Commit 907dc1e13f657f349dbdecf739b2f1a13ad7011a | zig

author	Daniele Cocca <daniele.cocca@gmail.com> 2022-03-20 21:04:28+00:00
committer	Veikka Tuominen <git@vexu.eu> 2022-03-30 12:10:02+03:00
log	907dc1e13f657f349dbdecf739b2f1a13ad7011a
tree	0026ce30fe407ce78c5e7b68a733b4c1f91b8a4a
parent	ebafdb958c1aa6b41c28fc7d45f44e38a69a3bd5

CBE: improve support for asm inputs

This is not complete support for asm expressions, but allows a few more
test cases from test/behavior/asm.zig to pass. Since the non-register
inputs are named `input_${n}` they can cause name collisions: I'm
wrapping the asm expressions in their own block to prevent that.

Contextually, this change also makes test/behavior/asm.zig run for
stage2, but skips individual tests for most backends (I only verified
the C and LLVM backends successfully run one new test case) and the
entire test file for aarch64, where it's running into preexisting
shortcomings.

3 files changed, 51 insertions(+), 10 deletions(-)

src
- codegen
  - c.zig
test
- behavior.zig
- behavior
  - asm.zig

src/codegen/c.zig+13-5

...	...	@@ -3014,9 +3014,10 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue {
3014	3014	} else null;
3015	3015
3016	3016	const writer = f.object.writer();
3017		const inputs_extra_begin = extra_i;
	3017	try writer.writeAll("{\n");
3018	3018
3019		for (inputs) \|input\| {
	3019	const inputs_extra_begin = extra_i;
	3020	for (inputs) \|input, i\| {
3020	3021	const constraint = std.mem.sliceTo(std.mem.sliceAsBytes(f.air.extra[extra_i..]), 0);
3021	3022	// This equation accounts for the fact that even if we have exactly 4 bytes
3022	3023	// for the string, we still use the next u32 for the null terminator.
...	...	@@ -3032,7 +3033,11 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue {
3032	3033	try f.writeCValue(writer, arg_c_value);
3033	3034	try writer.writeAll(";\n");
3034	3035	} else {
3035		return f.fail("TODO non-explicit inline asm regs", .{});
	3036	try writer.writeAll("register ");
	3037	try f.renderType(writer, f.air.typeOf(input));
	3038	try writer.print(" input_{d} = ", .{i});
	3039	try f.writeCValue(writer, try f.resolveInst(input));
	3040	try writer.writeAll(";\n");
3036	3041	}
3037	3042	}
3038	3043
...	...	@@ -3074,12 +3079,15 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue {
3074	3079	}
3075	3080	try writer.print("\"r\"({s}_constant)", .{reg});
3076	3081	} else {
3077		// This is blocked by the earlier test
3078		unreachable;
	3082	if (index > 0) {
	3083	try writer.writeAll(", ");
	3084	}
	3085	try writer.print("\"r\"(input_{d})", .{index});
3079	3086	}
3080	3087	}
3081	3088	}
3082	3089	try writer.writeAll(");\n");
	3090	try writer.writeAll("}\n");
3083	3091
3084	3092	if (f.liveness.isUnused(inst))
3085	3093	return CValue.none;

test/behavior.zig+1-4

...	...	@@ -165,10 +165,7 @@ test {
165	165	}
166	166
167	167	if (builtin.os.tag != .wasi) {
168		if (builtin.zig_backend == .stage1) {
169		// TODO get these tests passing with stage2
170		_ = @import("behavior/asm.zig");
171		}
	168	_ = @import("behavior/asm.zig");
172	169	}
173	170
174	171	if (builtin.zig_backend != .stage2_arm and

test/behavior/asm.zig+37-1

...	...	@@ -5,7 +5,10 @@ const expect = std.testing.expect;
5	5	const is_x86_64_linux = builtin.cpu.arch == .x86_64 and builtin.os.tag == .linux;
6	6
7	7	comptime {
8		if (is_x86_64_linux) {
	8	if (builtin.zig_backend != .stage2_arm and
	9	builtin.zig_backend != .stage2_aarch64 and
	10	is_x86_64_linux)
	11	{
9	12	asm (
10	13	\\.globl this_is_my_alias;
11	14	\\.type this_is_my_alias, @function;
...	...	@@ -15,12 +18,26 @@ comptime {
15	18	}
16	19
17	20	test "module level assembly" {
	21	if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
	22	if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
	23	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	24	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	25	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	26	if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // TODO
	27
18	28	if (is_x86_64_linux) {
19	29	try expect(this_is_my_alias() == 1234);
20	30	}
21	31	}
22	32
23	33	test "output constraint modifiers" {
	34	if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
	35	if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
	36	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	37	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	38	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	39	if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // TODO
	40
24	41	// This is only testing compilation.
25	42	var a: u32 = 3;
26	43	asm volatile (""
...	...	@@ -36,6 +53,13 @@ test "output constraint modifiers" {
36	53	}
37	54
38	55	test "alternative constraints" {
	56	if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
	57	if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
	58	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	59	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	60	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	61	if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // TODO
	62
39	63	// Make sure we allow commas as a separator for alternative constraints.
40	64	var a: u32 = 3;
41	65	asm volatile (""
...	...	@@ -46,6 +70,11 @@ test "alternative constraints" {
46	70	}
47	71
48	72	test "sized integer/float in asm input" {
	73	if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
	74	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	75	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	76	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	77
49	78	asm volatile (""
50	79	:
51	80	: [_] "m" (@as(usize, 3)),
...	...	@@ -89,6 +118,13 @@ test "sized integer/float in asm input" {
89	118	}
90	119
91	120	test "struct/array/union types as input values" {
	121	if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
	122	if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
	123	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	124	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	125	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	126	if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // TODO
	127
92	128	asm volatile (""
93	129	:
94	130	: [_] "m" (@as([1]u32, undefined)),