- we're now exporting tcc_prefixed symbols from libtcc only
- On windows, the msvcrt startup code would remove backslashes
from commandline arguments such as
-DFOO=\"foo\"
which would appear in argv as
-DFOO="foo"
Therefor before passing these to spawnvp, we need to restore
the backslashes.
Also:
- on windows i386 and x86-64, structures of size <= 8 are
NOT returned in registers if size is not one of 1,2,4,8.
- cleanup: put all tv-push/pop/swap/rot into one place
There seems nothing wrong. With
int t1 = 176401255;
float f = 0.25;
int t2 = t1 * f; // 176401255 * 0.25 = 44100313.75
according to the arithmetic conversion rules, the number
176401255 needs to be converted to float, and the compiler
can choose either the nearest higher or nearest lower
representable number "in an implementation-defined manner".
Which may be 176401248 or 176401264. So as result both
44100312 and 44100313 are correct.
This reverts commit 664c19ad5e.
In the previous implementation, the rx mapping was never
used. Therefor it is assumed that it is not needed.
With only one mapping there is no reason to use a real
/tmp/.xxxx file either as we can use an anonymous mapping.
Based on feedback from grischka, this commit
(1) updates the name of the alignment constant to be more specific
(2) aligns all sections, including the first (which previosly was
not aligned)
(3) reduces the x86-64 alignment from 512 to 64 bytes.
The original x86-64 alignment of 512 bytes was based on testing.
After ensuring that the initial section is also aligned, the same
tests indicated that 64 bytes is sufficient.
Tests found excessive cache thrashing on x86-64 architectures. The
problem was traced to the alignment of sections. This patch sets up
an architecture-specific alignment of 512 bytes for x86-64 and 16
bytes for all others. It uses preprocessor directives that, hopefully,
make it easy to tweak for other architectures.
tests/Makefile: fix out-of-tree build issues
Also:
- win64: align(16) MEM_DEBUG user memory
on win64 the struct jmp_buf in the TCCState structure which we
allocate by tcc_malloc needs alignment 16 because the msvcrt
setjmp uses MMX instructions.
- libtcc_test.c: win32/64 need __attribute__((dllimport)) for
extern data objects
- tcctest.c: exclude stuff that gcc does not compile
except for relocation_test() the other issues are mostly ASM
related. We should probably check GCC versions but I have
no idea which mingw/gcc versions support what and which don't.
- lib/Makefile: use tcc to compile libtcc1.a (except on arm
which needs arm-asm
Once-allocated buffers (here a string) that aren't explicitely freed
at program end but rather freed at _exit about 1 nanosecond later
are regarded a leak with MEM_DEBUG, so explicitely free it. Blaeh :-/
Some more subtle issues with code suppression:
- outputting asms but not their operand setup is broken
- but global asms must always be output
- statement expressions are transparent to code suppression
- vtop can't be transformed from VT_CMP/VT_JMP when nocode_wanted
Also remove .exe files from tests2 if they don't fail.
Restore ebx from *ebp because alloca might change esp.
Also disable USE_EBX for upcoming release.
Actually the benefit is less than one would expect, it
appears that tcc can't do much with more than 3 registers
except with extensive use of long longs where the disassembly
looks much prettier (and shorter also).
Also: tccgen/expr_cond() : fix wrong gv/save_regs order
handle mms-bitfields as sub-options of -m. (-mfloat-abi
is still special because it requires arguments)
tcc.c: help():
- list -mms-bitfields under 'Target specific options'
libtcc.c/MEM_DEBUG
- add check for past buffer writes
Also ...
tcctest.c:
- exclude stuff that gcc doesn't compile on windows.
libtcc.c/tccpp.c:
- use unsigned for memory sizes to avoid printf format warnings
- use "file:line: message" to make IDE error parsers happy.
tccgen.c: fix typo
tccgen.c: remove any 'nocode_wanted' checks, except in
- greloca(), disables output elf symbols and relocs
- get_reg(), will return just the first suitable reg)
- save_regs(), will do nothing
Some minor adjustments were made where nocode_wanted is set.
xxx-gen.c: disable code output directly where it happens
in functions:
- g(), output disabled
- gjmp(), will do nothing
- gtst(), dto.
on 32bit long long support was sometimes broken. This fixes
code-gen for long long values in switches, disables a x86-64 specific
testcase and avoid an undefined shift amount. It comments out
a bitfield test involving long long bitfields > 32 bit; with GCC layout
they can straddle multiple words and code generation isn't prepared
for this.
when an alignment is explicitely given on the member itself,
or on its types attributes then respect it always. Was only
allowed to increase before, but GCC is allowing it.
The linux kernel has some structures that are page aligned,
i.e. 4096. Instead of enlarging the bit fields to specify this,
use the fact that alignment is always power of two, and store only
the log2 minus 1 of it. The 5 bits are enough to specify an alignment
of 1 << 30.
Another corner case:
struct foo6_1
{
char x;
short p:8;
short :0;
short :0;
short p2:8;
char y;
};
In MS layout the second anon :0 bit-field does _not_ adjust size or
alignment of the struct again. The first one does, though.
Bit-fields are layed out differently in visual C, this implements
a compatible mode. Checked against Visual C/C++ 2016.
Unfortunately the GCC implementation of MS layout (behind
-mms-bitfields) actually is different, and hence not compatible
with MS in all cases :-/
Such struct decl:
struct S { char a; int i;} __attribute__((packed));
should be accepted and cause S to be five bytes long (i.e.
the packed attribute should matter). So we can't layout
the members during parsing already. Split off the offset
and alignment calculation for this.
See testcases. We now support 64bit case constants. At the same time
also 64bit enum constants on L64 platforms (otherwise the Sym struct
isn't large enough for now). The testcase also checks for various
cases where sign/zero extension was confused.
See testcase. We must always paste tokens (at least if not
currently substing a normal argument, which is a speed optimization
only now) but at the same time must not regard a ## token
coming from argument expansion as the token-paste operator, nor
if we constructed a ## token due to pasting itself (that was already
checked by pp/01.c).
libtcc1 is the compiler support library and therefore needs
to function in a freestanding environment. In particular
it can't just use fprintf or stderr, which it was on x86-64
(but only when compiled by GCC). The tight integration between
libtcc1 and tcc itself makes it impossible to ever reach that
case so the abort() there is enough. abort() is strictly speaking
also not available in a freestanding environment, but it often is
nevertheless.
In certain very specific situations (involving switches
with asms inside dead statement expressions) we could generate
invalid code (clobbering the buffer so much that we generated
invalid instructions). Don't emit the decision table if the
switch itself is dead.
The callee saved registers (among them r12-r15) really need
saving/restoring if mentioned in asm clobbers, even if TCC
itself doesn't use them. E.g. the linux kernel relies on that
in its switch_to() implementation.
When intializing members where the initializer needs relocations
and the member is initialized multiple times we can't allow
that to lead to multiple relocations to the same place. The last
one must win.
Similar to GCC a local asm register variable enforces the use of a
specified register in asm operands (and doesn't otherwise
matter). Works only if the variable is directly mentioned as
operand. For that we now generally store a backpointer from
an SValue to a Sym when the SValue was the result of unary()
parsing a symbol identifier.
If the destination is an indirect pointer access (which ends up
as VT_LLOCAL) the intermediate pointer must be loaded as VT_PTR,
not as whatever the pointed to type is.
Some routines were using the wrong type (int) in passing addends,
truncating it. This matters when bit 31 isn't set and the high
32 bits are set: the truncation would make it unsigned where in
reality it's signed (happen e.g. on the x86-64 with it's load
address at top-2GB).
