zig/lib/compiler_rt/fabs.zig
Luuk de Gram 30f2bb8464
compiler-rt: Set the symbol visibility
When we're compiling compiler_rt for any WebAssembly target, we do
not want to expose all the compiler-rt functions to the host runtime.
By setting the visibility of all exports to `hidden`, we allow the
linker to resolve the symbols during linktime, while not expose the
functions to the host runtime. This also means the linker can
properly garbage collect any compiler-rt function that does not get
resolved. The symbol visibility for all target remains the same as
before: `default`.
2022-12-28 14:57:17 +01:00

58 lines
1.9 KiB
Zig

const std = @import("std");
const builtin = @import("builtin");
const arch = builtin.cpu.arch;
const common = @import("common.zig");
pub const panic = common.panic;
comptime {
@export(__fabsh, .{ .name = "__fabsh", .linkage = common.linkage, .visibility = common.visibility });
@export(fabsf, .{ .name = "fabsf", .linkage = common.linkage, .visibility = common.visibility });
@export(fabs, .{ .name = "fabs", .linkage = common.linkage, .visibility = common.visibility });
@export(__fabsx, .{ .name = "__fabsx", .linkage = common.linkage, .visibility = common.visibility });
if (common.want_ppc_abi) {
@export(fabsq, .{ .name = "fabsf128", .linkage = common.linkage, .visibility = common.visibility });
}
@export(fabsq, .{ .name = "fabsq", .linkage = common.linkage, .visibility = common.visibility });
@export(fabsl, .{ .name = "fabsl", .linkage = common.linkage, .visibility = common.visibility });
}
pub fn __fabsh(a: f16) callconv(.C) f16 {
return generic_fabs(a);
}
pub fn fabsf(a: f32) callconv(.C) f32 {
return generic_fabs(a);
}
pub fn fabs(a: f64) callconv(.C) f64 {
return generic_fabs(a);
}
pub fn __fabsx(a: f80) callconv(.C) f80 {
return generic_fabs(a);
}
pub fn fabsq(a: f128) callconv(.C) f128 {
return generic_fabs(a);
}
pub fn fabsl(x: c_longdouble) callconv(.C) c_longdouble {
switch (@typeInfo(c_longdouble).Float.bits) {
16 => return __fabsh(x),
32 => return fabsf(x),
64 => return fabs(x),
80 => return __fabsx(x),
128 => return fabsq(x),
else => @compileError("unreachable"),
}
}
inline fn generic_fabs(x: anytype) @TypeOf(x) {
const T = @TypeOf(x);
const TBits = std.meta.Int(.unsigned, @typeInfo(T).Float.bits);
const float_bits = @bitCast(TBits, x);
const remove_sign = ~@as(TBits, 0) >> 1;
return @bitCast(T, float_bits & remove_sign);
}