Commit graph

11 commits

Author SHA1 Message Date
Keith Randall
3134ab3c2d cmd/compile: redo nil checks
Get rid of BlockCheck. Josh goaded me into it, and I went
down a rabbithole making it happen.

NilCheck now panics if the pointer is nil and returns void, as before.
BlockCheck is gone, and NilCheck is no longer a Control value for
any block. It just exists (and deadcode knows not to throw it away).

I rewrote the nilcheckelim pass to handle this case.  In particular,
there can now be multiple NilCheck ops per block.

I moved all of the arch-dependent nil check elimination done as
part of ssaGenValue into its own proper pass, so we don't have to
duplicate that code for every architecture.

Making the arch-dependent nil check its own pass means I needed
to add a bunch of flags to the opcode table so I could write
the code without arch-dependent ops everywhere.

Change-Id: I419f891ac9b0de313033ff09115c374163416a9f
Reviewed-on: https://go-review.googlesource.com/29120
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-09-15 02:42:13 +00:00
Cherry Zhang
38d35e714a cmd/compile, runtime/internal/atomic: intrinsify And8, Or8 on ARM64
Also add assembly implementation, in case intrinsics is disabled.

Change-Id: Iff0a8a8ce326651bd29f6c403f5ec08dd3629993
Reviewed-on: https://go-review.googlesource.com/28979
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-13 02:09:15 +00:00
Keith Randall
c345a3913f cmd/compile: get rid of BlockCall
No need for it, we can treat calls as (mostly) normal values
that take a memory and return a memory.

Lowers the number of basic blocks needed to represent a function.
"go test -c net/http" uses 27% fewer basic blocks.
Probably doesn't affect generated code much, but should help
various passes whose running time and/or space depends on
the number of basic blocks.

Fixes #15631

Change-Id: I0bf21e123f835e2cfa382753955a4f8bce03dfa6
Reviewed-on: https://go-review.googlesource.com/28950
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-12 23:27:02 +00:00
Cherry Zhang
4354ffd38b cmd/compile: intrinsify Ctz, Bswap, and some atomics on ARM64
Change-Id: Ia5bf72b70e6f6522d6fb8cd050e78f862d37b5ae
Reviewed-on: https://go-review.googlesource.com/27936
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-08 19:45:25 +00:00
Cherry Zhang
f9dafc742d cmd/compile, runtime, etc: get rid of constant FP registers
On ARM64, MIPS64, and PPC64, some floating point registers were
reserved for constants 0, 1, 2, 0.5, etc. This CL removes them.

On ARM64, they are never used. On MIPS64 and PPC64, the only use
case is a multiplication-by-2 in the old backend of the compiler,
which is replaced with an addition.

Change-Id: I737cbf43283756e3408964fc88c567a938c57036
Reviewed-on: https://go-review.googlesource.com/28095
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-30 23:16:17 +00:00
Cherry Zhang
659dd4f1d7 cmd/compile: add more ARM64 optimizations
- Use machine instructions for uint64<->float conversions
- Do not enforce alignment on Zero/Move
	ARM64 supports unaligned load/stores, but only aligned offset
	or small offset can be encoded into instructions.
- Do combined loads

Change-Id: Iffca7dd0f13070b17b784861ce5a30af584680eb
Reviewed-on: https://go-review.googlesource.com/27086
Reviewed-by: David Chase <drchase@google.com>
2016-08-17 18:44:39 +00:00
Cherry Zhang
d99cee79b9 [dev.ssa] cmd/compile, etc.: more ARM64 optimizations, and enable SSA by default
Add more ARM64 optimizations:
- use hardware zero register when it is possible.
- use shifted ops.
  The assembler supports shifted ops but not documented, nor knows
  how to print it. This CL adds them.
- enable fast division.
  This was disabled because it makes the old backend generate slower
  code. But with SSA it generates faster code.

Turn on SSA by default, also adjust tests.

Change-Id: I7794479954c83bb65008dcb457bc1e21d7496da6
Reviewed-on: https://go-review.googlesource.com/26950
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-08-15 03:37:34 +00:00
Cherry Zhang
ed1ad8f56c [dev.ssa] cmd/compile: add some ARM64 optimizations
Mostly mirrors ARM, includes:
- constant folding
- simplification of load, store, extension, and arithmetics
- nilcheck removal

Change-Id: Iffaa5fcdce100fe327429ecab316cb395e543469
Reviewed-on: https://go-review.googlesource.com/26710
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-08-11 18:08:47 +00:00
Cherry Zhang
0484052358 [dev.ssa] cmd/compile: remove flags from regMask
Reg allocator skips flag-typed values. Flag allocator uses the type
and whether the op has "clobberFlags" set.

Tested on AMD64, ARM, ARM64, 386. Passed 'toolstash -cmp' on AMD64.
PPC64 is coded blindly.

Change-Id: Ib1cc27efecef6a1bb27f7d7ed035a582660d244f
Reviewed-on: https://go-review.googlesource.com/25480
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-08-07 03:08:03 +00:00
Cherry Zhang
83208504fe [dev.ssa] cmd/compile: add more on ARM64 SSA
Support the following:
- Shifts. ARM64 machine instructions only use lowest 6 bits of the
  shift (i.e. mod 64). Use conditional selection instruction to
  ensure Go semantics.
- Zero/Move. Alignment is ensured.
- Hmul, Avg64u, Sqrt.
- reserve R18 (platform register in ARM64 ABI) and R29 (frame pointer
  in ARM64 ABI).

Everything compiles, all.bash passed (with non-SSA test disabled).

Change-Id: Ia8ed58dae5cbc001946f0b889357b258655078b1
Reviewed-on: https://go-review.googlesource.com/25290
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-07-27 16:37:23 +00:00
Cherry Zhang
ae9570a5b9 [dev.ssa] cmd/compile: initial ARM64 SSA port
Mostly copied from ARM port, with instruction names and Prog fields
adjusted, and 64-bit int ops added. Not complete.

Fib compiles and runs correctly.

Change-Id: Id3ecb0d4b571200a035344b3e8e4408769f76221
Reviewed-on: https://go-review.googlesource.com/25130
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-07-23 21:25:58 +00:00