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`.
The above changes might indeed introduce inconsistencies in the IR, but
the code is small and doesn't change often so it's unnecessary to always
check for errors. It will be tested again later anyway.
The compile time impact was somewhere around 6%, so that's a nice
improvement.
The SPI frequency is broken since b8c326d710
added I2C interface and changed the unrelated `PCLK2 = HCLK/4` initialization
to `PCLK2 = HCLK/1` (but I2C uses PCLK1 anyways).
This commit changes all baud rate prescalers to be /4 compared to before.
Note: it is not possible to find an equivalent for 125 KHz SPI speed,
it will be too fast (`f = 72 MHz / 256`)
Also add unit tests.
This is the first of several transformation (optimization/lowering)
passes that I'd like to move to the new transform package. This
separates the compiler from the optimizer.
Also, it finally adds unit tests for the compiler, not just end-to-end
compilation tests. This should improve robustness and should make it
easier to change these transformation passes in the future.
While the heap-to-stack transform is relatively simple, other passes are
much more complex. Adding unit tests not only helps robustness over
time, but also doubles as documentation as to what these transformation
passes do exactly.
False positives (pointers that point to nowhere but happen to point into
the heap) would result in the block just before that pointer to be
marked. This is clearly not intended, so ignore such a pointer.
This commit allows starting a new goroutine directly from a func value,
not just when the static callee is known.
This is necessary to support the whole time package, not just the
commonly used subset that was compiled with the SimpleDCE pass enabled.
A bug was introduced in the previous commit that led to miscompilations
in the time.Sleep function when the scheduler was disabled, because
time.Sleep (implemented in the runtime) tried to switch to the scheduler
stack.
This commit restores the binary size of most examples to what it was
before, but still reduces static RAM consumption (.bss) slightly. This
gives me some confidence that it does indeed fix the introduced bug.
This scheduler is intended to live along the (stackless) coroutine based
scheduler which is needed for WebAssembly and unsupported platforms. The
stack based scheduler is somewhat simpler in implementation as it does
not require full program transform passes and supports things like
function pointers and interface methods out of the box with no changes.
Code size is reduced in most cases, even in the case where no scheduler
scheduler is used at all. I'm not exactly sure why but these changes
likely allowed some further optimizations somewhere. Even RAM is
slightly reduced, perhaps some global was elminated in the process as
well.
Implements nearly all of the test logging methods for both T and B
structs. Majority of the code has been copied from:
golang.org/src/testing/testing.go
then updated to match the existing testing.go structure.
Code structure/function/method order mimics upstream.
Both FailNow() and SkipNow() cannot be completely implemented,
because they require an early exit from the goroutine. Instead,
they call Error() to report the limitation.
This incomplete implementation allows more detailed test logging and
increases compatiblity with upstream.
Linked lists are usually implemented as follows:
type linkedList struct {
next *linkedList
data int // whatever
}
This caused a stack overflow while writing out the reflect run-time type
information. This has now been fixed by splitting the allocation of a
named type number from setting the underlying type in the sidetable.
Previously it would use a bitcast, which cannot directly be used on AVR
because functions live in a different address space on AVR. To fix this,
use a ptrtoint/inttoptr pair.
This allows testdata/coroutines.go to be compiled, but due to what
appears to be an LLVM bug cannot be optimized and codegen'ed:
tinygo: /home/ayke/src/github.com/tinygo-org/tinygo/llvm-project/llvm/lib/IR/Constants.cpp:1776: static llvm::Constant *llvm::ConstantExpr::getBitCast(llvm::Constant *, llvm::Type *, bool): Assertion `CastInst::castIsValid(Instruction::BitCast, C, DstTy) && "Invalid constantexpr bitcast!"' failed.
This happens as one of the function passes after the TinyGo passes and
after the module has been verified so most likely it is a bug somewhere
in LLVM.
Strings are emitted in .rodata sections, which are not yet mentioned in the linker script.
I can't exactly explain why it didn't work before, as these sections should have been included in .bss and thus properly aligned, but it appears to work reliably.
cn
Jaden Weiss
Ayke van Laethem
Konstantin Itskov
Ron Evans
Phil Kedy
BCG
Elliott Sales de Andrade
Brad Erickson
Daniel Esteban
Kyle Lemons (Loon, LLC)