Shifts that drop an EM word don't need to coerce the word to REG.
Some arithmetic right shifts can use _cdq_.
Drop rules for illegal integer conversions. Sizes below a word are
illegal in EM, except as the source size of _cii_.
Add rules for 8-byte integers to m68020 ncg. Add 8-byte long long to
ACK C on linux68k. Enable long-long tests for linux68k. The tests
pass in our emulator using musahi; I don't have a real 68k processor
and haven't tried other emulators.
Still missing are conversions between 8-byte integers and any size of
floats. The long-long tests don't cover these conversions, and our
emulator can't do floating-point.
Our build always enables TBL68020 and uses word size 4. Without
TBL68020, 8-byte multiply and divide are missing. With word size 2,
some conversions between 2-byte and 8-byte integers are missing.
Fix .cii in libem, which didn't work when converting from 1-byte or
2-byte integers. Now .cii and .cuu work, but also add some rules to
skip .cii and .cuu when converting 8-byte integers. The new rule for
loc 4 loc 8 cii `with test_set4` exposes a bug: the table may believe
that the condition codes test a 4-byte register when they only test a
word or byte, and this incorrect test may describe an unsigned word or
byte as negative. Another rule `with exact test_set1+test_set2` works
around the bug by ignoring the negative flag, because a zero-extended
word or byte is never negative.
The old rules for comparison and logic do work with 8-byte integers
and bitsets, but add some specific 8-byte rules to skip libem calls or
loops. There were no rules for 8-byte arithmetic, shift, or rotate;
so add some. There is a register shortage, because the table requires
preserving d3 to d7, leaving only 3 data registers (d0, d1, d2) for
8-byte operations. Because of the shortage, the code may move data to
an address register, or read a memory location more than once.
The multiplication and division code are translations of the i386
code. They pass the tests, but might not give the best performance on
a real 68k processor.
The assembler wrongly defined _bfexts_ and _bfffo_ with the same bits
as _bfextu_; this turned all bfexts and bfffo instructions into
bfextu. Motorola's 68k Programmer's Reference Manual (1992) gives
different bits for bfexts, but still has wrong bits for bfffo. Change
bfexts and bfffo to match the 68k emulators musahi, aranym, syn68k.
The bitfield width is from 1 to 32, not 0 to 31, so move the warning
from 32 to 0. This doesn't change the warning message, so it will say
that 0 is "too big", when 0 is really too small.
Add EXACT to the rule for adi 8, in the same way that the old rules
for and 8, ior 8, xor 8 have EXACT.
Add rules for sli 8 and sru 8 when shifting 32 bits, and add
assertions in llshift_e.c to test these rules.
Add cases with long long a, b in hexadecimal, where it is more obvious
whether or not a + b or a - b carries to or borrows from bit 32. Add
failure codes to identify each case.
Given `long long o1` and `unsigned int o2`, then `o1 << o2` was
converting o2 to long long and then to int. Remove the first
conversion and just convert o2 to int.
My i386 code from 893df4b gave the wrong sign to some 8-byte
remainders. Fix by splitting .dvi8 and .rmi8 so each has its own code
to pick the sign. They and .dvu8 and .rmu8 share a private sub
.divrem8 for unsigned division.
Improve the i386 code by using instructions like _bsr_ and _shrd_.
Change the helpers to yield a quotient in ebx:eax or a remainder in
ecx:edx; this seems more convenient, because _div_ puts its quotient
in eax and remainder in edx.
Also change UINT32_MAX in <stdint.h> from 4294967295 to 4294967295U.
The U suffix avoids a promotion to long or unsigned long if it would
fit in unsigned int.
Define _EM_LLSIZE but not EM_LLSIZE. The leading underscore is a
convention for such macros. If code always uses _EM_LLSIZE, we will
never need to add EM_LLSIZE. The flag -D_EM_LLSIZE={q} is in
plat/linux386/descr, not lib/descr/fe, so platforms without long long
don't define _EM_LLSIZE.
<stdint.h> doesn't keep the old code for _EM_LSIZE == 8, because I
change it to _EM_LLSIZE == 8. No platform had _EM_LSIZE == 8, and the
old limits like INT64_MAX were wrong.
Add tests for comparisons and shifts. Also add enough integer
conversions to compile the shift test (llshift_e.c), and disable
some wrong rules for ldc and conversions.
Skip the long-long test set on other platforms, because they don't
have long long. Each platform would need to implement 8-byte
operations like `adi 8` in its code generator, and set long long to
8 bytes in its descr file.
The first test is for negation, addition, and subtraction. It also
requires comparison for equality.
For now, a long long literal must have the 'LL' or 'll' suffix. A
literal without 'LL' or 'll' acts as before: it may become unsigned
long but not long long. (For targets where int and long have the same
size, some literals change from unsigned int to unsigned long.)
Type `arith` may be too narrow for long long values. Add a second
type `writh` for wide arithmetic, and change some variables from arith
to writh. This may cause bugs if I forget to use writh, or if a
conversion from writh to arith overflows. I mark some conversions
with (arith) or (writh) casts.
- BigPars, SmallPars: Remove SPECIAL_ARITHMETICS. This feature
would change arith to a different type, but can't work, because it
would conflict with definitions of arith in both <em_arith.h> and
<flt_arith.h>.
- LLlex.c: Understand 'LL' or 'll' suffix. Cut size of constant when
it overflows writh, not only when it overflows the target machine's
types. (This cut might not be necessary, because we might cut it
again later.) When picking signed long or unsigned long, check the
target's long type, not the compiler's arith type; the old check
for `val >= 0` was broken where sizeof(arith) > 4.
- LLlex.h: Change struct token's tok_ival to writh, so it can hold a
long long literal.
- arith.c: Adjust to VL_VALUE being writh. Don't convert between
float and integer at compile-time if the integer might be too wide
for <flt_arith.h>. Add writh2str(), because writh might be too
wide for long2str().
- arith.h: Remove SPECIAL_ARITHMETICS. Declare full_mask[] here,
not in several *.c files. Declare writh2str().
- ch3.c, ch3bin.c, ch3mon.c, declarator.c, statement.g: Remove
obsolete casts. Adjust to VL_VALUE being writh.
- conversion.c, stab.c: Don't declare full_mask[].
- cstoper.c: Use writh for constant operations on VL_VALUE, and for
full_mask[].
- declar., field.c, ival.g: Add casts.
- dumpidf.c: Need to #include "parameters.h" before checking DEBUG.
Use writh2str, because "%ld" might not work.
- eval.c, eval.h: Add casts. Use writh when writing a wide constant
in EM.
- expr.c: Add and remove casts. In fill_int_expr(), make expression
from long long literal. In chk_cst_expr(), allow long long as
constant expression, so the compiler may accept `case 123LL:` in a
switch statement.
- expr.str: Change struct value's vl_value and struct expr's VL_VALUE
to writh, so an expression may have a long long value at compile
time.
- statement.g: Remove obsolete casts.
- switch.c, switch.str: Use writh in case entries for switch
statements, so `switch (ll) {...}` with long long ll works.
- tokenname.c: Add ULNGLNG so LLlex.c can use it for literals.
Add long long type, but without literals; you can't say '123LL' yet.
You can try constant operations, like `(long long)123 + 1`, but the
compiler's `arith` type might not be wide enough. Conversions,
shifts, and some other operations don't work in i386 ncg; I am using a
union instead of conversions:
union q {
long long ll;
unsigned long long ull;
int i[2];
};
Hack plat/linux386/descr to enable long long (size 8, alignment 4)
only for this platform. The default for other platforms is to disable
long long (size -1).
In lang/cem/cemcom.ansi,
- BigPars, SmallPars: Add default size, alignment of long long.
- align.h: Add lnglng_align.
- arith.c: Convert arithmetic operands to long long or unsigned long
long when necessary; avoid conversion from long long to long.
Allow long long as an arithmetic, integral, or logical operand.
- ch3.c: Handle long long like int and long when erroneously applying
a selector, like `long long ll; ll.member` or `ll->member`. Add
long long to integral and arithmetic types.
- code.c: Add long long to type stabs for debugging.
- conversion.c: Add long long to integral conversions.
- cstoper.c: Write masks up to full_mask[8]. Add FIXME comment.
- declar.g: Parse `long long` in code.
- decspecs.c: Understand long long in type declarations.
- eval.c: Add long long to operations, to generate code like `adi 8`.
Don't use `ldc` with constant over 4 bytes.
- ival.g: Allow long long in initializations.
- main.c: Set lnglng_type and related values.
- options.c: Add option like `-Vq8.4` to set long long to size 8,
alignment 4. I chose 'q', because Perl's pack and Ruby's
Array#pack use 'q' for 64-bit or long long values; it might be a
reference to BSD's old quad_t alias for long long.
- sizes.h: Add lnglng_size.
- stab.c: Allow long long when writing the type stab for debugging.
Switch from calculating the ranges to hardcoding them in strings;
add 8-byte ranges as a special case. This also hardcodes the
unsigned 4-byte range as "0;-1". Before it was either "0;-1" or
"0;4294967295", depending on sizeof(long) in the compiler.
- struct.c: Try long long bitfield, but it will probably give the
error, "bit field type long long does not fit in a word".
- switch.c: Update comment.
- tokenname.c: Define LNGLNG (long long) like LNGDBL (long double).
- type.c, type.str: Add lnglng_type and ulnglng_type. Add function
no_long_long() to check if long long is disabled.
This provides adi, sbi, mli, dvi, rmi, ngi, dvu, rmu 8, but is missing
shifts and rotates. It is also missing conversions between 8-byte
integers and other sizes of integers or floats. The code might not be
all correct, but works at least some of the time.
I adapted this from how ncg i86 does 4-byte integers, but I use a
different algorithm when dividing by a large value: i86 avoids the div
instruction and uses a shift-and-subtract loop; but I use the div
instruction to estimate a quotient, which is more like how big integer
libraries do division. My .dvi8 and .dvu8 also set ecx:ebx to the
remainder; this might be a bad idea, because it requires .dvi8 and
.dvu8 to always calculate the remainder, even when the caller only
wants the quotient.
To play with 8-byte integers, I wrote EM procedures like
mes 2, 4, 4
exp $ngi
pro $ngi,0
ldl 4
ngi 8
lol 0
sti 8
lol 0
ret 4
end
exp $adi
pro $adi,0
ldl 4
ldl 12
adi 8
lol 0
sti 8
lol 0
ret 4
end
and called them from C like
typedef struct { int l; int h; } q;
q ngi(q);
q adi(q, q);
This turns EM `con 5000000000I8` into assembly `.data8 5000000000` for
machines i386, i80, i86, m68020, powerpc, vc4. These are the only ncg
machines in our build.
i80 and i86 get con_mult(sz) for sz == 4 and sz == 8. The other
machines only get sz == 8, because they have 4-byte words, and ncg
only calls con_mult(sz) when sz is greater than the word size. The
tab "\t" after .data4 or .data8 is like the tabs in the con_*() macros
of mach/*/ncg/mach.h.
i86 now uses .data4, like i80. Also, i86 and i386 now use the numeric
string without converting it to an integer and back to a string.
This takes literal integers, not expressions, because each machine
defines its own valu_t for expressions, but valu_t can be too narrow
for an 8-byte integer, and I don't want to change all the machines to
use a wider valu_t. Instead, change how the assembler parses literal
integers. Remove the NUMBER token and add a NUMBER8 token for an
int64_t. The new .data8 pseudo emits all 8 bytes of the int64_t;
expressions narrow the int64_t to a valu_t. Don't add any checks for
integer overflow; expressions and .data* pseudos continue to ignore
overflow when a number is too wide.
This commit requires int64_t and uint64_t in the C compiler to build
the assembler. The ACK's own C compiler doesn't have these.
For the assembler's temporary file, add NUMBER4 to store 4-byte
integers. NUMBER4 acts like NUMBER[0-3] and only stores a
non-negative integer. Each negative integer now takes 8 bytes (up
from 4) in the temporary file.
Move the `\fI` and `\fP` in the uni_ass(6) manual, so the square
brackets in `thing [, thing]*` are not italic. This looks nicer in my
terminal, where italic text is underlined.
