You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Theodosius/Examples/Theodosius-Usermode/asmjit/x86/x86assembler.h

744 lines
30 KiB

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.
#ifndef ASMJIT_X86_X86ASSEMBLER_H_INCLUDED
#define ASMJIT_X86_X86ASSEMBLER_H_INCLUDED
#include "../core/assembler.h"
#include "../x86/x86emitter.h"
#include "../x86/x86operand.h"
ASMJIT_BEGIN_SUB_NAMESPACE(x86)
//! \addtogroup asmjit_x86
//! \{
// ============================================================================
// [asmjit::Assembler]
// ============================================================================
//! X86/X64 assembler implementation.
//!
//! x86::Assembler is a code emitter that emits machine code directly into the
//! \ref CodeBuffer. The assembler is capable of targeting both 32-bit and 64-bit
//! instruction sets, the instruction set can be configured through \ref CodeHolder.
//!
//! ### Basics
//!
//! The following example shows a basic use of `x86::Assembler`, how to generate
//! a function that works in both 32-bit and 64-bit modes, and how to connect
//! \ref JitRuntime, \ref CodeHolder, and `x86::Assembler`.
//!
//! ```
//! #include <asmjit/x86.h>
//! #include <stdio.h>
//!
//! using namespace asmjit;
//!
//! // Signature of the generated function.
//! typedef int (*SumFunc)(const int* arr, size_t count);
//!
//! int main() {
//! JitRuntime rt; // Create a runtime specialized for JIT.
//! CodeHolder code; // Create a CodeHolder.
//!
//! code.init(rt.environment()); // Initialize code to match the JIT environment.
//! x86::Assembler a(&code); // Create and attach x86::Assembler to code.
//!
//! // Decide between 32-bit CDECL, WIN64, and SysV64 calling conventions:
//! // 32-BIT - passed all arguments by stack.
//! // WIN64 - passes first 4 arguments by RCX, RDX, R8, and R9.
//! // UNIX64 - passes first 6 arguments by RDI, RSI, RCX, RDX, R8, and R9.
//! x86::Gp arr, cnt;
//! x86::Gp sum = x86::eax; // Use EAX as 'sum' as it's a return register.
//!
//! if (ASMJIT_ARCH_BITS == 64) {
//! #if defined(_WIN32)
//! arr = x86::rcx; // First argument (array ptr).
//! cnt = x86::rdx; // Second argument (number of elements)
//! #else
//! arr = x86::rdi; // First argument (array ptr).
//! cnt = x86::rsi; // Second argument (number of elements)
//! #endif
//! }
//! else {
//! arr = x86::edx; // Use EDX to hold the array pointer.
//! cnt = x86::ecx; // Use ECX to hold the counter.
//! // Fetch first and second arguments from [ESP + 4] and [ESP + 8].
//! a.mov(arr, x86::ptr(x86::esp, 4));
//! a.mov(cnt, x86::ptr(x86::esp, 8));
//! }
//!
//! Label Loop = a.newLabel(); // To construct the loop, we need some labels.
//! Label Exit = a.newLabel();
//!
//! a.xor_(sum, sum); // Clear 'sum' register (shorter than 'mov').
//! a.test(cnt, cnt); // Border case:
//! a.jz(Exit); // If 'cnt' is zero jump to 'Exit' now.
//!
//! a.bind(Loop); // Start of a loop iteration.
//! a.add(sum, x86::dword_ptr(arr)); // Add int at [arr] to 'sum'.
//! a.add(arr, 4); // Increment 'arr' pointer.
//! a.dec(cnt); // Decrease 'cnt'.
//! a.jnz(Loop); // If not zero jump to 'Loop'.
//!
//! a.bind(Exit); // Exit to handle the border case.
//! a.ret(); // Return from function ('sum' == 'eax').
//! // ----> x86::Assembler is no longer needed from here and can be destroyed <----
//!
//! SumFunc fn;
//! Error err = rt.add(&fn, &code); // Add the generated code to the runtime.
//!
//! if (err) return 1; // Handle a possible error returned by AsmJit.
//! // ----> CodeHolder is no longer needed from here and can be destroyed <----
//!
//! static const int array[6] = { 4, 8, 15, 16, 23, 42 };
//!
//! int result = fn(array, 6); // Execute the generated code.
//! printf("%d\n", result); // Print sum of array (108).
//!
//! rt.release(fn); // Explicitly remove the function from the runtime
//! return 0; // Everything successful...
//! }
//! ```
//!
//! The example should be self-explanatory. It shows how to work with labels,
//! how to use operands, and how to emit instructions that can use different
//! registers based on runtime selection. It implements 32-bit CDECL, WIN64,
//! and SysV64 caling conventions and will work on most X86/X64 environments.
//!
//! Although functions prologs / epilogs can be implemented manually, AsmJit
//! provides utilities that can be used to create function prologs and epilogs
//! automatically, see \ref asmjit_function for more details.
//!
//! ### Instruction Validation
//!
//! Assembler prefers speed over strictness by default. The implementation checks
//! the type of operands and fails if the signature of types is invalid, however,
//! it does only basic checks regarding registers and their groups used in
//! instructions. It's possible to pass operands that don't form any valid
//! signature to the implementation and succeed. This is usually not a problem
//! as Assembler provides typed API so operand types are normally checked by C++
//! compiler at compile time, however, Assembler is fully dynamic and its \ref
//! emit() function can be called with any instruction id, options, and operands.
//! Moreover, it's also possible to form instructions that will be accepted by
//! the typed API, for example by calling `mov(x86::eax, x86::al)` - the C++
//! compiler won't see a problem as both EAX and AL are \ref Gp registers.
//!
//! To help with common mistakes AsmJit allows to activate instruction validation.
//! This feature instruments the Assembler to call \ref InstAPI::validate() before
//! it attempts to encode any instruction.
//!
//! The example below illustrates how validation can be turned on:
//!
//! ```
//! #include <asmjit/x86.h>
//! #include <stdio.h>
//!
//! using namespace asmjit;
//!
//! int main(int argc, char* argv[]) {
//! JitRuntime rt; // Create a runtime specialized for JIT.
//! CodeHolder code; // Create a CodeHolder.
//!
//! code.init(rt.environment()); // Initialize code to match the JIT environment.
//! x86::Assembler a(&code); // Create and attach x86::Assembler to code.
//!
//! // Enable strict validation.
//! a.addValidationOptions(BaseEmitter::kValidationOptionAssembler);
//!
//! // Try to encode invalid or ill-formed instructions.
//! Error err;
//!
//! // Invalid instruction.
//! err = a.mov(x86::eax, x86::al);
//! printf("Status: %s\n", DebugUtils::errorAsString(err));
//!
//! // Invalid instruction.
//! err = a.emit(x86::Inst::kIdMovss, x86::eax, x86::xmm0);
//! printf("Status: %s\n", DebugUtils::errorAsString(err));
//!
//! // Ambiguous operand size - the pointer requires size.
//! err = a.inc(x86::ptr(x86::rax), 1);
//! printf("Status: %s\n", DebugUtils::errorAsString(err));
//!
//! return 0;
//! }
//! ```
//!
//! ### Native Registers
//!
//! All emitters provide functions to construct machine-size registers depending
//! on the target. This feature is for users that want to write code targeting
//! both 32-bit and 64-bit architectures at the same time. In AsmJit terminology
//! such registers have prefix `z`, so for example on X86 architecture the
//! following native registers are provided:
//!
//! - `zax` - mapped to either `eax` or `rax`
//! - `zbx` - mapped to either `ebx` or `rbx`
//! - `zcx` - mapped to either `ecx` or `rcx`
//! - `zdx` - mapped to either `edx` or `rdx`
//! - `zsp` - mapped to either `esp` or `rsp`
//! - `zbp` - mapped to either `ebp` or `rbp`
//! - `zsi` - mapped to either `esi` or `rsi`
//! - `zdi` - mapped to either `edi` or `rdi`
//!
//! They are accessible through \ref x86::Assembler, \ref x86::Builder, and
//! \ref x86::Compiler. The example below illustrates how to use this feature:
//!
//! ```
//! #include <asmjit/x86.h>
//! #include <stdio.h>
//!
//! using namespace asmjit;
//!
//! typedef int (*Func)(void);
//!
//! int main(int argc, char* argv[]) {
//! JitRuntime rt; // Create a runtime specialized for JIT.
//! CodeHolder code; // Create a CodeHolder.
//!
//! code.init(rt.environment()); // Initialize code to match the JIT environment.
//! x86::Assembler a(&code); // Create and attach x86::Assembler to code.
//!
//! // Let's get these registers from x86::Assembler.
//! x86::Gp zbp = a.zbp();
//! x86::Gp zsp = a.zsp();
//!
//! int stackSize = 32;
//!
//! // Function prolog.
//! a.push(zbp);
//! a.mov(zbp, zsp);
//! a.sub(zsp, stackSize);
//!
//! // ... emit some code (this just sets return value to zero) ...
//! a.xor_(x86::eax, x86::eax);
//!
//! // Function epilog and return.
//! a.mov(zsp, zbp);
//! a.pop(zbp);
//! a.ret();
//!
//! // To make the example complete let's call it.
//! Func fn;
//! Error err = rt.add(&fn, &code); // Add the generated code to the runtime.
//! if (err) return 1; // Handle a possible error returned by AsmJit.
//!
//! int result = fn(); // Execute the generated code.
//! printf("%d\n", result); // Print the resulting "0".
//!
//! rt.release(fn); // Remove the function from the runtime.
//! return 0;
//! }
//! ```
//!
//! The example just returns `0`, but the function generated contains a standard
//! prolog and epilog sequence and the function itself reserves 32 bytes of local
//! stack. The advantage is clear - a single code-base can handle multiple targets
//! easily. If you want to create a register of native size dynamically by
//! specifying its id it's also possible:
//!
//! ```
//! void example(x86::Assembler& a) {
//! x86::Gp zax = a.gpz(x86::Gp::kIdAx);
//! x86::Gp zbx = a.gpz(x86::Gp::kIdBx);
//! x86::Gp zcx = a.gpz(x86::Gp::kIdCx);
//! x86::Gp zdx = a.gpz(x86::Gp::kIdDx);
//!
//! // You can also change register's id easily.
//! x86::Gp zsp = zax;
//! zsp.setId(4); // or x86::Gp::kIdSp.
//! }
//! ```
//!
//! ### Data Embedding
//!
//! x86::Assembler extends the standard \ref BaseAssembler with X86/X64 specific
//! conventions that are often used by assemblers to embed data next to the code.
//! The following functions can be used to embed data:
//!
//! - \ref x86::Assembler::db() - embeds byte (8 bits) (x86 naming).
//! - \ref x86::Assembler::dw() - embeds word (16 bits) (x86 naming).
//! - \ref x86::Assembler::dd() - embeds dword (32 bits) (x86 naming).
//! - \ref x86::Assembler::dq() - embeds qword (64 bits) (x86 naming).
//!
//! - \ref BaseAssembler::embedInt8() - embeds int8_t (portable naming).
//! - \ref BaseAssembler::embedUInt8() - embeds uint8_t (portable naming).
//! - \ref BaseAssembler::embedInt16() - embeds int16_t (portable naming).
//! - \ref BaseAssembler::embedUInt16() - embeds uint16_t (portable naming).
//! - \ref BaseAssembler::embedInt32() - embeds int32_t (portable naming).
//! - \ref BaseAssembler::embedUInt32() - embeds uint32_t (portable naming).
//! - \ref BaseAssembler::embedInt64() - embeds int64_t (portable naming).
//! - \ref BaseAssembler::embedUInt64() - embeds uint64_t (portable naming).
//! - \ref BaseAssembler::embedFloat() - embeds float (portable naming).
//! - \ref BaseAssembler::embedDouble() - embeds double (portable naming).
//!
//! The following example illustrates how embed works:
//!
//! ```
//! #include <asmjit/x86.h>
//! using namespace asmjit;
//!
//! void embedData(x86::Assembler& a) {
//! a.db(0xFF); // Embeds 0xFF byte.
//! a.dw(0xFF00); // Embeds 0xFF00 word (little-endian).
//! a.dd(0xFF000000); // Embeds 0xFF000000 dword (little-endian).
//! a.embedFloat(0.4f); // Embeds 0.4f (32-bit float, little-endian).
//! }
//! ```
//!
//! Sometimes it's required to read the data that is embedded after code, for
//! example. This can be done through \ref Label as shown below:
//!
//! ```
//! #include <asmjit/x86.h>
//! using namespace asmjit;
//!
//! void embedData(x86::Assembler& a, const Label& L_Data) {
//! x86::Gp addr = a.zax(); // EAX or RAX.
//! x86::Gp val = x86::edi; // Where to store some value...
//!
//! // Approach 1 - Load the address to register through LEA. This approach
//! // is flexible as the address can be then manipulated, for
//! // example if you have a data array, which would need index.
//! a.lea(addr, L_Data); // Loads the address of the label to EAX or RAX.
//! a.mov(val, dword_ptr(addr));
//!
//! // Approach 2 - Load the data directly by using L_Data in address. It's
//! // worth noting that this doesn't work with indexes in X64
//! // mode. It will use absolute address in 32-bit mode and
//! // relative address (RIP) in 64-bit mode.
//! a.mov(val, dword_ptr(L_Data));
//! }
//! ```
//!
//! ### Label Embedding
//!
//! It's also possible to embed labels. In general AsmJit provides the following
//! options:
//!
//! - \ref BaseEmitter::embedLabel() - Embeds absolute address of a label.
//! This is target dependent and would embed either 32-bit or 64-bit data
//! that embeds absolute label address. This kind of embedding cannot be
//! used in a position independent code.
//!
//! - \ref BaseEmitter::embedLabelDelta() - Embeds a difference between two
//! labels. The size of the difference can be specified so it's possible to
//! embed 8-bit, 16-bit, 32-bit, and 64-bit difference, which is sufficient
//! for most purposes.
//!
//! The following example demonstrates how to embed labels and their differences:
//!
//! ```
//! #include <asmjit/x86.h>
//! using namespace asmjit;
//!
//! void embedLabel(x86::Assembler& a, const Label& L_Data) {
//! // [1] Embed L_Data - the size of the data will be dependent on the target.
//! a.embedLabel(L_Data);
//!
//! // [2] Embed a 32-bit difference of two labels.
//! Label L_Here = a.newLabel();
//! a.bind(L_Here);
//! // Embeds int32_t(L_Data - L_Here).
//! a.embedLabelDelta(L_Data, L_Here, 4);
//! }
//! ```
//!
//! ### Using FuncFrame and FuncDetail with x86::Assembler
//!
//! The example below demonstrates how \ref FuncFrame and \ref FuncDetail can be
//! used together with \ref x86::Assembler to generate a function that will use
//! platform dependent calling conventions automatically depending on the target:
//!
//! ```
//! #include <asmjit/x86.h>
//! #include <stdio.h>
//!
//! using namespace asmjit;
//!
//! typedef void (*SumIntsFunc)(int* dst, const int* a, const int* b);
//!
//! int main(int argc, char* argv[]) {
//! JitRuntime rt; // Create JIT Runtime.
//! CodeHolder code; // Create a CodeHolder.
//!
//! code.init(rt.environment()); // Initialize code to match the JIT environment.
//! x86::Assembler a(&code); // Create and attach x86::Assembler to code.
//!
//! // Decide which registers will be mapped to function arguments. Try changing
//! // registers of dst, src_a, and src_b and see what happens in function's
//! // prolog and epilog.
//! x86::Gp dst = a.zax();
//! x86::Gp src_a = a.zcx();
//! x86::Gp src_b = a.zdx();
//!
//! X86::Xmm vec0 = x86::xmm0;
//! X86::Xmm vec1 = x86::xmm1;
//!
//! // Create/initialize FuncDetail and FuncFrame.
//! FuncDetail func;
//! func.init(FuncSignatureT<void, int*, const int*, const int*>(CallConv::kIdHost));
//!
//! FuncFrame frame;
//! frame.init(func);
//!
//! // Make XMM0 and XMM1 dirty - kGroupVec describes XMM|YMM|ZMM registers.
//! frame.setDirtyRegs(x86::Reg::kGroupVec, IntUtils::mask(0, 1));
//!
//! // Alternatively, if you don't want to use register masks you can pass BaseReg
//! // to addDirtyRegs(). The following code would add both xmm0 and xmm1.
//! frame.addDirtyRegs(x86::xmm0, x86::xmm1);
//!
//! FuncArgsAssignment args(&func); // Create arguments assignment context.
//! args.assignAll(dst, src_a, src_b);// Assign our registers to arguments.
//! args.updateFrameInfo(frame); // Reflect our args in FuncFrame.
//! frame.finalize(); // Finalize the FuncFrame (updates it).
//!
//! a.emitProlog(frame); // Emit function prolog.
//! a.emitArgsAssignment(frame, args);// Assign arguments to registers.
//! a.movdqu(vec0, x86::ptr(src_a)); // Load 4 ints from [src_a] to XMM0.
//! a.movdqu(vec1, x86::ptr(src_b)); // Load 4 ints from [src_b] to XMM1.
//! a.paddd(vec0, vec1); // Add 4 ints in XMM1 to XMM0.
//! a.movdqu(x86::ptr(dst), vec0); // Store the result to [dst].
//! a.emitEpilog(frame); // Emit function epilog and return.
//!
//! SumIntsFunc fn;
//! Error err = rt.add(&fn, &code); // Add the generated code to the runtime.
//! if (err) return 1; // Handle a possible error case.
//!
//! // Execute the generated function.
//! int inA[4] = { 4, 3, 2, 1 };
//! int inB[4] = { 1, 5, 2, 8 };
//! int out[4];
//! fn(out, inA, inB);
//!
//! // Prints {5 8 4 9}
//! printf("{%d %d %d %d}\n", out[0], out[1], out[2], out[3]);
//!
//! rt.release(fn);
//! return 0;
//! }
//! ```
//!
//! ### Using x86::Assembler as Code-Patcher
//!
//! This is an advanced topic that is sometimes unavoidable. AsmJit by default
//! appends machine code it generates into a \ref CodeBuffer, however, it also
//! allows to set the offset in \ref CodeBuffer explicitly and to overwrite its
//! content. This technique is extremely dangerous as X86 instructions have
//! variable length (see below), so you should in general only patch code to
//! change instruction's immediate values or some other details not known the
//! at a time the instruction was emitted. A typical scenario that requires
//! code-patching is when you start emitting function and you don't know how
//! much stack you want to reserve for it.
//!
//! Before we go further it's important to introduce instruction options, because
//! they can help with code-patching (and not only patching, but that will be
//! explained in AVX-512 section):
//!
//! - Many general-purpose instructions (especially arithmetic ones) on X86
//! have multiple encodings - in AsmJit this is usually called 'short form'
//! and 'long form'.
//! - AsmJit always tries to use 'short form' as it makes the resulting
//! machine-code smaller, which is always good - this decision is used
//! by majority of assemblers out there.
//! - AsmJit allows to override the default decision by using `short_()`
//! and `long_()` instruction options to force short or long form,
//! respectively. The most useful is `long_()` as it basically forces
//! AsmJit to always emit the longest form. The `short_()` is not that
//! useful as it's automatic (except jumps to non-bound labels). Note that
//! the underscore after each function name avoids collision with built-in
//! C++ types.
//!
//! To illustrate what short form and long form means in binary let's assume
//! we want to emit "add esp, 16" instruction, which has two possible binary
//! encodings:
//!
//! - `83C410` - This is a short form aka `short add esp, 16` - You can see
//! opcode byte (0x8C), MOD/RM byte (0xC4) and an 8-bit immediate value
//! representing `16`.
//! - `81C410000000` - This is a long form aka `long add esp, 16` - You can
//! see a different opcode byte (0x81), the same Mod/RM byte (0xC4) and a
//! 32-bit immediate in little-endian representing `16`.
//!
//! It should be obvious that patching an existing instruction into an instruction
//! having a different size may create various problems. So it's recommended to be
//! careful and to only patch instructions into instructions having the same size.
//! The example below demonstrates how instruction options can be used to guarantee
//! the size of an instruction by forcing the assembler to use long-form encoding:
//!
//! ```
//! #include <asmjit/x86.h>
//! #include <stdio.h>
//!
//! using namespace asmjit;
//!
//! typedef int (*Func)(void);
//!
//! int main(int argc, char* argv[]) {
//! JitRuntime rt; // Create a runtime specialized for JIT.
//! CodeHolder code; // Create a CodeHolder.
//!
//! code.init(rt.environment()); // Initialize code to match the JIT environment.
//! x86::Assembler a(&code); // Create and attach x86::Assembler to code.
//!
//! // Let's get these registers from x86::Assembler.
//! x86::Gp zbp = a.zbp();
//! x86::Gp zsp = a.zsp();
//!
//! // Function prolog.
//! a.push(zbp);
//! a.mov(zbp, zsp);
//!
//! // This is where we are gonna patch the code later, so let's get the offset
//! // (the current location) from the beginning of the code-buffer.
//! size_t patchOffset = a.offset();
//! // Let's just emit 'sub zsp, 0' for now, but don't forget to use LONG form.
//! a.long_().sub(zsp, 0);
//!
//! // ... emit some code (this just sets return value to zero) ...
//! a.xor_(x86::eax, x86::eax);
//!
//! // Function epilog and return.
//! a.mov(zsp, zbp);
//! a.pop(zbp);
//! a.ret();
//!
//! // Now we know how much stack size we want to reserve. I have chosen 128
//! // bytes on purpose as it's encodable only in long form that we have used.
//!
//! int stackSize = 128; // Number of bytes to reserve on the stack.
//! a.setOffset(patchOffset); // Move the current cursor to `patchOffset`.
//! a.long_().sub(zsp, stackSize); // Patch the code; don't forget to use LONG form.
//!
//! // Now the code is ready to be called
//! Func fn;
//! Error err = rt.add(&fn, &code); // Add the generated code to the runtime.
//! if (err) return 1; // Handle a possible error returned by AsmJit.
//!
//! int result = fn(); // Execute the generated code.
//! printf("%d\n", result); // Print the resulting "0".
//!
//! rt.release(fn); // Remove the function from the runtime.
//! return 0;
//! }
//! ```
//!
//! If you run the example it will just work, because both instructions have
//! the same size. As an experiment you can try removing `long_()` form to
//! see what happens when wrong code is generated.
//!
//! ### Code Patching and REX Prefix
//!
//! In 64-bit mode there is one more thing to worry about when patching code:
//! REX prefix. It's a single byte prefix designed to address registers with
//! ids from 9 to 15 and to override the default width of operation from 32
//! to 64 bits. AsmJit, like other assemblers, only emits REX prefix when it's
//! necessary. If the patched code only changes the immediate value as shown
//! in the previous example then there is nothing to worry about as it doesn't
//! change the logic behind emitting REX prefix, however, if the patched code
//! changes register id or overrides the operation width then it's important
//! to take care of REX prefix as well.
//!
//! AsmJit contains another instruction option that controls (forces) REX
//! prefix - `rex()`. If you use it the instruction emitted will always use
//! REX prefix even when it's encodable without it. The following list contains
//! some instructions and their binary representations to illustrate when it's
//! emitted:
//!
//! - `__83C410` - `add esp, 16` - 32-bit operation in 64-bit mode doesn't require REX prefix.
//! - `4083C410` - `rex add esp, 16` - 32-bit operation in 64-bit mode with forced REX prefix (0x40).
//! - `4883C410` - `add rsp, 16` - 64-bit operation in 64-bit mode requires REX prefix (0x48).
//! - `4183C410` - `add r12d, 16` - 32-bit operation in 64-bit mode using R12D requires REX prefix (0x41).
//! - `4983C410` - `add r12, 16` - 64-bit operation in 64-bit mode using R12 requires REX prefix (0x49).
//!
//! ### More Prefixes
//!
//! X86 architecture is known for its prefixes. AsmJit supports all prefixes
//! that can affect how the instruction is encoded:
//!
//! ```
//! #include <asmjit/x86.h>
//!
//! using namespace asmjit;
//!
//! void prefixesExample(x86::Assembler& a) {
//! // Lock prefix for implementing atomics:
//! // lock add dword ptr [dst], 1
//! a.lock().add(x86::dword_ptr(dst), 1);
//!
//! // Similarly, XAcquire/XRelease prefixes are also available:
//! // xacquire add dword ptr [dst], 1
//! a.xacquire().add(x86::dword_ptr(dst), 1);
//!
//! // Rep prefix (see also repe/repz and repne/repnz):
//! // rep movs byte ptr [dst], byte ptr [src]
//! a.rep().movs(x86::byte_ptr(dst), x86::byte_ptr(src));
//!
//! // Forcing REX prefix in 64-bit mode.
//! // rex mov eax, 1
//! a.rex().mov(x86::eax, 1);
//!
//! // AVX instruction without forced prefix uses the shortest encoding:
//! // vaddpd xmm0, xmm1, xmm2 -> [C5|F1|58|C2]
//! a.vaddpd(x86::xmm0, x86::xmm1, x86::xmm2);
//!
//! // Forcing VEX3 prefix (AVX):
//! // vex3 vaddpd xmm0, xmm1, xmm2 -> [C4|E1|71|58|C2]
//! a.vex3().vaddpd(x86::xmm0, x86::xmm1, x86::xmm2);
//!
//! // Forcing EVEX prefix (AVX512):
//! // evex vaddpd xmm0, xmm1, xmm2 -> [62|F1|F5|08|58|C2]
//! a.evex().vaddpd(x86::xmm0, x86::xmm1, x86::xmm2);
//!
//! // Some instructions accept prefixes not originally intended to:
//! // rep ret
//! a.rep().ret();
//! }
//! ```
//!
//! It's important to understand that prefixes are part of instruction options.
//! When a member function that involves adding a prefix is called the prefix
//! is combined with existing instruction options, which will affect the next
//! instruction generated.
//!
//! ### Generating AVX512 code.
//!
//! x86::Assembler can generate AVX512+ code including the use of opmask
//! registers. Opmask can be specified through \ref x86::Assembler::k()
//! function, which stores it as an extra register, which will be used
//! by the next instruction. AsmJit uses such concept for manipulating
//! instruction options as well.
//!
//! The following AVX512 features are supported:
//!
//! - Opmask selector {k} and zeroing {z}.
//! - Rounding modes {rn|rd|ru|rz} and suppress-all-exceptions {sae} option.
//! - AVX512 broadcasts {1toN}.
//!
//! The following example demonstrates how AVX512 features can be used:
//!
//! ```
//! #include <asmjit/x86.h>
//!
//! using namespace asmjit;
//!
//! void generateAVX512Code(x86::Assembler& a) {
//! using namespace x86;
//!
//! // Opmask Selectors
//! // ----------------
//! //
//! // - Opmask / zeroing is part of the instruction options / extraReg.
//! // - k(reg) is like {kreg} in Intel syntax.
//! // - z() is like {z} in Intel syntax.
//!
//! // vaddpd zmm {k1} {z}, zmm1, zmm2
//! a.k(k1).z().vaddpd(zmm0, zmm1, zmm2);
//!
//! // Memory Broadcasts
//! // -----------------
//! //
//! // - Broadcast data is part of memory operand.
//! // - Use x86::Mem::_1toN(), which returns a new x86::Mem operand.
//!
//! // vaddpd zmm0 {k1} {z}, zmm1, [rcx] {1to8}
//! a.k(k1).z().vaddpd(zmm0, zmm1, x86::mem(rcx)._1to8());
//!
//! // Embedded Rounding & Suppress-All-Exceptoins
//! // -------------------------------------------
//! //
//! // - Rounding mode and {sae} are part of instruction options.
//! // - Use sae() to enable exception suppression.
//! // - Use rn_sae(), rd_sae(), ru_sae(), and rz_sae() - to enable rounding.
//! // - Embedded rounding implicitly sets {sae} as well, that's why the API
//! // also has sae() suffix, to make it clear.
//!
//! // vcmppd k1, zmm1, zmm2, 0x00 {sae}
//! a.sae().vcmppd(k1, zmm1, zmm2, 0);
//!
//! // vaddpd zmm0, zmm1, zmm2 {rz}
//! a.rz_sae().vaddpd(zmm0, zmm1, zmm2);
//! }
//! ```
class ASMJIT_VIRTAPI Assembler
: public BaseAssembler,
public EmitterImplicitT<Assembler> {
public:
ASMJIT_NONCOPYABLE(Assembler)
typedef BaseAssembler Base;
//! \name Construction & Destruction
//! \{
ASMJIT_API explicit Assembler(CodeHolder* code = nullptr) noexcept;
ASMJIT_API virtual ~Assembler() noexcept;
//! \}
//! \cond INTERNAL
//! \name Internal
//! \{
// NOTE: x86::Assembler uses _privateData to store 'address-override' bit that
// is used to decide whether to emit address-override (67H) prefix based on
// the memory BASE+INDEX registers. It's either `kX86MemInfo_67H_X86` or
// `kX86MemInfo_67H_X64`.
inline uint32_t _addressOverrideMask() const noexcept { return _privateData; }
inline void _setAddressOverrideMask(uint32_t m) noexcept { _privateData = m; }
//! \}
//! \endcond
//! \name Emit
//! \{
ASMJIT_API Error _emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_* opExt) override;
//! \}
//! \endcond
//! \name Align
//! \{
ASMJIT_API Error align(uint32_t alignMode, uint32_t alignment) override;
//! \}
//! \name Events
//! \{
ASMJIT_API Error onAttach(CodeHolder* code) noexcept override;
ASMJIT_API Error onDetach(CodeHolder* code) noexcept override;
//! \}
};
//! \}
ASMJIT_END_SUB_NAMESPACE
#endif // ASMJIT_X86_X86ASSEMBLER_H_INCLUDED