In particular subtracting a defined symbol from current section
makes the value PC relative, and .org accepts symbolic expressions
as well, if the symbol is from the current section.
Disjoint instruction types don't need to be a bit field, so
introduce an enumeration (3 bits). Also the 0x0f prefix can
be expressed by a bit, doesn't need a byte in the opcode field.
That enables to encode further prefixes still in 16 bit.
To not have to touch all insns do some macro fiddling filtering
out a 0x0f byte in the second position.
In particular those that are extensions of existing mmx (or sse1)
instructions by a simple 0x66 prefix. There's one caveat for
x86-64: as we don't yet correctly handle the 0xf3 prefix
the movq mem64->xmm is wrong (tested in asmtest.S). Needs
some refactoring of the instr_type member.
The problem was with tcctest.c:
unsigned set;
__asm__("btsl %1,%0" : "=m"(set) : "Ir"(20) : "cc");
when with tcc compiled with the HAVE_SELINUX option, run with
tcc -run, it would use large addresses far beyond the 32bits
range when tcc did not use the pc-relative mode for accessing
'set' in global data memory. In fact the assembler did not
know about %rip at all.
Changes:
- memory operands use (%rax) not (%eax)
- conversion from VT_LLOCAL: use type VT_PTR
- support 'k' modifier
- support %rip register
- support X(%rip) pc-relative addresses
The test in tcctest.c is from Michael Matz.
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.
A CString used to be copied into a token string, which is an int array.
On a 64-bit architecture the pointers were misaligned, so ASan gave
lots of warnings. On a 64-bit architecture that required memory
accesses to be correctly aligned it would not work at all.
The CString is now included in CValue instead.
* 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...
This enables native unwind semantics with longjmp on
win64 by putting an entry into the .pdata section for
each compiled fuction.
Also, the function now use a fixed stack and store arguments
into X(%rsp) rather than using push.
