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Theodosius/Examples/Theodosius-Usermode/asmjit/x86/x86func.cpp

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19 KiB

// 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"
#ifdef ASMJIT_BUILD_X86
#include "../x86/x86func_p.h"
#include "../x86/x86emithelper_p.h"
#include "../x86/x86operand.h"
ASMJIT_BEGIN_SUB_NAMESPACE(x86)
// ============================================================================
// [asmjit::x86::FuncInternal - Init]
// ============================================================================
namespace FuncInternal {
static inline bool shouldThreatAsCDeclIn64BitMode(uint32_t ccId) noexcept {
return ccId == CallConv::kIdCDecl ||
ccId == CallConv::kIdStdCall ||
ccId == CallConv::kIdThisCall ||
ccId == CallConv::kIdFastCall ||
ccId == CallConv::kIdRegParm1 ||
ccId == CallConv::kIdRegParm2 ||
ccId == CallConv::kIdRegParm3;
}
ASMJIT_FAVOR_SIZE Error initCallConv(CallConv& cc, uint32_t ccId, const Environment& environment) noexcept {
constexpr uint32_t kGroupGp = Reg::kGroupGp;
constexpr uint32_t kGroupVec = Reg::kGroupVec;
constexpr uint32_t kGroupMm = Reg::kGroupMm;
constexpr uint32_t kGroupKReg = Reg::kGroupKReg;
constexpr uint32_t kZax = Gp::kIdAx;
constexpr uint32_t kZbx = Gp::kIdBx;
constexpr uint32_t kZcx = Gp::kIdCx;
constexpr uint32_t kZdx = Gp::kIdDx;
constexpr uint32_t kZsp = Gp::kIdSp;
constexpr uint32_t kZbp = Gp::kIdBp;
constexpr uint32_t kZsi = Gp::kIdSi;
constexpr uint32_t kZdi = Gp::kIdDi;
bool winABI = environment.isPlatformWindows() || environment.isAbiMSVC();
cc.setArch(environment.arch());
cc.setSaveRestoreRegSize(Reg::kGroupVec, 16);
cc.setSaveRestoreRegSize(Reg::kGroupMm, 8);
cc.setSaveRestoreRegSize(Reg::kGroupKReg, 8);
cc.setSaveRestoreAlignment(Reg::kGroupVec, 16);
cc.setSaveRestoreAlignment(Reg::kGroupMm, 8);
cc.setSaveRestoreAlignment(Reg::kGroupKReg, 8);
if (environment.is32Bit()) {
bool isStandardCallConv = true;
cc.setSaveRestoreRegSize(Reg::kGroupGp, 4);
cc.setSaveRestoreAlignment(Reg::kGroupGp, 4);
cc.setPreservedRegs(Reg::kGroupGp, Support::bitMask(Gp::kIdBx, Gp::kIdSp, Gp::kIdBp, Gp::kIdSi, Gp::kIdDi));
cc.setNaturalStackAlignment(4);
switch (ccId) {
case CallConv::kIdCDecl:
break;
case CallConv::kIdStdCall:
cc.setFlags(CallConv::kFlagCalleePopsStack);
break;
case CallConv::kIdFastCall:
cc.setFlags(CallConv::kFlagCalleePopsStack);
cc.setPassedOrder(kGroupGp, kZcx, kZdx);
break;
case CallConv::kIdVectorCall:
cc.setFlags(CallConv::kFlagCalleePopsStack);
cc.setPassedOrder(kGroupGp, kZcx, kZdx);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3, 4, 5);
break;
case CallConv::kIdThisCall:
// NOTE: Even MINGW (starting with GCC 4.7.0) now uses __thiscall on MS Windows,
// so we won't bail to any other calling convention if __thiscall was specified.
if (winABI) {
cc.setFlags(CallConv::kFlagCalleePopsStack);
cc.setPassedOrder(kGroupGp, kZcx);
}
else {
ccId = CallConv::kIdCDecl;
}
break;
case CallConv::kIdRegParm1:
cc.setPassedOrder(kGroupGp, kZax);
break;
case CallConv::kIdRegParm2:
cc.setPassedOrder(kGroupGp, kZax, kZdx);
break;
case CallConv::kIdRegParm3:
cc.setPassedOrder(kGroupGp, kZax, kZdx, kZcx);
break;
case CallConv::kIdLightCall2:
case CallConv::kIdLightCall3:
case CallConv::kIdLightCall4: {
uint32_t n = (ccId - CallConv::kIdLightCall2) + 2;
cc.setFlags(CallConv::kFlagPassFloatsByVec);
cc.setPassedOrder(kGroupGp, kZax, kZdx, kZcx, kZsi, kZdi);
cc.setPassedOrder(kGroupMm, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPassedOrder(kGroupKReg, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPreservedRegs(kGroupGp, Support::lsbMask<uint32_t>(8));
cc.setPreservedRegs(kGroupVec, Support::lsbMask<uint32_t>(8) & ~Support::lsbMask<uint32_t>(n));
cc.setNaturalStackAlignment(16);
isStandardCallConv = false;
break;
}
default:
return DebugUtils::errored(kErrorInvalidArgument);
}
if (isStandardCallConv) {
// MMX arguments is something where compiler vendors disagree. For example
// GCC and MSVC would pass first three via registers and the rest via stack,
// however Clang passes all via stack. Returning MMX registers is even more
// fun, where GCC uses MM0, but Clang uses EAX:EDX pair. I'm not sure it's
// something we should be worried about as MMX is deprecated anyway.
cc.setPassedOrder(kGroupMm, 0, 1, 2);
// Vector arguments (XMM|YMM|ZMM) are passed via registers. However, if the
// function is variadic then they have to be passed via stack.
cc.setPassedOrder(kGroupVec, 0, 1, 2);
// Functions with variable arguments always use stack for MM and vector
// arguments.
cc.addFlags(CallConv::kFlagPassVecByStackIfVA);
}
if (ccId == CallConv::kIdCDecl) {
cc.addFlags(CallConv::kFlagVarArgCompatible);
}
}
else {
cc.setSaveRestoreRegSize(Reg::kGroupGp, 8);
cc.setSaveRestoreAlignment(Reg::kGroupGp, 8);
// Preprocess the calling convention into a common id as many conventions
// are normally ignored even by C/C++ compilers and treated as `__cdecl`.
if (shouldThreatAsCDeclIn64BitMode(ccId))
ccId = winABI ? CallConv::kIdX64Windows : CallConv::kIdX64SystemV;
switch (ccId) {
case CallConv::kIdX64SystemV: {
cc.setFlags(CallConv::kFlagPassFloatsByVec |
CallConv::kFlagPassMmxByXmm |
CallConv::kFlagVarArgCompatible);
cc.setNaturalStackAlignment(16);
cc.setRedZoneSize(128);
cc.setPassedOrder(kGroupGp, kZdi, kZsi, kZdx, kZcx, 8, 9);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPreservedRegs(kGroupGp, Support::bitMask(kZbx, kZsp, kZbp, 12, 13, 14, 15));
break;
}
case CallConv::kIdX64Windows: {
cc.setStrategy(CallConv::kStrategyX64Windows);
cc.setFlags(CallConv::kFlagPassFloatsByVec |
CallConv::kFlagIndirectVecArgs |
CallConv::kFlagPassMmxByGp |
CallConv::kFlagVarArgCompatible);
cc.setNaturalStackAlignment(16);
// Maximum 4 arguments in registers, each adds 8 bytes to the spill zone.
cc.setSpillZoneSize(4 * 8);
cc.setPassedOrder(kGroupGp, kZcx, kZdx, 8, 9);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3);
cc.setPreservedRegs(kGroupGp, Support::bitMask(kZbx, kZsp, kZbp, kZsi, kZdi, 12, 13, 14, 15));
cc.setPreservedRegs(kGroupVec, Support::bitMask(6, 7, 8, 9, 10, 11, 12, 13, 14, 15));
break;
}
case CallConv::kIdVectorCall: {
cc.setStrategy(CallConv::kStrategyX64VectorCall);
cc.setFlags(CallConv::kFlagPassFloatsByVec |
CallConv::kFlagPassMmxByGp );
cc.setNaturalStackAlignment(16);
// Maximum 6 arguments in registers, each adds 8 bytes to the spill zone.
cc.setSpillZoneSize(6 * 8);
cc.setPassedOrder(kGroupGp, kZcx, kZdx, 8, 9);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3, 4, 5);
cc.setPreservedRegs(kGroupGp, Support::bitMask(kZbx, kZsp, kZbp, kZsi, kZdi, 12, 13, 14, 15));
cc.setPreservedRegs(kGroupVec, Support::bitMask(6, 7, 8, 9, 10, 11, 12, 13, 14, 15));
break;
}
case CallConv::kIdLightCall2:
case CallConv::kIdLightCall3:
case CallConv::kIdLightCall4: {
uint32_t n = (ccId - CallConv::kIdLightCall2) + 2;
cc.setFlags(CallConv::kFlagPassFloatsByVec);
cc.setNaturalStackAlignment(16);
cc.setPassedOrder(kGroupGp, kZax, kZdx, kZcx, kZsi, kZdi);
cc.setPassedOrder(kGroupMm, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPassedOrder(kGroupVec, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPassedOrder(kGroupKReg, 0, 1, 2, 3, 4, 5, 6, 7);
cc.setPreservedRegs(kGroupGp, Support::lsbMask<uint32_t>(16));
cc.setPreservedRegs(kGroupVec, ~Support::lsbMask<uint32_t>(n));
break;
}
default:
return DebugUtils::errored(kErrorInvalidArgument);
}
}
cc.setId(ccId);
return kErrorOk;
}
ASMJIT_FAVOR_SIZE void unpackValues(FuncDetail& func, FuncValuePack& pack) noexcept {
uint32_t typeId = pack[0].typeId();
switch (typeId) {
case Type::kIdI64:
case Type::kIdU64: {
if (Environment::is32Bit(func.callConv().arch())) {
// Convert a 64-bit return value to two 32-bit return values.
pack[0].initTypeId(Type::kIdU32);
pack[1].initTypeId(typeId - 2);
break;
}
break;
}
}
}
ASMJIT_FAVOR_SIZE Error initFuncDetail(FuncDetail& func, const FuncSignature& signature, uint32_t registerSize) noexcept {
const CallConv& cc = func.callConv();
uint32_t arch = cc.arch();
uint32_t stackOffset = cc._spillZoneSize;
uint32_t argCount = func.argCount();
// Up to two return values can be returned in GP registers.
static const uint8_t gpReturnIndexes[4] = {
uint8_t(Gp::kIdAx),
uint8_t(Gp::kIdDx),
uint8_t(BaseReg::kIdBad),
uint8_t(BaseReg::kIdBad)
};
if (func.hasRet()) {
unpackValues(func, func._rets);
for (uint32_t valueIndex = 0; valueIndex < Globals::kMaxValuePack; valueIndex++) {
uint32_t typeId = func._rets[valueIndex].typeId();
// Terminate at the first void type (end of the pack).
if (!typeId)
break;
switch (typeId) {
case Type::kIdI64:
case Type::kIdU64: {
if (gpReturnIndexes[valueIndex] != BaseReg::kIdBad)
func._rets[valueIndex].initReg(Reg::kTypeGpq, gpReturnIndexes[valueIndex], typeId);
else
return DebugUtils::errored(kErrorInvalidState);
break;
}
case Type::kIdI8:
case Type::kIdI16:
case Type::kIdI32: {
if (gpReturnIndexes[valueIndex] != BaseReg::kIdBad)
func._rets[valueIndex].initReg(Reg::kTypeGpd, gpReturnIndexes[valueIndex], Type::kIdI32);
else
return DebugUtils::errored(kErrorInvalidState);
break;
}
case Type::kIdU8:
case Type::kIdU16:
case Type::kIdU32: {
if (gpReturnIndexes[valueIndex] != BaseReg::kIdBad)
func._rets[valueIndex].initReg(Reg::kTypeGpd, gpReturnIndexes[valueIndex], Type::kIdU32);
else
return DebugUtils::errored(kErrorInvalidState);
break;
}
case Type::kIdF32:
case Type::kIdF64: {
uint32_t regType = Environment::is32Bit(arch) ? Reg::kTypeSt : Reg::kTypeXmm;
func._rets[valueIndex].initReg(regType, valueIndex, typeId);
break;
}
case Type::kIdF80: {
// 80-bit floats are always returned by FP0.
func._rets[valueIndex].initReg(Reg::kTypeSt, valueIndex, typeId);
break;
}
case Type::kIdMmx32:
case Type::kIdMmx64: {
// MM registers are returned through XMM (SystemV) or GPQ (Win64).
uint32_t regType = Reg::kTypeMm;
uint32_t regIndex = valueIndex;
if (Environment::is64Bit(arch)) {
regType = cc.strategy() == CallConv::kStrategyDefault ? Reg::kTypeXmm : Reg::kTypeGpq;
regIndex = cc.strategy() == CallConv::kStrategyDefault ? valueIndex : gpReturnIndexes[valueIndex];
if (regIndex == BaseReg::kIdBad)
return DebugUtils::errored(kErrorInvalidState);
}
func._rets[valueIndex].initReg(regType, regIndex, typeId);
break;
}
default: {
func._rets[valueIndex].initReg(vecTypeIdToRegType(typeId), valueIndex, typeId);
break;
}
}
}
}
switch (cc.strategy()) {
case CallConv::kStrategyDefault: {
uint32_t gpzPos = 0;
uint32_t vecPos = 0;
for (uint32_t argIndex = 0; argIndex < argCount; argIndex++) {
unpackValues(func, func._args[argIndex]);
for (uint32_t valueIndex = 0; valueIndex < Globals::kMaxValuePack; valueIndex++) {
FuncValue& arg = func._args[argIndex][valueIndex];
// Terminate if there are no more arguments in the pack.
if (!arg)
break;
uint32_t typeId = arg.typeId();
if (Type::isInt(typeId)) {
uint32_t regId = BaseReg::kIdBad;
if (gpzPos < CallConv::kMaxRegArgsPerGroup)
regId = cc._passedOrder[Reg::kGroupGp].id[gpzPos];
if (regId != BaseReg::kIdBad) {
uint32_t regType = (typeId <= Type::kIdU32) ? Reg::kTypeGpd : Reg::kTypeGpq;
arg.assignRegData(regType, regId);
func.addUsedRegs(Reg::kGroupGp, Support::bitMask(regId));
gpzPos++;
}
else {
uint32_t size = Support::max<uint32_t>(Type::sizeOf(typeId), registerSize);
arg.assignStackOffset(int32_t(stackOffset));
stackOffset += size;
}
continue;
}
if (Type::isFloat(typeId) || Type::isVec(typeId)) {
uint32_t regId = BaseReg::kIdBad;
if (vecPos < CallConv::kMaxRegArgsPerGroup)
regId = cc._passedOrder[Reg::kGroupVec].id[vecPos];
if (Type::isFloat(typeId)) {
// If this is a float, but `kFlagPassFloatsByVec` is false, we have
// to use stack instead. This should be only used by 32-bit calling
// conventions.
if (!cc.hasFlag(CallConv::kFlagPassFloatsByVec))
regId = BaseReg::kIdBad;
}
else {
// Pass vector registers via stack if this is a variable arguments
// function. This should be only used by 32-bit calling conventions.
if (signature.hasVarArgs() && cc.hasFlag(CallConv::kFlagPassVecByStackIfVA))
regId = BaseReg::kIdBad;
}
if (regId != BaseReg::kIdBad) {
arg.initTypeId(typeId);
arg.assignRegData(vecTypeIdToRegType(typeId), regId);
func.addUsedRegs(Reg::kGroupVec, Support::bitMask(regId));
vecPos++;
}
else {
uint32_t size = Type::sizeOf(typeId);
arg.assignStackOffset(int32_t(stackOffset));
stackOffset += size;
}
continue;
}
}
}
break;
}
case CallConv::kStrategyX64Windows:
case CallConv::kStrategyX64VectorCall: {
// Both X64 and VectorCall behave similarly - arguments are indexed
// from left to right. The position of the argument determines in
// which register the argument is allocated, so it's either GP or
// one of XMM/YMM/ZMM registers.
//
// [ X64 ] [VecCall]
// Index: #0 #1 #2 #3 #4 #5
//
// GP : RCX RDX R8 R9
// VEC : XMM0 XMM1 XMM2 XMM3 XMM4 XMM5
//
// For example function `f(int a, double b, int c, double d)` will be:
//
// (a) (b) (c) (d)
// RCX XMM1 R8 XMM3
//
// Unused vector registers are used by HVA.
bool isVectorCall = (cc.strategy() == CallConv::kStrategyX64VectorCall);
for (uint32_t argIndex = 0; argIndex < argCount; argIndex++) {
unpackValues(func, func._args[argIndex]);
for (uint32_t valueIndex = 0; valueIndex < Globals::kMaxValuePack; valueIndex++) {
FuncValue& arg = func._args[argIndex][valueIndex];
// Terminate if there are no more arguments in the pack.
if (!arg)
break;
uint32_t typeId = arg.typeId();
uint32_t size = Type::sizeOf(typeId);
if (Type::isInt(typeId) || Type::isMmx(typeId)) {
uint32_t regId = BaseReg::kIdBad;
if (argIndex < CallConv::kMaxRegArgsPerGroup)
regId = cc._passedOrder[Reg::kGroupGp].id[argIndex];
if (regId != BaseReg::kIdBad) {
uint32_t regType = (size <= 4 && !Type::isMmx(typeId)) ? Reg::kTypeGpd : Reg::kTypeGpq;
arg.assignRegData(regType, regId);
func.addUsedRegs(Reg::kGroupGp, Support::bitMask(regId));
}
else {
arg.assignStackOffset(int32_t(stackOffset));
stackOffset += 8;
}
continue;
}
if (Type::isFloat(typeId) || Type::isVec(typeId)) {
uint32_t regId = BaseReg::kIdBad;
if (argIndex < CallConv::kMaxRegArgsPerGroup)
regId = cc._passedOrder[Reg::kGroupVec].id[argIndex];
if (regId != BaseReg::kIdBad) {
// X64-ABI doesn't allow vector types (XMM|YMM|ZMM) to be passed
// via registers, however, VectorCall was designed for that purpose.
if (Type::isFloat(typeId) || isVectorCall) {
uint32_t regType = vecTypeIdToRegType(typeId);
arg.assignRegData(regType, regId);
func.addUsedRegs(Reg::kGroupVec, Support::bitMask(regId));
continue;
}
}
// Passed via stack if the argument is float/double or indirectly.
// The trap is - if the argument is passed indirectly, the address
// can be passed via register, if the argument's index has GP one.
if (Type::isFloat(typeId)) {
arg.assignStackOffset(int32_t(stackOffset));
}
else {
uint32_t gpRegId = cc._passedOrder[Reg::kGroupGp].id[argIndex];
if (gpRegId != BaseReg::kIdBad)
arg.assignRegData(Reg::kTypeGpq, gpRegId);
else
arg.assignStackOffset(int32_t(stackOffset));
arg.addFlags(FuncValue::kFlagIsIndirect);
}
// Always 8 bytes (float/double/pointer).
stackOffset += 8;
continue;
}
}
}
break;
}
}
func._argStackSize = stackOffset;
return kErrorOk;
}
} // {FuncInternal}
ASMJIT_END_SUB_NAMESPACE
#endif // ASMJIT_BUILD_X86