This way I am hopeful they can be reused for every MIR lowering
function which follows a given encoding. Currently, support MI,
RM and MR encodings without SIB scaling.
* turns out MOV and other arithmetic instructions such as ADD can
naturally share the same lowering codepath (for the same variants)
* there are variants that are specific to ADD, or MOV which will be
implemented as standalone MIR tags
* tweak Isel tests to generate corresponding test cases for all
arithmetic instructions in comptime
* variant `0b11` when both `reg1 != .none` and `reg2 != .none` is
identical to `0b00` therefore it can safely be removed
* fix proper destination register size calculation when setting register from
another source register
* introduce `EmitResult` wrapper struct for easier manipulation of
intermediate emit results - this is mainly to track errors such as
size mismatch between operands
* create an informative `ErrorMsg` directly at the callsite
* ensure that every callsite of basic MOV MIR instruction follows the
Intel syntax (dst <- src)
* add extensive unit tests for MOV MIR -> Isel lowering
* leave TODOs for cases that are currently not handled and/or missing
* fix any ABI size mismatch between operands
When entries are inserted and removed into a hash map at an equivalent rate (maintaining a mostly-consistent total count of entries), it should never need to be resized. But `HashMapUnmanaged.available` does not presently count tombstoned slots as "available", so this put/remove pattern eventually panics (assertion failure) when `available` reaches `0`.
The solution implemented here is to count tombstoned slots as "available". Another approach (which hashbrown (b3eaf32e60/src/raw/mod.rs (L1455-L1542)) takes) would be to rehash all entries in place when there are too many tombstones. This is more complex but avoids an `O(n)` bad case when the hash map is full of many tombstones.
This number tracks the glibc version in the oldest still-active LTS
version of Debian, which is Jessie, extended LTS expiring in June 2022,
at which point this number can be bumped again.
Before this commit, glibc headers did the following mapping:
* (zig) mipsel-linux-gnu => (glibc) mipsel-linux-gnu
* (zig) mipsel-linux-gnu-soft => (glibc) (none)
* (zig) mips-linux-gnu => (glibc) mips-linux-gnu
* (zig) mips-linux-gnu-soft => (glibc) (none)
While the glibc ABI stubs used the (zig) gnueabi and gnueabihf ABIs,
and the stage2 available_libcs array listed:
* (zig) mipsel-linux-gnu
* (zig) mips-linux-gnu
The problem is the mismatch between the ABI component of the headers and
the stubs.
This commit makes the following clarifications:
* (zig) mips-linux-gnueabi means soft-float
* (zig) mipsel-linux-gnueabi means soft-float
* (zig) mips-linux-gnueabihf means hard-float
* (zig) mipsel-linux-gnueabihf means hard-float
Consequently, the glibc headers now do this mapping:
* (zig) mips-linux-gnueabihf => (glibc) mips-linux-gnu
* (zig) mipsel-linux-gnueabihf => (glibc) mipsel-linux-gnu
* (zig) mips-linux-gnueabi => (glibc) mips-linux-gnu-soft
* (zig) mipsel-linux-gnueabi => (glibc) mipsel-linux-gnu-soft
The glibc ABI stubs are unchanged, and the stage2 available_libcs
array's 2 entries are modified and it gains 2 more:
* (zig) mipsel-linux-gnueabi
* (zig) mipsel-linux-gnueabihf
* (zig) mips-linux-gnueabi
* (zig) mips-linux-gnueabihf
Now everything is consistent. Zig no longer recognizes a `mips-linux-gnu`
triple; one must use `mips-linux-gnueabi` (soft float) or
`mips-linux-gnueabihf` (hard float).
Upstream, some of the nonshared functions moved to be different for hurd
and for linux. Since our glibc is linux-only we update to use the
linux-specific files.
This fixes std lib tests for x86_64 when linking glibc.
This commit introduces tools/update_glibc.zig to update the start files
for next time.
Some notable changes in recent glibc:
* abi-note.S has been changed to abi-note.c but we resist the change to
keep it easier to compile the start files.
* elf-init.c has been deleted upstream. Further testing should be done
to verify that binaries against glibc omitting elf-init.c still run
properly on oldel glibc linux systems.
Closes#4926
execve can return EBADLIB on Linux. I observed this when passing
an x86_64 interpreter path to qemu-i386.
This error code is Linux and Solaris-only. I came up with an improved
pattern for dealing with OS-specific error codes.
Since `BoundedArray.insert` internally reserves space for the element
to be inserted, it can support inserting at the position that is
the current length of the array. Change the check for the insertion position
to allow this.
