The .note.GNU-stack section tells the linker that this object does not
require an executable stack.
The .note.GNU-split-stack section tells the linker that functions in
this object can be called directly by split-stack functions, without
require a large stack.
The .note.GNU-no-split-stack section tells the linker that functions
in this object do not have a split-stack prologue.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/198440
From-SVN: r276488
This CL serves as part of an initial change for enabling gollvm
building on arm64 linux, the rest of the change will be covered by
another one to the gollvm repo.
Incorporate type definition of 'uint128' to 'runtime' and 'syscall'
packges, the change is not specific to arm64 linux but made available
for all platforms.
Verified by building and unit-testing gollvm on linux x86-64 and arm64.
Verified by building and checking gccgo on linux x86-64 and arm64.
Fixesgolang/go#33711
Change-Id: I4720c7d810cfd4ef720962fb4104c5641b2459c0
From-SVN: r275919
This only matters on systems that pass a struct with a single pointer
field differently than passing a single pointer. I noticed it on
32-bit PPC, where the reflect package TestDirectIfaceMethod failed.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195878
From-SVN: r275814
PR go/91781
reflect: promote integer closure return to full word
The libffi library expects an integer return type to be promoted to a
full word. Implement that when returning from a closure written in Go.
This only matters on big-endian systems when returning an integer smaller
than the pointer size, which is why we didn't notice it until now.
Fixes https://gcc.gnu.org/PR91781.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195858
From-SVN: r275813
The function was always intended to be internal-only, but was exported
so that C code could call it. Now that have go:linkname for that, use it.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195857
From-SVN: r275809
When compiling the x_test package, force the test package to be
imported first. That ensures that we will see the types defined in
the test package before the types defined in the non-test version of
the package. This matters if the types differ in some way, such as by
adding a new method.
This avoids a failure in internal/poll on Solaris, in which the test
package adds a method to a type (FD.EOFError). I think it was Solaris-
specific because files are sorted in a different order by default.
The go tool handles this kind of thing correctly, by rebuilding
dependent packages. This is just a hack sufficient to run the libgo
testsuite without using the go tool.
Fixes https://gcc.gnu.org/PR91712
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194637
From-SVN: r275648
Restore Solaris compatibility fixes lost when internal/x/net/lif moved
to golang.org/x/net/lif. Also fix the Makefile for x/net/lif and
x/net/route.
Change x/sys/cpu to get the cache line size from goarch.sh as the
gofrontend version of internal/cpu does.
Partially based on work by Rainer Orth.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194438
From-SVN: r275611
Backport of https://golang.org/cl/194440. Original description:
If an embedded field refers to a type via a pointer, the parser needs
to know the name of the embedded field. It is possible that the
pointer type is not yet resolved. This CL fixes the parser to handle
that case by setting the pointer element type to the unresolved named
type while the pointer is being resolved.
Updates golang/go#34182
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194562
From-SVN: r275606
They were lost when the files were moved in the update to Go1.13beta1.
These changes should be made in the master repo for the 1.14 release,
as riscv64 support is added there.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194343
From-SVN: r275551
The C file has a build tag, but the procedure we use for building C
files ignores build tags.
This should fix the libgo build on non-x86 systems.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194378
From-SVN: r275544
The gc compiler has started permitting go:linkname comments with a
single argument to mean that a function should be externally visible
outside the package. Implement this in the Go frontend.
Change the libgo runtime package to use it, rather than repeating the
name just to export a function.
Remove a couple of unnecessary go:linkname comments on declarations.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/192197
From-SVN: r275239
Avoids problems with arm64 ILP32 mode. We might want to handle that
mode better in general, but always building panic32.go is simple and
fixes the build.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/192723
From-SVN: r275237
Permit putting structs with anonymous and empty fields in the C header
file runtime.inc that is used to build the C runtime code. This is
required for upcoming 1.13 support, as the m struct has picked up an
anonymous field.
Doing this lets the C header contain all the type descriptor structs,
so start using those in the C code. This cuts the number of copies of
type descriptor definitions from 3 to 2.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/192343
From-SVN: r275227
This is a step toward updating libgo to 1.13. This adds the 1.13
version of the osinit function to Go code, and removes the
corresponding code from the C runtime. This should simplify future updates.
Some additional 1.13 code was brought in to simplify this change.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/191717
From-SVN: r275010
Record when a local pointer variable is set to a value such that
indirecting through the pointer does not require a write barrier. Use
that to eliminate write barriers when indirecting through that local
pointer variable. Only keep this information per-block, so it's not
all that applicable.
This reduces the number of write barriers generated when compiling the
runtime package from 553 to 524.
The point of this is to eliminate a bad write barrier in the bytes
function in runtime/print.go. Mark that function nowritebarrier so
that the problem does not recur.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/191581
From-SVN: r274890
With CL 190599, along with what we do in greyobject, we ensure
that we only mark allocated heap objects. As a result we can be
more strict in GC:
- Enable "sweep increased allocation count" check, which checks
that the number of mark bits set are no more than the number of
allocation bits.
- Enable invalid pointer check on heap scan. We only trace
allocated heap objects, which should not contain invalid
pointer.
This also makes the libgo runtime more convergent with the gc
runtime.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/190797
From-SVN: r274678
When a defer is executed at most once in a function body,
we can allocate the defer record for it on the stack instead
of on the heap.
This should make defers like this (which are very common) faster.
This is a port of CL 171758 from the gc repo.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/190410
From-SVN: r274613
In gccgo, we insert the write barriers in the frontend, and so we
cannot completely prevent write barriers on stack writes. So it
is possible for a bad pointer appearing in the write barrier
buffer. When flushing the write barrier, treat it the same as
sacnning the stack. In particular, don't mark a pointer if it
does not point to an allocated object. We already have similar
logic in greyobject. With this, hopefully, we can prevent an
unallocated object from being marked completely.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/190599
From-SVN: r274598
Currently, getg is implemented in C, which loads the thread-local
g variable. The g variable is declared static in C.
This CL exposes the g variable, so it can be accessed from the Go
side. This allows the Go compiler to inline getg calls to direct
access of g.
Currently, the actual inlining is only implemented in the gollvm
compiler. The g variable is thread-local and the compiler backend
may choose to cache the TLS address in a register or on stack. If
a thread switch happens the cache may become invalid. I don't
know how to disable the TLS address cache in gccgo, therefore
the inlining of getg is not implemented. In the future gccgo may
gain this if we know how to do it safely.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/186238
From-SVN: r273499
For a select statement with zero-, one-, or two-case with a
default case, we can generate simpler code instead of calling the
generic selectgo. A zero-case select is just blocking the
execution. A one-case select is mostly just executing the case. A
two-case select with a default case is a non-blocking send or
receive. We add these special cases for lowering a select
statement.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/184998
From-SVN: r273034
On AIX, a function has two symbols, a text symbol (with a leading dot)
and a data one (without it).
As the tests must be run only once, only the data symbol can be used to
retrieve the final go symbol. Therefore, all symbols beginning with a dot
are ignored by symtogo.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/177837
From-SVN: r272666
The first call of ar must not show its output in order to avoid useless
error messages about D flag.
The corresponding Go toolchain patch is CL 182077.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/183817
From-SVN: r272661
Instead of going through a C function __go_memcmp, we can just
use __builtin_memcmp directly. This allows more optimizations in
the compiler backend.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/183537
From-SVN: r272620
Currently a string slice expression is implemented with a runtime
call __go_string_slice. Change it to open code it, which is more
efficient, and allows the backend to further optimize it.
Also omit the write barrier for length-only update (i.e.
s = s[:n]).
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/182540
From-SVN: r272549
runtime.concatstring{2,3,4,5} are just wrappers of concatstrings.
These wrappers don't provide any benefit, at least in the C
calling convention we use, where passing arrays by value isn't an
efficient thing. Change it to always use concatstrings.
Also, the cap field of the slice passed to concatstrings is not
necessary. So change it to pass a pointer and a length directly,
which is more efficient than passing a slice header by value.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/182539
From-SVN: r272476
Due to inlining, we can now see unexported functions and variables,
and functions and variables imported from different packages.
Ignore them rather than reporting them from this package.
Handle $hash and $equal functions consistently, so that we discard the
inline body if there is one.
Ignore names created for result parameters for inlining purposes.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180758
From-SVN: r272023
In the runtime there are specialized fast map routines for
certain kep types. This CL lets the compiler make use of these
functions, instead of always using the generic ones.
As we now generate multiple versions of map delete calls, to make
things easier we delay the expansion of the built-in delete
function to flatten phase.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180858
From-SVN: r271983
Scan inlinable methods for references to global variables and
functions (forgot to do that earlier).
Track all packages mentioned by exports (that should have been done
earlier too).
Record assembler name in export data, so that we can inline calls to
non-Go functions. Modify gccgoimporter code to skip assembler name.
This increases the number of inlinable functions in the standard
library from 215 to 439.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180677
From-SVN: r271976
Currently, the compiler already generates common symbols for type
descriptors, so the type descriptors are unique. However, when a
type is created through reflection, it is not deduplicated with
compiler-generated types. As a consequence, we cannot assume type
descriptors are unique, and cannot use pointer equality to
compare them. Also, when constructing a reflect.Type, it has to
go through a canonicalization map, which introduces overhead to
reflect.TypeOf, and lock contentions in concurrent programs.
In order for the reflect package to deduplicate types with
compiler-created types, we register all the compiler-created type
descriptors at startup time. The reflect package, when it needs
to create a type, looks up the registry of compiler-created types
before creates a new one. There is no lock contention since the
registry is read-only after initialization.
This lets us get rid of the canonicalization map, and also makes
it possible to compare type descriptors with pointer equality.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/179598
From-SVN: r271894
When the runtime collects a stack trace to associate it with some
profiling event (mem alloc, mutex, etc) there is a skip count passed
to runtime.Callers (or equivalent) to skip some known count of frames
in order to get to the "interesting" frame corresponding to the
profile event. Now that the profiling mechanism uses lazy fixup (when
removing compiler artifacts like thunks, morestack calls etc), we also
need to move the frame skipping logic after the fixup, so as to insure
that the skip count isn't thrown off by these artifacts.
Fixesgolang/go#32290.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/179740
From-SVN: r271892
The gc compiler recognizes append(s, make([]T, n)...), and
generates code to directly zero the tail instead of allocating a
new slice and copying. This CL lets the Go frontend do basically
the same.
The difficulty is that at the point we handle append, there may
already be temporaries introduced (e.g. in order_evaluations),
which makes it hard to find the append-of-make pattern. The
compiler could "see through" the value of a temporary, but it is
only safe to do if the temporary is not assigned multiple times.
For this, we add tracking of assignments and uses for temporaries.
This also helps in optimizing non-escape slice make. We already
optimize non-escape slice make with constant len/cap to stack
allocation. But it failed to handle things like f(make([]T, n))
(where the slice doesn't escape and n is constant), because of
the temporary. With tracking of temporary assignments and uses,
it can handle this now as well.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/179597
From-SVN: r271822
Currently, goroutine switches are implemented with libc
getcontext/setcontext functions, which saves/restores the machine
register states and also the signal context. This does more than
what we need, and performs an expensive syscall.
This CL implements a simplified version of getcontext/setcontext,
in assembly, that only saves/restores the necessary part, i.e.
the callee-save registers, and the PC, SP. A simplified version
of makecontext, written in C, is also added. Currently this is
only implemented on Linux/AMD64.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/178298
From-SVN: r271818
