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sse - 如何在有或没有 SIMD 内在函数的情况下从 Zig 构建和链接到 CGLM

问题描述

我想链接并使用 cglm C 库。我正在使用 Zig 0.7.1 和 Zig 0.8.0 (master) 在没有 msvc 的 Windows 上工作（因此针对 gnu C ABI），没有任何运气。

我已经能够从 Zig build.zig 构建 CGLM 静态库，但没有运气从 Zig 程序链接它，因为报告了 CGLM SIMD 内在优化错误。

const Builder = @import("std").build.Builder;

pub fn build(b: *Builder) void {
    // Standard target options allows the person running `zig build` to choose
    // what target to build for. Here we do not override the defaults, which
    // means any target is allowed, and the default is native. Other options
    // for restricting supported target set are available.
    const target = b.standardTargetOptions(.{});

    // Standard release options allow the person running `zig build` to select
    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
    const mode = b.standardReleaseOptions();

    // cglm
    const cglmLibBasePath = "vendor/cglm/";
    const cglmFiles = &[_][]const u8{ 
        cglmLibBasePath ++ "src/euler.c",
        cglmLibBasePath ++ "src/affine.c",
        cglmLibBasePath ++ "src/io.c",
        cglmLibBasePath ++ "src/quat.c",
        cglmLibBasePath ++ "src/cam.c",
        cglmLibBasePath ++ "src/vec2.c",
        cglmLibBasePath ++ "src/vec3.c",
        cglmLibBasePath ++ "src/vec4.c",
        cglmLibBasePath ++ "src/mat2.c",
        cglmLibBasePath ++ "src/mat3.c",
        cglmLibBasePath ++ "src/mat4.c",
        cglmLibBasePath ++ "src/plane.c",
        cglmLibBasePath ++ "src/frustum.c",
        cglmLibBasePath ++ "src/box.c",
        cglmLibBasePath ++ "src/project.c",
        cglmLibBasePath ++ "src/sphere.c",
        cglmLibBasePath ++ "src/ease.c",
        cglmLibBasePath ++ "src/curve.c",
        cglmLibBasePath ++ "src/bezier.c",
        cglmLibBasePath ++ "src/ray.c",
        cglmLibBasePath ++ "src/affine2d.c",
    };
    const cglmLib = b.addStaticLibrary("cglm", null);
    cglmLib.setBuildMode(mode);
    cglmLib.setTarget(target);
    cglmLib.defineCMacro("CGLM_STATIC");
    cglmLib.defineCMacro("WIN32");
    cglmLib.addIncludeDir(cglmLibBasePath ++ "src/");
    for (cglmFiles) |cglmFile| {
        cglmLib.addCSourceFile(cglmFile, &[_][]const u8 { 
            "-std=c11",
            "-Wall",
            "-Werror",
            "-O3",
        });
    }    
    cglmLib.linkLibC();
    cglmLib.install();

    const exe = b.addExecutable("app-zig-cglm", "src/main.zig");
    exe.setBuildMode(mode);
    exe.setTarget(target);  
    // cglm
    exe.linkLibrary(cglmLib);
    exe.addSystemIncludeDir(cglmLibBasePath ++ "include/");
    // C and win32
    exe.linkLibC();
    exe.install();
    

    const run_cmd = exe.run();
    run_cmd.step.dependOn(b.getInstallStep());
    if (b.args) |args| {
        run_cmd.addArgs(args);
    }

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);
}

当我尝试使用链接的生成库构建/运行 exe 时，会报告以下错误（在 Zig 版本 0.7.1 和 0.8.0 master 中类似）Ex 来自 0.7.1 Zig 版本。

alagt@LAPTOP-HS5L5VEH MINGW64 /c/Dev/Projects/test-bed/app-zig-cglm (master)
$ zig build -Dtarget=x86_64-windows-gnu
.\zig-cache\o\1bc9e6dc93c2ab6590b8006381a9000e\cimport.zig:4255:26: error: unable to translate function
pub const glm_mul_sse2 = @compileError("unable to translate function"); // C:\Dev\Projects\test-bed\app-zig-cglm\vendor\cglm\include\cglm/simd/sse2/affine.h:17:1
                         ^
.\zig-cache\o\1bc9e6dc93c2ab6590b8006381a9000e\cimport.zig:4264:5: note: referenced here
    glm_mul_sse2(m1, m2, dest);
    ^
.\zig-cache\o\1bc9e6dc93c2ab6590b8006381a9000e\cimport.zig:657:20: error: unable to resolve typedef child type
pub const __m128 = @compileError("unable to resolve typedef child type"); // C:\Dev\Tools\zig-0.7.1\lib\include\xmmintrin.h:17:15
                   ^
.\zig-cache\o\1bc9e6dc93c2ab6590b8006381a9000e\cimport.zig:1255:48: note: referenced here
pub fn _mm_store_ps(arg___p: [*c]f32, arg___a: __m128) callconv(.C) void {
                                               ^
.\zig-cache\o\1bc9e6dc93c2ab6590b8006381a9000e\cimport.zig:3557:5: note: referenced here
    _mm_store_ps(&dest[@intCast(c_uint, @as(c_int, 0))], _mm_load_ps(&mat[@intCast(c_uint, @as(c_int, 0))]));
    ^
app-zig-cglm...The following command exited with error code 1:
C:\Dev\Tools\zig-0.7.1\zig.exe build-exe C:\Dev\Projects\test-bed\app-zig-cglm\src\main.zig C:\Dev\Projects\test-bed\app-zig-cglm\zig-cache\o\dfacf78e7514990119de31b967d43202\cglm.lib --library c --cache-dir C:\Dev\Projects\test-bed\app-zig-cglm\zig-cache --global-cache-dir C:\Users\alagt\AppData\Local\zig --name app-zig-cglm -target x86_64-windows-gnu -isystem C:\Dev\Projects\test-bed\app-zig-cglm\vendor\cglm\include --enable-cache
error: the following build command failed with exit code 1:
C:\Dev\Projects\test-bed\app-zig-cglm\zig-cache\o\64a99c599e98cac00a19cffa57c71a68\build.exe C:\Dev\Tools\zig-0.7.1\zig.exe C:\Dev\Projects\test-bed\app-zig-cglm C:\Dev\Projects\test-bed\app-zig-cglm\zig-cache C:\Users\alagt\AppData\Local\zig -Dtarget=x86_64-windows-gnu

avxintrin.h 中的无法解析行如下

typedef float __m128 __attribute__((__vector_size__(16), __aligned__(16)));

我想知道使用内在函数的 C 库现在是否可以工作，如果不能，我想从 build.zig 禁用内在函数特性 sse/avx/... 以便可以在没有 SIMD 的情况下构建和链接 CGLM优化。

编辑（从 build.zig 禁用 SIMD 功能）

我在 lib/zig/std/build.zig 上进行了一些研究，以了解如何禁用 SIMD 功能，最后我能够在 build.zig 上使用以下代码禁用

var target = b.standardTargetOptions(.{});
    target.cpu_features_sub = x86.featureSet(&[_]x86.Feature{
        x86.Feature.avx,
        x86.Feature.avx2,
        x86.Feature.avx512bf16,
        x86.Feature.avx512bitalg,
        x86.Feature.avx512bw,
        x86.Feature.avx512cd,
        x86.Feature.avx512dq,
        x86.Feature.avx512er,
        x86.Feature.avx512f,
        x86.Feature.avx512ifma,
        x86.Feature.avx512pf,
        x86.Feature.avx512vbmi,
        x86.Feature.avx512vbmi2,
        x86.Feature.avx512vl,
        x86.Feature.avx512vnni,
        x86.Feature.avx512vp2intersect,
        x86.Feature.avx512vpopcntdq,
        x86.Feature.sse,
        x86.Feature.sse_unaligned_mem,
        x86.Feature.sse2,
        x86.Feature.sse3,
        x86.Feature.sse4_1,
        x86.Feature.sse4_2,
        x86.Feature.sse4a,
        x86.Feature.ssse3,
    });

状态：

现在我能够构建（没有 SIMD 优化，这是不理想的）并从 zig 代码链接 CGLM 库，但真正令人担忧的问题出现了，因为调用标准 C tanf 函数的代码正在计算真正错误的结果。

按照为 glm_perspective 函数生成的 zig 代码。

pub fn glm_perspective(arg_fovy: f32, arg_aspect: f32, arg_nearVal: f32, arg_farVal: f32, arg_dest: [*c]vec4) callconv(.C) void {
    var fovy = arg_fovy;
    var aspect = arg_aspect;
    var nearVal = arg_nearVal;
    var farVal = arg_farVal;
    var dest = arg_dest;
    var f: f32 = undefined;
    var @"fn": f32 = undefined;
    glm_mat4_zero(dest);
    f = (1 / tanf((fovy * 0.5)));
    @"fn" = (1 / (nearVal - farVal));
    dest[@intCast(c_uint, @as(c_int, 0))][@intCast(c_uint, @as(c_int, 0))] = (f / aspect);
    dest[@intCast(c_uint, @as(c_int, 1))][@intCast(c_uint, @as(c_int, 1))] = f;
    dest[@intCast(c_uint, @as(c_int, 2))][@intCast(c_uint, @as(c_int, 2))] = ((nearVal + farVal) * @"fn");
    dest[@intCast(c_uint, @as(c_int, 2))][@intCast(c_uint, @as(c_int, 3))] = -1;
    dest[@intCast(c_uint, @as(c_int, 3))][@intCast(c_uint, @as(c_int, 2))] = (((2 * nearVal) * farVal) * @"fn");
}

执行 f = (1 / tanf((fovy * 0.5))); 的结果 arg_fovy = 0.785398185（45 度弧度）的行返回 134217728。这是完全错误的。正确的结果应该是大约。2.4142134。

VSCode cppvsdbg 不允许我进入 tanf 以了解 tanf 实现可能有什么问题。

编辑（使用 Zig 编译器构建和编译最小 C 代码）：

我使用数学 tanf 编译了一个 min C 案例，并使用 Zig 构建器机制构建。

构建.zig

const Builder = @import("std").build.Builder;
const x86 = @import("std").Target.x86;

pub fn build(b: *Builder) void {
    // Standard target options allows the person running `zig build` to choose
    // what target to build for. Here we do not override the defaults, which
    // means any target is allowed, and the default is native. Other options
    // for restricting supported target set are available.
    var target = b.standardTargetOptions(.{});    
    target.cpu_features_sub = x86.featureSet(&[_]x86.Feature{
        x86.Feature.avx,
        x86.Feature.avx2,
        x86.Feature.avx512bf16,
        x86.Feature.avx512bitalg,
        x86.Feature.avx512bw,
        x86.Feature.avx512cd,
        x86.Feature.avx512dq,
        x86.Feature.avx512er,
        x86.Feature.avx512f,
        x86.Feature.avx512ifma,
        x86.Feature.avx512pf,
        x86.Feature.avx512vbmi,
        x86.Feature.avx512vbmi2,
        x86.Feature.avx512vl,
        x86.Feature.avx512vnni,
        x86.Feature.avx512vp2intersect,
        x86.Feature.avx512vpopcntdq,
        x86.Feature.sse,
        x86.Feature.sse_unaligned_mem,
        x86.Feature.sse2,
        x86.Feature.sse3,
        x86.Feature.sse4_1,
        x86.Feature.sse4_2,
        x86.Feature.sse4a,
        x86.Feature.ssse3,
    });
    

    // Standard release options allow the person running `zig build` to select
    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
    const mode = b.standardReleaseOptions();

    const exeC = b.addExecutable("app-c", "src/main.c");
    exeC.setBuildMode(mode);
    exeC.setTarget(target);    
    // C and win32
    exeC.linkLibC();
    exeC.install();
    

    const run_cmd = exeC.run();
    run_cmd.step.dependOn(b.getInstallStep());
    if (b.args) |args| {
        run_cmd.addArgs(args);
    }

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);
}

src/main.c

#include <stdio.h>
#include <math.h>

int main(int argc, char **argv) {
    float fovDeg = (argc == 1 ? 45.0f : 50.0f);
    while (1) {
        float fovRad = fovDeg * (M_PI / 180.0f);
        float tanFov = tanf(fovRad);
        fprintf(stdout, "fovDeg=%f, fovRad=%f, tanFov=%f\n", fovDeg, fovRad, tanFov);
    }
    return 0;
}

如果我在没有 SIMD 排除的情况下构建，或者只是将目标设置为本机，则代码会以预期的结果正确执行。

$ zig build -Dtarget=native-windows-gnu 运行 -- 1

fovDeg=50.000000, fovRad=0.872665, tanFov=1.191754

如果我使用 SIMD 排除项构建并执行它，则 tanf 返回 0

$ zig build -Dtarget=x86_64-windows-gnu 运行 -- 1

fovDeg=50.000000, fovRad=0.872665, tanFov=0.000000

当前状态

在我看来，这

如果有人能带来一些启示，以防我遗漏了什么，将不胜感激。

提前致谢。

标签： ssemingw-w64glm-mathintrinsicszig

解决方案

也许，我误解了你的问题，但这对我有用，没有错误。添加到您的 build.zig：

exe.addIncludeDir("path_to_your_cglm/cglm/include");
exe.addLibPath("path_to_your_cglm/cglm/win/Release");

exe.linkSystemLibrary("cglm");

此外，Discord 和 reddit Zig 社区非常活跃，因此请考虑在那里发帖。看看这个页面：https ://github.com/ziglang/zig/wiki/Community 。还有Zig 论坛。

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