David Chase 7fbb1b36c3 cmd/internal/gc: improve flow of input params to output params ... This includes the following information in the per-function summary: outK = paramJ encoded in outK bits for paramJ outK = *paramJ encoded in outK bits for paramJ heap = paramJ EscHeap heap = *paramJ EscContentEscapes Note that (currently) if the address of a parameter is taken and returned, necessarily a heap allocation occurred to contain that reference, and the heap can never refer to stack, therefore the parameter and everything downstream from it escapes to the heap. The per-function summary information now has a tuneable number of bits (2 is probably noticeably better than 1, 3 is likely overkill, but it is now easy to check and the -m debugging output includes information that allows you to figure out if more would be better.) A new test was added to check pointer flow through struct-typed and *struct-typed parameters and returns; some of these are sensitive to the number of summary bits, and ought to yield better results with a more competent escape analysis algorithm. Another new test checks (some) correctness with array parameters, results, and operations. The old analysis inferred a piece of plan9 runtime was non-escaping by counteracting overconservative analysis with buggy analysis; with the bug fixed, the result was too conservative (and it's not easy to fix in this framework) so the source code was tweaked to get the desired result. A test was added against the discovered bug. The escape analysis was further improved splitting the "level" into 3 parts, one tracking the conventional "level" and the other two computing the highest-level-suffix-from-copy, which is used to generally model the cancelling effect of indirection applied to address-of. With the improved escape analysis enabled, it was necessary to modify one of the runtime tests because it now attempts to allocate too much on the (small, fixed-size) G0 (system) stack and this failed the test. Compiling src/std after touching src/runtime/*.go with -m logging turned on shows 420 fewer heap allocation sites (10538 vs 10968). Profiling allocations in src/html/template with for i in {1..5} ; do go tool 6g -memprofile=mastx.${i}.prof -memprofilerate=1 *.go; go tool pprof -alloc_objects -text mastx.${i}.prof ; done showed a 15% reduction in allocations performed by the compiler. Update #3753 Update #4720 Fixes #10466 Change-Id: I0fd97d5f5ac527b45f49e2218d158a6e89951432 Reviewed-on: https://go-review.googlesource.com/8202 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>		2015-05-01 13:47:20 +00:00
..
bench	build: adjustments for move from src/pkg to src	2014-09-08 00:06:45 -04:00
bugs	test: migrate remaining tests to run.go	2014-12-22 22:41:34 +00:00
chan	cmd/gc: implement 'for range x {'	2014-07-16 19:27:10 -04:00
ddd2.dir	test: convert tests to run.go whenever possible.	2012-10-10 22:35:27 +02:00
dwarf	test: make rundir match compiledir/errorcheckdir.	2013-01-11 22:00:48 +01:00
fixedbugs	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
import2.dir	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import4.dir	test: match gccgo import error messages	2013-12-12 19:02:11 -08:00
interface	cmd/internal/gc: inline x := y.(*T) and x, ok := y.(*T)	2015-03-20 20:05:37 +00:00
ken
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	build: adjustments for move from src/pkg to src	2014-09-08 00:06:45 -04:00
syntax	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
64bit.go	cmd/gc: Error out on division by constant zero.	2013-01-30 20:21:08 +01:00
235.go
alias1.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
alias.go
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
bigalg.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
bigmap.go
blank1.go	test: match gccgo error messages for blank1.go	2013-09-28 15:19:05 -07:00
blank.go	test: revert changes made for Go SSA interpreter test.	2013-10-08 14:36:20 -04:00
bom.go	gc: initial BOM is legal.	2012-09-10 13:03:07 -07:00
bombad.go	gc: initial BOM is legal.	2012-09-10 13:03:07 -07:00
bounds.go	test: prepare for 64-bit ints	2012-09-24 00:06:41 -04:00
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
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	cmd/gc: do not nop-convert equivalent but different interface types.	2014-02-27 08:07:50 +01:00
cmplx.go	cmd/gc: reject complex calls with mismatched argument types.	2013-03-11 22:55:14 +01:00
cmplxdivide1.go
cmplxdivide.c	test: comment the behavior and use of cmplxdivide*	2015-01-15 00:00:06 +00:00
cmplxdivide.go	test: comment the behavior and use of cmplxdivide*	2015-01-15 00:00:06 +00:00
complit1.go
complit.go
compos.go
const1.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
const2.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
const3.go
const4.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
const5.go	cmd/gc: reject builtin function calls in len(fixed array) constants	2014-04-03 19:04:33 -04:00
const6.go	test: match gccgo error strings.	2013-06-26 18:05:02 +02:00
const.go	exp/ssa/interp: (#6 of 5): test interpretation of SSA form of $GOROOT/test/*.go.	2013-02-21 12:48:38 -05:00
convert1.go
convert3.go
convert.go
convlit1.go
convlit.go
convT2X.go
copy.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
crlf.go
ddd1.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
ddd2.go	test: convert tests to run.go whenever possible.	2012-10-10 22:35:27 +02:00
ddd.go
decl.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
declbad.go	test: correct type in declbad.go	2012-10-07 21:52:57 +02:00
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
deferprint.out
divide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
divmod.go	all: fix a few spelling errors in source comments	2013-12-27 08:59:02 -08:00
empty.go
env.go
eof1.go
eof.go
errchk	test/errchk: use "#!/usr/bin/env perl" shebang line	2013-05-23 04:41:22 +08:00
escape2.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape2n.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape3.go
escape4.go	cmd/internal/gc: transitive inlining	2015-02-26 17:36:00 +00:00
escape5.go	test: add tests for escape analysis of interface conversions	2015-03-28 16:15:27 +00:00
escape_array.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_calls.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_closure.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_field.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_iface.go	test: add tests for escape analysis of interface conversions	2015-03-28 16:15:27 +00:00
escape_indir.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_level.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_map.go	test: add tests for escape analysis of interface conversions	2015-03-28 16:15:27 +00:00
escape_param.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_slice.go	test: add tests for escape analysis of slices	2015-03-28 13:18:42 +00:00
escape_struct_param1.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_struct_param2.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_struct_return.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +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
float_lit2.go	test: fix two typos in float_lit2.go	2014-05-21 17:19:12 -04:00
float_lit3.go	test/float_lit2.go: rewrite to test values near boundaries	2014-05-21 17:12:06 -04:00
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
func7.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
func8.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
func.go
funcdup2.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
funcdup.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
gc1.go
gc2.go	test: check for build constraints only upto the first blank line	2015-02-06 05:36:26 +00:00
gc.go
gcstring.go	runtime: fix empty string handling in garbage collector	2014-03-11 23:58:39 -04:00
goprint.go	test: make goprint.go wait longer for go its routine to execute	2013-04-12 16:04:19 -07:00
goprint.out
goto.go
helloworld.go
helloworld.out
if.go
import1.go	test: match gccgo import error messages	2013-12-12 19:02:11 -08:00
import2.go	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import4.go	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import5.go
import.go
index0.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index1.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index2.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index.go	test: recognize gccgo error message in index.go	2013-09-27 20:38:52 -07:00
indirect1.go
indirect.go
init1.go	test: deflake init1.go test, tighten its bounds	2015-02-13 22:13:56 +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
inline.go	cmd/internal/gc: transitive inlining	2015-02-26 17:36:00 +00:00
int_lit.go
intcvt.go
iota.go
label1.go
label.go
linkx_run.go	cmd/go: put user ldflags at the end of the linker invocation	2015-01-02 18:36:44 +00:00
linkx.go	test: move linkx and sinit to run.go	2014-11-06 15:14:08 -05:00
literal.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
live1.go	cmd/gc: correct liveness for fat variables	2014-02-15 10:58:55 -05:00
live2.go	cmd/gc: allocate non-escaping maps on stack	2015-02-12 09:53:52 +00:00
live.go	test: add -update_errors flag to run script	2015-04-10 11:33:42 +00:00
mallocfin.go
map1.go
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
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	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
method5.go	cmd/gc: implement method values	2013-03-20 17:11:09 -04:00
method.go	test: a number of fixes.	2013-02-11 18:20:52 -05:00
named1.go	cmd/gc: comma-ok assignments produce untyped bool as 2nd result	2014-08-11 16:11:55 -07:00
named.go
nil.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
nilcheck.go	cmd/gc: optimize existence-only map lookups	2015-01-07 22:36:06 +00:00
nilptr2.go	test: revert changes made for Go SSA interpreter test.	2013-10-08 14:36:20 -04:00
nilptr3.go	cmd/7g: enable peephole optimizer	2015-04-08 08:16:54 +00:00
nilptr4.go	cmd/gc: fix bad checknil with ints on 32 bit compilers	2014-02-26 12:25:13 -08:00
nilptr.go	test/nilptr: add more tests	2013-09-05 23:06:34 -04:00
nosplit.go	test: fix nosplit test, and disable nilptr3 test on arm64	2015-03-16 18:46:35 +00:00
nul1.go	test: run some more tests by default	2012-11-08 09:04:27 -08:00
parentype.go
peano.go
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
range.go	cmd/gc: implement 'for range x {'	2014-07-16 19:27:10 -04:00
recover1.go
recover2.go
recover3.go	tests: remove two misuses of nil pointers	2013-08-15 11:51:04 -04:00
recover4.go	test: fix recover4 test on 64kb systems	2015-03-17 05:25:01 +00:00
recover.go	test: add more cases to recover.go	2014-10-22 08:06:15 -07:00
rename1.go
rename.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
reorder2.go	cmd/gc: shorten temporary lifetimes when possible	2014-04-01 13:31:38 -04:00
reorder.go	test: a number of fixes.	2013-02-11 18:20:52 -05:00
return.go	test: add cases to return.go that gccgo got wrong	2013-08-07 11:31:01 -07:00
rotate0.go	[dev.cc] test: disable rotate tests	2015-02-19 20:14:21 +00:00
rotate1.go	[dev.cc] test: disable rotate tests	2015-02-19 20:14:21 +00:00
rotate2.go	[dev.cc] test: disable rotate tests	2015-02-19 20:14:21 +00:00
rotate3.go	[dev.cc] test: disable rotate tests	2015-02-19 20:14:21 +00:00
rotate.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
run.go	test: gofmt run.go	2015-04-28 00:08:50 +00:00
rune.go
runtime.go
shift1.go	test: avoid "declared but not used" errors in shift1.go	2014-07-20 12:25:24 -07:00
shift2.go	test: add shift expression incorrectly rejected by gccgo.	2013-06-25 08:06:34 +02:00
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	test: fix nacl build	2014-11-09 21:10:49 -05:00
sinit.go	test: move linkx and sinit to run.go	2014-11-06 15:14:08 -05:00
sizeof.go	test: correct sizeof.go.	2013-06-02 19:10:11 +02:00
slice3.go	cmd/gc, runtime: treat slices and strings like pointers in garbage collection	2014-08-25 14:38:19 -04:00
slice3err.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
slicecap.go	cmd/gc, runtime: treat slices and strings like pointers in garbage collection	2014-08-25 14:38:19 -04:00
solitaire.go
stack.go
string_lit.go	test: add []rune case to string_lit.go	2013-12-12 17:17:02 -08:00
stringrange.go	all: make Unicode surrogate halves illegal as UTF-8	2012-08-08 14:01:23 -07:00
struct0.go
switch3.go	cmd/gc: accept switches on comparable arrays.	2012-08-03 21:47:26 +02:00
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: combine small NoScan allocations	2014-01-24 22:35:11 +04:00
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
typeswitch1.go
typeswitch2.go
typeswitch3.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
typeswitch.go
undef.go
utf.go
varerr.go
varinit.go
writebarrier.go	cmd/internal/gc: add and test write barrier debug output	2015-04-24 14:39:49 +00:00
zerodivide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00