Russ Cox 6722d45631 cmd/gc: liveness-related bug fixes ... 1. On entry to a function, only zero the ambiguously live stack variables. Before, we were zeroing all stack variables containing pointers. The zeroing is pretty inefficient right now (issue 7624), but there are also too many stack variables detected as ambiguously live (issue 7345), and that must be addressed before deciding how to improve the zeroing code. (Changes in 5g/ggen.c, 6g/ggen.c, 8g/ggen.c, gc/pgen.c) Fixes #7647. 2. Make the regopt word-based liveness analysis preserve the whole-variable liveness property expected by the garbage collection bitmap liveness analysis. That is, if the regopt liveness decides that one word in a struct needs to be preserved, make sure it preserves the entire struct. This is particularly important for multiword values such as strings, slices, and interfaces, in which all the words need to be present in order to understand the meaning. (Changes in 5g/reg.c, 6g/reg.c, 8g/reg.c.) Fixes #7591. 3. Make the regopt word-based liveness analysis treat a variable as having its address taken - which makes it preserved across all future calls - whenever n->addrtaken is set, for consistency with the gc bitmap liveness analysis, even if there is no machine instruction actually taking the address. In this case n->addrtaken is incorrect (a nicer way to put it is overconservative), and ideally there would be no such cases, but they can happen and the two analyses need to agree. (Changes in 5g/reg.c, 6g/reg.c, 8g/reg.c; test in bug484.go.) Fixes crashes found by turning off "zero everything" in step 1. 4. Remove spurious VARDEF annotations. As the comment in gc/pgen.c explains, the VARDEF must immediately precede the initialization. It cannot be too early, and it cannot be too late. In particular, if a function call sits between the VARDEF and the actual machine instructions doing the initialization, the variable will be treated as live during that function call even though it is uninitialized, leading to problems. (Changes in gc/gen.c; test in live.go.) Fixes crashes found by turning off "zero everything" in step 1. 5. Do not treat loading the address of a wide value as a signal that the value must be initialized. Instead depend on the existence of a VARDEF or the first actual read/write of a word in the value. If the load is in order to pass the address to a function that does the actual initialization, treating the load as an implicit VARDEF causes the same problems as described in step 4. The alternative is to arrange to zero every such value before passing it to the real initialization function, but this is a much easier and more efficient change. (Changes in gc/plive.c.) Fixes crashes found by turning off "zero everything" in step 1. 6. Treat wide input parameters with their address taken as initialized on entry to the function. Otherwise they look "ambiguously live" and we will try to emit code to zero them. (Changes in gc/plive.c.) Fixes crashes found by turning off "zero everything" in step 1. 7. An array of length 0 has no pointers, even if the element type does. Without this change, the zeroing code complains when asked to clear a 0-length array. (Changes in gc/reflect.c.) LGTM=khr R=khr CC=golang-codereviews https://golang.org/cl/80160044		2014-03-27 14:05:57 -04:00
..
bench	test: revert unintentional commits	2013-11-19 15:36:13 +04:00
bugs	cmd/gc: fix wrong interaction between inlining and embedded builtins.	2012-12-22 19:16:31 +01:00
chan	test/chan: avoid wrap-around in memstats comparison	2013-09-20 17:27:56 -07:00
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/gc: liveness-related bug fixes	2014-03-27 14:05:57 -04:00
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/gc: don't attempt to generate wrappers for blank interface methods	2013-08-19 11:53:34 +10:00
ken	go/test/chan1.go: fix typo	2012-02-25 08:47:04 +11:00
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	test/stress: fix a goroutine leak in threadRing stresstest	2013-06-03 07:07:31 -07:00
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	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
alias1.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
alias.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
append.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
args.go	test: run some more tests by default	2012-11-08 09:04:27 -08:00
assign1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
assign.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
bigalg.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
bigmap.go	runtime: handle and test large map values	2012-05-24 22:41:07 -04:00
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	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
char_lit1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
char_lit.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
closedchan.go	test: use testlib (first 100)	2012-02-16 23:48:57 -05:00
closure.go	test: enforce 1 proc in the test	2012-07-01 21:59:50 +04:00
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	test: use testlib in a few more cases	2012-03-22 02:14:44 +08:00
cmplxdivide.c	test: use testlib in a few more cases	2012-03-22 02:14:44 +08:00
cmplxdivide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
complit1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
complit.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
compos.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
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	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
const4.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
const5.go	cmd/gc: reject non-Go constants	2013-02-01 23:10:02 -05:00
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	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convert3.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convert.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convlit1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convlit.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convT2X.go	cmd/gc: cache itab lookup in convT2I.	2012-07-03 09:09:05 +10:00
copy.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
crlf.go	test: use testlib in a few more cases (part 2)	2012-04-20 23:45:43 +08:00
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	test: enable method expression tests in ddd.go	2012-03-07 11:17:26 -08:00
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	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
deferprint.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
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	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
env.go	os: remove Getenverror	2012-02-18 21:18:13 -08:00
eof1.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
eof.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
errchk	test/errchk: use "#!/usr/bin/env perl" shebang line	2013-05-23 04:41:22 +08:00
escape2.go	cmd/gc: relax address-of escape analysis	2014-02-13 19:59:09 -05:00
escape3.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
escape4.go	cmd/gc: fix escape analysis bug	2012-09-24 15:53:12 -04:00
escape5.go	cmd/gc: distinguish unnamed vs blank-named return variables better	2014-02-13 20:59:39 -05:00
escape.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
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	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func1.go	cmd/gc: ensure unique parameter and result names in function types	2013-03-15 15:24:13 -04:00
func2.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func3.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func4.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func5.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func6.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
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	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
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	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
gc2.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
gc.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
gcstring.go	runtime: fix empty string handling in garbage collector	2014-03-11 23:58:39 -04:00
golden.out	cmd/gc: do not generate code for var _ = ... unless necessary	2012-12-30 12:01:53 -05:00
goprint.go	test: make goprint.go wait longer for go its routine to execute	2013-04-12 16:04:19 -07:00
goprint.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
goto.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
helloworld.go	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
helloworld.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
if.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
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	gc: disallow absolute import paths	2012-02-29 15:28:36 -05:00
import.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
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	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
indirect.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
init1.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
init.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
initcomma.go	test/initcomma.go: restore what it's supposed to be testing	2012-02-20 07:44:24 +11:00
initialize.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
initializerr.go	test: add "duplicate" struct map key test	2012-12-17 11:05:58 -05:00
int_lit.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
intcvt.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
iota.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
label1.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
label.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
linkx.go	test: expand run.go's errorcheck, make clear which bugs run	2012-09-23 13:16:14 -04:00
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
live.go	cmd/gc: liveness-related bug fixes	2014-03-27 14:05:57 -04:00
mallocfin.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
map1.go	cmd/gc: fix type checking loop	2012-06-07 03:06:40 -04:00
map.go	test: fix flaky NaN-key map complexity test	2013-04-07 11:56:15 -07:00
mapnan.go	test/mapnan: use time.Now instead of syscall.Getrusage	2013-10-22 18:33:37 -04:00
method1.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
method2.go	cmd/gc: fix method values whose receiver is an unnamed interface.	2013-08-29 10:00:58 +02:00
method3.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
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	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
named.go	gc: return of ideal bool	2012-02-21 22:54:07 -05:00
nil.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
nilcheck.go	cmd/gc: &x panics if x does	2013-08-15 14:38:32 -04:00
nilptr2.go	test: revert changes made for Go SSA interpreter test.	2013-10-08 14:36:20 -04:00
nilptr3.go	cmd/gc: eliminate redundant &x.Field nil checks	2013-09-17 16:54:22 -04:00
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
nul1.go	test: run some more tests by default	2012-11-08 09:04:27 -08:00
parentype.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
peano.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
printbig.go	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
printbig.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
range.go	test: a number of fixes.	2013-02-11 18:20:52 -05:00
recover1.go	test: use testlib (final 61)	2012-02-16 23:51:04 -05:00
recover2.go	test: use testlib (final 61)	2012-02-16 23:51:04 -05:00
recover3.go	tests: remove two misuses of nil pointers	2013-08-15 11:51:04 -04:00
recover.go	test: disable failing tests under ssa/interp.	2013-09-18 14:44:57 -04:00
rename1.go	test: fix the fix of the rename tests.	2012-02-24 15:06:32 +11:00
rename.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
reorder2.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
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	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
rotate1.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
rotate2.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
rotate3.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
rotate.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
run	test/run: add /usr/pkg/bin to PATH.	2014-03-03 02:16:15 -05:00
run.go	test/run: make errorcheck tests faster	2014-03-11 23:58:24 -04:00
rune.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
runtime.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
shift1.go	test/shift1.go: recognize gccgo errors	2013-06-26 08:23:52 -07:00
shift2.go	test: add shift expression incorrectly rejected by gccgo.	2013-06-25 08:06:34 +02:00
sieve.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
sigchld.go	test: skip SIGCHLD test on Plan 9	2014-01-29 09:28:23 +01:00
sigchld.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
simassign.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
sinit.go	cmd/gc: do not generate code for var _ = ... unless necessary	2012-12-30 12:01:53 -05:00
sizeof.go	test: correct sizeof.go.	2013-06-02 19:10:11 +02:00
slice3.go	cmd/gc: support x[i:j:k]	2013-07-01 20:32:36 -04:00
slice3err.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
solitaire.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
stack.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
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	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
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
testlib	test/run: process build tags like go/build	2013-08-13 12:25:41 -04:00
tinyfin.go	runtime: combine small NoScan allocations	2014-01-24 22:35:11 +04:00
torture.go	cmd/8g: introduce temporaries in byte multiplication.	2012-12-21 23:46:16 +01:00
turing.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typecheck.go	cmd/gc: silence assignment errors to undefined symbols	2014-01-03 21:03:20 +01:00
typeswitch1.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typeswitch2.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typeswitch3.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
typeswitch.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
undef.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
utf.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
varerr.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
varinit.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
zerodivide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00