There were two errors in the arithmetic imm8 instruction. They accept
only REGW, and in case the user write a xxxb opcode that variant
needs to be rejected as well (it's not automatically rejected by REGW
in case the destination is memory).
Two things: negative constants were rejected (e.g. "add $-15,%eax").
Second the insn order was such that the arithmetic IM8S forms
weren't used (always the IM32 ones). Switching them prefers those
but requires a fix for size calculation in case the opcodes were
OPC_ARITH and OPC_WLX (whose size starts with 1, not zero).
Fix it to actually be able to parse 64bit immediates (enlarge
operand value type). Then, generally there's no need for accepting
IM64 anywhere, except in the 0xba+r mov opcodes, so OP_IM is
unnecessary, as is OPT_IMNO64. Improve the generated code a bit
by preferring the 0xc7 opcode for im32->reg64, instead of the
im64->reg64 form (which we therefore hardcode).
A bag of assembler fixes, to be either compatible with GAS
(e.g. order of 'test' operands), accept more instructions,
count correct foo{bwlq} variants on x86_64, fix modrm/sib bytes
on x86_64 to not use %rip relative addressing mode, to not use
invalid insns in tests/asmtest.S for x86_64.
Result is that now output of GAS and of tcc on tests/asmtest.S
is mostly the same.
Various x86 asm fixes: 64bit lcall/ljmp like 32bit a commit before,
xchgw accepted wrong operands on 32 and 64bit, and 64bit used
0x40/0x48+reg for incw/decw, but those are REX prefixes, not
instructions.
* Documentation is now in "docs".
* Source code is now in "src".
* Misc. fixes here and there so that everything still works.
I think I got everything in this commit, but I only tested this
on Linux (Make) and Windows (CMake), so I might've messed
something up on other platforms...
