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Optimize initializations of byte arrays with non-const byte to memset()

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It was previously restricted to a compile-time-constant right-hand-side byte.
This commit is contained in:
Martin 2017-01-21 19:42:27 +01:00
parent 5fcfd96560
commit f95d5fdf1d
1 changed files with 12 additions and 16 deletions
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28
gen/arrays.cpp
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@ -107,28 +107,24 @@ void DtoSetArrayToNull(LLValue *v) {
////////////////////////////////////////////////////////////////////////////////
static void DtoArrayInit(Loc &loc, LLValue *ptr, LLValue *length,
DValue *dvalue) {
DValue *elementValue) {
IF_LOG Logger::println("DtoArrayInit");
LOG_SCOPE;
// lets first optimize all zero/constant i8 initializations down to a memset.
// this simplifies codegen later on as llvm null's have no address!
if (!dvalue->isLVal()) {
LLConstant *constantVal = isaConstant(DtoRVal(dvalue));
if (constantVal &&
(constantVal->isNullValue() ||
constantVal->getType() == LLType::getInt8Ty(gIR->context()))) {
// Let's first optimize all zero/i8 initializations down to a memset.
// This simplifies codegen later on as llvm null's have no address!
if (!elementValue->isLVal() || !DtoIsInMemoryOnly(elementValue->type)) {
LLValue *val = DtoRVal(elementValue);
LLConstant *constantVal = isaConstant(val);
bool isNullConstant = (constantVal && constantVal->isNullValue());
if (isNullConstant || val->getType() == LLType::getInt8Ty(gIR->context())) {
LLValue *size = length;
size_t elementSize = getTypeAllocSize(constantVal->getType());
size_t elementSize = getTypeAllocSize(val->getType());
if (elementSize != 1) {
size = gIR->ir->CreateMul(length, DtoConstSize_t(elementSize),
".arraysize");
}
if (constantVal->isNullValue()) {
DtoMemSetZero(ptr, size);
} else {
DtoMemSet(ptr, constantVal, size);
}
DtoMemSet(ptr, isNullConstant ? DtoConstUbyte(0) : val, size);
return;
}
}
@ -161,9 +157,9 @@ static void DtoArrayInit(Loc &loc, LLValue *ptr, LLValue *length,
LLValue *itr_val = DtoLoad(itr);
// assign array element value
DLValue arrayelem(dvalue->type->toBasetype(),
DLValue arrayelem(elementValue->type->toBasetype(),
DtoGEP1(ptr, itr_val, true, "arrayinit.arrayelem"));
DtoAssign(loc, &arrayelem, dvalue, TOKblit);
DtoAssign(loc, &arrayelem, elementValue, TOKblit);
// increment iterator
DtoStore(gIR->ir->CreateAdd(itr_val, DtoConstSize_t(1), "arrayinit.new_itr"),