From 2b7d0b4c0d784d57ffc29cec2bdd167728d46f3c Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Thu, 15 Jan 2015 14:39:58 -0800 Subject: [release-branch.go1.4] cmd/5g: make sure we normalize after unary ops on small types We were failing ^uint16(0xffff) == 0, as we computed 0xffff0000 instead. I could only trigger a failure for the above case, the other two tests ^uint16(0xfffe) == 1 and -uint16(0xffff) == 1 didn't seem to fail previously. Somehow they get MOVHUs inserted for other reasons (used by CMP instead of TST?). I fixed OMINUS anyway, better safe than sorry. Fixes #9604 Change-Id: I4c2d5bdc667742873ac029fdbe3db0cf12893c27 Reviewed-on: https://go-review.googlesource.com/2940 Reviewed-by: Brad Fitzpatrick Reviewed-by: Minux Ma (cherry picked from commit daa64ddfe64dda368e80cf224dc485fa63386f81) Reviewed-on: https://go-review.googlesource.com/5002 --- src/cmd/5g/cgen.c | 11 +++++------ test/fixedbugs/issue9604.go | 29 +++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 6 deletions(-) create mode 100644 test/fixedbugs/issue9604.go diff --git a/src/cmd/5g/cgen.c b/src/cmd/5g/cgen.c index c535cfbefb..87c64f6e81 100644 --- a/src/cmd/5g/cgen.c +++ b/src/cmd/5g/cgen.c @@ -236,18 +236,14 @@ cgen(Node *n, Node *res) cgen(nl, &n1); nodconst(&n2, nl->type, -1); gins(a, &n2, &n1); - gmove(&n1, res); - regfree(&n1); - goto ret; + goto norm; case OMINUS: regalloc(&n1, nl->type, N); cgen(nl, &n1); nodconst(&n2, nl->type, 0); gins(optoas(OMINUS, nl->type), &n2, &n1); - gmove(&n1, res); - regfree(&n1); - goto ret; + goto norm; // symmetric binary case OAND: @@ -483,12 +479,15 @@ abop: // asymmetric binary cgen(nl, &n1); } gins(a, &n2, &n1); +norm: // Normalize result for types smaller than word. if(n->type->width < widthptr) { switch(n->op) { case OADD: case OSUB: case OMUL: + case OCOM: + case OMINUS: gins(optoas(OAS, n->type), &n1, &n1); break; } diff --git a/test/fixedbugs/issue9604.go b/test/fixedbugs/issue9604.go new file mode 100644 index 0000000000..cd9e9e49e5 --- /dev/null +++ b/test/fixedbugs/issue9604.go @@ -0,0 +1,29 @@ +// run + +// Copyright 2015 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. + +package main + +var x uint16 = 0xffff +var y uint16 = 0xfffe +var a uint16 = 0x7000 +var b uint16 = 0x9000 + +func main() { + // Make sure we truncate to smaller-width types after evaluating expressions. + // This is a problem for arm where there is no 16-bit comparison op. + if ^x != 0 { + panic("^uint16(0xffff) != 0") + } + if ^y != 1 { + panic("^uint16(0xfffe) != 1") + } + if -x != 1 { + panic("-uint16(0xffff) != 1") + } + if a+b != 0 { + panic("0x7000+0x9000 != 0") + } +} -- cgit v1.2.3-54-g00ecf