go/test
Josh Bleecher Snyder 03c0f3fea9 cmd/gc: alias more variables during register allocation
This is joint work with Daniel Morsing.

In order for the register allocator to alias two variables, they must have the same width, stack offset, and etype. Code generation was altering a variable's etype in a few places. This prevented the variable from being moved to a register, which in turn prevented peephole optimization. This failure to alias was very common, with almost 23,000 instances just running make.bash.

This phenomenon was not visible in the register allocation debug output because the variables that failed to alias had the same name. The debugging-only change to bits.c fixes this by printing the variable number with its name.

This CL fixes the source of all etype mismatches for 6g, all but one case for 8g, and depressingly few cases for 5g. (I believe that extending CL 6819083 to 5g is a prerequisite.) Fixing the remaining cases in 8g and 5g is work for the future.

The etype mismatch fixes are:

* [gc] Slicing changed the type of the base pointer into a uintptr in order to perform arithmetic on it. Instead, support addition directly on pointers.

* [*g] OSPTR was giving type uintptr to slice base pointers; undo that. This arose, for example, while compiling copy(dst, src).

* [8g] 64 bit float conversion was assigning int64 type during codegen, overwriting the existing uint64 type.

Note that some etype mismatches are appropriate, such as a struct with a single field or an array with a single element.

With these fixes, the number of registerizations that occur while running make.bash for 6g increases ~10%. Hello world binary size shrinks ~1.5%. Running all benchmarks in the standard library show performance improvements ranging from nominal to substantive (>10%); a full comparison using 6g on my laptop is available at https://gist.github.com/josharian/8f9b5beb46667c272064. The microbenchmarks must be taken with a grain of salt; see issue 7920. The few benchmarks that show real regressions are likely due to issue 7920. I manually examined the generated code for the top few regressions and none had any assembly output changes. The few benchmarks that show extraordinary improvements are likely also due to issue 7920.

Performance results from 8g appear similar to 6g.

5g shows no performance improvements. This is not surprising, given the discussion above.

Update #7316

LGTM=rsc
R=rsc, daniel.morsing, bradfitz
CC=dave, golang-codereviews
https://golang.org/cl/91850043
2014-05-12 17:10:36 -04:00
..
bench test/bench/shootout: support windows 2014-05-09 14:34:50 -07:00
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: alias more variables during register allocation 2014-05-12 17:10:36 -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
alias.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
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
assign.go test: [a-c]: add introductory comments to tests 2012-02-19 13:19:43 +11:00
assign1.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
blank.go test: revert changes made for Go SSA interpreter test. 2013-10-08 14:36:20 -04:00
blank1.go test: match gccgo error messages for blank1.go 2013-09-28 15:19:05 -07:00
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_lit.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
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
cmp.go cmd/gc: do not nop-convert equivalent but different interface types. 2014-02-27 08:07:50 +01:00
cmp6.go cmd/gc: do not consider length zero arrays as comparable. 2014-01-31 00:30:56 +01:00
cmplx.go cmd/gc: reject complex calls with mismatched argument types. 2013-03-11 22:55:14 +01:00
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
cmplxdivide1.go test: use testlib in a few more cases 2012-03-22 02:14:44 +08:00
complit.go test: [a-c]: add introductory comments to tests 2012-02-19 13:19:43 +11:00
complit1.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
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
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 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
convT2X.go cmd/gc: cache itab lookup in convT2I. 2012-07-03 09:09:05 +10:00
convert.go test: [a-c]: add introductory comments to tests 2012-02-19 13:19:43 +11:00
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
convlit.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
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
ddd.go test: enable method expression tests in ddd.go 2012-03-07 11:17:26 -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
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
eof.go test: explanatory comments [c-g]* 2012-02-19 14:28:53 +11:00
eof1.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
escape.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
escape2.go cmd/gc: fix escape analysis for slice of array 2014-05-12 14:45:05 -04:00
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
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
func.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
funcdup.go test: match gccgo error messages 2013-12-12 17:18:12 -08:00
funcdup2.go test: match gccgo error messages 2013-12-12 17:18:12 -08:00
gc.go test: explanatory comments [c-g]* 2012-02-19 14:28:53 +11:00
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
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
import.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
index.go test: recognize gccgo error message in index.go 2013-09-27 20:38:52 -07:00
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
indirect.go test: commentary for [h-m]*.go 2012-02-23 18:47:26 +11:00
indirect1.go test: commentary for [h-m]*.go 2012-02-23 18:47:26 +11:00
init.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
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
label.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
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
live.go cmd/gc, runtime: make GODEBUG=gcdead=1 mode work with liveness 2014-04-03 20:33:25 -04:00
live1.go cmd/gc: correct liveness for fat variables 2014-02-15 10:58:55 -05:00
mallocfin.go test: commentary for [h-m]*.go 2012-02-23 18:47:26 +11:00
map.go test: fix flaky NaN-key map complexity test 2013-04-07 11:56:15 -07:00
map1.go cmd/gc: fix type checking loop 2012-06-07 03:06:40 -04:00
mapnan.go test/mapnan: use time.Now instead of syscall.Getrusage 2013-10-22 18:33:37 -04:00
method.go test: a number of fixes. 2013-02-11 18:20:52 -05:00
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
named.go gc: return of ideal bool 2012-02-21 22:54:07 -05:00
named1.go test/[n-z]*.go: add documentation 2012-02-24 11:48:19 +11:00
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
nilptr.go test/nilptr: add more tests 2013-09-05 23:06:34 -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
nosplit.go liblink, cmd/ld: reenable nosplit checking and test 2014-04-16 22:08:00 -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
recover.go test: disable failing tests under ssa/interp. 2013-09-18 14:44:57 -04:00
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
rename.go test: ensure all failing tests exit nonzero. 2013-02-12 13:17:49 -05:00
rename1.go test: fix the fix of the rename tests. 2012-02-24 15:06:32 +11:00
reorder.go test: a number of fixes. 2013-02-11 18:20:52 -05:00
reorder2.go cmd/gc: shorten temporary lifetimes when possible 2014-04-01 13:31:38 -04:00
return.go test: add cases to return.go that gccgo got wrong 2013-08-07 11:31:01 -07:00
rotate.go test: add rotate.go and fixedbugs/bug313 2013-01-11 22:42:55 +01:00
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
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
switch.go cmd/gc: disallow fallthrough in final case of switch 2013-03-15 00:35:09 -04:00
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
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
typeswitch.go test/[n-z]*.go: add documentation 2012-02-24 11:48:19 +11:00
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
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