go/test/makemap.go
Martin Möhrmann cbc4e5d9c4 cmd/compile: generate makemap calls with int arguments
Where possible generate calls to runtime makemap with int hint argument
during compile time instead of makemap with int64 hint argument.

This eliminates converting the hint argument for calls to makemap with
int64 hint argument for platforms where int64 values do not fit into
an argument of type int.

A similar optimization for makeslice was introduced in CL
golang.org/cl/27851.

386:
name         old time/op    new time/op    delta
NewEmptyMap    53.5ns ± 5%    41.9ns ± 5%  -21.56%  (p=0.000 n=10+10)
NewSmallMap     182ns ± 1%     165ns ± 1%   -8.92%  (p=0.000 n=10+10)

Change-Id: Ibd2b4c57b36f171b173bf7a0602b3a59771e6e44
Reviewed-on: https://go-review.googlesource.com/55142
Reviewed-by: Keith Randall <khr@golang.org>
2017-08-22 20:28:21 +00:00

35 lines
1.3 KiB
Go

// errorcheck
// Copyright 2017 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.
// Ensure that typed non-integer, negative and too large
// values are not accepted as size argument in make for
// maps.
package main
type T map[int]int
var sink T
func main() {
sink = make(T, -1) // ERROR "negative size argument in make.*"
sink = make(T, uint64(1<<63)) // ERROR "size argument too large in make.*"
sink = make(T, 0.5) // ERROR "constant 0.5 truncated to integer"
sink = make(T, 1.0)
sink = make(T, float32(1.0)) // ERROR "non-integer size argument in make.*"
sink = make(T, float64(1.0)) // ERROR "non-integer size argument in make.*"
sink = make(T, 1.0)
sink = make(T, float32(1.0)) // ERROR "non-integer size argument in make.*"
sink = make(T, float64(1.0)) // ERROR "non-integer size argument in make.*"
sink = make(T, 1+0i)
sink = make(T, complex64(1+0i)) // ERROR "non-integer size argument in make.*"
sink = make(T, complex128(1+0i)) // ERROR "non-integer size argument in make.*"
sink = make(T, 1+0i)
sink = make(T, complex64(1+0i)) // ERROR "non-integer size argument in make.*"
sink = make(T, complex128(1+0i)) // ERROR "non-integer size argument in make.*"
}