Commit e4c053f04737d852766b6577e7b1fbfb4a8a3096 | zig

author	Jan Philipp Hafer <jan.hafer@rwth-aachen.de> 2021-12-01 11:27:40+01:00
committer	Andrew Kelley <andrew@ziglang.org> 2021-12-01 13:35:19-08:00
log	e4c053f04737d852766b6577e7b1fbfb4a8a3096
tree	9bef4ca4a82acdd0336808617fa0033b76420967
parent	02a1f838e67edc4107df19ba194a925958f1c669

compiler_rt: add paritysi2, paritydi2, __parityti2

- use Bit Twiddling Hacks: Compute parity in parallel
- test cases derived from popcount.zig
- tests: compare naive approach 10_000 times with random numbers created
  from naive seed 42
- compiler_rt.zig: sort by LLVM builtin order and add comments to improve structure

See #1290

6 files changed, 194 insertions(+), 21 deletions(-)

CMakeLists.txt
lib
- std
  - special
    compiler_rt.zig
    compiler_rt
    parity.zig
    paritydi2_test.zig
    paritysi2_test.zig
    parityti2_test.zig

CMakeLists.txt+1

...	...	@@ -498,6 +498,7 @@ set(ZIG_STAGE2_SOURCES
498	498	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/multi3.zig"
499	499	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/negXf2.zig"
500	500	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/os_version_check.zig"
	501	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/parity.zig"
501	502	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/popcount.zig"
502	503	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/shift.zig"
503	504	"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/stack_probe.zig"

lib/std/special/compiler_rt.zig+48-21

...	...	@@ -76,10 +76,11 @@ comptime {
76	76
77	77	@export(__extendhfsf2, .{ .name = "__gnu_h2f_ieee", .linkage = linkage });
78	78
79		const __muloti4 = @import("compiler_rt/muloti4.zig").__muloti4;
80		@export(__muloti4, .{ .name = "__muloti4", .linkage = linkage });
	79	// Integral arithmetic which returns if overflow
81	80	const __mulodi4 = @import("compiler_rt/mulodi4.zig").__mulodi4;
82	81	@export(__mulodi4, .{ .name = "__mulodi4", .linkage = linkage });
	82	const __muloti4 = @import("compiler_rt/muloti4.zig").__muloti4;
	83	@export(__muloti4, .{ .name = "__muloti4", .linkage = linkage });
83	84	}
84	85
85	86	if (builtin.os.tag == .windows) {
...	...	@@ -217,6 +218,7 @@ comptime {
217	218	const __divtf3 = @import("compiler_rt/divtf3.zig").__divtf3;
218	219	@export(__divtf3, .{ .name = "__divtf3", .linkage = linkage });
219	220
	221	// Integral bit manipulation
220	222	const __ashldi3 = @import("compiler_rt/shift.zig").__ashldi3;
221	223	@export(__ashldi3, .{ .name = "__ashldi3", .linkage = linkage });
222	224	const __ashlti3 = @import("compiler_rt/shift.zig").__ashlti3;
...	...	@@ -230,6 +232,33 @@ comptime {
230	232	const __lshrti3 = @import("compiler_rt/shift.zig").__lshrti3;
231	233	@export(__lshrti3, .{ .name = "__lshrti3", .linkage = linkage });
232	234
	235	const __clzsi2 = @import("compiler_rt/count0bits.zig").__clzsi2;
	236	@export(__clzsi2, .{ .name = "__clzsi2", .linkage = linkage });
	237	const __clzdi2 = @import("compiler_rt/count0bits.zig").__clzdi2;
	238	@export(__clzdi2, .{ .name = "__clzdi2", .linkage = linkage });
	239	const __clzti2 = @import("compiler_rt/count0bits.zig").__clzti2;
	240	@export(__clzti2, .{ .name = "__clzti2", .linkage = linkage });
	241	const __ctzsi2 = @import("compiler_rt/count0bits.zig").__ctzsi2;
	242	@export(__ctzsi2, .{ .name = "__ctzsi2", .linkage = linkage });
	243	const __ctzdi2 = @import("compiler_rt/count0bits.zig").__ctzdi2;
	244	@export(__ctzdi2, .{ .name = "__ctzdi2", .linkage = linkage });
	245	const __ctzti2 = @import("compiler_rt/count0bits.zig").__ctzti2;
	246	@export(__ctzti2, .{ .name = "__ctzti2", .linkage = linkage });
	247
	248	const __paritysi2 = @import("compiler_rt/parity.zig").__paritysi2;
	249	@export(__paritysi2, .{ .name = "__paritysi2", .linkage = linkage });
	250	const __paritydi2 = @import("compiler_rt/parity.zig").__paritydi2;
	251	@export(__paritydi2, .{ .name = "__paritydi2", .linkage = linkage });
	252	const __parityti2 = @import("compiler_rt/parity.zig").__parityti2;
	253	@export(__parityti2, .{ .name = "__parityti2", .linkage = linkage });
	254	const __popcountsi2 = @import("compiler_rt/popcount.zig").__popcountsi2;
	255	@export(__popcountsi2, .{ .name = "__popcountsi2", .linkage = linkage });
	256	const __popcountdi2 = @import("compiler_rt/popcount.zig").__popcountdi2;
	257	@export(__popcountdi2, .{ .name = "__popcountdi2", .linkage = linkage });
	258	const __popcountti2 = @import("compiler_rt/popcount.zig").__popcountti2;
	259	@export(__popcountti2, .{ .name = "__popcountti2", .linkage = linkage });
	260
	261	// Integral / floating point conversion (part 1/2)
233	262	const __floatsidf = @import("compiler_rt/floatsiXf.zig").__floatsidf;
234	263	@export(__floatsidf, .{ .name = "__floatsidf", .linkage = linkage });
235	264	const __floatsisf = @import("compiler_rt/floatsiXf.zig").__floatsisf;
...	...	@@ -291,6 +320,7 @@ comptime {
291	320	const __extendsfdf2 = @import("compiler_rt/extendXfYf2.zig").__extendsfdf2;
292	321	@export(__extendsfdf2, .{ .name = "__extendsfdf2", .linkage = linkage });
293	322
	323	// Integral / floating point conversion (part 2/2)
294	324	const __fixunssfsi = @import("compiler_rt/fixunssfsi.zig").__fixunssfsi;
295	325	@export(__fixunssfsi, .{ .name = "__fixunssfsi", .linkage = linkage });
296	326	const __fixunssfdi = @import("compiler_rt/fixunssfdi.zig").__fixunssfdi;
...	...	@@ -333,18 +363,13 @@ comptime {
333	363
334	364	const __udivmoddi4 = @import("compiler_rt/int.zig").__udivmoddi4;
335	365	@export(__udivmoddi4, .{ .name = "__udivmoddi4", .linkage = linkage });
336		const __popcountsi2 = @import("compiler_rt/popcount.zig").__popcountsi2;
337		@export(__popcountsi2, .{ .name = "__popcountsi2", .linkage = linkage });
338		const __popcountdi2 = @import("compiler_rt/popcount.zig").__popcountdi2;
339		@export(__popcountdi2, .{ .name = "__popcountdi2", .linkage = linkage });
340		const __popcountti2 = @import("compiler_rt/popcount.zig").__popcountti2;
341		@export(__popcountti2, .{ .name = "__popcountti2", .linkage = linkage });
342	366
343	367	if (is_darwin) {
344	368	const __isPlatformVersionAtLeast = @import("compiler_rt/os_version_check.zig").__isPlatformVersionAtLeast;
345	369	@export(__isPlatformVersionAtLeast, .{ .name = "__isPlatformVersionAtLeast", .linkage = linkage });
346	370	}
347	371
	372	// Integral arithmetic
348	373	const __mulsi3 = @import("compiler_rt/int.zig").__mulsi3;
349	374	@export(__mulsi3, .{ .name = "__mulsi3", .linkage = linkage });
350	375	const __muldi3 = @import("compiler_rt/muldi3.zig").__muldi3;
...	...	@@ -372,24 +397,26 @@ comptime {
372	397	const __udivmodsi4 = @import("compiler_rt/int.zig").__udivmodsi4;
373	398	@export(__udivmodsi4, .{ .name = "__udivmodsi4", .linkage = linkage });
374	399
	400	// missing: Integral arithmetic with trapping overflow
	401
	402	// missing: Integral arithmetic which returns if overflow
	403
	404	// missing: Integral comparison
	405	// (a < b) => 0
	406	// (a == b) => 1
	407	// (a > b) => 2
	408
	409	// missing: Floating point raised to integer power
	410
	411	// missing: Complex arithmetic
	412	// (a + ib) * (c + id)
	413	// (a + ib) / (c + id)
	414
375	415	const __negsf2 = @import("compiler_rt/negXf2.zig").__negsf2;
376	416	@export(__negsf2, .{ .name = "__negsf2", .linkage = linkage });
377	417	const __negdf2 = @import("compiler_rt/negXf2.zig").__negdf2;
378	418	@export(__negdf2, .{ .name = "__negdf2", .linkage = linkage });
379	419
380		const __clzsi2 = @import("compiler_rt/count0bits.zig").__clzsi2;
381		@export(__clzsi2, .{ .name = "__clzsi2", .linkage = linkage });
382		const __clzdi2 = @import("compiler_rt/count0bits.zig").__clzdi2;
383		@export(__clzdi2, .{ .name = "__clzdi2", .linkage = linkage });
384		const __clzti2 = @import("compiler_rt/count0bits.zig").__clzti2;
385		@export(__clzti2, .{ .name = "__clzti2", .linkage = linkage });
386		const __ctzsi2 = @import("compiler_rt/count0bits.zig").__ctzsi2;
387		@export(__ctzsi2, .{ .name = "__ctzsi2", .linkage = linkage });
388		const __ctzdi2 = @import("compiler_rt/count0bits.zig").__ctzdi2;
389		@export(__ctzdi2, .{ .name = "__ctzdi2", .linkage = linkage });
390		const __ctzti2 = @import("compiler_rt/count0bits.zig").__ctzti2;
391		@export(__ctzti2, .{ .name = "__ctzti2", .linkage = linkage });
392
393	420	if (builtin.link_libc and os_tag == .openbsd) {
394	421	const __emutls_get_address = @import("compiler_rt/emutls.zig").__emutls_get_address;
395	422	@export(__emutls_get_address, .{ .name = "__emutls_get_address", .linkage = linkage });

lib/std/special/compiler_rt/parity.zig created+40

...	...	@@ -0,0 +1,40 @@
	1	const std = @import("std");
	2	const builtin = @import("builtin");
	3
	4	// parity - if number of bits set is even => 0, else => 1
	5	// - pariytXi2_generic for big and little endian
	6
	7	fn parityXi2_generic(comptime T: type) fn (a: T) callconv(.C) i32 {
	8	return struct {
	9	fn f(a: T) callconv(.C) i32 {
	10	@setRuntimeSafety(builtin.is_test);
	11
	12	var x = switch (@bitSizeOf(T)) {
	13	32 => @bitCast(u32, a),
	14	64 => @bitCast(u64, a),
	15	128 => @bitCast(u128, a),
	16	else => unreachable,
	17	};
	18	// Bit Twiddling Hacks: Compute parity in parallel
	19	comptime var shift: u8 = @bitSizeOf(T) / 2;
	20	inline while (shift > 2) {
	21	x ^= x >> shift;
	22	shift = shift >> 1;
	23	}
	24	x &= 0xf;
	25	return (@intCast(u16, 0x6996) >> @intCast(u4, x)) & 1; // optimization for >>2 and >>1
	26	}
	27	}.f;
	28	}
	29
	30	pub const __paritysi2 = parityXi2_generic(i32);
	31
	32	pub const __paritydi2 = parityXi2_generic(i64);
	33
	34	pub const __parityti2 = parityXi2_generic(i128);
	35
	36	test {
	37	_ = @import("paritysi2_test.zig");
	38	_ = @import("paritydi2_test.zig");
	39	_ = @import("parityti2_test.zig");
	40	}

lib/std/special/compiler_rt/paritydi2_test.zig created+35

...	...	@@ -0,0 +1,35 @@
	1	const parity = @import("parity.zig");
	2	const testing = @import("std").testing;
	3
	4	fn paritydi2Naive(a: i64) i32 {
	5	var x = @bitCast(u64, a);
	6	var has_parity: bool = false;
	7	while (x > 0) {
	8	has_parity = !has_parity;
	9	x = x & (x - 1);
	10	}
	11	return @intCast(i32, @boolToInt(has_parity));
	12	}
	13
	14	fn test__paritydi2(a: i64) !void {
	15	var x = parity.__paritydi2(a);
	16	var expected: i64 = paritydi2Naive(a);
	17	try testing.expectEqual(expected, x);
	18	}
	19
	20	test "paritydi2" {
	21	try test__paritydi2(0);
	22	try test__paritydi2(1);
	23	try test__paritydi2(2);
	24	try test__paritydi2(@bitCast(i64, @as(u64, 0xffffffff_fffffffd)));
	25	try test__paritydi2(@bitCast(i64, @as(u64, 0xffffffff_fffffffe)));
	26	try test__paritydi2(@bitCast(i64, @as(u64, 0xffffffff_ffffffff)));
	27
	28	const RndGen = @import("std").rand.DefaultPrng;
	29	var rnd = RndGen.init(42);
	30	var i: u32 = 0;
	31	while (i < 10_000) : (i += 1) {
	32	var rand_num = rnd.random().int(i64);
	33	try test__paritydi2(rand_num);
	34	}
	35	}

lib/std/special/compiler_rt/paritysi2_test.zig created+35

...	...	@@ -0,0 +1,35 @@
	1	const parity = @import("parity.zig");
	2	const testing = @import("std").testing;
	3
	4	fn paritysi2Naive(a: i32) i32 {
	5	var x = @bitCast(u32, a);
	6	var has_parity: bool = false;
	7	while (x > 0) {
	8	has_parity = !has_parity;
	9	x = x & (x - 1);
	10	}
	11	return @intCast(i32, @boolToInt(has_parity));
	12	}
	13
	14	fn test__paritysi2(a: i32) !void {
	15	var x = parity.__paritysi2(a);
	16	var expected: i32 = paritysi2Naive(a);
	17	try testing.expectEqual(expected, x);
	18	}
	19
	20	test "paritysi2" {
	21	try test__paritysi2(0);
	22	try test__paritysi2(1);
	23	try test__paritysi2(2);
	24	try test__paritysi2(@bitCast(i32, @as(u32, 0xfffffffd)));
	25	try test__paritysi2(@bitCast(i32, @as(u32, 0xfffffffe)));
	26	try test__paritysi2(@bitCast(i32, @as(u32, 0xffffffff)));
	27
	28	const RndGen = @import("std").rand.DefaultPrng;
	29	var rnd = RndGen.init(42);
	30	var i: u32 = 0;
	31	while (i < 10_000) : (i += 1) {
	32	var rand_num = rnd.random().int(i32);
	33	try test__paritysi2(rand_num);
	34	}
	35	}

lib/std/special/compiler_rt/parityti2_test.zig created+35

...	...	@@ -0,0 +1,35 @@
	1	const parity = @import("parity.zig");
	2	const testing = @import("std").testing;
	3
	4	fn parityti2Naive(a: i128) i32 {
	5	var x = @bitCast(u128, a);
	6	var has_parity: bool = false;
	7	while (x > 0) {
	8	has_parity = !has_parity;
	9	x = x & (x - 1);
	10	}
	11	return @intCast(i32, @boolToInt(has_parity));
	12	}
	13
	14	fn test__parityti2(a: i128) !void {
	15	var x = parity.__parityti2(a);
	16	var expected: i128 = parityti2Naive(a);
	17	try testing.expectEqual(expected, x);
	18	}
	19
	20	test "parityti2" {
	21	try test__parityti2(0);
	22	try test__parityti2(1);
	23	try test__parityti2(2);
	24	try test__parityti2(@bitCast(i128, @as(u128, 0xffffffff_ffffffff_ffffffff_fffffffd)));
	25	try test__parityti2(@bitCast(i128, @as(u128, 0xffffffff_ffffffff_ffffffff_fffffffe)));
	26	try test__parityti2(@bitCast(i128, @as(u128, 0xffffffff_ffffffff_ffffffff_ffffffff)));
	27
	28	const RndGen = @import("std").rand.DefaultPrng;
	29	var rnd = RndGen.init(42);
	30	var i: u32 = 0;
	31	while (i < 10_000) : (i += 1) {
	32	var rand_num = rnd.random().int(i128);
	33	try test__parityti2(rand_num);
	34	}
	35	}

compiler_rt: add __paritysi2, __paritydi2, __parityti2

compiler_rt: add paritysi2, paritydi2, __parityti2