This omission was causing the new regalloc to fail.
Change-Id: If7ba7be38a436dbd0dd443828ddd7ebf6e35be0e
Reviewed-on: https://go-review.googlesource.com/13632
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Generating logging code every time causes large
diffs for small changes.
Since the intent is to use this for debugging only,
generate logging code only when requested.
Committed generated code will be logging free.
Change-Id: I9ef9e29c88b76c2557bad4c6b424b9db1255ec8b
Reviewed-on: https://go-review.googlesource.com/13623
Reviewed-by: Keith Randall <khr@golang.org>
Fix one test that build a violating CFG.
Change-Id: Ie0296ced602984d914a70461c76559c507ce2510
Reviewed-on: https://go-review.googlesource.com/13621
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This makes it easier to investigate and
understand rewrite behavior.
Change-Id: I790e8964922caf98362ce8a6d6972f52d83eefa8
Reviewed-on: https://go-review.googlesource.com/13588
Reviewed-by: Keith Randall <khr@golang.org>
This claims to be autogenerated from go tool dist,
but I don't see where.
In any case, the update is trivial.
Change-Id: I58daaba755f3d34a0396005046b89411a02ada7e
Reviewed-on: https://go-review.googlesource.com/13584
Reviewed-by: Keith Randall <khr@golang.org>
We need to move the memory variable update back to before endBlock
so that all successors use the right memory value.
See https://go-review.googlesource.com/13560
Change-Id: Id72e5526c56e5e070b933d3b28dc503a5a2978dc
Reviewed-on: https://go-review.googlesource.com/13586
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Fix the test broken with dee1f2 by implementing Elem()
Change-Id: I7a4a487885267c24fdc52d79fb7d450231328812
Reviewed-on: https://go-review.googlesource.com/13551
Reviewed-by: Keith Randall <khr@golang.org>
Consider OpZero to be a store so it can be eliminated by dse.
Change-Id: Idebb6a190657b76966f0c5b20f2ec9f52fe47499
Reviewed-on: https://go-review.googlesource.com/13447
Reviewed-by: Keith Randall <khr@golang.org>
Introduce pseudo-ops PanicMem and LoweredPanicMem.
PanicMem could be rewritten directly into MOVL
during lowering, but then we couldn't log nil checks.
With this change, runnable nil check tests pass:
GOSSAPKG=main go run run.go -- nil*.go
Compiler output nil check tests fail:
GOSSAPKG=p go run run.go -- nil*.go
This is due to several factors:
* SSA has improved elimination of unnecessary nil checks.
* SSA is missing elimination of implicit nil checks.
* SSA is missing extra logging about why nil checks were removed.
I'm not sure how best to resolve these failures,
particularly in a world in which the two backends
will live side by side for some time.
For now, punt on the problem.
Change-Id: Ib2ca6824551671f92e0e1800b036f5ca0905e2a3
Reviewed-on: https://go-review.googlesource.com/13474
Reviewed-by: Keith Randall <khr@golang.org>
We were not recording function calls as
changing the state of memory.
As a result, the scheduler was not aware that
storing values to the stack in order to make a
function call must happen *after* retrieving
results from the stack from a just-completed
function call.
This fixes the container/ring tests.
This was my first experience debugging an issue
using the HTML output. I'm feeling quite
pleased with it.
Change-Id: I9e8276846be9fd7a60422911b11816c5175e3d0a
Reviewed-on: https://go-review.googlesource.com/13560
Reviewed-by: Keith Randall <khr@golang.org>
Hardcoded the limit on constants only allowed.
Change-Id: Idb9b07b4871db7a752a79e492671e9b41207b956
Reviewed-on: https://go-review.googlesource.com/13257
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Move the known-non-nil scan outside the work loop to resolve an issue
with values that were declared outside the block being operated on.
Also consider phis whose arguments are all non-nil, as non-nil.
Change-Id: I4d5b840042de9eb181f2cb918f36913fb5d517a2
Reviewed-on: https://go-review.googlesource.com/13441
Reviewed-by: Keith Randall <khr@golang.org>
Use a version of Floyd's cycle finding algorithm,
but advance by 1 and 1/2 steps per cycle rather
than by 1 and 2. It is simpler and should be cheaper
in the normal, acyclic case.
This should fix the 386 and arm builds,
which are currently hung.
Change-Id: If8bd443011b28a5ecb004a549239991d3dfc862b
Reviewed-on: https://go-review.googlesource.com/13473
Reviewed-by: Keith Randall <khr@golang.org>
We must make sure that all loads that use a store are scheduled
before the next store. Add additional dependency edges to the
value graph to enforce this constraint.
Change-Id: Iab83644f68bc4c30637085b82ca7467b9d5513a5
Reviewed-on: https://go-review.googlesource.com/13470
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Don't nilcheck values that were constructed as a result of OpAddr or
OpAddPtr.
Change-Id: I38053e905d1b76a2a64e77f84e444d38a5217108
Reviewed-on: https://go-review.googlesource.com/13256
Reviewed-by: David Chase <drchase@google.com>
Rather than require an explicit Copy on the RHS of rewrite rules,
use rulegen magic to add it.
The advantages to handling this in rulegen are:
* simpler rules
* harder to accidentally miss a Copy
Change-Id: I46853bade83bdf517eee9495bf5a553175277b53
Reviewed-on: https://go-review.googlesource.com/13242
Reviewed-by: Keith Randall <khr@golang.org>
The lowering rules were missing the non-64 bit case.
SBBLcarrymask can be folded to a int32 integer whose
type has a smaller bit size. Without the new AND rules
the following would be generated:
v19 = MOVLconst <uint8> [-1] : SI
v20 = ANDB <uint8> v18 v19 : DI
which is obviously a NOP.
Fixes#12022
Change-Id: I5f4209f78edc0f118e5b9b2908739f09cefebca4
Reviewed-on: https://go-review.googlesource.com/13301
Reviewed-by: Keith Randall <khr@golang.org>
Make sure all referenced Blocks and Values are really there.
Fix deadcode to generate SSA graphs that pass this new test.
Change-Id: Ib002ce20e33490eb8c919bd189d209f769d61517
Reviewed-on: https://go-review.googlesource.com/13147
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
No functional changes.
The intent is just to make this
easier to read and maintain.
Change-Id: Iec207546482cd62bcb22eaae8efe5be6c4f15378
Reviewed-on: https://go-review.googlesource.com/13284
Reviewed-by: Keith Randall <khr@golang.org>
regalloc expects to find all OpSP and OpSB values
in the entry block.
There is no value to moving them; don't.
Change-Id: I775198f03ce7420348721ffc5e7d2bab065465b1
Reviewed-on: https://go-review.googlesource.com/13266
Reviewed-by: Keith Randall <khr@golang.org>
Given (say)
b1: <- b2 b3
v1 = Phi <t> v2 v3
b2:
v2 = ...
b3:
...
tighten will move v2 to b1, since it is only used in b1.
This is wrong; v2 needs to be evaluated before entering b1.
Fix it.
Change-Id: I2cc3b30e3ffd221cf594e36cec534dfd9cf3c6a7
Reviewed-on: https://go-review.googlesource.com/13264
Reviewed-by: Keith Randall <khr@golang.org>
Implement ITAB, selecting the itable field of an interface.
Soften the lowering check to allow lowerings that leave
generic but dead ops behind. (The ITAB lowering does this.)
Change-Id: Icc84961dd4060d143602f001311aa1d8be0d7fc0
Reviewed-on: https://go-review.googlesource.com/13144
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
I find myself always adding this in temporarily.
Make it permanent.
Change-Id: I1646b3930a07d0ea01840736ccd449b7fd24f06e
Reviewed-on: https://go-review.googlesource.com/13141
Reviewed-by: Keith Randall <khr@golang.org>
Failure to treat control ops as live can lead
to them being eliminated when they live in
other blocks.
Change-Id: I604a1977a3d3884b1f4516bea4e15885ce38272d
Reviewed-on: https://go-review.googlesource.com/13138
Reviewed-by: Keith Randall <khr@golang.org>
They were being omitted after scheduling.
Change-Id: Ia20e2dcb61fde9ec854918b958c3897bafd282a6
Reviewed-on: https://go-review.googlesource.com/13140
Reviewed-by: Keith Randall <khr@golang.org>
Don't put them in the control value's block.
That may be many blocks up the dominator tree.
Change-Id: Iab3ea36a890ffe0e355dadec7aeb676901c4f070
Reviewed-on: https://go-review.googlesource.com/13134
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This is helpful when debugging generated code.
Change-Id: I268efa3593a03bb2c4e9f07d9034c004cd40df41
Reviewed-on: https://go-review.googlesource.com/13099
Reviewed-by: Keith Randall <khr@golang.org>
Rewrite ^{n}x to be ^{n % 2}x. This will eventually resolve a fuzz
issue that breaks v1.5.
Updates #11352
Change-Id: I1b3f93872d06222f9ff5f6fd5580178ebaf4c003
Reviewed-on: https://go-review.googlesource.com/13110
Reviewed-by: Keith Randall <khr@golang.org>
The DFS scheduler doesn't do the right thing. If a Value x is used by
more than one other Value, then x is put into the DFS queue when
its first user (call it y) is visited. It is not removed and reinserted
when the second user of x (call it z) is visited, so the dependency
between x and z is not respected. There is no easy way to fix this with
the DFS queue because we'd have to rip values out of the middle of the
DFS queue.
The new scheduler works from the end of the block backwards, scheduling
instructions which have had all of their uses already scheduled.
A simple priority scheme breaks ties between multiple instructions that
are ready to schedule simultaneously.
Keep track of whether we've scheduled or not, and make print() use
the scheduled order if we have.
Fix some shift tests that this change tickles. Add unsigned right shift tests.
Change-Id: I44164c10bb92ae8ab8f76d7a5180cbafab826ea1
Reviewed-on: https://go-review.googlesource.com/13069
Reviewed-by: Todd Neal <todd@tneal.org>
Modify tests to use a known value instead of comparing the backends
directly.
Change-Id: I32e804e12515885bd94c4f83644cbca03b018fea
Reviewed-on: https://go-review.googlesource.com/13042
Reviewed-by: Keith Randall <khr@golang.org>
This fixes the crypto/subtle tests.
Change-Id: Ie6e721eec3481f67f13de1bfbd7988e227793148
Reviewed-on: https://go-review.googlesource.com/13000
Reviewed-by: Keith Randall <khr@golang.org>
The only types that remain in the ssa package
are special compiler-only types.
Change-Id: If957abf128ec0778910d67666c297f97f183b7ee
Reviewed-on: https://go-review.googlesource.com/12933
Reviewed-by: Keith Randall <khr@golang.org>
From compiling go there were 260 functions where XOR was needed.
Much of the required changes for implementing XOR were already
done in 12813.
Change-Id: I5a68aa028f5ed597bc1d62cedbef3620753dfe82
Reviewed-on: https://go-review.googlesource.com/12901
Reviewed-by: Keith Randall <khr@golang.org>
