Previously, the cycle was broken by inserting an unsafe.Pointer type in
some places. This is of course incorrect, and makes debugging harder.
However, LLVM provides a way to make temporary nodes that are later
replaced, exactly for this purpose.
This commit uses those temporary metadata nodes to allow such recursive
types.
Comparing slices against nil currently causes the slice to escape, due
to a limitation in LLVM 8. This leads to lots of unnecessary heap
allocations. With LLVM 9 and some modifications to TinyGo, this should
be fixed. However, this commit is an easy win right now.
Returning an error when both slices are nil is not necessary, when the
check is left out it should just do nothing.
For updating an SPI screen using the st7735 driver, this results in a
~7% performance win.
Instead of configuring machine.I2C0, machine.I2C1, etc. statically,
allow the pins to be set using machine.I2CConfig. This will also
automatically configure the correct pin mode for each pin instead of
having to specify that manually.
An optimization introduced in a04db67ea9
seems to have broken arduino uno compiled hex. Setting optimzation
flags to 1, 2, or s builds proper hex binaries though.
These patches have been the result of troubleshooting over slack:
> @aykevl
> that preinit also doesn't look right. Can you try this variant,
> with 8-bit stores instead of 32-bit stores?
> There might be some alignment issue: the _ebss might not be
> aligned resulting in ptr != unsafe.Pointer(&_ebss) never being true.
Co-authored-by: Ayke van Laethem <aykevanlaethem@gmail.com>
Co-authored-by: Jaden Weiss <jadr2ddude@gmail.com>
This implements the copy() built-in function. It may not work in all
cases, but should work in most cases.
This commit gets the following 3 packages to compile, according to
tinygo-site/imports/main.go:
* encoding/base32
* encoding/base64
* encoding/pem (was blocked by encoding/base64)
Unfortunately, while doing this I found that it doesn't actually apply
in any real-world programs (tested with `make smoketest`), apparently
because nil pointer checking messes with the functionattrs pass. I hope
to fix that after moving to LLVM 9, which has an optimization that makes
nil pointer checking easier to implement.
The SPI peripheral in the nrf chips support double buffering, which
makes it possible to keep sending continuously. This change introduces
double buffering on the nrf chips, which should improve SPI performance.
Tested on the pca10040 (nrf52832).
Compared to the already supported stm32f103xx "bluepill" board this:
- features 128 KiB flash memory size ("RB" suffix) instead of 64 KiB, see `targets/stm32f103rb.ld`
- has onboard ST-LINK/V2-1 programmer and debugger requiring different OpenOCD configuration file
- uses USART2 connected to ST-LINK/V2-1 debugger as virtual COM port over USB for `putchar()`
- has a user-accessible button besides the reset button
Motivation: The bluepill uses USART1 as UART0 but other boards like the
STM32 Nucleo boards (and disco as well) use USART2 for USB COM port.
To avoid duplication of code the same pattern as in `machine_atsamd21.go`
is applied where only UART-specific code is moved to `board_*.go`.
