From: Oleg Zaytsev <mail@olegzaytsev.com>
Date: Fri, 9 Dec 2022 12:05:34 +0000 (+0100)
Subject: cmd/gc: test temp string comparison with all ops
X-Git-Tag: go1.20rc2~1^2~34
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=61e2b8ec598e33b0d55a0652f86eeb075de3dc9d;p=gostls13.git

cmd/gc: test temp string comparison with all ops

The comment on `slicebytetostringtmp` mention that `==` operator does
not allocate []byte to string conversion, but the test was testing only
`==` and `!=` and the compiler actually optimizes all comparison
operators.

Also added a test for concatenation comparison, which also should not
allocate.

Change-Id: I6f4c5c4f238808138fa901732e1fd5b6ab25f725
Reviewed-on: https://go-review.googlesource.com/c/go/+/456415
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
---

diff --git a/src/runtime/string_test.go b/src/runtime/string_test.go
index 1ea7f5e481..cfc0ad7cde 100644
--- a/src/runtime/string_test.go
+++ b/src/runtime/string_test.go
@@ -223,6 +223,19 @@ func TestLargeStringConcat(t *testing.T) {
 	}
 }
 
+func TestConcatTempString(t *testing.T) {
+	s := "bytes"
+	b := []byte(s)
+	n := testing.AllocsPerRun(1000, func() {
+		if "prefix "+string(b)+" suffix" != "prefix bytes suffix" {
+			t.Fatalf("strings are not equal: '%v' and '%v'", "prefix "+string(b)+" suffix", "prefix bytes suffix")
+		}
+	})
+	if n != 0 {
+		t.Fatalf("want 0 allocs, got %v", n)
+	}
+}
+
 func TestCompareTempString(t *testing.T) {
 	s := strings.Repeat("x", sizeNoStack)
 	b := []byte(s)
@@ -230,10 +243,24 @@ func TestCompareTempString(t *testing.T) {
 		if string(b) != s {
 			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
 		}
+		if string(b) < s {
+			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
+		}
+		if string(b) > s {
+			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
+		}
 		if string(b) == s {
 		} else {
 			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
 		}
+		if string(b) <= s {
+		} else {
+			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
+		}
+		if string(b) >= s {
+		} else {
+			t.Fatalf("strings are not equal: '%v' and '%v'", string(b), s)
+		}
 	})
 	if n != 0 {
 		t.Fatalf("want 0 allocs, got %v", n)