Commit bf89482f23

@@ -5,145 +5,9 @@ const builtin = @import("builtin");
 comptime {
     if (builtin.object_format != .c) {
         @export(&memcpy, .{ .name = "memcpy", .linkage = common.linkage, .visibility = common.visibility });
-        @export(&memmove, .{ .name = "memmove", .linkage = common.linkage, .visibility = common.visibility });
     }
 }
 
-fn memcpy(noalias opt_dest: ?[*]u8, noalias opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
-    return memmove(opt_dest, opt_src, len);
-}
-
-fn memmove(opt_dest: ?[*]u8, opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
-    // a port of https://github.com/facebook/folly/blob/1c8bc50e88804e2a7361a57cd9b551dd10f6c5fd/folly/memcpy.S
-    if (len == 0) {
-        @branchHint(.unlikely);
-        return opt_dest;
-    }
-
-    const dest = opt_dest.?;
-    const src = opt_src.?;
-
-    if (len < 8) {
-        @branchHint(.unlikely);
-        if (len == 1) {
-            @branchHint(.unlikely);
-            dest[0] = src[0];
-        } else if (len >= 4) {
-            @branchHint(.unlikely);
-            blockCopy(dest, src, 4, len);
-        } else {
-            blockCopy(dest, src, 2, len);
-        }
-        return dest;
-    }
-
-    if (len > 32) {
-        @branchHint(.unlikely);
-        if (len > 256) {
-            @branchHint(.unlikely);
-            copyMove(dest, src, len);
-            return dest;
-        }
-        copyLong(dest, src, len);
-        return dest;
-    }
-
-    if (len > 16) {
-        @branchHint(.unlikely);
-        blockCopy(dest, src, 16, len);
-        return dest;
-    }
-
-    blockCopy(dest, src, 8, len);
-
-    return dest;
-}
-
-inline fn blockCopy(dest: [*]u8, src: [*]const u8, block_size: comptime_int, len: usize) void {
-    const first = @as(*align(1) const @Vector(block_size, u8), src[0..block_size]).*;
-    const second = @as(*align(1) const @Vector(block_size, u8), src[len - block_size ..][0..block_size]).*;
-    dest[0..block_size].* = first;
-    dest[len - block_size ..][0..block_size].* = second;
-}
-
-inline fn copyLong(dest: [*]u8, src: [*]const u8, len: usize) void {
-    var array: [8]@Vector(32, u8) = undefined;
-
-    inline for (.{ 64, 128, 192, 256 }, 0..) |N, i| {
-        array[i * 2] = src[(N / 2) - 32 ..][0..32].*;
-        array[(i * 2) + 1] = src[len - N / 2 ..][0..32].*;
-
-        if (len <= N) {
-            @branchHint(.unlikely);
-            for (0..i + 1) |j| {
-                dest[j * 32 ..][0..32].* = array[j * 2];
-                dest[len - ((j * 32) + 32) ..][0..32].* = array[(j * 2) + 1];
-            }
-            return;
-        }
-    }
-}
-
-inline fn copyMove(dest: [*]u8, src: [*]const u8, len: usize) void {
-    if (@intFromPtr(src) >= @intFromPtr(dest)) {
-        @branchHint(.unlikely);
-        copyForward(dest, src, len);
-    } else if (@intFromPtr(src) + len > @intFromPtr(dest)) {
-        @branchHint(.unlikely);
-        overlapBwd(dest, src, len);
-    } else {
-        copyForward(dest, src, len);
-    }
-}
-
-inline fn copyForward(dest: [*]u8, src: [*]const u8, len: usize) void {
-    const tail: @Vector(32, u8) = src[len - 32 ..][0..32].*;
-
-    const N: usize = len & ~@as(usize, 127);
-    var i: usize = 0;
-
-    while (i < N) : (i += 128) {
-        dest[i..][0..32].* = src[i..][0..32].*;
-        dest[i + 32 ..][0..32].* = src[i + 32 ..][0..32].*;
-        dest[i + 64 ..][0..32].* = src[i + 64 ..][0..32].*;
-        dest[i + 96 ..][0..32].* = src[i + 96 ..][0..32].*;
-    }
-
-    if (len - i <= 32) {
-        @branchHint(.unlikely);
-        dest[len - 32 ..][0..32].* = tail;
-    } else {
-        copyLong(dest[i..], src[i..], len - i);
-    }
-}
-
-inline fn overlapBwd(dest: [*]u8, src: [*]const u8, len: usize) void {
-    var array: [5]@Vector(32, u8) = undefined;
-    array[0] = src[len - 32 ..][0..32].*;
-    inline for (1..5) |i| array[i] = src[(i - 1) << 5 ..][0..32].*;
-
-    const end: usize = (@intFromPtr(dest) + len - 32) & 31;
-    const range = len - end;
-    var s = src + range;
-    var d = dest + range;
-
-    while (@intFromPtr(s) > @intFromPtr(src + 128)) {
-        // zig fmt: off
-        const first  = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 32)).*;
-        const second = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 64)).*;
-        const third  = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 96)).*;
-        const fourth = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 128)).*;
-
-        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 32))).*  = first;
-        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 64))).*  = second;
-        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 96))).*  = third;
-        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 128))).* = fourth;
-        // zig fmt: on
-
-        s -= 128;
-        d -= 128;
-    }
-
-    inline for (array[1..], 0..) |vec, i| dest[i * 32 ..][0..32].* = vec;
-    dest[len - 32 ..][0..32].* = array[0];
+fn memcpy(opt_dest: ?[*]u8, opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
+    return @call(.always_inline, @import("memmove.zig").memmove, .{ opt_dest, opt_src, len });
 }

@@ -0,0 +1,144 @@
+const std = @import("std");
+const common = @import("./common.zig");
+const builtin = @import("builtin");
+
+comptime {
+    if (builtin.object_format != .c) {
+        @export(&memmove, .{ .name = "memmove", .linkage = common.linkage, .visibility = common.visibility });
+    }
+}
+
+pub fn memmove(opt_dest: ?[*]u8, opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
+    // a port of https://github.com/facebook/folly/blob/1c8bc50e88804e2a7361a57cd9b551dd10f6c5fd/folly/memcpy.S
+    if (len == 0) {
+        @branchHint(.unlikely);
+        return opt_dest;
+    }
+
+    const dest = opt_dest.?;
+    const src = opt_src.?;
+
+    if (len < 8) {
+        @branchHint(.unlikely);
+        if (len == 1) {
+            @branchHint(.unlikely);
+            dest[0] = src[0];
+        } else if (len >= 4) {
+            @branchHint(.unlikely);
+            blockCopy(dest, src, 4, len);
+        } else {
+            blockCopy(dest, src, 2, len);
+        }
+        return dest;
+    }
+
+    if (len > 32) {
+        @branchHint(.unlikely);
+        if (len > 256) {
+            @branchHint(.unlikely);
+            copyMove(dest, src, len);
+            return dest;
+        }
+        copyLong(dest, src, len);
+        return dest;
+    }
+
+    if (len > 16) {
+        @branchHint(.unlikely);
+        blockCopy(dest, src, 16, len);
+        return dest;
+    }
+
+    blockCopy(dest, src, 8, len);
+
+    return dest;
+}
+
+inline fn blockCopy(dest: [*]u8, src: [*]const u8, block_size: comptime_int, len: usize) void {
+    const first = @as(*align(1) const @Vector(block_size, u8), src[0..block_size]).*;
+    const second = @as(*align(1) const @Vector(block_size, u8), src[len - block_size ..][0..block_size]).*;
+    dest[0..block_size].* = first;
+    dest[len - block_size ..][0..block_size].* = second;
+}
+
+inline fn copyLong(dest: [*]u8, src: [*]const u8, len: usize) void {
+    var array: [8]@Vector(32, u8) = undefined;
+
+    inline for (.{ 64, 128, 192, 256 }, 0..) |N, i| {
+        array[i * 2] = src[(N / 2) - 32 ..][0..32].*;
+        array[(i * 2) + 1] = src[len - N / 2 ..][0..32].*;
+
+        if (len <= N) {
+            @branchHint(.unlikely);
+            for (0..i + 1) |j| {
+                dest[j * 32 ..][0..32].* = array[j * 2];
+                dest[len - ((j * 32) + 32) ..][0..32].* = array[(j * 2) + 1];
+            }
+            return;
+        }
+    }
+}
+
+inline fn copyMove(dest: [*]u8, src: [*]const u8, len: usize) void {
+    if (@intFromPtr(src) >= @intFromPtr(dest)) {
+        @branchHint(.unlikely);
+        copyForward(dest, src, len);
+    } else if (@intFromPtr(src) + len > @intFromPtr(dest)) {
+        @branchHint(.unlikely);
+        overlapBwd(dest, src, len);
+    } else {
+        copyForward(dest, src, len);
+    }
+}
+
+inline fn copyForward(dest: [*]u8, src: [*]const u8, len: usize) void {
+    const tail: @Vector(32, u8) = src[len - 32 ..][0..32].*;
+
+    const N: usize = len & ~@as(usize, 127);
+    var i: usize = 0;
+
+    while (i < N) : (i += 128) {
+        dest[i..][0..32].* = src[i..][0..32].*;
+        dest[i + 32 ..][0..32].* = src[i + 32 ..][0..32].*;
+        dest[i + 64 ..][0..32].* = src[i + 64 ..][0..32].*;
+        dest[i + 96 ..][0..32].* = src[i + 96 ..][0..32].*;
+    }
+
+    if (len - i <= 32) {
+        @branchHint(.unlikely);
+        dest[len - 32 ..][0..32].* = tail;
+    } else {
+        copyLong(dest[i..], src[i..], len - i);
+    }
+}
+
+inline fn overlapBwd(dest: [*]u8, src: [*]const u8, len: usize) void {
+    var array: [5]@Vector(32, u8) = undefined;
+    array[0] = src[len - 32 ..][0..32].*;
+    inline for (1..5) |i| array[i] = src[(i - 1) << 5 ..][0..32].*;
+
+    const end: usize = (@intFromPtr(dest) + len - 32) & 31;
+    const range = len - end;
+    var s = src + range;
+    var d = dest + range;
+
+    while (@intFromPtr(s) > @intFromPtr(src + 128)) {
+        // zig fmt: off
+        const first  = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 32)).*;
+        const second = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 64)).*;
+        const third  = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 96)).*;
+        const fourth = @as(*align(1) const @Vector(32, u8), @ptrCast(s - 128)).*;
+
+        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 32))).*  = first;
+        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 64))).*  = second;
+        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 96))).*  = third;
+        @as(*align(32) @Vector(32, u8), @alignCast(@ptrCast(d - 128))).* = fourth;
+        // zig fmt: on
+
+        s -= 128;
+        d -= 128;
+    }
+
+    inline for (array[1..], 0..) |vec, i| dest[i * 32 ..][0..32].* = vec;
+    dest[len - 32 ..][0..32].* = array[0];
+}

@@ -233,6 +233,7 @@ comptime {
 
         _ = @import("compiler_rt/memcpy.zig");
         _ = @import("compiler_rt/memset.zig");
+        _ = @import("compiler_rt/memmove.zig");
         _ = @import("compiler_rt/memcmp.zig");
         _ = @import("compiler_rt/bcmp.zig");
         _ = @import("compiler_rt/ssp.zig");