cmd/compile: establish limits of bool to uint8 conversions
Improves bound check elimination for:
func arrayLargeEnough(b bool, a [2]int64) int64 {
c := byte(0)
if b {
c = 1
}
// this bound check gets elided
return a[c]
}
We also detect never true branches like:
func cCanOnlyBe0or1(b bool) byte {
var c byte
if b {
c = 1
}
// this statement can never be true so we can elide it
if c == 2 {
c = 3
}
return c
}
Hits a few times:
crypto/internal/sysrand
crypto/internal/sysrand.Read 357 -> 349 (-2.24%)
testing
testing.(*F).Fuzz.func1.1 837 -> 828 (-1.08%)
image/png
image/png.(*Encoder).Encode 1735 -> 1733 (-0.12%)
vendor/golang.org/x/crypto/cryptobyte
vendor/golang.org/x/crypto/cryptobyte.(*Builder).callContinuation 187 -> 185 (-1.07%)
crypto/internal/sysrand [cmd/compile]
crypto/internal/sysrand.Read 357 -> 349 (-2.24%)
go/parser
go/parser.(*parser).parseType 463 -> 457 (-1.30%)
go/parser.(*parser).embeddedElem 633 -> 626 (-1.11%)
go/parser.(*parser).parseFuncDecl 917 -> 914 (-0.33%)
go/parser.(*parser).parseDotsType 393 -> 391 (-0.51%)
go/parser.(*parser).error 1061 -> 1054 (-0.66%)
go/parser.(*parser).parseTypeName 537 -> 532 (-0.93%)
go/parser.(*parser).parseParamDecl 1478 -> 1451 (-1.83%)
go/parser.(*parser).parseFuncTypeOrLit 498 -> 495 (-0.60%)
go/parser.(*parser).parseValue 375 -> 371 (-1.07%)
go/parser.(*parser).parseElementList 594 -> 593 (-0.17%)
go/parser.(*parser).parseResult 593 -> 583 (-1.69%)
go/parser.(*parser).parseElement 506 -> 504 (-0.40%)
go/parser.(*parser).parseImportSpec 1110 -> 1108 (-0.18%)
go/parser.(*parser).parseStructType 741 -> 735 (-0.81%)
go/parser.(*parser).parseTypeSpec 1054 -> 1048 (-0.57%)
go/parser.(*parser).parseIdentList 625 -> 623 (-0.32%)
go/parser.(*parser).parseOperand 1221 -> 1199 (-1.80%)
go/parser.(*parser).parseIndexOrSliceOrInstance 2713 -> 2694 (-0.70%)
go/parser.(*parser).parseSwitchStmt 1458 -> 1447 (-0.75%)
go/parser.(*parser).parseArrayFieldOrTypeInstance 1865 -> 1861 (-0.21%)
go/parser.(*parser).parseExpr 307 -> 305 (-0.65%)
go/parser.(*parser).parseSelector 427 -> 425 (-0.47%)
go/parser.(*parser).parseTypeInstance 1433 -> 1420 (-0.91%)
go/parser.(*parser).parseCaseClause 629 -> 626 (-0.48%)
go/parser.(*parser).parseParameterList 4212 -> 4189 (-0.55%)
go/parser.(*parser).parsePointerType 393 -> 391 (-0.51%)
go/parser.(*parser).parseFuncType 465 -> 463 (-0.43%)
go/parser.(*parser).parseTypeAssertion 559 -> 557 (-0.36%)
go/parser.(*parser).parseSimpleStmt 2443 -> 2388 (-2.25%)
go/parser.(*parser).parseCallOrConversion 1093 -> 1087 (-0.55%)
go/parser.(*parser).parseForStmt 2168 -> 2159 (-0.42%)
go/parser.(*parser).embeddedTerm 657 -> 649 (-1.22%)
go/parser.(*parser).parseCommClause 1509 -> 1501 (-0.53%)
cmd/internal/objfile
cmd/internal/objfile.(*goobjFile).symbols 5299 -> 5274 (-0.47%)
net
net.initConfVal 378 -> 374 (-1.06%)
net.(*conf).hostLookupOrder 269 -> 267 (-0.74%)
net.(*conf).addrLookupOrder 261 -> 255 (-2.30%)
cmd/internal/obj/loong64
cmd/internal/obj/loong64.(*ctxt0).oplook 1829 -> 1813 (-0.87%)
cmd/internal/obj/mips
cmd/internal/obj/mips.(*ctxt0).oplook 1428 -> 1400 (-1.96%)
go/types
go/types.(*typeWriter).signature 605 -> 601 (-0.66%)
go/types.(*Checker).instantiateSignature 1469 -> 1467 (-0.14%)
go/parser [cmd/compile]
go/parser.(*parser).parseSwitchStmt 1458 -> 1447 (-0.75%)
go/parser.(*parser).parseDotsType 393 -> 391 (-0.51%)
go/parser.(*parser).embeddedElem 633 -> 626 (-1.11%)
go/parser.(*parser).parseTypeAssertion 559 -> 557 (-0.36%)
go/parser.(*parser).parseCommClause 1509 -> 1501 (-0.53%)
go/parser.(*parser).parseCaseClause 629 -> 626 (-0.48%)
go/parser.(*parser).parseImportSpec 1110 -> 1108 (-0.18%)
go/parser.(*parser).parseTypeSpec 1054 -> 1048 (-0.57%)
go/parser.(*parser).parseElementList 594 -> 593 (-0.17%)
go/parser.(*parser).parseParamDecl 1478 -> 1451 (-1.83%)
go/parser.(*parser).parseType 463 -> 457 (-1.30%)
go/parser.(*parser).parseSimpleStmt 2443 -> 2388 (-2.25%)
go/parser.(*parser).parseIdentList 625 -> 623 (-0.32%)
go/parser.(*parser).parseTypeInstance 1433 -> 1420 (-0.91%)
go/parser.(*parser).parseResult 593 -> 583 (-1.69%)
go/parser.(*parser).parseValue 375 -> 371 (-1.07%)
go/parser.(*parser).parseFuncDecl 917 -> 914 (-0.33%)
go/parser.(*parser).error 1061 -> 1054 (-0.66%)
go/parser.(*parser).parseElement 506 -> 504 (-0.40%)
go/parser.(*parser).parseFuncType 465 -> 463 (-0.43%)
go/parser.(*parser).parsePointerType 393 -> 391 (-0.51%)
go/parser.(*parser).parseTypeName 537 -> 532 (-0.93%)
go/parser.(*parser).parseExpr 307 -> 305 (-0.65%)
go/parser.(*parser).parseFuncTypeOrLit 498 -> 495 (-0.60%)
go/parser.(*parser).parseStructType 741 -> 735 (-0.81%)
go/parser.(*parser).parseOperand 1221 -> 1199 (-1.80%)
go/parser.(*parser).parseIndexOrSliceOrInstance 2713 -> 2694 (-0.70%)
go/parser.(*parser).parseForStmt 2168 -> 2159 (-0.42%)
go/parser.(*parser).parseParameterList 4212 -> 4189 (-0.55%)
go/parser.(*parser).parseArrayFieldOrTypeInstance 1865 -> 1861 (-0.21%)
go/parser.(*parser).parseSelector 427 -> 425 (-0.47%)
go/parser.(*parser).parseCallOrConversion 1093 -> 1087 (-0.55%)
go/parser.(*parser).embeddedTerm 657 -> 649 (-1.22%)
crypto/tls
crypto/tls.(*Conn).clientHandshake 3430 -> 3421 (-0.26%)
cmd/internal/obj/mips [cmd/compile]
cmd/internal/obj/mips.(*ctxt0).oplook 1428 -> 1400 (-1.96%)
cmd/internal/obj/loong64 [cmd/compile]
cmd/internal/obj/loong64.(*ctxt0).oplook 1829 -> 1813 (-0.87%)
cmd/compile/internal/types2
cmd/compile/internal/types2.(*typeWriter).signature 605 -> 601 (-0.66%)
cmd/compile/internal/types2.(*Checker).infer 10646 -> 10614 (-0.30%)
cmd/compile/internal/types2.(*Checker).instantiateSignature 1567 -> 1561 (-0.38%)
cmd/compile/internal/types2 [cmd/compile]
cmd/compile/internal/types2.(*Checker).instantiateSignature 1567 -> 1561 (-0.38%)
cmd/compile/internal/types2.(*typeWriter).signature 605 -> 601 (-0.66%)
cmd/compile/internal/types2.(*Checker).infer 10718 -> 10654 (-0.60%)
cmd/vendor/golang.org/x/arch/s390x/s390xasm
cmd/vendor/golang.org/x/arch/s390x/s390xasm.GoSyntax 36778 -> 36682 (-0.26%)
net/http
net/http.(*Client).do 4202 -> 4170 (-0.76%)
net/http.(*http2clientStream).writeRequest 3692 -> 3686 (-0.16%)
cmd/vendor/github.com/ianlancetaylor/demangle
cmd/vendor/github.com/ianlancetaylor/demangle.(*rustState).genericArgs 466 -> 463 (-0.64%)
cmd/compile/internal/devirtualize
cmd/compile/internal/devirtualize.ProfileGuided.func1 1364 -> 1357 (-0.51%)
cmd/compile/internal/inline/interleaved
cmd/compile/internal/inline/interleaved.DevirtualizeAndInlinePackage.func2 533 -> 526 (-1.31%)
cmd/compile/internal/devirtualize [cmd/compile]
cmd/compile/internal/devirtualize.ProfileGuided.func1 1343 -> 1332 (-0.82%)
cmd/compile/internal/inline/interleaved [cmd/compile]
cmd/compile/internal/inline/interleaved.DevirtualizeAndInlinePackage.func2 533 -> 526 (-1.31%)
cmd/link/internal/ld
cmd/link/internal/ld.mustLinkExternal 2739 -> 2674 (-2.37%)
cmd/compile/internal/ssa
cmd/compile/internal/ssa.(*poset).Ordered 391 -> 389 (-0.51%)
cmd/compile/internal/ssa.(*poset).Equal 318 -> 313 (-1.57%)
cmd/compile/internal/ssa.(*poset).Undo 1842 -> 1832 (-0.54%)
cmd/compile/internal/ssa.(*expandState).decomposeAsNecessary 4587 -> 4555 (-0.70%)
cmd/compile/internal/ssa.(*poset).OrderedOrEqual 390 -> 389 (-0.26%)
cmd/compile/internal/ssa.(*poset).NonEqual 613 -> 606 (-1.14%)
cmd/compile/internal/ssa [cmd/compile]
cmd/compile/internal/ssa.(*poset).OrderedOrEqual 368 -> 365 (-0.82%)
cmd/compile/internal/ssa.(*poset).Equal 318 -> 313 (-1.57%)
cmd/compile/internal/ssa.(*expandState).decomposeAsNecessary 4952 -> 4938 (-0.28%)
cmd/compile/internal/ssa.(*poset).NonEqual 613 -> 606 (-1.14%)
cmd/compile/internal/ssa.(*poset).SetEqual 2533 -> 2505 (-1.11%)
cmd/compile/internal/ssa.(*poset).SetNonEqual 785 -> 777 (-1.02%)
cmd/compile/internal/ssa.(*poset).Ordered 370 -> 366 (-1.08%)
cmd/compile/internal/gc [cmd/compile]
cmd/compile/internal/gc.Main.DevirtualizeAndInlinePackage.func2 492 -> 489 (-0.61%)
file before after Δ %
crypto/internal/sysrand.s 1553 1545 -8 -0.515%
internal/zstd.s 49179 49190 +11 +0.022%
testing.s 115197 115188 -9 -0.008%
image/png.s 36109 36107 -2 -0.006%
vendor/golang.org/x/crypto/cryptobyte.s 30980 30978 -2 -0.006%
crypto/internal/sysrand [cmd/compile].s 1553 1545 -8 -0.515%
go/parser.s 112638 112354 -284 -0.252%
cmd/internal/objfile.s 49994 49969 -25 -0.050%
net.s 299558 299546 -12 -0.004%
cmd/internal/obj/loong64.s 71651 71635 -16 -0.022%
cmd/internal/obj/mips.s 59681 59653 -28 -0.047%
go/types.s 558839 558833 -6 -0.001%
cmd/compile/internal/types.s 71305 71306 +1 +0.001%
go/parser [cmd/compile].s 112749 112465 -284 -0.252%
crypto/tls.s 388859 388850 -9 -0.002%
cmd/internal/obj/mips [cmd/compile].s 59792 59764 -28 -0.047%
cmd/internal/obj/loong64 [cmd/compile].s 71762 71746 -16 -0.022%
cmd/compile/internal/types2.s 540608 540566 -42 -0.008%
cmd/compile/internal/types2 [cmd/compile].s 577428 577354 -74 -0.013%
cmd/vendor/golang.org/x/arch/s390x/s390xasm.s 267664 267568 -96 -0.036%
net/http.s 620704 620666 -38 -0.006%
cmd/vendor/github.com/ianlancetaylor/demangle.s 299991 299988 -3 -0.001%
cmd/compile/internal/devirtualize.s 21452 21445 -7 -0.033%
cmd/compile/internal/inline/interleaved.s 8358 8351 -7 -0.084%
cmd/compile/internal/devirtualize [cmd/compile].s 20994 20983 -11 -0.052%
cmd/compile/internal/inline/interleaved [cmd/compile].s 8328 8321 -7 -0.084%
cmd/link/internal/ld.s 641802 641737 -65 -0.010%
cmd/compile/internal/ssa.s
3552939 3552957 +18 +0.001%
cmd/compile/internal/ssa [cmd/compile].s
3752191 3752197 +6 +0.000%
cmd/compile/internal/ssagen.s 405780 405786 +6 +0.001%
cmd/compile/internal/ssagen [cmd/compile].s 434472 434496 +24 +0.006%
cmd/compile/internal/gc [cmd/compile].s 38499 38496 -3 -0.008%
total
36185267 36184243 -1024 -0.003%
Change-Id: I867222b0f907b29d32b2676e55c6b5789ec56511
Reviewed-on: https://go-review.googlesource.com/c/go/+/642716
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>