(location - 4, lo16);
- spliceLo11(location - 3, lo16);
- spliceHi5(location - 2, hi16);
- spliceLo11(location - 1, hi16);
+ ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(value));
+ ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(value >> 16));
+ location[-4] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOV_imm_T3, lo16);
+ location[-3] = twoWordOp5i6Imm4Reg4EncodedImmSecond((location[-3] >> 8) & 0xf, lo16);
+ location[-2] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
+ location[-1] = twoWordOp5i6Imm4Reg4EncodedImmSecond((location[-1] >> 8) & 0xf, hi16);
ExecutableAllocator::cacheFlush(location - 4, 4 * sizeof(uint16_t));
}
@@ -1630,41 +1651,89 @@ private:
setInt32(code, reinterpret_cast<uint32_t>(value));
}
- // Linking & patching:
- // This method assumes that the JmpSrc being linked is a T4 b instruction.
- static void linkWithOffset(uint16_t* instruction, intptr_t relative)
- {
- // Currently branches > 16m = mostly deathy.
- if (((relative << 7) >> 7) != relative) {
- // FIXME: This CRASH means we cannot turn the JIT on by default on arm-v7.
- fprintf(stderr, "Error: Cannot link T4b.\n");
- CRASH();
- }
-
- // ARM encoding for the top two bits below the sign bit is 'peculiar'.
- if (relative >= 0)
- relative ^= 0xC00000;
+ static bool isB(void* address)
+ {
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return ((instruction[0] & 0xf800) == OP_B_T4a) && ((instruction[1] & 0xd000) == OP_B_T4b);
+ }
+
+ static bool isBX(void* address)
+ {
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return (instruction[0] & 0xff87) == OP_BX;
+ }
- // All branch offsets should be an even distance.
- ASSERT(!(relative & 1));
+ static bool isMOV_imm_T3(void* address)
+ {
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return ((instruction[0] & 0xFBF0) == OP_MOV_imm_T3) && ((instruction[1] & 0x8000) == 0);
+ }
- int word1 = ((relative & 0x1000000) >> 14) | ((relative & 0x3ff000) >> 12);
- int word2 = ((relative & 0x800000) >> 10) | ((relative & 0x400000) >> 11) | ((relative & 0xffe) >> 1);
+ static bool isMOVT(void* address)
+ {
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return ((instruction[0] & 0xFBF0) == OP_MOVT) && ((instruction[1] & 0x8000) == 0);
+ }
- instruction[-2] = OP_B_T4a | word1;
- instruction[-1] = OP_B_T4b | word2;
+ static bool isNOP_T1(void* address)
+ {
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return instruction[0] == OP_NOP_T1;
}
- // These functions can be used to splice 16-bit immediates back into previously generated instructions.
- static void spliceHi5(uint16_t* where, uint16_t what)
+ static bool isNOP_T2(void* address)
{
- uint16_t pattern = (what >> 12) | ((what & 0x0800) >> 1);
- *where = (*where & 0xFBF0) | pattern;
+ uint16_t* instruction = static_cast<uint16_t*>(address);
+ return (instruction[0] == OP_NOP_T2a) && (instruction[1] == OP_NOP_T2b);
}
- static void spliceLo11(uint16_t* where, uint16_t what)
+
+ static void linkJumpAbsolute(uint16_t* instruction, void* target)
{
- uint16_t pattern = ((what & 0x0700) << 4) | (what & 0x00FF);
- *where = (*where & 0x8F00) | pattern;
+ // FIMXE: this should be up in the MacroAssembler layer. :-(
+ const uint16_t JUMP_TEMPORARY_REGISTER = ARMRegisters::ip;
+
+ ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
+ ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
+
+ ASSERT( (isMOV_imm_T3(instruction - 5) && isMOVT(instruction - 3) && isBX(instruction - 1))
+ || (isNOP_T1(instruction - 5) && isNOP_T2(instruction - 4) && isB(instruction - 2)) );
+
+ intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
+ if (((relative << 7) >> 7) == relative) {
+ // ARM encoding for the top two bits below the sign bit is 'peculiar'.
+ if (relative >= 0)
+ relative ^= 0xC00000;
+
+ // All branch offsets should be an even distance.
+ ASSERT(!(relative & 1));
+ // There may be a better way to fix this, but right now put the NOPs first, since in the
+ // case of an conditional branch this will be coming after an ITTT predicating *three*
+ // instructions! Looking backwards to modify the ITTT to an IT is not easy, due to
+ // variable wdith encoding - the previous instruction might *look* like an ITTT but
+ // actually be the second half of a 2-word op.
+ instruction[-5] = OP_NOP_T1;
+ instruction[-4] = OP_NOP_T2a;
+ instruction[-3] = OP_NOP_T2b;
+ instruction[-2] = OP_B_T4a | ((relative & 0x1000000) >> 14) | ((relative & 0x3ff000) >> 12);
+ instruction[-1] = OP_B_T4b | ((relative & 0x800000) >> 10) | ((relative & 0x400000) >> 11) | ((relative & 0xffe) >> 1);
+ } else {
+ ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) + 1));
+ ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) >> 16));
+ instruction[-5] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOV_imm_T3, lo16);
+ instruction[-4] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, lo16);
+ instruction[-3] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
+ instruction[-2] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, hi16);
+ instruction[-1] = OP_BX | (JUMP_TEMPORARY_REGISTER << 3);
+ }
+ }
+
+ static uint16_t twoWordOp5i6Imm4Reg4EncodedImmFirst(uint16_t op, ARMThumbImmediate imm)
+ {
+ return op | (imm.m_value.i << 10) | imm.m_value.imm4;
+ }
+ static uint16_t twoWordOp5i6Imm4Reg4EncodedImmSecond(uint16_t rd, ARMThumbImmediate imm)
+ {
+ return (imm.m_value.imm3 << 12) | (rd << 8) | imm.m_value.imm8;
}
class ARMInstructionFormatter {
@@ -1723,8 +1792,11 @@ private:
void twoWordOp5i6Imm4Reg4EncodedImm(OpcodeID1 op, int imm4, RegisterID rd, ARMThumbImmediate imm)
{
- m_buffer.putShort(op | (imm.m_value.i << 10) | imm4);
- m_buffer.putShort((imm.m_value.imm3 << 12) | (rd << 8) | imm.m_value.imm8);
+ ARMThumbImmediate newImm = imm;
+ newImm.m_value.imm4 = imm4;
+
+ m_buffer.putShort(ARMv7Assembler::twoWordOp5i6Imm4Reg4EncodedImmFirst(op, newImm));
+ m_buffer.putShort(ARMv7Assembler::twoWordOp5i6Imm4Reg4EncodedImmSecond(rd, newImm));
}
void twoWordOp12Reg4Reg4Imm12(OpcodeID1 op, RegisterID reg1, RegisterID reg2, uint16_t imm)
@@ -1749,6 +1821,8 @@ private:
private:
AssemblerBuffer m_buffer;
} m_formatter;
+
+ Vector<LinkRecord> m_jumpsToLink;
};
} // namespace JSC
diff --git a/JavaScriptCore/assembler/MacroAssemblerARM.h b/JavaScriptCore/assembler/MacroAssemblerARM.h
index aa8cbb0..7a72b06 100644
--- a/JavaScriptCore/assembler/MacroAssemblerARM.h
+++ b/JavaScriptCore/assembler/MacroAssemblerARM.h
@@ -65,6 +65,7 @@ public:
};
static const RegisterID stackPointerRegister = ARMRegisters::sp;
+ static const RegisterID linkRegister = ARMRegisters::lr;
static const Scale ScalePtr = TimesFour;
@@ -530,7 +531,7 @@ public:
void ret()
{
- pop(ARMRegisters::pc);
+ m_assembler.mov_r(ARMRegisters::pc, linkRegister);
}
void set32(Condition cond, RegisterID left, RegisterID right, RegisterID dest)
@@ -746,11 +747,9 @@ protected:
void prepareCall()
{
- ensureSpace(3 * sizeof(ARMWord), sizeof(ARMWord));
+ ensureSpace(2 * sizeof(ARMWord), sizeof(ARMWord));
- // S0 might be used for parameter passing
- m_assembler.add_r(ARMRegisters::S1, ARMRegisters::pc, ARMAssembler::OP2_IMM | 0x4);
- m_assembler.push_r(ARMRegisters::S1);
+ m_assembler.mov_r(linkRegister, ARMRegisters::pc);
}
void call32(RegisterID base, int32_t offset)
diff --git a/JavaScriptCore/assembler/MacroAssemblerARMv7.h b/JavaScriptCore/assembler/MacroAssemblerARMv7.h
index a549604..c479517 100644
--- a/JavaScriptCore/assembler/MacroAssemblerARMv7.h
+++ b/JavaScriptCore/assembler/MacroAssemblerARMv7.h
@@ -990,13 +990,15 @@ public:
protected:
ARMv7Assembler::JmpSrc makeJump()
{
- return m_assembler.b();
+ moveFixedWidthEncoding(Imm32(0), dataTempRegister);
+ return m_assembler.bx(dataTempRegister);
}
ARMv7Assembler::JmpSrc makeBranch(ARMv7Assembler::Condition cond)
{
- m_assembler.it(cond);
- return m_assembler.b();
+ m_assembler.it(cond, true, true);
+ moveFixedWidthEncoding(Imm32(0), dataTempRegister);
+ return m_assembler.bx(dataTempRegister);
}
ARMv7Assembler::JmpSrc makeBranch(Condition cond) { return makeBranch(armV7Condition(cond)); }
ARMv7Assembler::JmpSrc makeBranch(DoubleCondition cond) { return makeBranch(armV7Condition(cond)); }
diff --git a/JavaScriptCore/assembler/MacroAssemblerCodeRef.h b/JavaScriptCore/assembler/MacroAssemblerCodeRef.h
index 568260a..3681af8 100644
--- a/JavaScriptCore/assembler/MacroAssemblerCodeRef.h
+++ b/JavaScriptCore/assembler/MacroAssemblerCodeRef.h
@@ -69,7 +69,13 @@ public:
template<typename FunctionType>
explicit FunctionPtr(FunctionType* value)
+#if COMPILER(RVCT)
+ // RVTC compiler needs C-style cast as it fails with the following error
+ // Error: #694: reinterpret_cast cannot cast away const or other type qualifiers
+ : m_value((void*)(value))
+#else
: m_value(reinterpret_cast<void*>(value))
+#endif
{
ASSERT_VALID_CODE_POINTER(m_value);
}
generated by cgit v1.1 at 2025-05-15 08:55:27 +0000