Redo how we keep track of forward references when building SSA.
When the forward reference is resolved, update the Value node
in place.
Improve the phi elimination pass so it can simplify phis of phis.
Give SSA package access to decoded line numbers. Fix line numbers
for constant booleans.
Change-Id: I3dc9896148d260be2f3dd14cbe5db639ec9fa6b7
Reviewed-on: https://go-review.googlesource.com/18674
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Distinguish move/load/store ops. Unify some of this code a bit.
Reduces Mandelbrot slowdown with SSA from 58% to 12%.
Change-Id: I3276eaebcbcdd9de3f8299c79b5f25c0429194c4
Reviewed-on: https://go-review.googlesource.com/18677
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
If a failure occurs in SSA processing, we always report the
last line of the function we're compiling. Modify the callbacks
from SSA to the GC compiler so we can pass a line number back
and use it in Fatalf.
Change-Id: Ifbfad50d5e167e997e0a96f0775bcc369f5c397e
Reviewed-on: https://go-review.googlesource.com/18599
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Otherwise it is impossible to vendor a/b/c without hiding the real a/b.
I also updated golang.org/s/go15vendor.
Fixes#13832.
Change-Id: Iee3d53c11ea870721803f6e8e67845b405686e79
Reviewed-on: https://go-review.googlesource.com/18644
Reviewed-by: Andrew Gerrand <adg@golang.org>
Fixes build on those systems.
Also fix printing of AVARLIVE.
Change-Id: I1b38cca0125689bc08e4e1bdd0d0c140b1ea079a
Reviewed-on: https://go-review.googlesource.com/18641
Reviewed-by: Russ Cox <rsc@golang.org>
This will allow the compiler to crunch Prog lists down to code as each
function is compiled, instead of waiting until the end, which should
reduce the working set of the compiler. But not until Go 1.7.
This also makes it easier to write some machine code output tests
for the assembler, which is why it's being done now.
For #13822.
Change-Id: I0811123bc6e5717cebb8948f9cea18e1b9baf6f7
Reviewed-on: https://go-review.googlesource.com/18311
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Consider this code:
func f(*int)
func g() {
p := new(int)
f(p)
}
where f is an assembly function.
In general liveness analysis assumes that during the call to f, p is dead
in this frame. If f has retained p, p will be found alive in f's frame and keep
the new(int) from being garbage collected. This is all correct and works.
We use the Go func declaration for f to give the assembly function
liveness information (the arguments are assumed live for the entire call).
Now consider this code:
func h1() {
p := new(int)
syscall.Syscall(1, 2, 3, uintptr(unsafe.Pointer(p)))
}
Here syscall.Syscall is taking the place of f, but because its arguments
are uintptr, the liveness analysis and the garbage collector ignore them.
Since p is no longer live in h once the call starts, if the garbage collector
scans the stack while the system call is blocked, it will find no reference
to the new(int) and reclaim it. If the kernel is going to write to *p once
the call finishes, reclaiming the memory is a mistake.
We can't change the arguments or the liveness information for
syscall.Syscall itself, both for compatibility and because sometimes the
arguments really are integers, and the garbage collector will get quite upset
if it finds an integer where it expects a pointer. The problem is that
these arguments are fundamentally untyped.
The solution we have taken in the syscall package's wrappers in past
releases is to insert a call to a dummy function named "use", to make
it look like the argument is live during the call to syscall.Syscall:
func h2() {
p := new(int)
syscall.Syscall(1, 2, 3, uintptr(unsafe.Pointer(p)))
use(unsafe.Pointer(p))
}
Keeping p alive during the call means that if the garbage collector
scans the stack during the system call now, it will find the reference to p.
Unfortunately, this approach is not available to users outside syscall,
because 'use' is unexported, and people also have to realize they need
to use it and do so. There is much existing code using syscall.Syscall
without a 'use'-like function. That code will fail very occasionally in
mysterious ways (see #13372).
This CL fixes all that existing code by making the compiler do the right
thing automatically, without any code modifications. That is, it takes h1
above, which is incorrect code today, and makes it correct code.
Specifically, if the compiler sees a foreign func definition (one
without a body) that has uintptr arguments, it marks those arguments
as "unsafe uintptrs". If it later sees the function being called
with uintptr(unsafe.Pointer(x)) as an argument, it arranges to mark x
as having escaped, and it makes sure to hold x in a live temporary
variable until the call returns, so that the garbage collector cannot
reclaim whatever heap memory x points to.
For now I am leaving the explicit calls to use in package syscall,
but they can be removed early in a future cycle (likely Go 1.7).
The rule has no effect on escape analysis, only on liveness analysis.
Fixes#13372.
Change-Id: I2addb83f70d08db08c64d394f9d06ff0a063c500
Reviewed-on: https://go-review.googlesource.com/18584
Reviewed-by: Ian Lance Taylor <iant@golang.org>
GCC 4.8 exits 1 on an unrecognized option, but GCC 4.4 and 4.5 exit 0.
I didn't check other versions, or try to figure out just when this
changed.
Fixes#13937.
Change-Id: If193e9053fbb535999c9bde99f430f465a8c7c57
Reviewed-on: https://go-review.googlesource.com/18597
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This makes lldb willing to debug them.
The minimum version is hard-coded at OS X 10.7,
because that is the minimum that Go requires.
For more control over the version, users can
use linkmode=external and pass the relevant flags to the host linker.
Fixes#12941.
Change-Id: I20027be8aa034d07dd2a3326828f75170afe905f
Reviewed-on: https://go-review.googlesource.com/18588
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add new constant-flags opcodes. These can be generated from
comparisons that we know the result of, like x&31 < 32.
Constant-fold the constant-flags opcodes into all flag users.
Reorder some CMPxconst args so they read in the comparison direction.
Reorg deadcode removal a bit - it needs to remove the OpCopy ops it
generates when strength-reducing Phi ops. So it needs to splice out all
the dead blocks and do a copy elimination before it computes live
values.
Change-Id: Ie922602033592ad8212efe4345394973d3b94d9f
Reviewed-on: https://go-review.googlesource.com/18267
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
In code that does:
var x, z int32
var y int64
z = phi(x, int32(y))
We silently drop the int32 cast because truncation is a no-op.
The phi operation needs to make sure it uses the size of the
phi, not the size of its arguments, when generating spills.
Change-Id: I1f7baf44f019256977a46fdd3dad1972be209042
Reviewed-on: https://go-review.googlesource.com/18390
Reviewed-by: David Chase <drchase@google.com>
* Enable c-shared buildmode on darwin/386
* dyld does not support text relocation on i386. Add -read_only_relocs suppress flag to linker
Fixes#13904
Change-Id: I9adbd20d3f36ce9bbccf1bffb746b391780d088f
Reviewed-on: https://go-review.googlesource.com/18500
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The fucomi* opcodes were only introduced for the Pentium Pro.
They do not exist for an MMX Pentium. Use the fucom* instructions
instead and move the condition codes from the fp flags register to
the integer flags register explicitly.
The use of fucomi* opcodes in ggen.go was introduced in 1.5 (CL 8738).
The bad ops were generated for 64-bit floating-point comparisons.
The use of fucomi* opcodes in gsubr.go dates back to at least 1.1.
The bad ops were generated for float{32,64} to uint64 conversions.
Fixes#13923
Change-Id: I5290599f5edea8abf8fb18036f44fa78bd1fc9e6
Reviewed-on: https://go-review.googlesource.com/18590
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Install pkg.h rather than libpkg.h.
Link against -lc.
Fixes#13860.
Change-Id: I4e429426f8363712a5dbbd2655b9aab802ab2888
Reviewed-on: https://go-review.googlesource.com/18592
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Add several instructions that were used via BYTE and use them.
Instructions added: PEXTRB, PEXTRD, PEXTRQ, PINSRB, XGETBV, POPCNT.
Change-Id: I5a80cd390dc01f3555dbbe856a475f74b5e6df65
Reviewed-on: https://go-review.googlesource.com/18593
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Brief background on "why heap allocate". Things can be
forced to the heap for the following reasons:
1) address published, hence lifetime unknown.
2) size unknown/too large, cannot be stack allocated
3) multiplicity unknown/too large, cannot be stack allocated
4) reachable from heap (not necessarily published)
The bug here is a case of failing to enforce 4) when an
object Y was reachable from a heap allocation X forced
because of 3). It was found in the case of a closure
allocated within a loop (X) and assigned to a variable
outside the loop (multiplicity unknown) where the closure
also captured a map (Y) declared outside the loop (reachable
from heap). Note the variable declared outside the loop (Y)
is not published, has known size, and known multiplicity
(one). The only reason for heap allocation is that it was
reached from a heap allocated item (X), but because that was
not forced by publication, it has to be tracked by loop
level, but escape-loop level was not tracked and thus a bug
results.
The fix is that when a heap allocation is newly discovered,
use its looplevel as the minimum loop level for downstream
escape flooding.
Every attempt to generalize this bug to X-in-loop-
references-Y-outside loop succeeded, so the fix was aimed
to be general. Anywhere that loop level forces heap
allocation, the loop level is tracked. This is not yet
tested for all possible X and Y, but it is correctness-
conservative and because it caused only one trivial
regression in the escape tests, it is probably also
performance-conservative.
The new test checks the following:
1) in the map case, that if fn escapes, so does the map.
2) in the map case, if fn does not escape, neither does the map.
3) in the &x case, that if fn escapes, so does &x.
4) in the &x case, if fn does not escape, neither does &x.
Fixes#13799.
Change-Id: Ie280bef2bb86ec869c7c206789d0b68f080c3fdb
Reviewed-on: https://go-review.googlesource.com/18234
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Go fails to build on a system which has PIE enabled by default like this:
/usr/bin/ld: -r and -pie may not be used together
collect2: error: ld returned 1 exit status
The only system I know that has this property right now is Ubuntu Xenial
running on s390x, which is hardly the most accessible system, but it's planned
to enable this on amd64 soon too. The fix is to pass -no-pie along with -Wl,-r
to the compiler, but unfortunately that flag is very new as well. So this does
a test compile of a trivial file to see if the flag is supported.
Change-Id: I1345571142b7c3a96212e43297d19e84ec4a3d41
Reviewed-on: https://go-review.googlesource.com/18359
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
mips64 builder and one machine of the mips64le builder has small amount
of memory. Since CL 18199, they have been running slowly, as more
processes were launched in running 'test' directory, and a lot of swap
were used. This CL brings all.bash from 5h back to 3h on Loongson 2E
with 512 MB memory.
Change-Id: I4a22e239a542a99ba5986753205d8cd1f4b3d3c6
Reviewed-on: https://go-review.googlesource.com/18483
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
There are fewer special cases this way: the import map applies
to all import paths, not just the ones not spelled "unsafe".
This is also consistent with what the code in cmd/go and go/build expects.
They make no exception for "unsafe".
For #13703.
Change-Id: I622295261ca35a6c1e83e8508d363bddbddb6c0a
Reviewed-on: https://go-review.googlesource.com/18438
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Looking for vendor directories is a better default.
Fixes#13772
Change-Id: Iabbaea71ccc67b72f14f1f412dc8ab70cb41996d
Reviewed-on: https://go-review.googlesource.com/18450
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The cgoTestSO test currently fails when run on FreeBSD amd64 with
GOHOSTARCH=386. This is due to it failing to find the shared object.
On FreeBSD 64-bit architectures, the linker for 32-bit objects
looks for a separate environment variable. Export both LD_LIBRARY_PATH
and LD_32_LIBRARY_PATH on FreeBSD when GOHOSTARCH=386.
Update issue #13873.
Change-Id: I1fb20dd04eb2007061768b2e4530886521813d42
Reviewed-on: https://go-review.googlesource.com/18420
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It's fairly common to call cgo functions with conversions to
unsafe.Pointer or other C types. Apply the simpler checking of address
expressions when possible when the address expression occurs within a
type conversion.
Change-Id: I5187d4eb4d27a6542621c396cad9ee4b8647d1cd
Reviewed-on: https://go-review.googlesource.com/18391
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Adding the evconst(n) call for OANDAND and OOROR in
golang.org/cl/18262 was originally just to parallel the above iscmp
branch, but upon further inspection it seemed odd that removing it
caused test/fixedbugs/issue6671.go's
var b mybool
// ...
b = bool(true) && true // ERROR "cannot use"
to start failing (i.e., by not emitting the expected "cannot use"
error).
The problem is that evconst(n)'s settrue and setfalse paths always
reset n.Type to idealbool, even for logical operators where n.Type
should preserve the operand type. Adding the evconst(n) call for
OANDAND/OOROR inadvertantly worked around this by turning the later
evconst(n) call at line 2167 into a noop, so the "n.Type = t"
assignment at line 739 would preserve the operand type.
However, that means evconst(n) was still clobbering n.Type for ONOT,
so declarations like:
const _ bool = !mybool(true)
were erroneously accepted.
Update #13821.
Change-Id: I18e37287f05398fdaeecc0f0d23984e244f025da
Reviewed-on: https://go-review.googlesource.com/18362
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
On Windows, externalthreadhandler currently sets the assumed stack
size for the profiler thread and the ctrlhandler threads to 8KB. The
actual stack size is determined by the SizeOfStackReserve field in the
binary set by the linker, which is currently at least 64KB (and
typically 128KB).
It turns out the profiler thread is running within a few words of the
8KB-(stack guard) bound set by externalthreadhandler. If it overflows
this bound, morestack crashes unceremoniously with an access
violation, which we then fail to handle, causing the whole process to
exit without explanation.
To avoid this problem and give us some breathing room, increase the
assumed stack size in externalthreadhandler to 32KB (there's some
unknown amount of stack already in use, so it's not safe to increase
this all the way to the reserve size).
We also document the relationships between externalthreadhandler and
SizeOfStackReserve to make this more obvious in the future.
Change-Id: I2f9f9c0892076d78e09827022ff0f2bedd9680a9
Reviewed-on: https://go-review.googlesource.com/18304
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Minux Ma <minux@golang.org>
Simply checking the exit code of `git rev-parse --git-dir` should
suffice here, but that requires deviating from the infrastructure
provided by `run`, so I've left that for a future change.
Originally by Tamir Duberstein but updated by iant & rsc to add
the filepath.Join logic.
Fixes#11211 (again).
Change-Id: I6d29b5ae39ba456088ae1fb5d41014cb91c86897
Reviewed-on: https://go-review.googlesource.com/18323
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The flag is already named -insecure. Make it more so.
If we're willing to accept HTTP, it's not much worse to accept
HTTPS man-in-the-middle attacks too. This allows servers
with self-signed certificates to work.
Fixes#13197.
Change-Id: Ia5491410bc886da0a26ef3bce4bf7d732f5e19e4
Reviewed-on: https://go-review.googlesource.com/18324
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This time with a test.
Also adjust another test to skip when hg is not present,
and delete no longer needed fixDetachedHead code.
Fixes#9032 (again).
Change-Id: I481717409e1d44b524f83c70a8dc377699d1a2a5
Reviewed-on: https://go-review.googlesource.com/18334
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We don't use these for benchmarking anymore.
Now we have the go1 dir and the benchmarks subrepo.
Some have problematic copyright notices, so move out of main repo.
Preserved in golang.org/x/exp/shootout.
Fixes#12688.
Fixes#13584.
Change-Id: Ic0b71191ca1a286d33d7813aca94bab1617a1c82
Reviewed-on: https://go-review.googlesource.com/18320
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Simply checking the exit code of `git rev-parse --git-dir` should
suffice here, but that requires deviating from the infrastructure
provided by `run`, so I've left that for a future change.
Fixes#11211.
Change-Id: I7cbad86a8a06578f52f66f734f5447b597ddc962
Reviewed-on: https://go-review.googlesource.com/18213
Reviewed-by: Russ Cox <rsc@golang.org>
Before golang.org/cl/13921, "go install -buildmode=shared prefix/..." created a
file called "libprefix.so", which was obviously a problem when prefix was
something like "." or "../". However, now it expands the ... into all the
matched packages, joins them with -, which can clearly be a very long name
indeed. Because I plan to build shared libraries for Ubuntu by running commands
exactly like "go install -buildmode=shared prefix/...", this special cases this
to produce the old behaviour (but de-relativises prefix first).
Fixes#13714
Change-Id: I4fd8d4934279f9a18cc70a13e4ef3e23f6abcb6e
Reviewed-on: https://go-review.googlesource.com/18114
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Forgot to reset these masks before each merge edge is processed.
Change-Id: I2f593189b63f50a1cd12b2dd4645ca7b9614f1f3
Reviewed-on: https://go-review.googlesource.com/18223
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
Added a format option to inhibit output of .Note field in
printing, and enabled that option during export.
Added test.
Fixes#13777.
Change-Id: I739f9785eb040f2fecbeb96d5a9ceb8c1ca0f772
Reviewed-on: https://go-review.googlesource.com/18217
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
When 'go tool dist test' stops, it was intended that it first wait for
pending background tests, like a failed compilation waits for pending
background compiles. But these three lines prevented that.
Fix by deleting them. (The actual loop already contains the correct
logic to avoid running the others and to wait for what's left.)
Change-Id: I4e945495ada903fb0af567910626241bc1c52ba6
Reviewed-on: https://go-review.googlesource.com/18232
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL changes the source file information in the
standard library's .a files to say "$GOROOT/src/runtime/chan.go"
(with a literal "$GOROOT") instead of spelling out the actual directory.
The linker then substitutes the actual $GOROOT (or $GOROOT_FINAL)
as appropriate.
If people download a binary distribution to an alternate location,
following the instructions at https://golang.org/doc/install#install,
the code before this CL would end up with source paths pointing to
/usr/local/go no matter where the actual sources were.
Now the source paths for built binaries will point to the actual sources
(hopefully).
The source line information in distributed binaries is not affected:
those will still say /usr/local/go. But binaries people build themselves
(their own programs, not the go distribution programs) will be correct.
Fixing this path also fixes the lookup of the runtime-gdb.py file.
Fixes#5533.
Change-Id: I03729baae3fbd8cd636e016275ee5ad2606e4663
Reviewed-on: https://go-review.googlesource.com/18200
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I broke the rule: never click the Submit button on the web.
Change-Id: If81a5cc31c1f28664960bad124cc596f5cab1222
Reviewed-on: https://go-review.googlesource.com/18203
Reviewed-by: Russ Cox <rsc@golang.org>
These find approximately nothing.
Takes 5% off my all.bash run time.
For #10571.
Change-Id: I21d3a844af756eb37f59bba0064f24995626da0d
Reviewed-on: https://go-review.googlesource.com/18198
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
