Because -fno-llvm is now the default on x86_64-linux, this target was
exactly equivalent to one specified earlier in the matrix. This was
probably just missed when doing the work to enable the self-hosted
backend by default for x86_64.
The memory operand might use one of the extended GPRs R8 through R15 and
hence require a REX prefix, but having a REX prefix makes the high-byte
register AH unencodeable as the src operand. This latent bug was exposed
by this branch, presumably because `select` now happens to be putting
something in an extended GPR instead of a legacy GPR.
In theory this could be fixed with minimal cost by introducing a way to
communicate to `select` that neither the destination memory nor the
other temporary can be in an extended GPR. However, I just went for the
simple solution which comes at a cost of one trivial instruction: copy
the remainder from AH to AL, and *then* copy AL to the destination.
`rep movsb` isn't usually a great idea here. This commit makes the logic
which tentatively existed in `genInlineMemcpy` apply in more cases, and
in particular applies it to the "new" backend logic. Put simply, all
copies of 128 bytes or fewer will now attempt this path first,
where---provided there is an SSE register and/or a general-purpose
register available---we will lower the operation using a sequence of 32,
16, 8, 4, 2, and 1 byte copy operations.
The feedback I got on this diff was "Push it to master and if it
miscomps I'll revert it" so don't blame me when it explodes
* Add missing functions like ISDIR() or ISREG(). This is required to
build the zig compiler
* Use octal notation for the S_ constants. This is how it is done for
".freebsd" and it is also the notation used by DragonFly in
"sys/stat.h"
* Reorder S_ constants in the same order as ".freebsd" does. Again, this
follows the ordering within "sys/stat.h"
Before https://github.com/ziglang/zig/pull/18160, error tracing defaulted to true in ReleaseSafe, but that is no longer the case. These option descriptions were never updating accordingly.
--debug-rt previously would make rt libs match the root module. Now they
are always debug when --debug-rt is passed. This includes compiler-rt,
fuzzer lib, and others.
Moving towards our function naming convention of having one word per
concept and constructing function names out of concatenated concepts.
In `std.mem` the concepts are:
* "find" - return index of substring
* "pos" - starting index parameter
* "last" - search from the end
* "linear" - simple for loop rather than fancy algo
* "scalar" - substring is a single element
