This hack was originally introduced in
https://github.com/tinygo-org/tinygo/pull/251 to fix an escape analysis
regression after https://github.com/tinygo-org/tinygo/pull/222
introduced nil checks. Since a new optimization in LLVM (see
https://reviews.llvm.org/D60047) this hack is not necessary anymore and
can be removed.
I've compared all regular tests and smoke tests before and after to
check the size. In most cases this change was an improvement although
there are a few regressions.
The unsafe.Pointer type is used for many low-level operations,
especially in the runtime. It can for example be used to copy the
contents of a slice (in the copy builtin) independent of the slice
element type.
The x/tools/go/ssa package splits slice loads/stores into two
operations. So for code like this:
x = p[3]
It has two instructions:
x_ptr = &p[3]
x = *x_ptr
This makes the IR simpler, but also means we're accidentally inserting
more nil checks than necessary: the slice index operation has
effectively already checked for nil by performing a bounds check.
Therefore, omit nil pointer checks for pointers created by
*ssa.IndexAddr.
This change is necessary to make sure a future removal of runtime.isnil
will not cause the escape analysis pass to regress. Apart from that, it
reduces code size slightly in many smoke tests (with no increases in
code size).
This gives a hint to the compiler that such parameters are either NULL
or point to a valid object that can be dereferenced. This is not
directly very useful, but is very useful when combined with
https://reviews.llvm.org/D60047 to remove the runtime.isnil hack without
regressing escape analysis.
This commit merges NewCompiler and Compile into one simplifying the
external interface. More importantly, it does away with the entire
Compiler object so the public API becomes a lot smaller.
The refactor is not complete: eventually, the compiler should just
compile a single package without trying to load it first (that should be
done by the builder package).
Now that most of the utility compiler methods are ported over to the
builder or compilerContext, it is possible to avoid having to do the
wrapper creation in two steps. A new builder is created just to create
the wrapper.
This is a small reduction in line count (and a significant reduction in
complexity!), even though more documentation was added.
This is a fairly big commit, but it actually changes very little.
getValue should really be a property of the builder (or frame), where
the previously created instructions are kept.
This commit unfortunately introduces a significant amount of code
duplication. However, all that duplicate code should be removed once
this refactor is done.
This is the first commit in a series to refactor the compiler. The
intention is to make sure every function to be compiled eventually has
its own IR builder. This will make it much easier to do other
refactorings in the future:
* Most code won't depend (directly) on the central Compiler object,
perhaps making it possible to eliminate it in the future. Right now
it's embedded in the `builder` struct but individual fields from the
`Compiler` can easily be moved into the `builder` object.
* Some functions are not directly exposed in Go SSA, they are wrapper
functions for something. At the moment they are included in the list
of functions to be compiled with the reachability analysis
(SimpleDCE) in the ir package, but eventually this reachability
analys will be removed. At that point, it would be very convenient
to be able to simply build a function with a new IR builder.
The `compilerContext` struct makes sure that it is not possible for
`builder` methods to accidentally use global state such as the global IR
builder. It is a transitional mechanism and may be removed when
finished.
It appears that LLVM can sometimes recognize that multiple calls to
runtime.interfaceMethod can be merged into one. When that happens, the
interface lowering pass shows an error as it didn't expect that
situation.
Luckily the fix is very easy.
Panics are bad for usability: whenever something breaks, the user is
shown a (not very informative) backtrace. Replace it with real error
messages instead, that even try to display the Go source location.
This commit teaches the interp scanner that supported interface
operations (type assertions, interface assertions) are supported.
This fixes a problem with math/rand in Go 1.14.
This should avoid the rather frequent "test ran too long,
terminating..." error message that often occurs in CI and when running
`go test` manually. Apparently I was too optimistic: some tests take
longer than 1 second to run.
This is necessary for better CGo support on bare metal. Existing
libraries expect to be able to include parts of libc and expect to be
able to link to those symbols.
Because with this all targets have a working libc, it is now possible to
add tests to check that a libc in fact works basically.
Not all parts of picolibc are included, such as the math or stdio parts.
These should be added later, when needed.
This commit also avoids the need for the custom memcpy/memset/memcmp
symbols that are sometimes emitted by LLVM. The C library will take care
of that.
This refactor makes adding a new library (such as a libc) much easier in
the future as it avoids a lot of duplicate code. Additionally, CI should
become a little bit faster (~15s) as build-builtins now uses the build
cache.
Somehow I forgot to add this emulator. With this, you can easily emulate
programs:
$ tinygo run -target=atmega1284p examples/serial
Loaded 698 .text at address 0x0
Loaded 12 .data
hello world!..
hello world!..
hello world!..
This allows packages other than the compiler to know (from a single
source of truth) which implemenation is used for Go func values.
This refactor is necessary to be able to move the Optimize function to
the transform package.
Non-constant type asserts are not yet implemented, but should be
relatively easy to add at a later time. They should result in a clear
error message for now.
This convention is followed by most of the avr-gcc toolchain but older
versions of binutils don't mind overlapping program/data spaces.
However, newer versions start complaining about an overlap in address
space:
avr-ld: section .stack VMA [0000000000000100,00000000000002ff] overlaps section .text VMA [0000000000000000,0000000000000225]
This commit moves the data space in the linker script to 0x800000, like
the rest of the toolchain does.
This adds support for the `-scheduler=tasks` flag for AVR. On most AVR
chips you wouldn't want to run a real scheduler but it may be useful in
some cases, especially on devices with more RAM. It is disabled by
default.
