Compiler::fgWalkResult Rationalizer::RewriteNode(GenTree** useEdge, ArrayStack<GenTree*>& parentStack)
{
assert(useEdge != nullptr);
GenTree* node = *useEdge;
assert(node != nullptr);
#ifdef DEBUG
const bool isLateArg = (node->gtFlags & GTF_LATE_ARG) != 0;
#endif
// First, remove any preceeding GT_LIST nodes, which are not otherwise visited by the tree walk.
//
// NOTE: GT_LIST nodes that are used by block ops and phi nodes will in fact be visited.
for (GenTree* prev = node->gtPrev; prev != nullptr && prev->OperGet() == GT_LIST; prev = node->gtPrev)
{
BlockRange().Remove(prev);
}
// In addition, remove the current node if it is a GT_LIST node.
if ((*useEdge)->OperGet() == GT_LIST)
{
BlockRange().Remove(*useEdge);
return Compiler::WALK_CONTINUE;
}
LIR::Use use;
if (parentStack.Height() < 2)
{
use = LIR::Use::GetDummyUse(BlockRange(), *useEdge);
}
else
{
use = LIR::Use(BlockRange(), useEdge, parentStack.Index(1));
}
assert(node == use.Def());
switch (node->OperGet())
{
case GT_ASG:
RewriteAssignment(use);
break;
case GT_BOX:
// GT_BOX at this level just passes through so get rid of it
use.ReplaceWith(comp, node->gtGetOp1());
BlockRange().Remove(node);
break;
case GT_ADDR:
RewriteAddress(use);
break;
case GT_NOP:
// fgMorph sometimes inserts NOP nodes between defs and uses
// supposedly 'to prevent constant folding'. In this case, remove the
// NOP.
if (node->gtGetOp1() != nullptr)
{
use.ReplaceWith(comp, node->gtGetOp1());
BlockRange().Remove(node);
}
break;
case GT_COMMA:
{
GenTree* op1 = node->gtGetOp1();
if ((op1->gtFlags & GTF_ALL_EFFECT) == 0)
{
// The LHS has no side effects. Remove it.
bool isClosed = false;
unsigned sideEffects = 0;
LIR::ReadOnlyRange lhsRange = BlockRange().GetTreeRange(op1, &isClosed, &sideEffects);
// None of the transforms performed herein violate tree order, so these
// should always be true.
assert(isClosed);
assert((sideEffects & GTF_ALL_EFFECT) == 0);
BlockRange().Delete(comp, m_block, std::move(lhsRange));
}
GenTree* replacement = node->gtGetOp2();
if (!use.IsDummyUse())
{
use.ReplaceWith(comp, replacement);
}
else
{
// This is a top-level comma. If the RHS has no side effects we can remove
// it as well.
if ((replacement->gtFlags & GTF_ALL_EFFECT) == 0)
{
bool isClosed = false;
unsigned sideEffects = 0;
LIR::ReadOnlyRange rhsRange = BlockRange().GetTreeRange(replacement, &isClosed, &sideEffects);
// None of the transforms performed herein violate tree order, so these
// should always be true.
assert(isClosed);
assert((sideEffects & GTF_ALL_EFFECT) == 0);
BlockRange().Delete(comp, m_block, std::move(rhsRange));
}
}
BlockRange().Remove(node);
}
break;
case GT_ARGPLACE:
// Remove argplace and list nodes from the execution order.
//
// TODO: remove phi args and phi nodes as well?
BlockRange().Remove(node);
break;
#ifdef _TARGET_XARCH_
case GT_CLS_VAR:
{
// Class vars that are the target of an assignment will get rewritten into
// GT_STOREIND(GT_CLS_VAR_ADDR, val) by RewriteAssignment. This check is
// not strictly necessary--the GT_IND(GT_CLS_VAR_ADDR) pattern that would
// otherwise be generated would also be picked up by RewriteAssignment--but
// skipping the rewrite here saves an allocation and a bit of extra work.
const bool isLHSOfAssignment = (use.User()->OperGet() == GT_ASG) && (use.User()->gtGetOp1() == node);
if (!isLHSOfAssignment)
{
GenTree* ind = comp->gtNewOperNode(GT_IND, node->TypeGet(), node);
node->SetOper(GT_CLS_VAR_ADDR);
node->gtType = TYP_BYREF;
BlockRange().InsertAfter(node, ind);
use.ReplaceWith(comp, ind);
// TODO: JIT dump
}
}
break;
#endif // _TARGET_XARCH_
case GT_INTRINSIC:
// Non-target intrinsics should have already been rewritten back into user calls.
assert(Compiler::IsTargetIntrinsic(node->gtIntrinsic.gtIntrinsicId));
break;
#ifdef FEATURE_SIMD
case GT_INITBLK:
RewriteInitBlk(use);
break;
case GT_COPYBLK:
RewriteCopyBlk(use);
break;
case GT_OBJ:
RewriteObj(use);
break;
case GT_LCL_FLD:
case GT_STORE_LCL_FLD:
// TODO-1stClassStructs: Eliminate this.
FixupIfSIMDLocal(node->AsLclVarCommon());
break;
case GT_STOREIND:
case GT_IND:
if (node->gtType == TYP_STRUCT)
{
GenTree* addr = node->AsIndir()->Addr();
assert(addr->TypeGet() == TYP_BYREF);
if (addr->OperIsLocal())
{
LclVarDsc* varDsc = &(comp->lvaTable[addr->AsLclVarCommon()->gtLclNum]);
assert(varDsc->lvSIMDType);
unsigned simdSize = (unsigned int)roundUp(varDsc->lvExactSize, TARGET_POINTER_SIZE);
node->gtType = comp->getSIMDTypeForSize(simdSize);
}
#if DEBUG
else
{
// If the address is not a local var, assert that the user of this IND is an ADDR node.
assert((use.User()->OperGet() == GT_ADDR) || use.User()->OperIsLocalAddr());
}
#endif
}
break;
case GT_SIMD:
{
noway_assert(comp->featureSIMD);
GenTreeSIMD* simdNode = node->AsSIMD();
unsigned simdSize = simdNode->gtSIMDSize;
var_types simdType = comp->getSIMDTypeForSize(simdSize);
// TODO-1stClassStructs: This should be handled more generally for enregistered or promoted
// structs that are passed or returned in a different register type than their enregistered
// type(s).
if (simdNode->gtType == TYP_I_IMPL && simdNode->gtSIMDSize == TARGET_POINTER_SIZE)
{
// This happens when it is consumed by a GT_RET_EXPR.
// It can only be a Vector2f or Vector2i.
assert(genTypeSize(simdNode->gtSIMDBaseType) == 4);
simdNode->gtType = TYP_SIMD8;
}
else if (simdNode->gtType == TYP_STRUCT || varTypeIsSIMD(simdNode))
{
node->gtType = simdType;
}
// Certain SIMD trees require rationalizing.
if (simdNode->gtSIMD.gtSIMDIntrinsicID == SIMDIntrinsicInitArray)
{
// Rewrite this as an explicit load.
JITDUMP("Rewriting GT_SIMD array init as an explicit load:\n");
unsigned int baseTypeSize = genTypeSize(simdNode->gtSIMDBaseType);
GenTree* address = new (comp, GT_LEA) GenTreeAddrMode(TYP_BYREF, simdNode->gtOp1, simdNode->gtOp2,
baseTypeSize, offsetof(CORINFO_Array, u1Elems));
GenTree* ind = comp->gtNewOperNode(GT_IND, simdType, address);
BlockRange().InsertBefore(simdNode, address, ind);
use.ReplaceWith(comp, ind);
BlockRange().Remove(simdNode);
DISPTREERANGE(BlockRange(), use.Def());
JITDUMP("\n");
}
else
{
// This code depends on the fact that NONE of the SIMD intrinsics take vector operands
// of a different width. If that assumption changes, we will EITHER have to make these type
// transformations during importation, and plumb the types all the way through the JIT,
// OR add a lot of special handling here.
GenTree* op1 = simdNode->gtGetOp1();
if (op1 != nullptr && op1->gtType == TYP_STRUCT)
{
op1->gtType = simdType;
}
GenTree* op2 = simdNode->gtGetOp2();
if (op2 != nullptr && op2->gtType == TYP_STRUCT)
{
op2->gtType = simdType;
}
}
}
break;
#endif // FEATURE_SIMD
default:
break;
}
// Do some extra processing on top-level nodes to remove unused local reads.
if (use.IsDummyUse() && node->OperIsLocalRead())
{
assert((node->gtFlags & GTF_ALL_EFFECT) == 0);
comp->lvaDecRefCnts(node);
BlockRange().Remove(node);
}
assert(isLateArg == ((node->gtFlags & GTF_LATE_ARG) != 0));
return Compiler::WALK_CONTINUE;
}
void Tiger_gc ()
{
// Your code here:
//
printf("Tiger_gc start!\n");
printf("heap.toStart=%d\n",(int*)heap.toStart);
printf("heap.toNext=%d\n",(int*)heap.toNext);
while(previous!=0)
{
printf("\n-------------------this is a frame----------------------\n");
char* arguments_gc_map = *((int*)((char *)previous + 4));
/*
* 此处的指针使用
* (int*)修饰是因为要对这个指针进行取地址操作。具体如何操作就是由(int*)说明。
* 此处的意思是取地址操作以4byte进行。所以，这个位置替换成(long*),(int**),(char**)都不影响结果。
*/
int* arguments_address=(int*)((char*)previous+8);
int locals_gc_map=*((char*)previous+12);
printf("arguments_gc_map is:\"%s\"\n",arguments_gc_map);
printf("arguments_gc_map address is:0x%d\n",*arguments_address);
printf("locals_gc_map :%d local value\n",locals_gc_map);
void* temp=0;
//arguments
if(arguments_gc_map!=0)
{
printf("\n this is a argument_gc_map---------\n");
int* addr=arguments_address;
int len=strlen(arguments_gc_map);
int i=0;
printf("arguments_gc_map length is %d\n",len);
for(i=0;i<len;i++)
{
if(arguments_gc_map[i]=='1')
{//字符用''
temp=*((int*)addr);
printf("\nin arguments obj address is:0x%d\n",*(int*)temp);
//Copy
temp=Copy(temp);
printf("copy finished...\n");
addr=(char*)addr+4;
}
}
}
//locals
if(locals_gc_map!=0)
{
printf("\n this is a locals_gc_map----------------------\n");
int j=0;
int* localStart=(int*)((char*)previous+16);
int* localTemp=localStart;
for(j=0;j<locals_gc_map;j++)
{
temp=localTemp;
printf("\nlocals_obj address is:%d\n",*(int*)temp);
//Copy
temp=Copy(temp);
printf("copy finished...\n");
//每次向下移动一次
localTemp=(char*)localTemp+4;
}
}
previous = (*(int*)previous);
/*
*此处指针的用法(同上)!!!(*(long*)previous)也是可以的。
*/
printf("-------------------------frame finished-----------------------\n");
}
//previous遍历结束
//修改对象内部的指针
RewriteObj();
//交换heap和Free
Exchange();
return;
}
