Austin Clements [Fri, 14 Nov 2014 18:58:31 +0000 (13:58 -0500)]
[dev.power64] 6g,9g: formatters for Prog and Addr details
The pretty printers for these make it hard to understand
what's actually in the fields of these structures. These
"ugly printers" show exactly what's in each field, which can
be useful for understanding and debugging code.
Austin Clements [Fri, 14 Nov 2014 17:08:46 +0000 (12:08 -0500)]
[dev.power64] liblink: generate dnames[5689] for D_* constants
This is more complicated than the other enums because the D_*
enums are full of explicit initializers and repeated values.
This tries its best. (This will get much cleaner once we
tease these constants apart better.)
Austin Clements [Fri, 14 Nov 2014 16:56:31 +0000 (11:56 -0500)]
[dev.power64] 5g,6g,8g,9g: debug prints for regopt pass 6 and paint2
Theses were very helpful in understanding the regions and
register selection when porting regopt to 9g. Add them to the
other compilers (and improve 9g's successor debug print).
Austin Clements [Thu, 13 Nov 2014 18:34:20 +0000 (13:34 -0500)]
[dev.power64] 6g,8g: remove unnecessary and incorrect reg use scanning
Previously, the 6g and 8g registerizers scanned for used
registers beyond the end of a region being considered for
registerization. This ancient artifact was copied from the C
compilers, where it was probably necessary to track implicitly
used registers. In the Go compilers it's harmless (because it
can only over-restrict the set of available registers), but no
longer necessary because the Go compilers correctly track
register use/set information. The consequences of this extra
scan were (at least) that 1) we would not consider allocating
the AX register if there was a deferproc call in the future
because deferproc uses AX as a return register, so we see the
use of AX, but don't track that AX is set by the CALL, and 2)
we could not consider allocating the DX register if there was
a MUL in the future because MUL implicitly sets DX and (thanks
to an abuse of copyu in this code) we would also consider DX
used.
This commit fixes these problems by nuking this code.
Austin Clements [Fri, 7 Nov 2014 15:43:55 +0000 (10:43 -0500)]
[dev.power64] 5g: fix mistaken bit-wise AND in regopt
Replace a bit-wise AND with a logical one. This happened to
work before because bany returns 0 or 1, but the intent here
is clearly logical (and this makes 5g match with 6g and 8g).
Austin Clements [Thu, 6 Nov 2014 19:37:39 +0000 (14:37 -0500)]
[dev.power64] gc: fix etype of strings
The etype of references to strings was being incorrectly set
to TINT32 on all platforms. Change it to TSTRING. It seems
this doesn't matter for compilation, since x86 uses LEA
instructions to load string addresses and arm and power64
disassemble the string into its constituent pieces (with the
correct types), but it helps when debugging.
Austin Clements [Wed, 5 Nov 2014 20:36:47 +0000 (15:36 -0500)]
[dev.power64] 6g: don't create variables for indirect addresses
Previously, mkvar treated, for example, 0(AX) the same as AX.
As a result, a move to an indirect address would be marked as
*setting* the register, rather than just using it, resulting
in unnecessary register moves. Fix this by not producing
variables for indirect addresses.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/164610043
Austin Clements [Tue, 4 Nov 2014 21:34:56 +0000 (16:34 -0500)]
[dev.power64] gc: convert Bits to a uint64 array
So far all of our architectures have had at most 32 registers,
so we've been able to use entry 0 in the Bits uint32 array
directly as a register mask. Power64 has 64 registers, so
this converts Bits to a uint64 array so we can continue to use
entry 0 directly as a register mask on Power64.
Austin Clements [Mon, 3 Nov 2014 22:25:36 +0000 (17:25 -0500)]
[dev.power64] test: "fix" live.go test on power64x
On power64x, this one line in live.go reports that t is live
because of missing optimization passes. This isn't what this
test is trying to test, so shuffle bad40 so that it still
accomplishes the intent of the test without also depending on
optimization.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/167110043
Austin Clements [Mon, 3 Nov 2014 22:24:13 +0000 (17:24 -0500)]
[dev.power64] liblink: fix printing of branch targets
Print PC stored in target Prog* of branch instructions when
available instead of the offset stored in the branch
instruction. The offset tends to be wrong after code
transformations, so previously this led to confusing listings.
Austin Clements [Mon, 3 Nov 2014 20:48:51 +0000 (15:48 -0500)]
[dev.power64] 9g: fix nilopt
Previously, nilopt was disabled on power64x because it threw
away "seemly random segments of code." Indeed, excise on
power64x failed to preserve the link field, so it excised not
only the requested instruction but all following instructions
in the function. Fix excise to retain the link field while
otherwise zeroing the instruction.
This makes nilopt safe on power64x. It still fails
nilptr3.go's tests for removal of repeated nil checks because
those depend on also optimizing away repeated loads, which
doesn't currently happen on power64x.
LGTM=dave, rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/168120043
Austin Clements [Fri, 31 Oct 2014 20:58:12 +0000 (16:58 -0400)]
[dev.power64] runtime: fix gcinfo_test on power64x
The GC info masks for slices and strings were changed in
commit caab29a25f68, but the reference masks used by
gcinfo_test for power64x hadn't caught up. Now they're
identical to amd64, so this CL fixes this test by combining
the reference masks for these platforms.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/162620044
Austin Clements [Fri, 31 Oct 2014 19:29:03 +0000 (15:29 -0400)]
[dev.power64] reflect: fix asm on power64x
reflect/asm_power64x.s was missing changes made to other
platforms for stack maps. This CL ports those changes. With
this fix, the reflect test passes on power64x.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/170870043
Austin Clements [Fri, 31 Oct 2014 17:39:36 +0000 (13:39 -0400)]
[dev.power64] runtime: fix fastrand1 on power64x
fastrand1 depends on testing the high bit of its uint32 state.
For efficiency, all of the architectures implement this as a
sign bit test. However, on power64, fastrand1 was using a
64-bit sign test on the zero-extended 32-bit state. This
always failed, causing fastrand1 to have very short periods
and often decay to 0 and get stuck.
Fix this by using a 32-bit signed compare instead of a 64-bit
compare. This fixes various tests for the randomization of
select of map iteration.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/166990043
Austin Clements [Fri, 31 Oct 2014 15:08:27 +0000 (11:08 -0400)]
[dev.power64] 9g: fix under-zeroing in clearfat
All three cases of clearfat were wrong on power64x.
The cases that handle 1032 bytes and up and 32 bytes and up
both use MOVDU (one directly generated in a loop and the other
via duffzero), which leaves the pointer register pointing at
the *last written* address. The generated code was not
accounting for this, so the byte fill loop was re-zeroing the
last zeroed dword, rather than the bytes following the last
zeroed dword. Fix this by simply adding an additional 8 byte
offset to the byte zeroing loop.
The case that handled under 32 bytes was also wrong. It
didn't update the pointer register at all, so the byte zeroing
loop was simply re-zeroing the beginning of region. Again,
the fix is to add an offset to the byte zeroing loop to
account for this.
Austin Clements [Thu, 30 Oct 2014 14:45:41 +0000 (10:45 -0400)]
[dev.power64] runtime: match argument/return type signedness in power64x assembly
Previously, the power64x runtime assembly was sloppy about
using sign-extending versus zero-extending moves of arguments
and return values. I think all of the cases that actually
mattered have been fixed in recent CLs; this CL fixes up the
few remaining mismatches.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/162480043
Russ Cox [Thu, 30 Oct 2014 00:37:44 +0000 (20:37 -0400)]
runtime: change top-most return PC from goexit to goexit+PCQuantum
If you get a stack of PCs from Callers, it would be expected
that every PC is immediately after a call instruction, so to find
the line of the call, you look up the line for PC-1.
CL 163550043 now explicitly documents that.
The most common exception to this is the top-most return PC
on the stack, which is the entry address of the runtime.goexit
function. Subtracting 1 from that PC will end up in a different
function entirely.
To remove this special case, make the top-most return PC
goexit+PCQuantum and then implement goexit in assembly
so that the first instruction can be skipped.
Russ Cox [Wed, 29 Oct 2014 22:07:24 +0000 (18:07 -0400)]
cmd/objdump: use cmd/internal/objfile
This removes a bunch of ugly duplicate code.
The end goal is to factor the disassembly code
into cmd/internal/objfile too, so that pprof can use it,
but one step at a time.
Russ Cox [Wed, 29 Oct 2014 19:14:24 +0000 (15:14 -0400)]
runtime: fix line number in first stack frame in printed stack trace
Originally traceback was only used for printing the stack
when an unexpected signal came in. In that case, the
initial PC is taken from the signal and should be used
unaltered. For the callers, the PC is the return address,
which might be on the line after the call; we subtract 1
to get to the CALL instruction.
Traceback is now used for a variety of things, and for
almost all of those the initial PC is a return address,
whether from getcallerpc, or gp->sched.pc, or gp->syscallpc.
In those cases, we need to subtract 1 from this initial PC,
but the traceback code had a hard rule "never subtract 1
from the initial PC", left over from the signal handling days.
Change gentraceback to take a flag that specifies whether
we are tracing a trap.
Change traceback to default to "starting with a return PC",
which is the overwhelmingly common case.
Add tracebacktrap, like traceback but starting with a trap PC.
Use tracebacktrap in signal handlers.
Fixes #7690.
LGTM=iant, r
R=r, iant
CC=golang-codereviews
https://golang.org/cl/167810044
Russ Cox [Wed, 29 Oct 2014 01:50:16 +0000 (21:50 -0400)]
[dev.power64] cmd/5a, cmd/6a, cmd/8a, cmd/9a: make labels function-scoped
I removed support for jumping between functions years ago,
as part of doing the instruction layout for each function separately.
Given that, it makes sense to treat labels as function-scoped.
This lets each function have its own 'loop' label, for example.
Makes the assembly much cleaner and removes the last
reason anyone would reach for the 123(PC) form instead.
Note that this is on the dev.power64 branch, but it changes all
the assemblers. The change will ship in Go 1.5 (perhaps after
being ported into the new assembler).
David du Colombier [Tue, 28 Oct 2014 21:44:59 +0000 (22:44 +0100)]
os: fix write on Plan 9
In CL 160670043 the write function was changed
so a zero-length write is now allowed. This leads
the ExampleWriter_Init test to fail.
The reason is that Plan 9 preserves message
boundaries, while the os library expects systems
that don't preserve them. We have to ignore
zero-length writes so they will never turn into EOF.
This issue was previously discussed in CL 7406046.
Austin Clements [Tue, 28 Oct 2014 19:57:33 +0000 (15:57 -0400)]
[dev.power64] runtime: fix atomicor8 for power64x
Power64 servers do not currently support sub-word size atomic
memory access, so atomicor8 uses word size atomic access.
However, previously atomicor8 made no attempt to align this
access, resulting in errors. Fix this by aligning the pointer
to a word boundary and shifting the value appropriately.
Since atomicor8 is used in GC, add a test to runtime·check to
make sure this doesn't break in the future.
This also fixes an incorrect branch label, an incorrectly
sized argument move, and adds argument names to help go vet.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/165820043
Austin Clements [Tue, 28 Oct 2014 19:08:09 +0000 (15:08 -0400)]
[dev.power64] 9a: correct generation of four argument ops
The "to" field was the penultimate argument to outgcode,
instead of the last argument, which swapped the third and
fourth operands. The argument order was correct in a.y, so
just swap the meaning of the arguments in outgcode. This
hadn't come up because we hadn't used these more obscure
operations in any hand-written assembly until now.
LGTM=rsc, dave
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/160690043
Russ Cox [Tue, 28 Oct 2014 15:35:00 +0000 (11:35 -0400)]
syscall: fix ParseRoutingSockaddr with unexpected submessages
No easy way to test (would have to actually trigger some routing
events from kernel) but the code is clearly wrong as written.
If the header says there is a submessage, we need to at least
skip over its bytes, not just continue to the next iteration.
Fixes #8203.
LGTM=r
R=r
CC=golang-codereviews, mikioh.mikioh, p
https://golang.org/cl/164140044
Russ Cox [Tue, 28 Oct 2014 15:14:25 +0000 (11:14 -0400)]
cmd/go: add get -f flag
get -u now checks that remote repo paths match the
ones predicted by the import paths: if you are get -u'ing
rsc.io/pdf, it has to be checked out from the right location.
This is important in case the rsc.io/pdf redirect changes.
In some cases, people have good reasons to use
non-standard remote repos. Add -f flag to allow that.
The f can stand for force or fork, as you see fit.
Mikio Hara [Tue, 28 Oct 2014 07:20:49 +0000 (16:20 +0900)]
net: add test for lookupIPDeadline
Just to confirm the fix, by typing the follwing:
go test -run=TestLookupIPDeadline -dnsflood or
go test -run=TestLookupIPDeadline -dnsflood -tags netgo
Rob Pike [Tue, 28 Oct 2014 00:08:50 +0000 (17:08 -0700)]
doc/go_mem.html: don't be clever
Add a short introductory section saying what most Go
programmers really need to know, which is that you
shouldn't have to read this document to understand
the behavior of your program.
Robert Griesemer [Mon, 27 Oct 2014 23:31:15 +0000 (16:31 -0700)]
spec: permit parentheses around builtin function names
Not a language change.
This is simply documenting the status quo which permits
builtin function names to be parenthesized in calls; e.g.,
both
len(s)
and
(((len)))(s)
are accepted by all compilers and go/types.
Changed the grammar by merging the details of BuiltinCall
with ordinary Calls. Also renamed the Call production to
Arguments which more clearly identifies that part of the
grammar and also matches better with its counterpart on
the declaration side (Parameters).
The fact that the first argument can be a type (for builtins)
or cannot be a type (for regular function calls) is expressed
in the prose, no need to make the grammar more complicated.
Fixes #9001.
LGTM=iant, r, rsc
R=r, rsc, iant, ken, dave
CC=golang-codereviews
https://golang.org/cl/160570043
Russ Cox [Mon, 27 Oct 2014 22:59:02 +0000 (18:59 -0400)]
test: make maplinear more robust
The test just doubled a certain number of times
and then gave up. On a mostly fast but occasionally
slow machine this may never make the test run
long enough to see the linear growth.
Change test to keep doubling until the first round
takes at least a full second, to reduce the effect of
occasional scheduling or other jitter.
The failure we saw had a time for the first round
of around 100ms.
Note that this test still passes once it sees a linear
effect, even with a very small total time.
The timeout here only applies to how long the execution
must be to support a reported failure.
Austin Clements [Mon, 27 Oct 2014 21:27:03 +0000 (17:27 -0400)]
[dev.power64] runtime: power64 fixes and ports of changes
Fix include paths that got moved in the great pkg/ rename. Add
missing runtime/arch_* files for power64. Port changes that
happened on default since branching to
runtime/{asm,atomic,sys_linux}_power64x.s (precise stacks,
calling convention change, various new and deleted functions.
Port struct renaming and fix some bugs in
runtime/defs_linux_power64.h.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/161450043
Austin Clements [Mon, 27 Oct 2014 21:19:41 +0000 (17:19 -0400)]
[dev.power64] liblink: fix lost branch target
A recent commit lost the branch target in the really-big-stack
case of splitstack, causing an infinite loop stack preempt
case. Revive the branch target.