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mirror of https://github.com/golang/go synced 2024-11-27 03:51:30 -07:00
go/test
Russ Cox b6dc3e6f66 cmd/compile: fix liveness computation for heap-escaped parameters
The liveness computation of parameters generally was never
correct, but forcing all parameters to be live throughout the
function covered up that problem. The new SSA back end is
too clever: even though it currently keeps the parameter values live
throughout the function, it may find optimizations that mean
the current values are not written back to the original parameter
stack slots immediately or ever (for example if a parameter is set
to nil, SSA constant propagation may replace all later uses of the
parameter with a constant nil, eliminating the need to write the nil
value back to the stack slot), so the liveness code must now
track the actual operations on the stack slots, exposing these
problems.

One small problem in the handling of arguments is that nodarg
can return ONAME PPARAM nodes with adjusted offsets, so that
there are actually multiple *Node pointers for the same parameter
in the instruction stream. This might be possible to correct, but
not in this CL. For now, we fix this by using n.Orig instead of n
when considering PPARAM and PPARAMOUT nodes.

The major problem in the handling of arguments is general
confusion in the liveness code about the meaning of PPARAM|PHEAP
and PPARAMOUT|PHEAP nodes, especially as contrasted with PAUTO|PHEAP.
The difference between these two is that when a local variable "moves"
to the heap, it's really just allocated there to start with; in contrast,
when an argument moves to the heap, the actual data has to be copied
there from the stack at the beginning of the function, and when a
result "moves" to the heap the value in the heap has to be copied
back to the stack when the function returns
This general confusion is also present in the SSA back end.

The PHEAP bit worked decently when I first introduced it 7 years ago (!)
in 391425ae. The back end did nothing sophisticated, and in particular
there was no analysis at all: no escape analysis, no liveness analysis,
and certainly no SSA back end. But the complications caused in the
various downstream consumers suggest that this should be a detail
kept mainly in the front end.

This CL therefore eliminates both the PHEAP bit and even the idea of
"heap variables" from the back ends.

First, it replaces the PPARAM|PHEAP, PPARAMOUT|PHEAP, and PAUTO|PHEAP
variable classes with the single PAUTOHEAP, a pseudo-class indicating
a variable maintained on the heap and available by indirecting a
local variable kept on the stack (a plain PAUTO).

Second, walkexpr replaces all references to PAUTOHEAP variables
with indirections of the corresponding PAUTO variable.
The back ends and the liveness code now just see plain indirected
variables. This may actually produce better code, but the real goal
here is to eliminate these little-used and somewhat suspect code
paths in the back end analyses.

The OPARAM node type goes away too.

A followup CL will do the same to PPARAMREF. I'm not sure that
the back ends (SSA in particular) are handling those right either,
and with the framework established in this CL that change is trivial
and the result clearly more correct.

Fixes #15747.

Change-Id: I2770b1ce3cbc93981bfc7166be66a9da12013d74
Reviewed-on: https://go-review.googlesource.com/23393
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 03:19:52 +00:00
..
bench all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
bugs all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
chan all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
ddd2.dir all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
dwarf test: make rundir match compiledir/errorcheckdir. 2013-01-11 22:00:48 +01:00
fixedbugs cmd/compile: fix liveness computation for heap-escaped parameters 2016-05-27 03:19:52 +00:00
import2.dir all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
import4.dir test: adjust gccgo expected import errors 2015-10-07 14:37:44 +00:00
interface all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
intrinsic.dir cmd/compile: added some intrinsics to SSA back end 2016-03-28 16:29:59 +00:00
ken all: fix spelling mistakes 2016-04-03 17:03:15 +00:00
method4.dir cmd/gc: do not omit wrapper for expression (interface{...}).F 2014-01-07 13:26:48 +01:00
safe test: adapt old-style tests to new flag parsing. 2013-01-11 22:05:46 +01:00
stress all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
syntax all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
64bit.go cmd/gc: Error out on division by constant zero. 2013-01-30 20:21:08 +01:00
235.go
alg.go test: add test that required algs get generated 2016-04-24 21:36:52 +00:00
alias1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
alias.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
append.go
args.go test: run some more tests by default 2012-11-08 09:04:27 -08:00
assign1.go
assign.go cmd/gc: prohibit short variable declarations containing duplicate symbols 2014-10-06 17:16:39 -04:00
atomicload.go cmd/compile: keep value use counts in SSA 2016-03-17 04:20:02 +00:00
bigalg.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
bigmap.go
blank1.go cmd/compile: don't allow blank method declarations on builtins 2015-12-02 18:26:38 +00:00
blank.go test: revert changes made for Go SSA interpreter test. 2013-10-08 14:36:20 -04:00
bom.go
bombad.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
bounds.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
chancap.go
chanlinear.go runtime: test for linear enqueue/dequeue behavior 2014-12-08 22:18:17 +00:00
char_lit1.go
char_lit.go
checkbce.go cmd/compile: bce when max and limit are consts 2016-04-11 16:01:22 +00:00
clearfat.go [dev.power64] 9g: fix under-zeroing in clearfat 2014-10-31 11:08:27 -04:00
closedchan.go
closure1.go cmd/gc: capture variables by value 2015-01-29 13:07:30 +00:00
closure2.go cmd/gc: fix capturing by value for range statements 2015-02-03 15:48:48 +00:00
closure.go
cmp6.go cmd/gc: do not consider length zero arrays as comparable. 2014-01-31 00:30:56 +01:00
cmp.go Fix several out of date references to 4g/5g/6g/8g/9g. 2015-06-26 03:38:21 +00:00
cmplx.go cmd/gc: reject complex calls with mismatched argument types. 2013-03-11 22:55:14 +01:00
cmplxdivide1.go
cmplxdivide.c all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
cmplxdivide.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
complit1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
complit.go
compos.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
const1.go test: match gccgo error messages 2013-12-12 17:18:12 -08:00
const2.go
const3.go
const4.go all: link to https instead of http 2015-07-11 14:36:33 +00:00
const5.go all: link to https instead of http 2015-07-11 14:36:33 +00:00
const6.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
const.go cmd/compile: allow huge rsh in constants arithmetic 2015-08-21 20:27:22 +00:00
convert1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
convert3.go
convert.go
convlit1.go
convlit.go cmd/internal/gc: unsafe.Pointer constants may only be converted to uintptr 2015-05-07 23:54:28 +00:00
convT2X.go
copy.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
crlf.go
ddd1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
ddd2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
ddd.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
decl.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
declbad.go
defer.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
deferfin.go runtime: combine small NoScan allocations 2014-01-24 22:35:11 +04:00
deferprint.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
deferprint.out
divide.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
divmod.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
empty.go
env.go
eof1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
eof.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
errchk Fix several out of date references to 4g/5g/6g/8g/9g. 2015-06-26 03:38:21 +00:00
escape2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape2n.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape4.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape5.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_array.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_because.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_calls.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_closure.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_field.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_iface.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_indir.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_level.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_map.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_param.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_slice.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_struct_param1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_struct_param2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape_struct_return.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
escape.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
fibo.go Fix whitespace (use blanks consistently). 2014-12-08 22:22:58 +00:00
finprofiled.go runtime: fix finalization and profiling of tiny allocations 2015-11-03 18:57:18 +00:00
float_lit2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
float_lit3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
float_lit.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
floatcmp.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
for.go
func1.go cmd/gc: ensure unique parameter and result names in function types 2013-03-15 15:24:13 -04:00
func2.go
func3.go
func4.go
func5.go
func6.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
func7.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
func8.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
func.go
funcdup2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
funcdup.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
gc1.go
gc2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
gc.go
gcstring.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
goprint.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
goprint.out
goto.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
heapsampling.go test: really force heap profile update in heapsampling.go 2015-11-12 18:32:13 +00:00
helloworld.go
helloworld.out
if.go
import1.go test: match gccgo import error messages 2013-12-12 19:02:11 -08:00
import2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
import4.go
import5.go
import.go
index0.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
index1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
index2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
index.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
indirect1.go
indirect.go
init1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
init.go
initcomma.go
initialize.go
initializerr.go test: add "duplicate" struct map key test 2012-12-17 11:05:58 -05:00
initloop.go cmd/compile: use []*Node instead of NodeList in sinit 2015-09-05 02:25:01 +00:00
inline.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
int_lit.go
intcvt.go
intrinsic.go cmd/compile: added some intrinsics to SSA back end 2016-03-28 16:29:59 +00:00
iota.go
label1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
label.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
linkmain_run.go test: fix linkmain test 2015-12-17 23:36:13 +00:00
linkmain.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
linkobj.go cmd/compile: add -linkobj flag to allow writing object file in two parts 2016-05-09 17:31:45 +00:00
linkx_run.go test: print output on link -X failure 2016-04-20 17:37:35 +00:00
linkx.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
literal.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
live1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
live2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
live_ssa.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
live_syscall.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
live.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
loopbce.go cmd/compile: bce when max and limit are consts 2016-04-11 16:01:22 +00:00
mallocfin.go
map1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
map.go test/mapnan.go: add regression test for non-empty interfaces. 2014-08-06 17:02:55 -04:00
maplinear.go test: make maplinear more robust 2014-10-27 18:59:02 -04:00
method1.go cmd/compile: ignore receiver parameters in Eqtype 2016-03-17 00:38:15 +00:00
method2.go cmd/gc: fix method values whose receiver is an unnamed interface. 2013-08-29 10:00:58 +02:00
method3.go
method4.go
method5.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
method.go test: a number of fixes. 2013-02-11 18:20:52 -05:00
named1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
named.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nil.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
nilcheck.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nilptr2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nilptr3_ssa.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nilptr3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nilptr4.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nilptr.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nosplit.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nul1.go test: run some more tests by default 2012-11-08 09:04:27 -08:00
opt_branchlikely.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
parentype.go
peano.go
phiopt.go cmd/compile: introduce bool operations. 2016-04-25 20:43:04 +00:00
print.go runtime: move built-in print routines to go. 2014-07-31 13:48:48 -07:00
print.out runtime: move built-in print routines to go. 2014-07-31 13:48:48 -07:00
printbig.go
printbig.out
prove.go cmd/compile: transform some Phis into Or8. 2016-04-19 22:04:30 +00:00
range.go cmd/gc: implement 'for range x {' 2014-07-16 19:27:10 -04:00
recover1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
recover2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
recover3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
recover4.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
recover.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
reflectmethod1.go cmd/compile: track reflect.Type.Method in deadcode 2016-03-11 21:19:20 +00:00
reflectmethod2.go cmd/compile: track reflect.Type.Method in deadcode 2016-03-11 21:19:20 +00:00
reflectmethod3.go cmd/compile: track reflect.Type.Method in deadcode 2016-03-11 21:19:20 +00:00
reflectmethod4.go cmd/link: treat reflect.Value.Method like Call 2016-03-11 22:07:02 +00:00
rename1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rename.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
reorder2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
reorder.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
return.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rotate0.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rotate1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rotate2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rotate3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rotate.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
run.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
rune.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
runtime.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
shift1.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
shift2.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
sieve.go
sigchld.go test: skip SIGCHLD test on Plan 9 2014-01-29 09:28:23 +01:00
sigchld.out
simassign.go
sinit_run.go all: retire architecture letter in file names, public API 2015-05-21 17:32:17 +00:00
sinit.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
sizeof.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
slice3.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
slice3err.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
slicecap.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
sliceopt.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
solitaire.go
stack.go
strength.go cmd/compile: generalize strength reduction of mulq 2016-03-30 22:27:13 +00:00
string_lit.go test: add []rune case to string_lit.go 2013-12-12 17:17:02 -08:00
stringrange.go
struct0.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
switch2.go cmd/compile: address several more 1.6 TODOs in parser 2015-11-21 07:21:23 +00:00
switch3.go
switch4.go cmd/gc: disallow fallthrough in final case of switch 2013-03-15 00:35:09 -04:00
switch.go cmd/gc: disallow fallthrough in final case of switch 2013-03-15 00:35:09 -04:00
tinyfin.go runtime: fix finalization and profiling of tiny allocations 2015-11-03 18:57:18 +00:00
torture.go cmd/8g: don't allocate a register early for cap(CHAN). 2014-07-01 09:20:51 +02:00
turing.go
typecheck.go cmd/gc: silence assignment errors to undefined symbols 2014-01-03 21:03:20 +01:00
typecheckloop.go cmd/compile: convert typecheck_stack to []*Node 2015-09-06 23:50:51 +00:00
typeswitch1.go
typeswitch2.go
typeswitch3.go
typeswitch.go
undef.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
utf.go
varerr.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
varinit.go
writebarrier.go all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
zerodivide.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00