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Theodosius/Examples/Theodosius-Usermode/asmjit/core/emithelper.cpp

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4 years ago
// AsmJit - Machine code generation for C++
//
// * Official AsmJit Home Page: https://asmjit.com
// * Official Github Repository: https://github.com/asmjit/asmjit
//
// Copyright (c) 2008-2020 The AsmJit Authors
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#include "../core/api-build_p.h"
#include "../core/archtraits.h"
#include "../core/emithelper_p.h"
#include "../core/formatter.h"
#include "../core/funcargscontext_p.h"
#include "../core/radefs_p.h"
// Can be used for debugging...
// #define ASMJIT_DUMP_ARGS_ASSIGNMENT
ASMJIT_BEGIN_NAMESPACE
// ============================================================================
// [asmjit::BaseEmitHelper - Formatting]
// ============================================================================
#ifdef ASMJIT_DUMP_ARGS_ASSIGNMENT
static void dumpFuncValue(String& sb, uint32_t arch, const FuncValue& value) noexcept {
Formatter::formatTypeId(sb, value.typeId());
sb.append('@');
if (value.isIndirect())
sb.append('[');
if (value.isReg())
Formatter::formatRegister(sb, 0, nullptr, arch, value.regType(), value.regId());
else if (value.isStack())
sb.appendFormat("[%d]", value.stackOffset());
else
sb.append("<none>");
if (value.isIndirect())
sb.append(']');
}
static void dumpAssignment(String& sb, const FuncArgsContext& ctx) noexcept {
typedef FuncArgsContext::Var Var;
uint32_t arch = ctx.arch();
uint32_t varCount = ctx.varCount();
for (uint32_t i = 0; i < varCount; i++) {
const Var& var = ctx.var(i);
const FuncValue& dst = var.out;
const FuncValue& cur = var.cur;
sb.appendFormat("Var%u: ", i);
dumpFuncValue(sb, arch, dst);
sb.append(" <- ");
dumpFuncValue(sb, arch, cur);
if (var.isDone())
sb.append(" {Done}");
sb.append('\n');
}
}
#endif
// ============================================================================
// [asmjit::BaseEmitHelper - EmitArgsAssignment]
// ============================================================================
ASMJIT_FAVOR_SIZE Error BaseEmitHelper::emitArgsAssignment(const FuncFrame& frame, const FuncArgsAssignment& args) {
typedef FuncArgsContext::Var Var;
typedef FuncArgsContext::WorkData WorkData;
enum WorkFlags : uint32_t {
kWorkNone = 0x00,
kWorkDidSome = 0x01,
kWorkPending = 0x02,
kWorkPostponed = 0x04
};
uint32_t arch = frame.arch();
const ArchTraits& archTraits = ArchTraits::byArch(arch);
RAConstraints constraints;
FuncArgsContext ctx;
ASMJIT_PROPAGATE(constraints.init(arch));
ASMJIT_PROPAGATE(ctx.initWorkData(frame, args, &constraints));
#ifdef ASMJIT_DUMP_ARGS_ASSIGNMENT
{
String sb;
dumpAssignment(sb, ctx);
printf("%s\n", sb.data());
}
#endif
uint32_t varCount = ctx._varCount;
WorkData* workData = ctx._workData;
uint32_t saVarId = ctx._saVarId;
BaseReg sp = BaseReg::fromSignatureAndId(_emitter->_gpRegInfo.signature(), archTraits.spRegId());
BaseReg sa = sp;
if (frame.hasDynamicAlignment()) {
if (frame.hasPreservedFP())
sa.setId(archTraits.fpRegId());
else
sa.setId(saVarId < varCount ? ctx._vars[saVarId].cur.regId() : frame.saRegId());
}
// --------------------------------------------------------------------------
// Register to stack and stack to stack moves must be first as now we have
// the biggest chance of having as many as possible unassigned registers.
// --------------------------------------------------------------------------
if (ctx._stackDstMask) {
// Base address of all arguments passed by stack.
BaseMem baseArgPtr(sa, int32_t(frame.saOffset(sa.id())));
BaseMem baseStackPtr(sp, 0);
for (uint32_t varId = 0; varId < varCount; varId++) {
Var& var = ctx._vars[varId];
if (!var.out.isStack())
continue;
FuncValue& cur = var.cur;
FuncValue& out = var.out;
ASMJIT_ASSERT(cur.isReg() || cur.isStack());
BaseReg reg;
BaseMem dstStackPtr = baseStackPtr.cloneAdjusted(out.stackOffset());
BaseMem srcStackPtr = baseArgPtr.cloneAdjusted(cur.stackOffset());
if (cur.isIndirect()) {
if (cur.isStack()) {
// TODO: Indirect stack.
return DebugUtils::errored(kErrorInvalidAssignment);
}
else {
srcStackPtr.setBaseId(cur.regId());
}
}
if (cur.isReg() && !cur.isIndirect()) {
WorkData& wd = workData[archTraits.regTypeToGroup(cur.regType())];
uint32_t rId = cur.regId();
reg.setSignatureAndId(archTraits.regTypeToSignature(cur.regType()), rId);
wd.unassign(varId, rId);
}
else {
// Stack to reg move - tricky since we move stack to stack we can decide which
// register to use. In general we follow the rule that IntToInt moves will use
// GP regs with possibility to signature or zero extend, and all other moves will
// either use GP or VEC regs depending on the size of the move.
RegInfo rInfo = getSuitableRegForMemToMemMove(arch, out.typeId(), cur.typeId());
if (ASMJIT_UNLIKELY(!rInfo.isValid()))
return DebugUtils::errored(kErrorInvalidState);
WorkData& wd = workData[rInfo.group()];
uint32_t availableRegs = wd.availableRegs();
if (ASMJIT_UNLIKELY(!availableRegs))
return DebugUtils::errored(kErrorInvalidState);
uint32_t rId = Support::ctz(availableRegs);
reg.setSignatureAndId(rInfo.signature(), rId);
ASMJIT_PROPAGATE(emitArgMove(reg, out.typeId(), srcStackPtr, cur.typeId()));
}
if (cur.isIndirect() && cur.isReg())
workData[BaseReg::kGroupGp].unassign(varId, cur.regId());
// Register to stack move.
ASMJIT_PROPAGATE(emitRegMove(dstStackPtr, reg, cur.typeId()));
var.markDone();
}
}
// --------------------------------------------------------------------------
// Shuffle all registers that are currently assigned accordingly to target
// assignment.
// --------------------------------------------------------------------------
uint32_t workFlags = kWorkNone;
for (;;) {
for (uint32_t varId = 0; varId < varCount; varId++) {
Var& var = ctx._vars[varId];
if (var.isDone() || !var.cur.isReg())
continue;
FuncValue& cur = var.cur;
FuncValue& out = var.out;
uint32_t curGroup = archTraits.regTypeToGroup(cur.regType());
uint32_t outGroup = archTraits.regTypeToGroup(out.regType());
uint32_t curId = cur.regId();
uint32_t outId = out.regId();
if (curGroup != outGroup) {
// TODO: Conversion is not supported.
return DebugUtils::errored(kErrorInvalidAssignment);
}
else {
WorkData& wd = workData[outGroup];
if (!wd.isAssigned(outId)) {
EmitMove:
ASMJIT_PROPAGATE(
emitArgMove(
BaseReg::fromSignatureAndId(archTraits.regTypeToSignature(out.regType()), outId), out.typeId(),
BaseReg::fromSignatureAndId(archTraits.regTypeToSignature(cur.regType()), curId), cur.typeId()));
wd.reassign(varId, outId, curId);
cur.initReg(out.regType(), outId, out.typeId());
if (outId == out.regId())
var.markDone();
workFlags |= kWorkDidSome | kWorkPending;
}
else {
uint32_t altId = wd._physToVarId[outId];
Var& altVar = ctx._vars[altId];
if (!altVar.out.isInitialized() || (altVar.out.isReg() && altVar.out.regId() == curId)) {
// Only few architectures provide swap operations, and only for few register groups.
if (archTraits.hasSwap(curGroup)) {
uint32_t highestType = Support::max(cur.regType(), altVar.cur.regType());
if (Support::isBetween<uint32_t>(highestType, BaseReg::kTypeGp8Lo, BaseReg::kTypeGp16))
highestType = BaseReg::kTypeGp32;
uint32_t signature = archTraits.regTypeToSignature(highestType);
ASMJIT_PROPAGATE(
emitRegSwap(BaseReg::fromSignatureAndId(signature, outId),
BaseReg::fromSignatureAndId(signature, curId)));
wd.swap(varId, curId, altId, outId);
cur.setRegId(outId);
var.markDone();
altVar.cur.setRegId(curId);
if (altVar.out.isInitialized())
altVar.markDone();
workFlags |= kWorkDidSome;
}
else {
// If there is a scratch register it can be used to perform the swap.
uint32_t availableRegs = wd.availableRegs();
if (availableRegs) {
uint32_t inOutRegs = wd.dstRegs();
if (availableRegs & ~inOutRegs)
availableRegs &= ~inOutRegs;
outId = Support::ctz(availableRegs);
goto EmitMove;
}
else {
workFlags |= kWorkPending;
}
}
}
else {
workFlags |= kWorkPending;
}
}
}
}
if (!(workFlags & kWorkPending))
break;
// If we did nothing twice it means that something is really broken.
if ((workFlags & (kWorkDidSome | kWorkPostponed)) == kWorkPostponed)
return DebugUtils::errored(kErrorInvalidState);
workFlags = (workFlags & kWorkDidSome) ? kWorkNone : kWorkPostponed;
}
// --------------------------------------------------------------------------
// Load arguments passed by stack into registers. This is pretty simple and
// it never requires multiple iterations like the previous phase.
// --------------------------------------------------------------------------
if (ctx._hasStackSrc) {
uint32_t iterCount = 1;
if (frame.hasDynamicAlignment() && !frame.hasPreservedFP())
sa.setId(saVarId < varCount ? ctx._vars[saVarId].cur.regId() : frame.saRegId());
// Base address of all arguments passed by stack.
BaseMem baseArgPtr(sa, int32_t(frame.saOffset(sa.id())));
for (uint32_t iter = 0; iter < iterCount; iter++) {
for (uint32_t varId = 0; varId < varCount; varId++) {
Var& var = ctx._vars[varId];
if (var.isDone())
continue;
if (var.cur.isStack()) {
ASMJIT_ASSERT(var.out.isReg());
uint32_t outId = var.out.regId();
uint32_t outType = var.out.regType();
uint32_t group = archTraits.regTypeToGroup(outType);
WorkData& wd = ctx._workData[group];
if (outId == sa.id() && group == BaseReg::kGroupGp) {
// This register will be processed last as we still need `saRegId`.
if (iterCount == 1) {
iterCount++;
continue;
}
wd.unassign(wd._physToVarId[outId], outId);
}
BaseReg dstReg = BaseReg::fromSignatureAndId(archTraits.regTypeToSignature(outType), outId);
BaseMem srcMem = baseArgPtr.cloneAdjusted(var.cur.stackOffset());
ASMJIT_PROPAGATE(emitArgMove(
dstReg, var.out.typeId(),
srcMem, var.cur.typeId()));
wd.assign(varId, outId);
var.cur.initReg(outType, outId, var.cur.typeId(), FuncValue::kFlagIsDone);
}
}
}
}
return kErrorOk;
}
ASMJIT_END_NAMESPACE