Comment reproduced here:
Note the following u64 alignments:
x86-linux: 4
x86-windows: 8
LLVM makes x86_fp80 have the following alignment and sizes regardless
of operating system:
x86_64: size=16, align=16
x86: size=12, align=4
However in Zig we override x86-windows to have size=16, align=16
in order for the property to hold that u80 and f80 have the same ABI size.
Fixes "error: destination type 'f80' has size 12 but source type 'u80'
has size 16" when trying to bitcast between f80 and u80 on i386-windows.
Get rid of `std.math.F80Repr`. Instead of trying to match the memory
layout of f80, we treat it as a value, same as the other floating point
types. The functions `make_f80` and `break_f80` are introduced to
compose an f80 value out of its parts, and the inverse operation.
stage2 LLVM backend: fix pointer to zero length array tripping LLVM
assertion. It now checks for when the element type is a zero-bit type
and lowers such thing the same way that pointers to other zero-bit types
are lowered.
Both stage1 and stage2 LLVM backends are adjusted so that f80 is lowered
as x86_fp80 on x86_64 and i386 architectures, and identical to a u80 on
others. LLVM constants are lowered in a less hacky way now that #10860
is fixed, by using the expression `(exp << 64) | fraction` using llvm
constants.
Sema is improved to handle c_longdouble by recursively handling it
correctly for whatever the float bit width is. In both stage1 and
stage2.
* F80Repr extern struct needs no explicit padding; let's match the
target padding.
* stage2: fix lowering of f80 constants.
* stage1: decide ABI size and alignment of f80 based on alignment of
u64. x86 has alignof u64 equal to 4 but arm has it as 8.
* stage2: fix Value.floatReadFromMemory to use F80Repr
replaceAllUsesWith requires the type to be unchanged. So we bitcast
the new global to the old type and use that as the thing to replace
old uses.
Fixes an LLVM assertion found while troubleshooting #10837.
Match changes required to `Elf` linker, which enable lowering
of const slices on `MachO` targets.
Expand `Mir` instructions requiring the knowledge of the containing
atom - pass the symbol index into the linker's table from codegen
via mir to emitter, to then utilise it in the linker.
In `getDeclVAddr`, it may happen that the target `Decl` has not
been allocated space in virtual memory. In this case, we store a
relocation in the linker-global table which we will iterate over
when flushing the module, and fill in any missing address in the
final binary. Note that for optimisation, if the address was resolved
at the time of a call to `getDeclVAddr`, we skip relocating this
atom.
This commit also adds the glue code for lowering const slices in
the ARM backend.
This moves the single bugs behavior tests to the outer branch and disables the test cases
for all non-passing backends.
For the larger files, we move it up a single branch and disable it for the c backend.
All test cases that do pass for the c backend however, are enabled.
This implements the `field_ptr` value for pointers. As the value only provides us with the index,
we must calculate the offset from the container type using said index. (i.e. the offset from a struct field at index 2).
Besides this, small miscellaneous fixes/updates were done to get remaining behavior tests passing:
- We start the function table index at 1, so unresolved function pointers don't can be null-checked properly.
- Implement genTypedValue for floats up to f64.
- Fix zero-sized arguments by only creating `args` for non-zero-sized types.
- lowerConstant now works for all decl_ref's.
- lowerConstant properly lowers optional pointers, so `null` pointers are lowered to `0`.
LLVM union globals have to be lowered as unnamed structs if the
non-most-aligned field is the active tag. In this case it bubbles up so
that structs containing unions have the same restriction.
This fix needs to be applied to optionals and other callsites of
createNamedStruct.
The bug fixed in this commit was revealed in searching for
the cause of #10837.
We need to pad out the file to the required maximum size equal the
final section's offset plus the section's size. We only need to
this when populating initial metadata and only when section header
was updated.
In the previous commit I got mixed up and cut-pasted instead of
copy-pasting. In this commit I made c_stage1.zig additionally included
for stage1 and everything else included for both. So moving forward we
move stuff over from c_stage1.zig to c.zig instead of copying.
This reverts commit 846eb701821a3f2af514bbad770478e3276b2d89.
This did not properly translate the upload portion of the CI script to
powershell which broke our CI pipeline.
For some projects, they can't help themselves, -lgcc_s ends up on the
compiler command line even though it does not belong there. In Zig we
know what -lgcc_s does. It's an alternative to compiler-rt. With this
commit we emit a warning telling that it is unnecessary to put such
thing on the command line, and happily ignore it, since we will fulfill
the dependency with compiler-rt.
When Sema sees a store_node instruction, it now checks for
the possibility of this pattern:
%a = ret_ptr
%b = store(%a, %c)
Where %c is an error union. In such case we need to add to the
current function's inferred error set, if any.
Coercion from error union to error union will be handled ideally if the
operand is comptime known. In such case it does the appropriate
unwrapping, then wraps again.
In the future, coercion from error union to error union should do the
same thing for a runtime value; emitting a runtime branch to check if
the value is an error or not.
`Value.arrayLen` for structs returns the number of fields. This is so
that Liveness can use it for the `vector_init` instruction (soon to be
renamed to `aggregate_init`).
