Precise globals require a whole program optimization pass that is hard
to support when building packages separately. This patch removes support
for these globals by converting the last use (Linux) to use
linker-defined symbols instead.
For details, see: https://github.com/tinygo-org/tinygo/issues/2870
This replaces "precise" global scanning in LLVM with conservative
scanning of writable MachO segments. Eventually I'd like to get rid of
the AddGlobalsBitmap pass, and this is one step towards that goal.
Simplify the interrupt-based timer code in a few ways:
- Do not recalibrate the timer every 100ms. Instead, rely on the fact
that the machine package will calbrate the timer if necessary if it
makes changes to Timer0.
- Do not configure Timer0 and then set nanosecondsInTick based on that
value. Instead, use a fixed value.
These two changes together mean that in code that doesn't use PWM,
nanosecondsInTick will be constant which makes the TIMER0_OVF interrupt
handler a lot smaller.
Together this reduces the code size of AVR binaries by about 1200 bytes,
making it pretty close to the pre-timer code size (only about 250 bytes
larger).
It also somehow fixes a problem with
tinygo.org/x/drivers/examples/ws2812 on the Arduino Uno. I'm not quite
sure what was going wrong, but bisecting pointed towards the timer code
(https://github.com/tinygo-org/tinygo/pull/2428) and with this
simplification the bug appears to be gone.
Scan globals conservatively by reading writable sections from the PE
header.
I'd like to get rid of needing to precisely scan globals eventually, and
this brings us one step closer. It also avoids a bug with ThinLTO on
Windows.
This patch adds support for generating GOOS=darwin GOARCH=arm64
binaries. This means that it will become possible to run `go test` on
recent Macs, for example.
1.15 specific files deleted.
1.16 specific files folded carefully into generic files, with goal of reducing diff with upstream.
Follows upstream 1.16 in making PathError etc. be aliases for the same errors in io/fs.
This fixes#2817 and lets us add io/ioutil to "make test-tinygo" on linux and mac.
See the comment in the source for details.
Also see the discussion in
https://github.com/tinygo-org/tinygo/pull/2755, which originally
triggered this bug.
Somewhat surprising, this results in a slight code size decrease for ARM
targets of a few bytes.
Memory references (`*m` in LLVM IR inline assembly) need a pointer type
starting in LLVM 14. This is a bit inconvenient and requires a new API
in the go-llvm package.
Instead of doing that, I'd like to remove support for memory references
from AsmFull (and possibly AsmFull entirely if possible: it's hard to
use correctly).
This breaks tinygo.org/x/drivers/ws2812 for AVR, ARM, and RISC-V which
need to be updated. Probably using CGo.
Evidently when you read from pipes in Go, you have to adjust your slice length to reflect the number of bytes read.
Verified upstream behaves the same way.
