I only wanted to fix a bug originally, but this logic was kind of a
rat's nest. But now... okay, it still *is*, but it's now a slightly more
navigable nest, with cute little signs occasionally, painted by adorable
rats desparately trying to follow the specification.
Hopefully #3806 comes along at some point to simplify this logic a
little.
Resolves: #23139
The old isARM() function was a portability trap. With the name it had, it seemed
like the obviously correct function to use, but it didn't include Thumb. In the
vast majority of cases where someone wants to ask "is the target Arm?", Thumb
*should* be included.
There are exactly 3 cases in the codebase where we do actually need to exclude
Thumb, although one of those is in Aro and mirrors a check in Clang that is
itself likely a bug. These rare cases can just add an extra isThumb() check.
The min and max builtins in Zig have some intricate behavior
related to floats, that is not replicated with the min and max
wasm instructions or using simple select operations. By lowering
these instructions to compiler_rt, handling around NaNs is done
correctly.
See also https://github.com/WebAssembly/design/issues/214
* Generalise NaN handling and make std.math.nan() give quiet NaNs
* Address uses of std.math.qnan_* and std.math.nan_* consts
* Comment out failing test due to issues with signalling NaN
* Fix issue in c_builtins.zig where we need qnan_u32
I achieved this through a major refactor of the logic of analyzeMinMax.
This change should be compatible with vectors of comptime_int, which
Andrew said are supposed to work (but which currently do not).
This shuffles some tests do ensure the new instructions are tested for the wasm backend,
by moving vectors into their own tests as well as move the f16 test cases as those require
special operating also.
* Identify the ones that are passing and stop skipping them.
* Flatten out the main behavior.zig file and have each individual test
disable itself if it is not passing.
