blob: 20124f9d0577b9fca500c7cd62309b5b1af25aff [file] [log] [blame]
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* This file contains codegen for the Thumb2 ISA and is intended to be
* includes by:
*
* Codegen-$(TARGET_ARCH_VARIANT).c
*
*/
#include "oat_compilation_unit.h"
namespace art {
/*
* Generate a Thumb2 IT instruction, which can nullify up to
* four subsequent instructions based on a condition and its
* inverse. The condition applies to the first instruction, which
* is executed if the condition is met. The string "guide" consists
* of 0 to 3 chars, and applies to the 2nd through 4th instruction.
* A "T" means the instruction is executed if the condition is
* met, and an "E" means the instruction is executed if the condition
* is not met.
*/
LIR* opIT(CompilationUnit* cUnit, ArmConditionCode code, const char* guide)
{
int mask;
int condBit = code & 1;
int altBit = condBit ^ 1;
int mask3 = 0;
int mask2 = 0;
int mask1 = 0;
//Note: case fallthroughs intentional
switch(strlen(guide)) {
case 3:
mask1 = (guide[2] == 'T') ? condBit : altBit;
case 2:
mask2 = (guide[1] == 'T') ? condBit : altBit;
case 1:
mask3 = (guide[0] == 'T') ? condBit : altBit;
break;
case 0:
break;
default:
LOG(FATAL) << "OAT: bad case in opIT";
}
mask = (mask3 << 3) | (mask2 << 2) | (mask1 << 1) |
(1 << (3 - strlen(guide)));
return newLIR2(cUnit, kThumb2It, code, mask);
}
/*
* The sparse table in the literal pool is an array of <key,displacement>
* pairs. For each set, we'll load them as a pair using ldmia.
* This means that the register number of the temp we use for the key
* must be lower than the reg for the displacement.
*
* The test loop will look something like:
*
* adr rBase, <table>
* ldr rVal, [rSP, vRegOff]
* mov rIdx, #tableSize
* lp:
* ldmia rBase!, {rKey, rDisp}
* sub rIdx, #1
* cmp rVal, rKey
* ifeq
* add rPC, rDisp ; This is the branch from which we compute displacement
* cbnz rIdx, lp
*/
void genSparseSwitch(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc)
{
const u2* table = cUnit->insns + mir->offset + mir->dalvikInsn.vB;
if (cUnit->printMe) {
dumpSparseSwitchTable(table);
}
// Add the table to the list - we'll process it later
SwitchTable *tabRec = (SwitchTable *)oatNew(cUnit, sizeof(SwitchTable),
true, kAllocData);
tabRec->table = table;
tabRec->vaddr = mir->offset;
int size = table[1];
tabRec->targets = (LIR* *)oatNew(cUnit, size * sizeof(LIR*), true,
kAllocLIR);
oatInsertGrowableList(cUnit, &cUnit->switchTables, (intptr_t)tabRec);
// Get the switch value
rlSrc = loadValue(cUnit, rlSrc, kCoreReg);
int rBase = oatAllocTemp(cUnit);
/* Allocate key and disp temps */
int rKey = oatAllocTemp(cUnit);
int rDisp = oatAllocTemp(cUnit);
// Make sure rKey's register number is less than rDisp's number for ldmia
if (rKey > rDisp) {
int tmp = rDisp;
rDisp = rKey;
rKey = tmp;
}
// Materialize a pointer to the switch table
newLIR3(cUnit, kThumb2Adr, rBase, 0, (intptr_t)tabRec);
// Set up rIdx
int rIdx = oatAllocTemp(cUnit);
loadConstant(cUnit, rIdx, size);
// Establish loop branch target
LIR* target = newLIR0(cUnit, kPseudoTargetLabel);
// Load next key/disp
newLIR2(cUnit, kThumb2LdmiaWB, rBase, (1 << rKey) | (1 << rDisp));
opRegReg(cUnit, kOpCmp, rKey, rlSrc.lowReg);
// Go if match. NOTE: No instruction set switch here - must stay Thumb2
opIT(cUnit, kArmCondEq, "");
LIR* switchBranch = newLIR1(cUnit, kThumb2AddPCR, rDisp);
tabRec->anchor = switchBranch;
// Needs to use setflags encoding here
newLIR3(cUnit, kThumb2SubsRRI12, rIdx, rIdx, 1);
opCondBranch(cUnit, kCondNe, target);
}
void genPackedSwitch(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc)
{
const u2* table = cUnit->insns + mir->offset + mir->dalvikInsn.vB;
if (cUnit->printMe) {
dumpPackedSwitchTable(table);
}
// Add the table to the list - we'll process it later
SwitchTable *tabRec = (SwitchTable *)oatNew(cUnit, sizeof(SwitchTable),
true, kAllocData);
tabRec->table = table;
tabRec->vaddr = mir->offset;
int size = table[1];
tabRec->targets = (LIR* *)oatNew(cUnit, size * sizeof(LIR*), true,
kAllocLIR);
oatInsertGrowableList(cUnit, &cUnit->switchTables, (intptr_t)tabRec);
// Get the switch value
rlSrc = loadValue(cUnit, rlSrc, kCoreReg);
int tableBase = oatAllocTemp(cUnit);
// Materialize a pointer to the switch table
newLIR3(cUnit, kThumb2Adr, tableBase, 0, (intptr_t)tabRec);
int lowKey = s4FromSwitchData(&table[2]);
int keyReg;
// Remove the bias, if necessary
if (lowKey == 0) {
keyReg = rlSrc.lowReg;
} else {
keyReg = oatAllocTemp(cUnit);
opRegRegImm(cUnit, kOpSub, keyReg, rlSrc.lowReg, lowKey);
}
// Bounds check - if < 0 or >= size continue following switch
opRegImm(cUnit, kOpCmp, keyReg, size-1);
LIR* branchOver = opCondBranch(cUnit, kCondHi, NULL);
// Load the displacement from the switch table
int dispReg = oatAllocTemp(cUnit);
loadBaseIndexed(cUnit, tableBase, keyReg, dispReg, 2, kWord);
// ..and go! NOTE: No instruction set switch here - must stay Thumb2
LIR* switchBranch = newLIR1(cUnit, kThumb2AddPCR, dispReg);
tabRec->anchor = switchBranch;
/* branchOver target here */
LIR* target = newLIR0(cUnit, kPseudoTargetLabel);
branchOver->target = (LIR*)target;
}
/*
* Array data table format:
* ushort ident = 0x0300 magic value
* ushort width width of each element in the table
* uint size number of elements in the table
* ubyte data[size*width] table of data values (may contain a single-byte
* padding at the end)
*
* Total size is 4+(width * size + 1)/2 16-bit code units.
*/
void genFillArrayData(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc)
{
const u2* table = cUnit->insns + mir->offset + mir->dalvikInsn.vB;
// Add the table to the list - we'll process it later
FillArrayData *tabRec = (FillArrayData *)
oatNew(cUnit, sizeof(FillArrayData), true, kAllocData);
tabRec->table = table;
tabRec->vaddr = mir->offset;
u2 width = tabRec->table[1];
u4 size = tabRec->table[2] | (((u4)tabRec->table[3]) << 16);
tabRec->size = (size * width) + 8;
oatInsertGrowableList(cUnit, &cUnit->fillArrayData, (intptr_t)tabRec);
// Making a call - use explicit registers
oatFlushAllRegs(cUnit); /* Everything to home location */
loadValueDirectFixed(cUnit, rlSrc, r0);
loadWordDisp(cUnit, rSELF,
OFFSETOF_MEMBER(Thread, pHandleFillArrayDataFromCode), rLR);
// Materialize a pointer to the fill data image
newLIR3(cUnit, kThumb2Adr, r1, 0, (intptr_t)tabRec);
callRuntimeHelper(cUnit, rLR);
}
void genNegFloat(CompilationUnit* cUnit, RegLocation rlDest, RegLocation rlSrc)
{
RegLocation rlResult;
rlSrc = loadValue(cUnit, rlSrc, kFPReg);
rlResult = oatEvalLoc(cUnit, rlDest, kFPReg, true);
newLIR2(cUnit, kThumb2Vnegs, rlResult.lowReg, rlSrc.lowReg);
storeValue(cUnit, rlDest, rlResult);
}
void genNegDouble(CompilationUnit* cUnit, RegLocation rlDest, RegLocation rlSrc)
{
RegLocation rlResult;
rlSrc = loadValueWide(cUnit, rlSrc, kFPReg);
rlResult = oatEvalLoc(cUnit, rlDest, kFPReg, true);
newLIR2(cUnit, kThumb2Vnegd, S2D(rlResult.lowReg, rlResult.highReg),
S2D(rlSrc.lowReg, rlSrc.highReg));
storeValueWide(cUnit, rlDest, rlResult);
}
/*
* Handle simple case (thin lock) inline. If it's complicated, bail
* out to the heavyweight lock/unlock routines. We'll use dedicated
* registers here in order to be in the right position in case we
* to bail to dvm[Lock/Unlock]Object(self, object)
*
* r0 -> self pointer [arg0 for dvm[Lock/Unlock]Object
* r1 -> object [arg1 for dvm[Lock/Unlock]Object
* r2 -> intial contents of object->lock, later result of strex
* r3 -> self->threadId
* r12 -> allow to be used by utilities as general temp
*
* The result of the strex is 0 if we acquire the lock.
*
* See comments in Sync.c for the layout of the lock word.
* Of particular interest to this code is the test for the
* simple case - which we handle inline. For monitor enter, the
* simple case is thin lock, held by no-one. For monitor exit,
* the simple case is thin lock, held by the unlocking thread with
* a recurse count of 0.
*
* A minor complication is that there is a field in the lock word
* unrelated to locking: the hash state. This field must be ignored, but
* preserved.
*
*/
void genMonitorEnter(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc)
{
LIR* target;
LIR* hopTarget;
LIR* branch;
LIR* hopBranch;
oatFlushAllRegs(cUnit);
DCHECK_EQ(LW_SHAPE_THIN, 0);
loadValueDirectFixed(cUnit, rlSrc, r0); // Get obj
oatLockCallTemps(cUnit); // Prepare for explicit register usage
genNullCheck(cUnit, rlSrc.sRegLow, r0, mir);
loadWordDisp(cUnit, rSELF, Thread::ThinLockIdOffset().Int32Value(), r2);
newLIR3(cUnit, kThumb2Ldrex, r1, r0,
Object::MonitorOffset().Int32Value() >> 2); // Get object->lock
// Align owner
opRegImm(cUnit, kOpLsl, r2, LW_LOCK_OWNER_SHIFT);
// Is lock unheld on lock or held by us (==threadId) on unlock?
newLIR4(cUnit, kThumb2Bfi, r2, r1, 0, LW_LOCK_OWNER_SHIFT - 1);
newLIR3(cUnit, kThumb2Bfc, r1, LW_HASH_STATE_SHIFT, LW_LOCK_OWNER_SHIFT - 1);
hopBranch = newLIR2(cUnit, kThumb2Cbnz, r1, 0);
newLIR4(cUnit, kThumb2Strex, r1, r2, r0,
Object::MonitorOffset().Int32Value() >> 2);
oatGenMemBarrier(cUnit, kSY);
branch = newLIR2(cUnit, kThumb2Cbz, r1, 0);
hopTarget = newLIR0(cUnit, kPseudoTargetLabel);
hopBranch->target = (LIR*)hopTarget;
// Go expensive route - artLockObjectFromCode(self, obj);
loadWordDisp(cUnit, rSELF, OFFSETOF_MEMBER(Thread, pLockObjectFromCode),
rLR);
callRuntimeHelper(cUnit, rLR);
// Resume here
target = newLIR0(cUnit, kPseudoTargetLabel);
branch->target = (LIR*)target;
}
/*
* For monitor unlock, we don't have to use ldrex/strex. Once
* we've determined that the lock is thin and that we own it with
* a zero recursion count, it's safe to punch it back to the
* initial, unlock thin state with a store word.
*/
void genMonitorExit(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc)
{
LIR* target;
LIR* branch;
LIR* hopTarget;
LIR* hopBranch;
DCHECK_EQ(LW_SHAPE_THIN, 0);
oatFlushAllRegs(cUnit);
loadValueDirectFixed(cUnit, rlSrc, r0); // Get obj
oatLockCallTemps(cUnit); // Prepare for explicit register usage
genNullCheck(cUnit, rlSrc.sRegLow, r0, mir);
loadWordDisp(cUnit, r0, Object::MonitorOffset().Int32Value(), r1); // Get lock
loadWordDisp(cUnit, rSELF, Thread::ThinLockIdOffset().Int32Value(), r2);
// Is lock unheld on lock or held by us (==threadId) on unlock?
opRegRegImm(cUnit, kOpAnd, r3, r1, (LW_HASH_STATE_MASK << LW_HASH_STATE_SHIFT));
// Align owner
opRegImm(cUnit, kOpLsl, r2, LW_LOCK_OWNER_SHIFT);
newLIR3(cUnit, kThumb2Bfc, r1, LW_HASH_STATE_SHIFT, LW_LOCK_OWNER_SHIFT - 1);
opRegReg(cUnit, kOpSub, r1, r2);
hopBranch = opCondBranch(cUnit, kCondNe, NULL);
oatGenMemBarrier(cUnit, kSY);
storeWordDisp(cUnit, r0, Object::MonitorOffset().Int32Value(), r3);
branch = opBranchUnconditional(cUnit, kOpUncondBr);
hopTarget = newLIR0(cUnit, kPseudoTargetLabel);
hopBranch->target = (LIR*)hopTarget;
// Go expensive route - UnlockObjectFromCode(obj);
loadWordDisp(cUnit, rSELF, OFFSETOF_MEMBER(Thread, pUnlockObjectFromCode),
rLR);
callRuntimeHelper(cUnit, rLR);
// Resume here
target = newLIR0(cUnit, kPseudoTargetLabel);
branch->target = (LIR*)target;
}
/*
* 64-bit 3way compare function.
* mov rX, #-1
* cmp op1hi, op2hi
* blt done
* bgt flip
* sub rX, op1lo, op2lo (treat as unsigned)
* beq done
* ite hi
* mov(hi) rX, #-1
* mov(!hi) rX, #1
* flip:
* neg rX
* done:
*/
void genCmpLong(CompilationUnit* cUnit, MIR* mir, RegLocation rlDest,
RegLocation rlSrc1, RegLocation rlSrc2)
{
LIR* target1;
LIR* target2;
rlSrc1 = loadValueWide(cUnit, rlSrc1, kCoreReg);
rlSrc2 = loadValueWide(cUnit, rlSrc2, kCoreReg);
int tReg = oatAllocTemp(cUnit);
loadConstant(cUnit, tReg, -1);
opRegReg(cUnit, kOpCmp, rlSrc1.highReg, rlSrc2.highReg);
LIR* branch1 = opCondBranch(cUnit, kCondLt, NULL);
LIR* branch2 = opCondBranch(cUnit, kCondGt, NULL);
opRegRegReg(cUnit, kOpSub, tReg, rlSrc1.lowReg, rlSrc2.lowReg);
LIR* branch3 = opCondBranch(cUnit, kCondEq, NULL);
opIT(cUnit, kArmCondHi, "E");
newLIR2(cUnit, kThumb2MovImmShift, tReg, modifiedImmediate(-1));
loadConstant(cUnit, tReg, 1);
genBarrier(cUnit);
target2 = newLIR0(cUnit, kPseudoTargetLabel);
opRegReg(cUnit, kOpNeg, tReg, tReg);
target1 = newLIR0(cUnit, kPseudoTargetLabel);
RegLocation rlTemp = LOC_C_RETURN; // Just using as template, will change
rlTemp.lowReg = tReg;
storeValue(cUnit, rlDest, rlTemp);
oatFreeTemp(cUnit, tReg);
branch1->target = (LIR*)target1;
branch2->target = (LIR*)target2;
branch3->target = branch1->target;
}
/*
* Generate a register comparison to an immediate and branch. Caller
* is responsible for setting branch target field.
*/
LIR* opCmpImmBranch(CompilationUnit* cUnit, ConditionCode cond, int reg,
int checkValue, LIR* target)
{
LIR* branch;
int modImm;
ArmConditionCode armCond = oatArmConditionEncoding(cond);
if ((LOWREG(reg)) && (checkValue == 0) &&
((armCond == kArmCondEq) || (armCond == kArmCondNe))) {
branch = newLIR2(cUnit,
(armCond == kArmCondEq) ? kThumb2Cbz : kThumb2Cbnz,
reg, 0);
} else {
modImm = modifiedImmediate(checkValue);
if (LOWREG(reg) && ((checkValue & 0xff) == checkValue)) {
newLIR2(cUnit, kThumbCmpRI8, reg, checkValue);
} else if (modImm >= 0) {
newLIR2(cUnit, kThumb2CmpRI8, reg, modImm);
} else {
int tReg = oatAllocTemp(cUnit);
loadConstant(cUnit, tReg, checkValue);
opRegReg(cUnit, kOpCmp, reg, tReg);
}
branch = newLIR2(cUnit, kThumbBCond, 0, armCond);
}
branch->target = target;
return branch;
}
LIR* opRegCopyNoInsert(CompilationUnit* cUnit, int rDest, int rSrc)
{
LIR* res;
ArmOpcode opcode;
if (FPREG(rDest) || FPREG(rSrc))
return fpRegCopy(cUnit, rDest, rSrc);
if (LOWREG(rDest) && LOWREG(rSrc))
opcode = kThumbMovRR;
else if (!LOWREG(rDest) && !LOWREG(rSrc))
opcode = kThumbMovRR_H2H;
else if (LOWREG(rDest))
opcode = kThumbMovRR_H2L;
else
opcode = kThumbMovRR_L2H;
res = rawLIR(cUnit, cUnit->currentDalvikOffset, opcode, rDest, rSrc);
if (!(cUnit->disableOpt & (1 << kSafeOptimizations)) && rDest == rSrc) {
res->flags.isNop = true;
}
return res;
}
LIR* opRegCopy(CompilationUnit* cUnit, int rDest, int rSrc)
{
LIR* res = opRegCopyNoInsert(cUnit, rDest, rSrc);
oatAppendLIR(cUnit, (LIR*)res);
return res;
}
void opRegCopyWide(CompilationUnit* cUnit, int destLo, int destHi,
int srcLo, int srcHi)
{
bool destFP = FPREG(destLo) && FPREG(destHi);
bool srcFP = FPREG(srcLo) && FPREG(srcHi);
DCHECK_EQ(FPREG(srcLo), FPREG(srcHi));
DCHECK_EQ(FPREG(destLo), FPREG(destHi));
if (destFP) {
if (srcFP) {
opRegCopy(cUnit, S2D(destLo, destHi), S2D(srcLo, srcHi));
} else {
newLIR3(cUnit, kThumb2Fmdrr, S2D(destLo, destHi), srcLo, srcHi);
}
} else {
if (srcFP) {
newLIR3(cUnit, kThumb2Fmrrd, destLo, destHi, S2D(srcLo, srcHi));
} else {
// Handle overlap
if (srcHi == destLo) {
opRegCopy(cUnit, destHi, srcHi);
opRegCopy(cUnit, destLo, srcLo);
} else {
opRegCopy(cUnit, destLo, srcLo);
opRegCopy(cUnit, destHi, srcHi);
}
}
}
}
} // namespace art