Commit Graph

41 Commits

Author SHA1 Message Date
Stephen Heumann
bb1bd176f4 Add a command-line option to select the C standard to use.
This provides a more straightforward way to place the compiler in a "strict conformance" mode. This could essentially be achieved by setting several pragma options, but having a single setting is simpler. "Compatibility modes" for older standards can also be selected, although these actually continue to enable most C17 features (since they are unlikely to cause compatibility problems for older code).
2022-12-07 21:35:15 -06:00
Stephen Heumann
d56cf7e666 Pass constant data to backend as pointers into buffer.
This avoids needing to generate many intermediate code records representing the data at most 8 bytes at a time, which should reduce memory use and probably improve performance for large initialized arrays or structs.
2022-12-03 00:14:15 -06:00
Stephen Heumann
99a10590b1 Avoid out-of-range branches around asm code using dcl directives.
The branch range calculation treated dcl directives as taking 2 bytes rather than 4, which could result in out-of-range branches. These could result in linker errors (for forward branches) or silently generating wrong code (for backward branches).

This patch now treats dcb, dcw, and dcl as separate directives in the native-code layer, so the appropriate length can be calculated for each.

Here is an example of code affected by this:

int main(int argc, char **argv) {
top:
        if (!argc) { /* this caused a linker error */
                asm {
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                        dcl 0
                }
                goto top; /* this generated bad code with no error */
        }
}
2022-10-13 18:00:16 -05:00
Stephen Heumann
19683706cc Do not optimize code from asm statements.
Previously, the assembly-level optimizations applied to code in asm statements. In many cases, this was fine (and could even do useful optimizations), but occasionally the optimizations could be invalid. This was especially the case if the assembly involved tricky things like self-modifying code.

To avoid these problems, this patch makes the assembly optimizers ignore code from asm statements, so it is always emitted as-is, without any changes.

This fixes #34.
2022-10-12 22:03:37 -05:00
Stephen Heumann
ca21e33ba7 Generate more efficient code for indirect function calls. 2022-10-11 21:14:40 -05:00
Stephen Heumann
05ecf5eef3 Add option to use the declared type for float/double/comp params.
This differs from the usual ORCA/C behavior of treating all floating-point parameters as extended. With the option enabled, they will still be passed in the extended format, but will be converted to their declared type at the start of the function. This is needed for strict standards conformance, because you should be able to take the address of a parameter and get a usable pointer to its declared type. The difference in types can also affect the behavior of _Generic expressions.

The implementation of this is based on ORCA/Pascal, which already did the same thing (unconditionally) with real/double/comp parameters.
2022-09-18 21:16:46 -05:00
Stephen Heumann
60efb4d882 Generate better code for indexed jumps.
They now use a jmp (addr,X) instruction, rather than a more complicated code sequence using rts. This is an improvement that was suggested in an old Genie message from Todd Whitesel.
2022-07-18 21:18:26 -05:00
Stephen Heumann
9b31e7f72a Improve code generation for comparisons.
This converts comparisons like x > N (with constant N) to instead be evaluated as x >= N+1, since >= comparisons generate better code. This is possible as long as N is not the maximum value in the type, but in that case the comparison is always false. There are also a few other tweaks to the generated code in some cases.
2022-07-10 22:27:38 -05:00
Stephen Heumann
76e4b1f038 Optimize away some tax/tay instructions used only to set flags. 2022-07-10 17:35:56 -05:00
Stephen Heumann
00e7fe7125 Increase some size limits.
The new value of maxLocalLabel is aligned with the C99+ requirement to support "511 identifiers with block scope declared in one block".

The value of maxLabel is now the maximum it can be while keeping the size of the labelTab array under 32 KiB. (I'm not entirely sure the address calculations in the code generated by ORCA/Pascal would work correctly beyond that.)
2022-07-08 21:30:14 -05:00
Stephen Heumann
393b7304a0 Optimize 16-bit multiplication by various constants.
This optimizes most multiplications by a power of 2 or the sum of two powers of 2, converting them to equivalent operations using shifts which should be faster than the general-purpose multiplication routine.
2022-07-06 22:24:54 -05:00
Stephen Heumann
161bb952e3 Dynamically allocate string space, and make it larger.
This increases the limit on total bytes of strings in a function, and also frees up space in the blank segment.
2022-06-08 22:09:30 -05:00
Stephen Heumann
02fbf97a1e Work around the SANE comp conversion bug in another place.
This affects casts to comp evaluated at compile time, e.g.:

static comp c = (comp)-53019223785472.0;
2022-01-22 18:22:37 -06:00
Stephen Heumann
b43036409e Add a new optimize flag for FP math optimizations that break IEEE rules.
There were several existing optimizations that could change behavior in ways that violated the IEEE standard with regard to infinities, NaNs, or signed zeros. They are now gated behind a new #pragma optimize flag. This change allows intermediate code peephole optimization and common subexpression elimination to be used while maintaining IEEE conformance, but also keeps the rule-breaking optimizations available if desired.

See section F.9.2 of recent C standards for a discussion of how these optimizations violate IEEE rules.
2021-11-29 20:31:15 -06:00
Stephen Heumann
fc515108f4 Make floating-point casts reduce the range and precision of numbers.
The C standards generally allow floating-point operations to be done with extra range and precision, but they require that explicit casts convert to the actual type specified. ORCA/C was not previously doing that.

This patch relies on some new library routines (currently in ORCALib) to do this precision reduction.

This fixes #64.
2021-03-06 22:28:39 -06:00
Stephen Heumann
c0727315e0 Recognize byte swapping and generate an xba instruction for it.
Specifically, this recognizes the pattern "(exp << 8) | (exp >> 8)", where exp has an unsigned 16-bit type and does not have side effects.
2021-03-05 22:00:13 -06:00
Stephen Heumann
4ad7a65de6 Process floating-point values within the compiler using the extended type.
This means that floating-point constants can now have the range and precision of the extended type (aka long double), and floating-point constant expressions evaluated within the compiler also have that same range and precision (matching expressions evaluated at run time). This new behavior is intended to match the behavior specified in the C99 and later standards for FLT_EVAL_METHOD 2.

This fixes the previous problem where long double constants and constant expressions of type long double were not represented and evaluated with the full range and precision that they should be. It also gives extra range and precision to constants and constant expressions of type double or float. This may have pluses and minuses, but at any rate it is consistent with the existing behavior for expressions evaluated at run time, and with one of the possible models of floating point evaluation specified in the C standards.
2021-03-04 23:58:08 -06:00
Stephen Heumann
f19d21365a Recognize more indirect long instructions in the native code optimizer.
These instructions can be generated for indirect accesses to quad values, and the optimization can sometimes make those code sequences more efficient (e.g. avoiding unnecessary reloads of Y).
2021-03-02 19:19:00 -06:00
Stephen Heumann
043124db93 Implement support for doing quad ops without loading operands on stack.
This works when both operands are simple loads, such that they can be broken up into operations on their subwords in a standard format.

Currently, this is implemented for bitwise binary ops, but it can also be expanded to arithmetic, etc.
2021-02-24 19:44:46 -06:00
Stephen Heumann
8faafcc7c8 Implement 64-bit shifts. 2021-02-12 15:06:15 -06:00
Stephen Heumann
cb97623878 Do not copy CGI.Comments into CGI.pas.
This has no functional effect, since it is all comments. It does mean that printed listings of CGI.pas would not contain those comments, but it is easy enough to restore if someone wants such listings.

This change should make compilation slightly faster, and it also avoids issues with filetypes when using certain tools (since they cannot infer the filetype of CGI.Comments from its extension).
2021-02-11 18:53:25 -06:00
Stephen Heumann
05868667b2 Implement 64-bit division and remainder, signed and unsigned.
These operations rely on new library routines in ORCALib (~CDIV8 and ~UDIV8).
2021-02-05 12:42:48 -06:00
Stephen Heumann
08cf7a0181 Implement 64-bit multiplication support.
Signed multiplication uses the existing ~MUL8 routine in SysLib. Unsigned multiplication will use a new ~UMUL8 library routine.
2021-02-04 22:23:59 -06:00
Stephen Heumann
168a06b7bf Add support for emitting 64-bit constants in statically-initialized data. 2021-02-04 02:17:10 -06:00
Stephen Heumann
793f0a57cc Initial support for constants with long long types.
Currently, the actual values they can have are still constrained to the 32-bit range. Also, there are some bits of functionality (e.g. for initializers) that are not implemented yet.
2021-02-03 23:11:23 -06:00
Stephen Heumann
807a143e51 Implement 64-bit addition and subtraction. 2021-01-30 23:31:18 -06:00
Stephen Heumann
2e44c36c59 Implement unary negation and bitwise complement for 64-bit types. 2021-01-30 13:49:06 -06:00
Stephen Heumann
abb0fa0fc1 Implement bitwise and/or/xor for 64-bit types.
This introduces three new intermediate codes for these operations.
2021-01-30 00:25:15 -06:00
Stephen Heumann
085cd7eb1b Initial code to recognize 'long long' as a type. 2021-01-29 22:27:11 -06:00
Stephen Heumann
ffe6c4e924 Spellcheck comments throughout the code.
There are no non-comment changes.
2020-01-29 17:09:52 -06:00
Stephen Heumann
4a7644e0b5 Don't allocate stack space for varargs stack repair unless it's needed.
If there are no varargs calls (and nothing else that saves stack positions), then space doesn't need to be allocated for the saved stack position. This can also lead to more efficient prolog/epilog code for small functions.
2018-01-13 20:02:43 -06:00
Stephen Heumann
e7cc513ad4 Add support for inline procedure names as documented in IIgs tech note #103.
These are enabled when bit 15 is set in the #pragma debug directive.

Support is still needed to ensure these work properly with pre-compiled headers.

This patch is from Kelvin Sherlock.
2017-10-21 20:36:21 -05:00
Stephen Heumann
c46cf79c79 Increase the maximum allowed number of local variables from 200 to 220. 2017-10-21 20:36:21 -05:00
Stephen Heumann
ccd653ddb9 Move some more code out of the blank segment to make space for static data. 2017-10-21 20:36:21 -05:00
Stephen Heumann
02de5f4137 Increase the total size of string constants permitted in each function.
The size limit is increased from 8000 bytes to 12500 bytes. This was needed to compile some functions with many string constants.
2017-10-21 20:36:21 -05:00
Stephen Heumann
a4bffe65e5 Increase the limit on the number of intermediate code labels in a function from 2400 to 3200.
This is necessary to compile some very large functions, such as the main interpreter loop in Git.

This consumes about 8K of extra memory for the additional label records.
2017-10-21 20:36:21 -05:00
Stephen Heumann
709f9b3f25 Fix bug where comparing 32-bit values in static arrays or structs against 0 may give wrong results with large memory model.
The issue was that 16-bit absolute addressing (in the data bank) was being used to access the data to compare, but with the large memory model the static arrays or structs are not necessarily in the same bank, so absolute long addressing should be used.

This was sometimes causing failures in the C4.6.4.1.CC and C4.6.6.1.CC conformance tests in the ORCA/C test suite.

The following program often demonstrates the problem (depending on memory layout and contents):

#pragma memorymodel 1
#pragma optimize 1

#include <stdio.h>

int i;
char ch1[32000];
long L1[1];

int main (void)
{
    if (L1 [0] != 0)
        printf("%li\n", L1[0]); /* shouldn't print */

    /* buggy behavior can happen if the bank bytes of these pointers differ */
    printf("%p %p\n", &L1[0], &i);
}
2017-10-21 20:36:21 -05:00
Stephen Heumann
0df71da4f1 Change Byte -> UByte conversion to use a "Word -> UByte" conversion, rather than introducing a new "Byte -> UByte" conversion.
The latter would require more changes to the code generator to understand it, whereas this approach doesn't require any changes. This is arguably less clean, but it matches other places where a byte value is subsequently operated on as a word without an explicit conversion, and the assembly instruction generated is the same.
2017-10-21 20:36:20 -05:00
Stephen Heumann
c28e48a54f Do an explicit conversion when converting from signed to unsigned byte values. This is needed because the value is held in a 16-bit register, sign-extended. The high 8 bits need to be cleared to convert to an unsigned byte.
This fixes the compca06.c test case.

Note that this generates inefficient code in the case of loading a signed byte value and then immediately casting it to unsigned (it first sign-extends the value, then masks off the high bits). This should be optimized, but at least the generated code is correct now.
2017-10-21 20:36:20 -05:00
Stephen Heumann
46b6aa389f Change all text/source files to LF line endings. 2017-10-21 18:40:19 -05:00
mikew50
e72177985e ORCA/C 2.1.0 source from the Opus ][ CD 2017-10-01 17:47:47 -06:00