delta/go-git.git/src/cmd/internal/obj/arm, branch dev.link

cmd/internal/obj/{arm,s390x}: make return jump print nicer

2020-10-26T19:15:06+00:00

When a function with non-zero frame size makes a return jump
(RET target), it assembles to, conceptually,

MOV (SP), LR
ADD $framesize, SP
JMP target

We did not clear some fields in the first instruction's Prog.To,
causing it printed like (on ARM)

MOVW.P	4(R13), (R14)(R14)(REG)

Clear the fields to make it print nicer.

Change-Id: I180901aeea41f1ff287d7c6034a6d69005927744
Reviewed-on: https://go-review.googlesource.com/c/go/+/264343
Trust: Cherry Zhang 
Reviewed-by: Joel Sing

cmd/internal/obj: move LSym.Func into LSym.Extra

2020-10-16T03:02:36+00:00

This creates space for a different kind of extension field
in LSym without making the struct any larger.
(There are many LSym, so we care about keeping the struct small.)

Change-Id: Ib16edb9e15f54c2a7351c8b875e19684058711e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/243943
Trust: Russ Cox 
Run-TryBot: Russ Cox 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Zhang

cmd/compile,cmd/asm: simplify recording of branch targets, take 2

2020-08-31T17:36:08+00:00

We currently use two fields to store the targets of branches.
Some phases use p.To.Val, some use p.Pcond. Rewrite so that
every branch instruction uses p.To.Val.
p.From.Val is also used in rare instances.
Introduce a Pool link for use by arm/arm64, instead of
repurposing Pcond.

This is a cleanup CL in preparation for some stack frame CLs.

Change-Id: If8239177e4b1ea2bccd0608eb39553d23210d405
Reviewed-on: https://go-review.googlesource.com/c/go/+/251437
Run-TryBot: Keith Randall 
TryBot-Result: Gobot Gobot 
Reviewed-by: Cherry Zhang

Revert "cmd/compile,cmd/asm: simplify recording of branch targets"

2020-08-28T02:10:13+00:00

This reverts CL 243318.

Reason for revert: Seems to be crashing some builders.

Change-Id: I2ffc59bc5535be60b884b281c8d0eff4647dc756
Reviewed-on: https://go-review.googlesource.com/c/go/+/251169
Reviewed-by: Bryan C. Mills

cmd/compile,cmd/asm: simplify recording of branch targets

2020-08-27T22:35:45+00:00

We currently use two fields to store the targets of branches.
Some phases use p.To.Val, some use p.Pcond. Rewrite so that
every branch instruction uses p.To.Val.
p.From.Val is also used in rare instances.
Introduce a Pool link for use by arm/arm64, instead of
repurposing Pcond.

This is a cleanup CL in preparation for some stack frame CLs.

Change-Id: I9055bf0a1d986aff421e47951a1dedc301c846f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/243318
Run-TryBot: Keith Randall 
TryBot-Result: Gobot Gobot 
Reviewed-by: Cherry Zhang

cmd/internal/obj: stop removing NOPs from instruction stream

2020-08-20T01:12:34+00:00

This has already been done for s390x, ppc64. This CL is for
all the other architectures.

Fixes #40796

Change-Id: Idd1816e057df63022d47e99fa06617811d8c8489
Reviewed-on: https://go-review.googlesource.com/c/go/+/248684
Run-TryBot: Cherry Zhang 
TryBot-Result: Gobot Gobot 
Reviewed-by: Cherry Zhang

all: fix dead links to inferno-os bitbucket repository

2020-06-04T07:25:06+00:00

Generated using:

  perl -i -npe 's#inferno-os/src/default#inferno-os/src/master#' $(git grep -l "inferno-os/src/default" | grep -v vendor)

Change-Id: I4b6443bd09a8ea4c8aaeb40a1c73520d1f7ca648
Reviewed-on: https://go-review.googlesource.com/c/go/+/235821
Reviewed-by: Cherry Zhang 
Reviewed-by: Austin Clements

cmd/asm, cmd/compile, runtime: add -spectre=ret mode

2020-03-13T19:05:54+00:00

This commit extends the -spectre flag to cmd/asm and adds
a new Spectre mitigation mode "ret", which enables the use
of retpolines.

Retpolines prevent speculation about the target of an indirect
jump or call and are described in more detail here:
https://support.google.com/faqs/answer/7625886

Change-Id: I4f2cb982fa94e44d91e49bd98974fd125619c93a
Reviewed-on: https://go-review.googlesource.com/c/go/+/222661
Reviewed-by: Keith Randall

cmd/internal/obj: mark split-stack prologue nonpreemptible

2019-11-27T01:30:19+00:00

When there are both a synchronous preemption request (by
clobbering the stack guard) and an asynchronous one (by signal),
the running goroutine may observe the synchronous request first
in stack bounds check, and go to the path of calling morestack.
If the preemption signal arrives at this point before the call to
morestack, the goroutine will be asynchronously preempted,
entering the scheduler. When it is resumed, the scheduler clears
the preemption request, unclobbers the stack guard. But the
resumed goroutine will still call morestack, as it is already on
its way. morestack will, as there is no preemption request,
double the stack unnecessarily. If this happens multiple times,
the stack may grow too big, although only a small amount is
actually used.

To fix this, we mark the stack bounds check and the call to
morestack async-nonpreemptible, starting after the memory
instruction (mostly a load, on x86 CMP with memory).

Not done for Wasm as it does not support async preemption.

Fixes #35470.

Change-Id: Ibd7f3d935a3649b80f47539116ec9b9556680cf2
Reviewed-on: https://go-review.googlesource.com/c/go/+/207350
Reviewed-by: David Chase

cmd/internal/obj/arm: remove NaCl related DATABUNDLE

2019-10-16T15:58:33+00:00

Updates golang/go#30439

Change-Id: Ieaf18b7cfd22a768eb1b7ac549ebc03637258876
Reviewed-on: https://go-review.googlesource.com/c/go/+/201377
Run-TryBot: Ben Shi 
TryBot-Result: Gobot Gobot 
Reviewed-by: Keith Randall