Nothing uses it, nothing should start using it.
Stop leaving plausible-looking values there.
It would be nice to remove entirely, but that would
require a new version number for the object file format,
in order not to break external readers like debug/gosym.
It's easier to leave and poison.
I came across an old mail thread suggesting we start using it
to speed up tracebacks. I want to make sure that doesn't happen.
(The values there were never quite right, and the number is
fundamentally PC-specific anyway.)
Change-Id: Iaf38e8a6b523cbae30b69c28497c4588ef397519
Reviewed-on: https://go-review.googlesource.com/6890
Reviewed-by: Minux Ma <minux@golang.org>
Make cmd/internal/obj/x86 support 32-bit mode and use
instead of cmd/internal/obj/i386. Delete cmd/internal/obj/i386.
Clean up encoding of PINSRQ, CMPSD to use explicit third arg
instead of jamming it into an unused slot of a different arg.
Also fix bug in old6a, which declared the wrong grammar.
The accepted (and encoded) arguments to CMPSD etc are mem,reg not reg,mem.
Code that did try to use mem,reg before would be rejected by liblink,
so only reg,reg ever worked, so existing code is not affected.
After this change, code can use mem,reg successfully.
The real bug here is that the encoding tables inverted the argument
order, making the comparisons all backward from what they say on the page.
It's too late to swap them, though: people have already written code that
expects the inverted comparisons (like in package math, and likely externally).
The best we can do is make the argument that should and can take a
memory operand accept it.
Bit-for-bit compatibility checked against tree without this CL.
Change-Id: Ife5685bc98c95001f64407f35066b34b4dae11c1
Reviewed-on: https://go-review.googlesource.com/6810
Reviewed-by: Rob Pike <r@golang.org>
Add unused (but initialized) from3 field to ytab, f3t to movtab.
Remove level of indentation in movtab processing.
Change-Id: I8475988f46b541ecaccf8d34608da8bef7d12e24
Reviewed-on: https://go-review.googlesource.com/6892
Reviewed-by: Rob Pike <r@golang.org>
Node.Needzero only has two values and acts as a bool, so make it a bool.
Change-Id: Ica46e5ebafbe478017ea52ce6bb335f404059677
Reviewed-on: https://go-review.googlesource.com/6800
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This avoids repeated allocation and map lookups
when constructing the pcln tables.
For 6g compiling cmd/internal/gc/*.go this saves about 8% wall time.
Change-Id: I6a1a80e278ae2c2a44bd1537015ea7b4e7a4d6ca
Reviewed-on: https://go-review.googlesource.com/6793
Reviewed-by: Rob Pike <r@golang.org>
For OSes that use elf on intel, 2*Ptrsize bytes are reserved for TLS.
But only one pointer (g) has been stored in the TLS for a while now.
So we can set it to just Ptrsize, which happily matches what happens
when externally linking.
Fixes#9913
Change-Id: Ic816369d3a55a8cdcc23be349b1a1791d53f5f81
Reviewed-on: https://go-review.googlesource.com/6584
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: Ice4f78e74ec3025a974ffd9ca5e3d28bb3164f40
Reviewed-on: https://go-review.googlesource.com/6794
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
This is an experiment to see if removing the boundary bit logic will
lead to fewer cache misses and improved performance. Instead of using
boundary bits we use the span information to get element size and use
some bit whacking to get the boundary without having to touch the
random heap bits which cause cache misses.
Furthermore once the boundary bit is removed we can either use that
bit for a simpler checkmark routine or we can reduce the number of
bits in the GC bitmap to 2 bits per pointer sized work. For example
the 2 bits at the boundary can be used for marking and pointer/scalar
differentiation. Since we don't need the mark bit except at the
boundary nibble of the object other nibbles can use this bit
as a noscan bit to indicate that there are no more pointers in
the object.
Currently the changed included in this CL slows down the garbage
benchmark. With the boundary bits garbage gives 5.78 and without
(this CL) it gives 5.88 which is a 2% slowdown.
Change-Id: Id68f831ad668176f7dc9f7b57b339e4ebb6dc4c2
Reviewed-on: https://go-review.googlesource.com/6665
Reviewed-by: Austin Clements <austin@google.com>
Shifts are trivially implemented by combining
Float.MantExp and Float.SetMantExp.
Change-Id: Ia2fb49297d8ea7aa7d64c8b1318dc3dc7c8af2f7
Reviewed-on: https://go-review.googlesource.com/6671
Reviewed-by: Alan Donovan <adonovan@google.com>
This change represents Accuracy as a bit pattern rather than
an ordered value; with a new value Undef which is both Below
and Above.
Change-Id: Ibb96294c1417fb3cf2c3cf2374c993b0a4e106b3
Reviewed-on: https://go-review.googlesource.com/6650
Reviewed-by: Alan Donovan <adonovan@google.com>
This change introduces NaNs (for situations like Inf-Inf, etc.).
The implementation is incomplete (the four basic operations produce
a NaN if any of the operands is an Inf or a NaN); and some operations
produce incorrect accuracy for NaN arguments. These are known bugs
which are documented.
Change-Id: Ia88841209e47930681cef19f113e178f92ceeb33
Reviewed-on: https://go-review.googlesource.com/6540
Reviewed-by: Alan Donovan <adonovan@google.com>
Gc already calculates n as an int, so converting to int64 to call
growslice doesn't serve any purpose except to emit slightly larger
code on 32-bit platforms. Passing n as an int shrinks godoc's text
segment by 8kB (9472633 => 9464133) when building for ARM.
Change-Id: Ief9492c21d01afcb624d3f2a484df741450b788d
Reviewed-on: https://go-review.googlesource.com/6231
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
SHRQ CX, DX:AX is changing to SHRQ CX, AX, DX.
This is the first step: using SHRQ From=CX, From3=AX, To=DX
as the preferred encoding.
Once the assemblers and 6g have been updated,
support for the old encoding can be removed.
Change-Id: Ie603fb8ac25a6df78e42f7ddcae078a7684a7c26
Reviewed-on: https://go-review.googlesource.com/6693
Reviewed-by: Rob Pike <r@golang.org>
The unbounded list-based defer pool can grow infinitely.
This can happen if a goroutine routinely allocates a defer;
then blocks on one P; and then unblocked, scheduled and
frees the defer on another P.
The scenario was reported on golang-nuts list.
We've been here several times. Any unbounded local caches
are bad and grow to infinite size. This change introduces
central defer pool; local pools become fixed-size
with the only purpose of amortizing accesses to the
central pool.
Freedefer now executes on system stack to not consume
nosplit stack space.
Change-Id: I1a27695838409259d1586a0adfa9f92bccf7ceba
Reviewed-on: https://go-review.googlesource.com/3967
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
The unbounded list-based sudog cache can grow infinitely.
This can happen if a goroutine is routinely blocked on one P
and then unblocked and scheduled on another P.
The scenario was reported on golang-nuts list.
We've been here several times. Any unbounded local caches
are bad and grow to infinite size. This change introduces
central sudog cache; local caches become fixed-size
with the only purpose of amortizing accesses to the
central cache.
The change required to move sudog cache from mcache to P,
because mcache is not scanned by GC.
Change-Id: I3bb7b14710354c026dcba28b3d3c8936a8db4e90
Reviewed-on: https://go-review.googlesource.com/3742
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
The original C code is: (x->type & SHIDDEN) ? 2 : 0, however when
cleaning up the code for c2go, the ternary operator is rewritten in
the exact opposite way.
We need a test for this, and that's being tracked as #10070.
Fixes#10067.
Change-Id: I24a5e021597d8bc44218c6e75bab6446513b76cf
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/6730
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The creation of liblink and subsequent introduction of more explicit
TLS handling broke 6l's (unsupported) -shared flag. This change adds
-shared flags to cmd/asm and 6g and changes liblink to generate shared-
library compatible instruction sequences when they are passed, and
changes 6l to emit the appropriate ELF relocation.
A proper fix probably also requires go tool changes.
Fixes#9652.
Change-Id: I7b7718fe7305c802ac994f4a5c8de68cfbe6c76b
Reviewed-on: https://go-review.googlesource.com/4321
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The name g is an alias for R10 and R30, respectively. Have Rconv
print the alias, for consistency with the input language.
Change-Id: Ic3f40037884a0c8de5089d8c8a8efbcdc38c0d56
Reviewed-on: https://go-review.googlesource.com/6630
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This will enable test sharding over multiple VMs, to speed trybot answers.
Update #10029
Change-Id: Ie277c6459bc38005e4d6af14d22effeaa0a4667e
Reviewed-on: https://go-review.googlesource.com/6531
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
We now wait until we see the completed prompt from a command before
proceeding. This seems to cut down on a spurious error I have seen
this afternoon.
Change-Id: Ic0a3481d8c265c3c3b4449ec7ac1c2752b85b0b6
Reviewed-on: https://go-review.googlesource.com/6691
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Just a missed case in in the handling of branches.
Fixes#10065
Change-Id: I6be054d30bf1f383c12b4c7626abd5f8ae22b22e
Reviewed-on: https://go-review.googlesource.com/6631
Reviewed-by: Minux Ma <minux@golang.org>
c2go produced accurate but complex constant definitions like
"ElfSymBindLocal = 0 + iota - 67" which break when any constants
are added above them in the list. Change them to explicit values
in separate blocks by class. I wrote a little program (using awk)
to dump the values of the constants:
https://gist.github.com/mwhudson/82f82008279a38ce584e
and confirmed that its output before and after this change is the
same.
Change-Id: Ib4aea4a0d688a16cdcb76af4715d1a97ec0f013c
Reviewed-on: https://go-review.googlesource.com/6581
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
- use Bvec, not *Bvec, and bulk allocate backing store
- use range loops
- put Bvecs in BasicBlock struct instead of indexing into parallel slices
Change-Id: I5cb30f50dccb4d38cc18fae422f7f132c52876be
Reviewed-on: https://go-review.googlesource.com/6602
Reviewed-by: Rob Pike <r@golang.org>
Also change gc.Naddr to return the Addr instead of filling it in.
Change-Id: I98a86705d23bee49626a12a042a4d51cabe290ea
Reviewed-on: https://go-review.googlesource.com/6601
Reviewed-by: Rob Pike <r@golang.org>
The C version of the compiler had just one hash table,
indexed by a (name string, pkg *Pkg) pair.
Because we always know the pkg during a lookup,
replace the one table with a per-Pkg map[string]*Sym.
This also lets us do non-allocating []byte key lookups.
This CL *does* change the generated object files.
In the old code, export data and init calls were emitted
in "hash table order". Now they are emitted in the order
in which they were added to the table.
Change-Id: I5a48d5c9add996dc43ad04a905641d901522de0b
Reviewed-on: https://go-review.googlesource.com/6600
Reviewed-by: Rob Pike <r@golang.org>
Strlit was just a poor excuse for a Go string.
Use a Go string.
In the one case where it was a string-or-nil (Type.Note), use a *string.
Zconv was a poor excuse for %q. Use %q.
The only important part about Zconv's implementation
was that the compiler and linker agreed on the quoting rules.
Now they both use %q instead of having two Zconvs.
This CL *does* change the generated object files, because the
quoted strings end up in symbol names.
For example the string "\r\n" used to be named go.string."\r\n"
and is now go.string."\x0d\n".
Change-Id: I5c0d38e1570ffc495f0db1a20273c9564104a7e8
Reviewed-on: https://go-review.googlesource.com/6519
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
This avoids the argument appearing to escape
(due to the fact that proginfo is always called
via a function pointer).
Change-Id: Ib9351ba18c80fd89e6a1d4f19dea386d4c657337
Reviewed-on: https://go-review.googlesource.com/6518
Reviewed-by: Rob Pike <r@golang.org>
Run rsc.io/grind rev 796d0f2 on C->Go conversions.
This replaces various awkward := initializations with plain var declarations.
Checked bit-for-bit compatibility with toolstash + buildall.
Change-Id: I601101d8177894adb9b0e3fb55dfe0ed4f544716
Reviewed-on: https://go-review.googlesource.com/6517
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Change-Id: If2d303caae933eec61634152e5d83faaba591315
Reviewed-on: https://go-review.googlesource.com/6660
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Mishandled the mask for the arm instructions.
TBR=rsc
Change-Id: Idc596097c0fa61dcacdfb4aca5bc6d0b4fd40eeb
Reviewed-on: https://go-review.googlesource.com/6641
Reviewed-by: Rob Pike <r@golang.org>
