From: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Date: Sat, 6 Aug 2022 18:55:52 +0000 (+0700)
Subject: cmd/compile: remove index out of bounds check in walkIndex
X-Git-Tag: go1.20rc1~1775
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=98f5152368b4afd31eac1df2b3c172052d9b062a;p=gostls13.git

cmd/compile: remove index out of bounds check in walkIndex

Since when any user errors about out-of-bounds constants should have
been already reported by types2.

Change-Id: I81b6bfec53201bbf546c48157fc8154cdb3c6e45
Reviewed-on: https://go-review.googlesource.com/c/go/+/421876
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
---

diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go
index 83fcea38d5..dfa82e7ec0 100644
--- a/src/cmd/compile/internal/walk/expr.go
+++ b/src/cmd/compile/internal/walk/expr.go
@@ -727,23 +727,11 @@ func walkIndex(n *ir.IndexExpr, init *ir.Nodes) ir.Node {
 		if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
 			base.Warn("index bounds check elided")
 		}
-		if ir.IsSmallIntConst(n.Index) && !n.Bounded() {
-			base.Errorf("index out of bounds")
-		}
 	} else if ir.IsConst(n.X, constant.String) {
 		n.SetBounded(bounded(r, int64(len(ir.StringVal(n.X)))))
 		if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
 			base.Warn("index bounds check elided")
 		}
-		if ir.IsSmallIntConst(n.Index) && !n.Bounded() {
-			base.Errorf("index out of bounds")
-		}
-	}
-
-	if ir.IsConst(n.Index, constant.Int) {
-		if v := n.Index.Val(); constant.Sign(v) < 0 || ir.ConstOverflow(v, types.Types[types.TINT]) {
-			base.Errorf("index out of bounds")
-		}
 	}
 	return n
 }