From 135abd769e17b88c2bb8fde4b5963b71c582ea0f Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Fri, 24 Oct 2014 10:27:39 -0400 Subject: cmd/gc: synthesize zeroed value for non-assignment context CL 157910047 introduced code to turn a node representing a zeroed composite literal into N, the nil Node* pointer (which represents any zero, not the Go literal nil). That's great for assignments like x = T{}, but it doesn't work when T{} is used in a value context like T{}.v or x == T{}. Fix those. Should have no effect on performance; confirmed. The deltas below are noise (compare ns/op): benchmark old ns/op new ns/op delta BenchmarkBinaryTree17 2902919192 2915228424 +0.42% BenchmarkFannkuch11 2597417605 2630363685 +1.27% BenchmarkFmtFprintfEmpty 73.7 74.8 +1.49% BenchmarkFmtFprintfString 196 199 +1.53% BenchmarkFmtFprintfInt 213 217 +1.88% BenchmarkFmtFprintfIntInt 336 356 +5.95% BenchmarkFmtFprintfPrefixedInt 289 294 +1.73% BenchmarkFmtFprintfFloat 415 416 +0.24% BenchmarkFmtManyArgs 1281 1271 -0.78% BenchmarkGobDecode 10271734 10307978 +0.35% BenchmarkGobEncode 8985021 9079442 +1.05% BenchmarkGzip 410233227 412266944 +0.50% BenchmarkGunzip 102114554 103272443 +1.13% BenchmarkHTTPClientServer 45297 44993 -0.67% BenchmarkJSONEncode 19499741 19498489 -0.01% BenchmarkJSONDecode 76436733 74247497 -2.86% BenchmarkMandelbrot200 4273814 4307292 +0.78% BenchmarkGoParse 4024594 4028937 +0.11% BenchmarkRegexpMatchEasy0_32 131 135 +3.05% BenchmarkRegexpMatchEasy0_1K 328 333 +1.52% BenchmarkRegexpMatchEasy1_32 115 117 +1.74% BenchmarkRegexpMatchEasy1_1K 931 948 +1.83% BenchmarkRegexpMatchMedium_32 216 217 +0.46% BenchmarkRegexpMatchMedium_1K 72669 72857 +0.26% BenchmarkRegexpMatchHard_32 3818 3809 -0.24% BenchmarkRegexpMatchHard_1K 121398 121945 +0.45% BenchmarkRevcomp 613996550 615145436 +0.19% BenchmarkTemplate 93678525 93267391 -0.44% BenchmarkTimeParse 414 411 -0.72% BenchmarkTimeFormat 396 399 +0.76% Fixes issue 8947. LGTM=r R=r, dave CC=golang-codereviews https://codereview.appspot.com/162130043 --- test/fixedbugs/issue8947.go | 53 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 test/fixedbugs/issue8947.go (limited to 'test') diff --git a/test/fixedbugs/issue8947.go b/test/fixedbugs/issue8947.go new file mode 100644 index 000000000..f40c02e99 --- /dev/null +++ b/test/fixedbugs/issue8947.go @@ -0,0 +1,53 @@ +// run + +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Some uses of zeroed constants in non-assignment +// expressions broke with our more aggressive zeroing +// of assignments (internal compiler errors). + +package main + +func f1() { + type T [2]int + p := T{0, 1} + switch p { + case T{0, 0}: + panic("wrong1") + case T{0, 1}: + // ok + default: + panic("wrong2") + } + + if p == (T{0, 0}) { + panic("wrong3") + } else if p == (T{0, 1}) { + // ok + } else { + panic("wrong4") + } +} + +type T struct { + V int +} + +var X = T{}.V + +func f2() { + var x = T{}.V + if x != 0 { + panic("wrongx") + } + if X != 0 { + panic("wrongX") + } +} + +func main() { + f1() + f2() +} -- cgit v1.2.1