Flat Assembler 1.67.21

The flat assembler is a fast and efficient self-assembling 80x86 assembler for DOS, Windows, and Linux operating systems. Currently, it supports all 8086-80486/Pentium instructions with MMX, SSE, SSE2, SSE3, and 3DNow! extensions.
It can produce output in binary, MZ, PE, COFF, or ELF format. Flat Assembler includes the powerful but easy-to-use macroinstruction support, and does multiple passes to optimize the instruction codes for size. The flat assembler is entirely written in assembly language.
Enhancements:
- 32-bit relocations are now allowed in PE64 output format.
- EIP-relative addressing was added.
- The PLT operator was added for the ELF output format.
- SSSE3 (Supplemental SSE3) instructions were added.
- Some Win64 headers and examples were provided in the Windows package.
- The SYSRETQ mnemonic was added, and RDMSRQ/WRMSRQ/SYSEXITQ mnemonics were added for the 64-bit variants of respective instructions.
- R8L-R15L (Intel-style) aliases were added for R8B-R15B registers. Support for the AMD SVM technology instructions was added. Numerous bugs were fixed.