mirror of https://github.com/golang/go.git
ceb0c371d9
Do []byte(string) conversions more efficiently when the string
is a constant. Instead of calling stringtobyteslice, allocate
just the space we need and encode the initialization directly.
[]byte("foo") rewrites to the following pseudocode:
var s [3]byte // on heap or stack, depending on whether b escapes
s = *(*[3]byte)(&"foo"[0]) // initialize s from the string
b = s[:]
which generates this assembly:
0x001d 00029 (tmp1.go:9) LEAQ type.[3]uint8(SB), AX
0x0024 00036 (tmp1.go:9) MOVQ AX, (SP)
0x0028 00040 (tmp1.go:9) CALL runtime.newobject(SB)
0x002d 00045 (tmp1.go:9) MOVQ 8(SP), AX
0x0032 00050 (tmp1.go:9) MOVBLZX go.string."foo"+2(SB), CX
0x0039 00057 (tmp1.go:9) MOVWLZX go.string."foo"(SB), DX
0x0040 00064 (tmp1.go:9) MOVW DX, (AX)
0x0043 00067 (tmp1.go:9) MOVB CL, 2(AX)
// Then the slice is b = {AX, 3, 3}
The generated code is still not optimal, as it still does load/store
from read-only memory instead of constant stores. Next CL...
Update #26498
Fixes #10170
Change-Id: I4b990b19f9a308f60c8f4f148934acffefe0a5bd
Reviewed-on: https://go-review.googlesource.com/c/140698
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
|
||
|---|---|---|
| .. | ||
| alias3.dir | ||
| bench | ||
| chan | ||
| closure3.dir | ||
| codegen | ||
| ddd2.dir | ||
| dwarf | ||
| fixedbugs | ||
| import2.dir | ||
| import4.dir | ||
| interface | ||
| intrinsic.dir | ||
| ken | ||
| linkname.dir | ||
| method4.dir | ||
| retjmp.dir | ||
| stress | ||
| syntax | ||
| uintptrescapes.dir | ||
| 64bit.go | ||
| 235.go | ||
| README.md | ||
| alg.go | ||
| alias.go | ||
| alias1.go | ||
| alias2.go | ||
| alias3.go | ||
| align.go | ||
| append.go | ||
| append1.go | ||
| args.go | ||
| armimm.go | ||
| assign.go | ||
| assign1.go | ||
| atomicload.go | ||
| bigalg.go | ||
| bigmap.go | ||
| blank.go | ||
| blank1.go | ||
| bom.go | ||
| bombad.go | ||
| bounds.go | ||
| chancap.go | ||
| chanlinear.go | ||
| char_lit.go | ||
| char_lit1.go | ||
| checkbce.go | ||
| clearfat.go | ||
| closedchan.go | ||
| closure.go | ||
| closure1.go | ||
| closure2.go | ||
| closure3.go | ||
| closure4.go | ||
| cmp.go | ||
| cmp6.go | ||
| cmplx.go | ||
| cmplxdivide.c | ||
| cmplxdivide.go | ||
| cmplxdivide1.go | ||
| complit.go | ||
| complit1.go | ||
| compos.go | ||
| const.go | ||
| const1.go | ||
| const2.go | ||
| const3.go | ||
| const4.go | ||
| const5.go | ||
| const6.go | ||
| convT2X.go | ||
| convert.go | ||
| convert1.go | ||
| convert2.go | ||
| convert3.go | ||
| convlit.go | ||
| convlit1.go | ||
| copy.go | ||
| copy1.go | ||
| crlf.go | ||
| ddd.go | ||
| ddd1.go | ||
| ddd2.go | ||
| decl.go | ||
| declbad.go | ||
| defer.go | ||
| deferfin.go | ||
| deferprint.go | ||
| deferprint.out | ||
| devirt.go | ||
| divide.go | ||
| divmod.go | ||
| empty.go | ||
| env.go | ||
| eof.go | ||
| eof1.go | ||
| escape.go | ||
| escape2.go | ||
| escape2n.go | ||
| escape3.go | ||
| escape4.go | ||
| escape5.go | ||
| escape_array.go | ||
| escape_because.go | ||
| escape_calls.go | ||
| escape_closure.go | ||
| escape_field.go | ||
| escape_iface.go | ||
| escape_indir.go | ||
| escape_level.go | ||
| escape_map.go | ||
| escape_param.go | ||
| escape_slice.go | ||
| escape_struct_param1.go | ||
| escape_struct_param2.go | ||
| escape_struct_return.go | ||
| fibo.go | ||
| finprofiled.go | ||
| float_lit.go | ||
| float_lit2.go | ||
| float_lit3.go | ||
| floatcmp.go | ||
| for.go | ||
| func.go | ||
| func1.go | ||
| func2.go | ||
| func3.go | ||
| func4.go | ||
| func5.go | ||
| func6.go | ||
| func7.go | ||
| func8.go | ||
| funcdup.go | ||
| funcdup2.go | ||
| gc.go | ||
| gc1.go | ||
| gc2.go | ||
| gcgort.go | ||
| gcstring.go | ||
| goprint.go | ||
| goprint.out | ||
| goto.go | ||
| heapsampling.go | ||
| helloworld.go | ||
| helloworld.out | ||
| if.go | ||
| import.go | ||
| import1.go | ||
| import2.go | ||
| import4.go | ||
| import5.go | ||
| import6.go | ||
| index.go | ||
| index0.go | ||
| index1.go | ||
| index2.go | ||
| indirect.go | ||
| indirect1.go | ||
| init.go | ||
| init1.go | ||
| initcomma.go | ||
| initialize.go | ||
| initializerr.go | ||
| initloop.go | ||
| inline.go | ||
| inline_big.go | ||
| inline_caller.go | ||
| inline_callers.go | ||
| inline_literal.go | ||
| inline_math_bits_rotate.go | ||
| inline_variadic.go | ||
| int_lit.go | ||
| intcvt.go | ||
| intrinsic.go | ||
| intrinsic_atomic.go | ||
| iota.go | ||
| label.go | ||
| label1.go | ||
| linkmain.go | ||
| linkmain_run.go | ||
| linkname.go | ||
| linkobj.go | ||
| linkx.go | ||
| linkx_run.go | ||
| literal.go | ||
| live.go | ||
| live1.go | ||
| live2.go | ||
| live_syscall.go | ||
| locklinear.go | ||
| loopbce.go | ||
| makechan.go | ||
| makemap.go | ||
| makenew.go | ||
| mallocfin.go | ||
| map.go | ||
| map1.go | ||
| mapclear.go | ||
| maplinear.go | ||
| mergemul.go | ||
| method.go | ||
| method1.go | ||
| method2.go | ||
| method3.go | ||
| method4.go | ||
| method5.go | ||
| method6.go | ||
| method7.go | ||
| named.go | ||
| named1.go | ||
| nil.go | ||
| nilcheck.go | ||
| nilptr.go | ||
| nilptr2.go | ||
| nilptr3.go | ||
| nilptr3_wasm.go | ||
| nilptr4.go | ||
| nosplit.go | ||
| notinheap.go | ||
| notinheap2.go | ||
| notinheap3.go | ||
| nowritebarrier.go | ||
| nul1.go | ||
| opt_branchlikely.go | ||
| parentype.go | ||
| peano.go | ||
| phiopt.go | ||
| print.go | ||
| print.out | ||
| printbig.go | ||
| printbig.out | ||
| prove.go | ||
| range.go | ||
| recover.go | ||
| recover1.go | ||
| recover2.go | ||
| recover3.go | ||
| recover4.go | ||
| recover5.go | ||
| reflectmethod1.go | ||
| reflectmethod2.go | ||
| reflectmethod3.go | ||
| reflectmethod4.go | ||
| rename.go | ||
| rename1.go | ||
| reorder.go | ||
| reorder2.go | ||
| retjmp.go | ||
| return.go | ||
| rotate.go | ||
| rotate0.go | ||
| rotate1.go | ||
| rotate2.go | ||
| rotate3.go | ||
| run.go | ||
| rune.go | ||
| runtime.go | ||
| shift1.go | ||
| shift2.go | ||
| sieve.go | ||
| sigchld.go | ||
| sigchld.out | ||
| simassign.go | ||
| sinit.go | ||
| sinit_run.go | ||
| sizeof.go | ||
| slice3.go | ||
| slice3err.go | ||
| slicecap.go | ||
| sliceopt.go | ||
| solitaire.go | ||
| stack.go | ||
| stackobj.go | ||
| stackobj2.go | ||
| stackobj3.go | ||
| strcopy.go | ||
| strength.go | ||
| string_lit.go | ||
| stringrange.go | ||
| struct0.go | ||
| switch.go | ||
| switch2.go | ||
| switch3.go | ||
| switch4.go | ||
| switch5.go | ||
| switch6.go | ||
| switch7.go | ||
| tinyfin.go | ||
| torture.go | ||
| turing.go | ||
| typecheck.go | ||
| typecheckloop.go | ||
| typeswitch.go | ||
| typeswitch1.go | ||
| typeswitch2.go | ||
| typeswitch3.go | ||
| uintptrescapes.go | ||
| uintptrescapes2.go | ||
| undef.go | ||
| unsafereject1.go | ||
| unsafereject2.go | ||
| utf.go | ||
| varerr.go | ||
| varinit.go | ||
| writebarrier.go | ||
| zerodivide.go | ||
README.md
The test directory contains tests of the Go tool chain and runtime. It includes black box tests, regression tests, and error output tests. They are run as part of all.bash.
To run just these tests, execute:
../bin/go run run.go
Standard library tests should be written as regular Go tests in the appropriate package.
The tool chain and runtime also have regular Go tests in their packages. The main reasons to add a new test to this directory are:
- it is most naturally expressed using the test runner; or
- it is also applicable to
gccgoand other Go tool chains.