Commit Graph
100 Commits
Author SHA1 Message Date
Michael Matz 5d0c16a884 Support attribute between double pointer stars
"int * __attribute__((something)) *" is supported by GCC.
2016-12-15 17:47:09 +01:00
Michael Matz 662338f116 Fix function to pointer conversion
This snippet is valid:
  void foo(void);
  ... foo + 42 ...
the function designator is converted to pointer to function
implicitely.  gen_op didn't do that and bailed out.
2016-12-15 17:47:08 +01:00
Michael Matz e034853b38 Fix parsing array typedefs of unknown size
This must compile:
 typedef int arrtype1[];
 arrtype1 sinit19 = {1};
 arrtype1 sinit20 = {2,3};
and generate two arrays of one resp. two elements.  Before the fix
the determined size of the first array was encoded in the type
directly, so sinit20 couldn't be parsed anymore (because arrtype1
was thought to be only one element long).
2016-12-15 17:47:08 +01:00
Michael Matz b7e0b693a6 tccpp: Implement __BASE_FILE__ macro
Like __FILE__ but always refers to the command line file name also
from inside headers.
2016-12-15 17:47:08 +01:00
Michael Matz 8a1a2a6033 Implement __builtin_choose_expr
Follows GCC implementation.
2016-12-15 17:47:08 +01:00
Michael Matz 10e4db45dc x86-asm: Implement prefetchw opcode 2016-12-15 17:47:08 +01:00
Michael Matz 5692716770 x86-asm: Fix lar opcode operands
lar can accept multiple sizes as well (wlx), like lsl.  When using
autosize it's important to look at the destination operand first;
when it's a register that one determines the size, not the input
operand.
2016-12-15 17:47:08 +01:00
Michael Matz e3f2a68311 tcc-asm: Parse .size directive correctly
When the .size directive was closed with a ';' tcc eat everything after
it up to lineend.
2016-12-15 17:47:08 +01:00
Michael Matz 6a5ec8cb3c x86-asm: More opcodes
Some new opcodes and some aliases: ljmp[wl], prefetch{nta,t0,t1,t2},
bswap[lq], sysretq, swapgs.
2016-12-15 17:47:08 +01:00
Michael Matz d9d029006c x86-asm: Add [sl][ig]dtq opcodes
GAS has alias lgdtq for lgdt (similar for saves and GDT).  It doesn't
have the same for LDT.
2016-12-15 17:47:08 +01:00
Michael Matz 75e8df126f inline asm: Accept 'R' constraint
This is like 'r' but only accepts the eight legacy regs.  Currently
that's the same as 'r' because we don't support the high ones.
2016-12-15 17:47:08 +01:00
Michael Matz f6c1eb10e2 x86-asm: Implement fxrstorq and fxsaveq 2016-12-15 17:47:08 +01:00
Michael Matz 2b618c1ab4 Fix parsing attributes for struct decls
Given this code:

  struct __attribute__((...)) Name {...};

TCC was eating "Name", hence generating an anonymous struct.
It also didn't apply any packed attributes to the parsed
members.  Both fixed.  The testcase also contains a case
that isn't yet handled by TCC (under a BROKEN #define).
2016-12-15 17:47:08 +01:00
Michael Matz 7e51546624 x86-asm: Implement clflush opcode 2016-12-15 17:47:08 +01:00
Michael Matz e5f4f8d0e7 inline asm: Accept "e" constraint
This is meant to be a (sign-extended) 32bit constant (possibly
symbolic).  We don't do any checks and simply regard it as "i".
2016-12-15 17:47:08 +01:00
Michael Matz bbce31552e inline asm: accept concatenated strings in constraints
This really should be handled implicitly in the preprocessor,
but for now this is enough.
2016-12-15 17:47:08 +01:00
Michael Matz f9423ff3fa inline asm: Fix 'P' and accept some r<nr> registers
A 'P' template modifier should avoid adding a '$' to literal
arguments.  Also accept the numbered r8+ registers in an inline
asm clobber list (ignoring them for now).
2016-12-15 17:47:07 +01:00
Michael Matz 10c3514889 Accept symbols in initializers also on 64 bit
Those should use long or long long type, and generate a 64bit reloc.
2016-12-15 17:47:07 +01:00
Michael Matz 920474115c x86-64-asm: More opcodes
Implement some more opcodes, syscall, sysret, lfence, mfence, sfence.
2016-12-15 17:47:07 +01:00
Michael Matz 1a5eacb445 tccasm: Implement compare expressions
I.e. implement < > <= >= == !=.  Comparisons are signed and result
is -1 if true, 0 if false.
2016-12-15 17:47:07 +01:00
Michael Matz ff5561ff7d x86-64-asm: Accept expressions for .quad
The x86-64 target has 64bit relocs, and hence can accept
generic expressions for '.quad'.
2016-12-15 17:47:07 +01:00
Michael Matz 253afeed1e inline asm: Accept 'p' constraint and 'P' template mod
'p' is conservatively the same as 'r' and 'P' as template
modifier can be ignored in TCC.
2016-12-15 17:47:07 +01:00
Michael Matz 63e3ff7cca tccasm: Accept .balign 2016-12-15 17:47:07 +01:00
Michael Matz 8e4da42384 Accept more asm expressions
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.
2016-12-15 17:47:07 +01:00
Michael Matz c82e52d55b tccasm: Implement .pushsection and .popsection 2016-12-15 17:47:06 +01:00
Michael Matz 6763b02abc Accept empty struct member decls
struct S { /*nothing*/; int a; };

is an acceptable struct declaration, there may be stray semicolons
in the member list.
2016-12-15 17:47:06 +01:00
Michael Matz d5d881d9e9 x86-asm: Accept 'q' modifier
In inline extended asm '%q1' refers to the 64bit register of operand 1.
2016-12-15 17:47:06 +01:00
Michael Matz 8531de319a Accept concatenated strings in attributes
attribute(section("one" "two")) should be accepted (the section
name being "onetwo"), it's normal string concatenation.
2016-12-15 17:47:06 +01:00
Michael Matz b6799ccd2e Accept -Wp,args
These are preprocessor cmdline arguments, but even in GCC they
aren't specified but rather left as being subject to changes.
Nobody should use them, but let's to a half-assed attempt
at accepting them.
2016-12-15 17:47:06 +01:00
Michael Matz 2b3c7d2287 Change dependency file format a bit
The linux fixdep parse is very stupid and only recognizes
a target token when ':' is part of it.  A space is permitted
in Makefile syntax, but it's easier to change our emitter
than all fixdep parsers out there.
2016-12-15 17:47:06 +01:00
Michael Matz b285fc50f3 Add --param, reject -mARG if ARG not 32 or 64 2016-12-15 17:47:06 +01:00
Michael Matz 9285149548 Implement -include cmdline option
This option includes a file as if '#include "file"' is the first
line of compiled files.  It's processed after all -D/-U options
and is processed per input file.
2016-12-15 17:47:06 +01:00
Michael Matz 21d2b71b5c Free defines before gen_inline_functions
gen_inline_functions uses the macro facilities of the preprocessor,
which would interact when macros would still be defined in a
different pre-processor implementation I'm working on.
So always free defines before generating inline functions, they
are all macro expanded already.
2016-12-15 17:47:06 +01:00
Michael Matz 38e5cf0983 tccpp: Fix macro_is_equal
When tokens in macro definitions need cstr_buf inside get_tok_str,
the second might overwrite the first (happens when tokens are
multi-character non-identifiers, see testcase) in macro_is_equal,
failing to diagnose a difference.  Use a real local buffer.
2016-12-15 17:47:05 +01:00
Michael Matz 8080401ab0 tccpp: free defines also with PP_BENCH
When benchmarking preprocessing of multiple files we need to
free the defines like when not benchmarking.
2016-12-15 17:47:05 +01:00
Michael Matz e2f489aaff x86-asm: Get rid of OPC_JMP and OPC_SHORTJMP
Those two insn types are nicer to handle as operand types, because
the pressure for bits on instr_type is higher than for operands.
2016-12-15 17:47:05 +01:00
Michael Matz 4094f7c5fc x86-64-asm: Tidy 2016-12-15 17:47:05 +01:00
Michael Matz 58963828ab x86-asm: Correct mem64->xmm movq
Now we can express prefixes with 0x0fxx opcodes we can correct the
movq mem64->xmm opcode, and restrict the movq xmm->mem64 movq to
not invalidly accept mmx.
2016-12-15 17:47:05 +01:00
Michael Matz 5a222588a8 x86-asm: Remove OPC_D16
Now that we can store prefixes even for 0x0fXX opcodes we can remove
the OPC_D16 bit.
2016-12-15 17:47:05 +01:00
Michael Matz 8a10a442ff x86-asm: Fix register order
Inserting random registers in the middle of the 8-blocks
breaks register assignment.
2016-12-15 17:47:05 +01:00
Michael Matz bde802df29 x86-asm: Reorganize instr_type
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.
2016-12-15 17:47:05 +01:00
Michael Matz 4af6e087dd x86-asm: move stats code
The old place (tccasm.c) didn't have access to the variables anymore
and was ifdefed out.  Move it to i386-asm.c.
2016-12-15 17:47:05 +01:00
Michael Matz ed35ac841b x86-asm: Add more SSE2 instructions
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.
2016-12-15 17:47:05 +01:00
Michael Matz 6fbcc14a5d system-hacks: define __GNUC__ for FreeBSD
FreeBSDs system headers contain unconditional usage of
macros like __aligned(x), which are only conditionally defined
in sys/cdefs.h (conditional on __GNUC__ or __INTEL_COMPILER).

Bug in FreeBSD, but as work-around we can define __GNUC__ which
picks up these defs.

[This also moves back the glibc defines we had before into the
non-BSD ifdef branch]
2016-10-17 01:08:29 +02:00
Michael Matz 68a7af632c x86-64: Fix long long bug
With the last improvements to lexpand it's now harmful
to use on native 64bit platforms when not necessary.  For gv_dup
it's not necessary there.  It can still be used with really
transforming a 64bit value into two 32bit ones.
2016-10-17 00:57:16 +02:00
Michael Matz 383f568a64 Fix misleading indentation 2016-10-14 17:46:04 +02:00
Michael Matz 682ecc1745 arm64: Fix -run
With -run the call instruction and a defined function can be
far away, if the function is defined in the executable itself,
not in the to be compiled code.  So we always need PLT slots
for -run, not just for undefined symbols.
2016-10-14 17:32:10 +02:00
Michael Matz 7600b03f35 arm64: Support PREL32 relocation
A PC-relative 32bit value is stored.
2016-10-14 16:47:43 +02:00
Michael Matz c232af7ddb Support archives with 64 bit indices
Some systems started using SYM64 .a libraries, so start
supporting them.
2016-10-14 16:47:43 +02:00
Michael Matz f2a4cb0a0e x86-asm: Reject some invalid arith imm8 instruction
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).
2016-05-16 05:10:21 +02:00
Michael Matz 7cfd21440b x86-asm: Add .fill test 2016-05-14 04:41:06 +02:00
Michael Matz 4f27e217a8 x86-asm: Fix signed constants and opcode order
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).
2016-05-14 04:33:41 +02:00
Michael Matz 080ec9fadd x86-asm: Consolidate insn descriptions
Use OPC_BWLX and OPC_WLX in i386-asm.h and x86_64-asm.h to
reduce number of differences between both.
2016-05-14 04:05:34 +02:00
Michael Matz a66ba1f2a1 Error out on operations on structs
The check for structs was too late and on amd64 and aarch64 could
lead to accepting and then asserting with code like:
  struct S {...} s;
  char *c = (char*)0x10 - s;
2016-05-12 01:12:04 +02:00
Michael Matz 6bd8c936e3 x86-64-asm: Add mov[sz]xq opcodes
This adds the zero/sign-extending opcodes with 64bit destinations.
2016-05-12 00:57:02 +02:00
Michael Matz b9f01dffc6 x86-64-asm: Clean up 64bit immediate support
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).
2016-05-11 23:47:02 +02:00
Michael Matz f3cee9ceff x86-asm: Get rid of is_short_jump
Can be implemented differently.
2016-05-11 23:45:14 +02:00
Michael Matz 55bd08c5ae x86-asm: Remove old ASM_16 code
This code was inactive since a long time (and was deactivated because
it was wrong to start with) and just clutters the sources.  Remove
it.
2016-05-11 19:13:38 +02:00
Michael Matz f0fa5603cf x86-64: Run asmtest as well
This fixes and activates the asm test that's part of tcctest.c
also on x86-64, requiring a small fix for the 'm' constraint.
2016-05-11 19:00:02 +02:00
Michael Matz 4d68828259 tests: Compile asmtest.S without -m32
Don't hardcode that option, if you want it do make CC="gcc -m32".
The test assembles with -m64 as well now.
2016-05-11 18:58:14 +02:00
Michael Matz 613962e353 x86-64 asm: Remove useless jmp opcode
Also remove the hacky mod/rm byte emission during
disp/imm writing.
2016-05-11 18:56:19 +02:00
Michael Matz bd93dc6923 x86: Improve cmov handling
cmov can accept multi sizes, but is also a OPC_TEST opcode,
deal with this.
2016-05-11 18:54:24 +02:00
Michael Matz 9645b62a65 x86_64: Use addend on relocs
Traditional behaviour on x86-64 is to encode the relocation
addend in r_addend, not in the relocated field (after all,
that's the reason to use RELA relocs to begin with).  Our
linker can deal with both, other linkers as well.  But using
e.g. the GNU assembler one can detect differences (equivalent
code in the end, but still a difference).

Now there's only a trivial difference in tests/asmtest.S
(having to do with ordering of prefixes).
2016-05-09 23:17:47 +02:00
Michael Matz 5e47b08dc8 [x86] Fix some asm problems
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.
2016-05-09 23:17:47 +02:00
Michael Matz 78ee3759b8 x86-asm: Fix lcall/ljmp, xchg and inc/dec
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.
2016-05-03 01:16:43 +02:00
Michael Matz d1515a0536 i386-asm: correct lcall/ljmp encoding
The 0xff/3 form of lcall needs a mod/rm byte, so reflect this.
2016-05-02 04:50:12 +02:00
Michael Matz d25f67ec12 Run testcases in sorted order
Without sorting they run in whatever order readdir returns,
I like it better when the order is reliable (and alphanumeric).
2016-04-22 15:57:23 +02:00
Michael Matz 80343ab7d8 Fix assignment to/from volatile types
Code like this was broken:

   char volatile vi = i;

See testcase, happens in ideosyncratic legacy code sprinkling
volatile all over.
2016-03-26 17:57:22 +01:00
Michael Matz 8fc5a6a2a4 Fix tokenization of TOK_DOTS
We really need to use PEEKC during tokenization so as to
skip line continuations automatically.
2016-03-24 15:58:32 +01:00
Michael Matz f85db99ff0 Fix type parsing
the check on incomplete struct/union/enum types was too early,
disallowing mixed specifiers and qualifiers.  Simply rely on
the size (->c) field for that.  See testcases.
2016-03-24 15:44:01 +01:00
Michael Matz ceccd3ead3 tccgen.c: Fix flex array members some more
Last fix didn't work for function f1int in the added testcase.
2016-03-11 22:35:44 +01:00
Michael Matz f15c0a9333 x86-64: fix shared libs
The introduction of read32le everywhere created a subtle issue, going
from
   x = *(int*)p;
to
   x = read32le(p);
is not equivalent if x is a larger than 32bit quantity, like an
address on x86_64, because read32le returns an unsigned int.  The first
sign extends, the latter zero extends.  This broke shared library
creation for gawk.  It's enough to amend the case of the above
situation, cases like "write32le(p, read32le(p) +- something)" are okay,
no extensions happen or matter.
2015-12-17 19:41:20 +01:00
Michael Matz e264243adc x86-64: Define symbol constant for new relocs
Whoops, we have our own <elf.h> copy, so I can just as well add
the symbol defines for the relocs instead of hard-coding numbers
in tccelf.c.
2015-12-17 07:30:35 +01:00
Michael Matz c4d0498b3a x86-64: Add support for new psABI relocations
R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX can occur in object files
comiled by new binutils.  They are not dynamic relocations, so normally
wouldn't be a problem for tcc (one doesn't normally mix object files
created by different compiler/binutils, static archives are so out :)).
If it weren't for the glibc startup code, crt*.o, of course.  They now
do contain such relocs --> boom.  Handle them in the trivial way.
2015-12-17 07:17:34 +01:00
Michael Matz 25b2779c3d x86-64: Fix stdarg for large non-float structs
Some structs are passed in registers.  When they need more than
one the implementation of __va_arg on x86-64 didn't correctly account
for this.  This fixes only the cases where the structs consist of
integer types, as there the register save area is consecutive.

Fixes some tests from 73_arm64.c, but still leaves those failing
that use floating point in the large-but-regpassed structs.
2015-03-09 03:54:33 +01:00
Michael Matz 2eb4f4a3ba Remove incorrect comment
Not the code was confused, I was :)
2015-03-09 01:33:42 +01:00
Michael Matz 0ecee0072d Find libtcc1.a on arm32
The directory is called "arm", not "ARM".
2015-03-09 00:47:27 +01:00
Michael Matz 50899e30ab Fix stack overwrite on structure return
The common code to move a returned structure packed into
registers into memory on the caller side didn't take the
register size into account when allocating local storage,
so sometimes that lead to stack overwrites (e.g. in 73_arm64.c),
on x86_64.  This fixes it by generally making gfunc_sret also return
the register size.
2015-03-09 00:19:59 +01:00
Michael Matz 6d055312a2 aarch64: Fix -run.
This adds some more support for properly transfering some
offsets over the different stages of a relocations life.
Still not at all psABI compliant and DSOs can't yet be generated.
But it runs the testsuite in qemu-arm64.
2015-02-23 22:51:10 +00:00
Michael Matz 356c6f6293 Remove unused variable 2014-04-14 05:41:57 +02:00
Michael Matz e69c506617 x86_64: Handle PLT relocs to hidden symbols
For calls to hidden symbols we don't need a PLT slot, rewrite
the reloc into PC32.
2014-04-14 04:58:05 +02:00
Michael Matz a9fda392a0 Parse assembler .hidden directive
This makes TCCs assembler understand the '.hidden symbol' directive
(and emits a STV_HIDDEN ELF symbol then).
2014-04-14 03:33:50 +02:00
Michael Matz fbda78aefe Parse and emit hidden visibility
This adds parsing of (GCC compatible) visibility attribute
in order to mark selected global symbols as hidden.  The generated
.o files contain hidden symbols already, the TCC linker doesn't
yet do the right thing.
2014-04-14 02:53:11 +02:00
Michael Matz f01373765b stdbool.h: Make conformant to ISOC99
For conformance to ISO C the stdbool.h header has to provide
the macro __bool_true_false_are_defined (defined to 1).  Yep,
that name is really in the standard.
2014-04-07 00:30:31 +02:00
Michael Matz 0961a38493 Declare wint_t in <stddef.h> when needed
Some old glibcs <wctype.h> require <stddef.h> to provide
wint_t, accomodate them.
2014-04-07 00:27:46 +02:00
Michael Matz 6a947d9d26 ELF: Remove traces of old RUNTIME_PLTGOT code
The last users of it went away, no use in keeping
this code.
2014-04-06 01:59:35 +02:00
Michael Matz 01c0419234 arm: Use proper PLT/GOT for -run.
Same as with x86_64, disable the runtime_plt_and_got hack
for -run on arm as well.  For that we need to handle several
relocations as (potentially) generating PLT slots as well.
Tested with mpfr-3.1.2 and gawk (both using --disable-shared),
there are two resp. five pre-existing problems, so no regressions.

This also works toward enabling real shared libs for arm,
but it's not there yet.
2014-04-06 01:50:35 +02:00
Michael Matz 9750d0b725 x86_64: Create proper PLT and GOT also for -run
This makes us use the normal PLT/GOT codepaths also for -run,
which formerly used an on-the-side blob for the jump tables.
For x86_64 only for now, arm coming up.
2014-04-06 00:30:22 +02:00
Michael Matz c4427747e6 arm: Provide alloca()
This provides a simple implementation of alloca for ARM (and enables
the associated testcase).  As tcc for ARM doesn't contain an assembler,
we'll have to resort using gcc for compiling it.
2014-04-05 22:54:11 +02:00
Michael Matz b0f8ca5e03 Git should ignore tests2 executables. 2014-04-05 22:52:17 +02:00
Michael Matz 3d18c9aa64 tests2: Build executables as well
The individual tests in tests2 are checked only with -run.  Build
(and check) executables as well, to test also building executables.
2014-04-05 17:35:00 +02:00
Michael Matz 0688afdd34 arm: Handle R_ARM_NONE relocs
These relocations are used to express a dependency on a certain
symbol (e.g. for EABIs exception handling to the
__aeabi_unwind_cpp_pr{0,1,2} routines).  Just ignore them in
reloc processing.
2014-04-04 23:33:04 +02:00
Michael Matz 2024c44541 run: Always create .got relocs
When output is memory we applied the correct GOT offset for certain
relocations (e.g. _GOT32), but we forgot to actually fill the got
entries with the final symbol values, so unconditionally create relocs
against .got as well.
2014-04-04 17:54:52 +02:00
Michael Matz f2c8491fc0 ELF: Make first PT_LOAD cover headers
This makes it so that the first PT_LOAD segment covers
ELF and program header and .interp (contained in the same page anyway,
right before the start of the first loaded section).  binutils
strip creates invalid output otherwise (which strictly is a binutils
bug, but let's be nice anyway).
2014-04-03 18:00:44 +02:00
Michael Matz a913ee6082 x86-64: Use correct ELF values
The x86-64 uses different segment alignment (2MB) and a different
start address.
2014-04-03 17:59:41 +02:00
Michael Matz ea2805f097 shared libs: Build libtcc1.a with -fPIC
TCCs runtime library must be compiled as position independend code,
so it can be linked into shared libraries.
2014-04-02 21:27:22 +02:00
Michael Matz 0bd1282059 x86-64: shared libs improvement
This correctly resolves local references to global functions from
shared libs to their PLT slot (instead of directly to the target
symbol), so that interposition works.

This is still not 100% conforming (executables don't export symbols
that are also defined in linked shared libs, as they must), but
normal shared lib situations work.
2014-03-31 05:36:12 +02:00
Michael Matz 080ad7e62a x86-64: Add basic shared lib support
Initial support for shared libraries on x86-64.
2014-03-31 03:45:35 +02:00
Michael Matz f42a02efda tcctest: One more signed zero test
This also checks that -(-0.0) is +0.0.
2014-01-12 04:53:29 +01:00
Michael Matz 05c9b76131 Fix floating point unary minus and plus
negate(x) is subtract(-0,x), not subtract(+0,x), which makes
a difference with signed zeros.  Also +x was expressed as x+0,
in order for the integer promotions to happen, but also mangles signed
zeros, so just don't do that with floating types.
2014-01-12 04:44:27 +01:00