From a5f8128e39d081c972e7bf3182122bac79bb6f8c Mon Sep 17 00:00:00 2001 From: bill_ofarrell Date: Thu, 28 Jun 2018 18:39:37 -0400 Subject: [PATCH] bytes, strings: fix comparison of long byte slices on s390x The existing implementation of bytes.Compare on s390x doesn't work properly for slices longer than 256 elements. This change fixes that. Added tests for long strings and slices of bytes. Fixes #26114 Change-Id: If6d8b68ee6dbcf99a24f867a1d3438b1f208954f Reviewed-on: https://go-review.googlesource.com/121495 Reviewed-by: Brad Fitzpatrick Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot --- src/bytes/compare_test.go | 15 +++++++++++++-- src/internal/bytealg/compare_s390x.s | 2 ++ src/strings/compare_test.go | 15 +++++++++++++-- 3 files changed, 28 insertions(+), 4 deletions(-) diff --git a/src/bytes/compare_test.go b/src/bytes/compare_test.go index 35088a1b2e..3e33c27c9c 100644 --- a/src/bytes/compare_test.go +++ b/src/bytes/compare_test.go @@ -6,6 +6,7 @@ package bytes_test import ( . "bytes" + "internal/testenv" "testing" ) @@ -58,10 +59,20 @@ func TestCompareIdenticalSlice(t *testing.T) { } func TestCompareBytes(t *testing.T) { - n := 128 + lengths := make([]int, 0) // lengths to test in ascending order + for i := 0; i <= 128; i++ { + lengths = append(lengths, i) + } + lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097) + + if !testing.Short() || testenv.Builder() != "" { + lengths = append(lengths, 65535, 65536, 65537, 99999) + } + + n := lengths[len(lengths)-1] a := make([]byte, n+1) b := make([]byte, n+1) - for len := 0; len < 128; len++ { + for _, len := range lengths { // randomish but deterministic data. No 0 or 255. for i := 0; i < len; i++ { a[i] = byte(1 + 31*i%254) diff --git a/src/internal/bytealg/compare_s390x.s b/src/internal/bytealg/compare_s390x.s index 7f27b08c0e..d0d76166aa 100644 --- a/src/internal/bytealg/compare_s390x.s +++ b/src/internal/bytealg/compare_s390x.s @@ -49,6 +49,8 @@ loop: BGT gt BLT lt SUB $256, R8 + MOVD $256(R3), R3 + MOVD $256(R5), R5 CMP R8, $256 BGT loop tail: diff --git a/src/strings/compare_test.go b/src/strings/compare_test.go index bc12e421b0..712e5a741e 100644 --- a/src/strings/compare_test.go +++ b/src/strings/compare_test.go @@ -8,6 +8,7 @@ package strings_test // Benchmarks omitted since the underlying implementation is identical. import ( + "internal/testenv" . "strings" "testing" ) @@ -52,10 +53,20 @@ func TestCompareIdenticalString(t *testing.T) { } func TestCompareStrings(t *testing.T) { - n := 128 + lengths := make([]int, 0) // lengths to test in ascending order + for i := 0; i <= 128; i++ { + lengths = append(lengths, i) + } + lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097) + + if !testing.Short() || testenv.Builder() != "" { + lengths = append(lengths, 65535, 65536, 65537, 99999) + } + + n := lengths[len(lengths)-1] a := make([]byte, n+1) b := make([]byte, n+1) - for len := 0; len < 128; len++ { + for _, len := range lengths { // randomish but deterministic data. No 0 or 255. for i := 0; i < len; i++ { a[i] = byte(1 + 31*i%254) -- 2.50.0