Commit 0bd53dd2033c60d3446abfb83209237c6eb6c9e2 | zig

author	Frank Denis <124872+jedisct1@users.noreply.github.com> 2020-08-25 22:43:42+02:00
committer	Frank Denis <124872+jedisct1@users.noreply.github.com> 2020-08-26 10:50:34+02:00
log	0bd53dd2033c60d3446abfb83209237c6eb6c9e2
tree	c9e3936f62f3526acee4e23d97c9997d973e19df
parent	ff2e82f382b253ca50977d16fe58865e0de3223f

Rename blackBox, move it to std.mem.forceEval()

3 files changed, 19 insertions(+), 40 deletions(-)

lib
- std
  - crypto
    benchmark.zig
  - math.zig
  - mem.zig

lib/std/crypto/benchmark.zig+6-13

...	...	@@ -7,6 +7,7 @@
7	7
8	8	const builtin = @import("builtin");
9	9	const std = @import("std");
	10	const mem = std.mem;
10	11	const time = std.time;
11	12	const Timer = time.Timer;
12	13	const crypto = std.crypto;
...	...	@@ -21,14 +22,6 @@ const Crypto = struct {
21	22	name: []const u8,
22	23	};
23	24
24		fn blackBox(x: anytype) void {
25		asm volatile (""
26		:
27		: [x] "rm" (x)
28		: "memory"
29		);
30		}
31
32	25	const hashes = [_]Crypto{
33	26	Crypto{ .ty = crypto.hash.Md5, .name = "md5" },
34	27	Crypto{ .ty = crypto.hash.Sha1, .name = "sha1" },
...	...	@@ -54,7 +47,7 @@ pub fn benchmarkHash(comptime Hash: anytype, comptime bytes: comptime_int) !u64
54	47	while (offset < bytes) : (offset += block.len) {
55	48	h.update(block[0..]);
56	49	}
57		blackBox(&h);
	50	mem.forceEval(&h);
58	51	const end = timer.read();
59	52
60	53	const elapsed_s = @intToFloat(f64, end - start) / time.ns_per_s;
...	...	@@ -89,7 +82,7 @@ pub fn benchmarkMac(comptime Mac: anytype, comptime bytes: comptime_int) !u64 {
89	82	const start = timer.lap();
90	83	while (offset < bytes) : (offset += in.len) {
91	84	Mac.create(mac[0..], in[0..], key[0..]);
92		blackBox(&mac);
	85	mem.forceEval(&mac);
93	86	}
94	87	const end = timer.read();
95	88
...	...	@@ -116,7 +109,7 @@ pub fn benchmarkKeyExchange(comptime DhKeyExchange: anytype, comptime exchange_c
116	109	var i: usize = 0;
117	110	while (i < exchange_count) : (i += 1) {
118	111	_ = DhKeyExchange.create(out[0..], out[0..], in[0..]);
119		blackBox(&out);
	112	mem.forceEval(&out);
120	113	}
121	114	}
122	115	const end = timer.read();
...	...	@@ -141,7 +134,7 @@ pub fn benchmarkSignature(comptime Signature: anytype, comptime signatures_count
141	134	var i: usize = 0;
142	135	while (i < signatures_count) : (i += 1) {
143	136	const s = try Signature.sign(&msg, key_pair, null);
144		blackBox(&s);
	137	mem.forceEval(&s);
145	138	}
146	139	}
147	140	const end = timer.read();
...	...	@@ -177,7 +170,7 @@ pub fn benchmarkAead(comptime Aead: anytype, comptime bytes: comptime_int) !u64
177	170	Aead.encrypt(in[0..], tag[0..], in[0..], &[_]u8{}, nonce, key);
178	171	Aead.decrypt(in[0..], in[0..], tag, &[_]u8{}, nonce, key) catch unreachable;
179	172	}
180		blackBox(&in);
	173	mem.forceEval(&in);
181	174	const end = timer.read();
182	175
183	176	const elapsed_s = @intToFloat(f64, end - start) / time.ns_per_s;

lib/std/math.zig+2-27

...	...	@@ -5,6 +5,7 @@
5	5	// and substantial portions of the software.
6	6	const std = @import("std.zig");
7	7	const assert = std.debug.assert;
	8	const mem = std.mem;
8	9	const testing = std.testing;
9	10
10	11	/// Euler's number (e)
...	...	@@ -108,34 +109,8 @@ pub fn approxEq(comptime T: type, x: T, y: T, epsilon: T) bool {
108	109	return fabs(x - y) < epsilon;
109	110	}
110	111
111		// TODO: Hide the following in an internal module.
112	112	pub fn forceEval(value: anytype) void {
113		const T = @TypeOf(value);
114		switch (T) {
115		f16 => {
116		var x: f16 = undefined;
117		const p = @ptrCast(*volatile f16, &x);
118		p.* = x;
119		},
120		f32 => {
121		var x: f32 = undefined;
122		const p = @ptrCast(*volatile f32, &x);
123		p.* = x;
124		},
125		f64 => {
126		var x: f64 = undefined;
127		const p = @ptrCast(*volatile f64, &x);
128		p.* = x;
129		},
130		f128 => {
131		var x: f128 = undefined;
132		const p = @ptrCast(*volatile f128, &x);
133		p.* = x;
134		},
135		else => {
136		@compileError("forceEval not implemented for " ++ @typeName(T));
137		},
138		}
	113	mem.forceEval(value);
139	114	}
140	115
141	116	pub fn raiseInvalid() void {

lib/std/mem.zig+11

...	...	@@ -2158,6 +2158,17 @@ pub fn alignForwardGeneric(comptime T: type, addr: T, alignment: T) T {
2158	2158	return alignBackwardGeneric(T, addr + (alignment - 1), alignment);
2159	2159	}
2160	2160
	2161	/// Force an evaluation of the expression; this tries to prevent
	2162	/// the compiler from optimizing the computation away even if the
	2163	/// result eventually gets discarded.
	2164	pub fn forceEval(val: anytype) void {
	2165	asm volatile (""
	2166	:
	2167	: [val] "rm" (val)
	2168	: "memory"
	2169	);
	2170	}
	2171
2161	2172	test "alignForward" {
2162	2173	testing.expect(alignForward(1, 1) == 1);
2163	2174	testing.expect(alignForward(2, 1) == 2);