add musl memcpy and avx2 dispatching

crates/compiler/builtins/bitcode/src/libc.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const builtin = @import("builtin");
 const arch = builtin.cpu.arch;
+const musl_memcpy = @import("libc/musl/memcpy.zig");
+const cpuid = @import("libc/cpuid.zig");
 
 comptime {
     @export(memcpy, .{ .name = "roc_memcpy", .linkage = .Weak });
@@ -10,14 +12,15 @@ comptime {
 const Memcpy = fn (noalias [*]u8, noalias [*]const u8, len: usize) callconv(.C) [*]u8;
 
 pub var memcpy_target: Memcpy = switch (arch) {
-    .x86_64 => memcpy,
+    // TODO(): Switch to dispatch_memcpy once the surgical linker can support it.
+    // .x86_64 => dispatch_memcpy,
+    .x86_64 => musl_memcpy.musl_memcpy,
     else => unreachable,
 };
 
 pub fn memcpy(noalias dest: [*]u8, noalias src: [*]const u8, len: usize) callconv(.C) [*]u8 {
     switch (arch) {
         .x86_64 => {
-            @memcpy(dest, src, len);
             return memcpy_target(dest, src, len);
         },
         .i386 => {
@@ -39,3 +42,17 @@ pub fn memcpy(noalias dest: [*]u8, noalias src: [*]const u8, len: usize) callcon
         else => @compileError("Unsupported architecture for memcpy"),
     }
 }
+
+fn dispatch_memcpy(noalias dest: [*]u8, noalias src: [*]const u8, len: usize) callconv(.C) [*]u8 {
+    switch (arch) {
+        .x86_64 => {
+            if (cpuid.supports_avx2()) {
+                memcpy_target = musl_memcpy.musl_memcpy;
+            } else {
+                memcpy_target = musl_memcpy.musl_memcpy;
+            }
+        },
+        else => unreachable,
+    }
+    return memcpy_target(dest, src, len);
+}

crates/compiler/builtins/bitcode/src/libc/cpuid.zig

@@ -0,0 +1,43 @@
+const builtin = @import("builtin");
+const arch = builtin.cpu.arch;
+
+// I couldn't manage to define this in a PIE friendly way with inline assembly.
+// Instead, I am definining it as a global assembly function.
+comptime {
+    switch (arch) {
+        .x86_64 => {
+            asm (
+                \\  # Check if AVX2 is supported.
+                \\  # Returns 1 if AVX2 is supported, 0 otherwise.
+                \\ .global supports_avx2;
+                \\ supports_avx2:
+                \\     # Save the EBX register.
+                \\     push %rbx
+                \\
+                \\     # Call the CPUID instruction with the EAX register set to 7 and ECX set to 0.
+                \\     # This will get the CPUID information for the current CPU.
+                \\     mov $7, %eax
+                \\     mov $0, %ecx
+                \\     cpuid
+                \\
+                \\     # Check if the AVX2 feature flag is set.
+                \\     # The AVX2 feature flag is located in the EBX register at bit 5.
+                \\     bt $5, %ebx
+                \\     jc .AVX2Supported
+                \\
+                \\     # AVX2 is not supported.
+                \\     pop %rbx
+                \\     mov $0, %eax
+                \\     ret
+                \\
+                \\     .AVX2Supported:
+                \\     pop %rbx
+                \\     mov $1, %eax
+                \\     ret
+            );
+        },
+        else => unreachable,
+    }
+}
+
+pub extern fn supports_avx2() bool;

crates/compiler/builtins/bitcode/src/libc/musl/COPYRIGHT

@@ -0,0 +1,193 @@
+musl as a whole is licensed under the following standard MIT license:
+
+----------------------------------------------------------------------
+Copyright © 2005-2020 Rich Felker, et al.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+----------------------------------------------------------------------
+
+Authors/contributors include:
+
+A. Wilcox
+Ada Worcester
+Alex Dowad
+Alex Suykov
+Alexander Monakov
+Andre McCurdy
+Andrew Kelley
+Anthony G. Basile
+Aric Belsito
+Arvid Picciani
+Bartosz Brachaczek
+Benjamin Peterson
+Bobby Bingham
+Boris Brezillon
+Brent Cook
+Chris Spiegel
+Clément Vasseur
+Daniel Micay
+Daniel Sabogal
+Daurnimator
+David Carlier
+David Edelsohn
+Denys Vlasenko
+Dmitry Ivanov
+Dmitry V. Levin
+Drew DeVault
+Emil Renner Berthing
+Fangrui Song
+Felix Fietkau
+Felix Janda
+Gianluca Anzolin
+Hauke Mehrtens
+He X
+Hiltjo Posthuma
+Isaac Dunham
+Jaydeep Patil
+Jens Gustedt
+Jeremy Huntwork
+Jo-Philipp Wich
+Joakim Sindholt
+John Spencer
+Julien Ramseier
+Justin Cormack
+Kaarle Ritvanen
+Khem Raj
+Kylie McClain
+Leah Neukirchen
+Luca Barbato
+Luka Perkov
+M Farkas-Dyck (Strake)
+Mahesh Bodapati
+Markus Wichmann
+Masanori Ogino
+Michael Clark
+Michael Forney
+Mikhail Kremnyov
+Natanael Copa
+Nicholas J. Kain
+orc
+Pascal Cuoq
+Patrick Oppenlander
+Petr Hosek
+Petr Skocik
+Pierre Carrier
+Reini Urban
+Rich Felker
+Richard Pennington
+Ryan Fairfax
+Samuel Holland
+Segev Finer
+Shiz
+sin
+Solar Designer
+Stefan Kristiansson
+Stefan O'Rear
+Szabolcs Nagy
+Timo Teräs
+Trutz Behn
+Valentin Ochs
+Will Dietz
+William Haddon
+William Pitcock
+
+Portions of this software are derived from third-party works licensed
+under terms compatible with the above MIT license:
+
+The TRE regular expression implementation (src/regex/reg* and
+src/regex/tre*) is Copyright © 2001-2008 Ville Laurikari and licensed
+under a 2-clause BSD license (license text in the source files). The
+included version has been heavily modified by Rich Felker in 2012, in
+the interests of size, simplicity, and namespace cleanliness.
+
+Much of the math library code (src/math/* and src/complex/*) is
+Copyright © 1993,2004 Sun Microsystems or
+Copyright © 2003-2011 David Schultz or
+Copyright © 2003-2009 Steven G. Kargl or
+Copyright © 2003-2009 Bruce D. Evans or
+Copyright © 2008 Stephen L. Moshier or
+Copyright © 2017-2018 Arm Limited
+and labelled as such in comments in the individual source files. All
+have been licensed under extremely permissive terms.
+
+The ARM memcpy code (src/string/arm/memcpy.S) is Copyright © 2008
+The Android Open Source Project and is licensed under a two-clause BSD
+license. It was taken from Bionic libc, used on Android.
+
+The AArch64 memcpy and memset code (src/string/aarch64/*) are
+Copyright © 1999-2019, Arm Limited.
+
+The implementation of DES for crypt (src/crypt/crypt_des.c) is
+Copyright © 1994 David Burren. It is licensed under a BSD license.
+
+The implementation of blowfish crypt (src/crypt/crypt_blowfish.c) was
+originally written by Solar Designer and placed into the public
+domain. The code also comes with a fallback permissive license for use
+in jurisdictions that may not recognize the public domain.
+
+The smoothsort implementation (src/stdlib/qsort.c) is Copyright © 2011
+Valentin Ochs and is licensed under an MIT-style license.
+
+The x86_64 port was written by Nicholas J. Kain and is licensed under
+the standard MIT terms.
+
+The mips and microblaze ports were originally written by Richard
+Pennington for use in the ellcc project. The original code was adapted
+by Rich Felker for build system and code conventions during upstream
+integration. It is licensed under the standard MIT terms.
+
+The mips64 port was contributed by Imagination Technologies and is
+licensed under the standard MIT terms.
+
+The powerpc port was also originally written by Richard Pennington,
+and later supplemented and integrated by John Spencer. It is licensed
+under the standard MIT terms.
+
+All other files which have no copyright comments are original works
+produced specifically for use as part of this library, written either
+by Rich Felker, the main author of the library, or by one or more
+contibutors listed above. Details on authorship of individual files
+can be found in the git version control history of the project. The
+omission of copyright and license comments in each file is in the
+interest of source tree size.
+
+In addition, permission is hereby granted for all public header files
+(include/* and arch/*/bits/*) and crt files intended to be linked into
+applications (crt/*, ldso/dlstart.c, and arch/*/crt_arch.h) to omit
+the copyright notice and permission notice otherwise required by the
+license, and to use these files without any requirement of
+attribution. These files include substantial contributions from:
+
+Bobby Bingham
+John Spencer
+Nicholas J. Kain
+Rich Felker
+Richard Pennington
+Stefan Kristiansson
+Szabolcs Nagy
+
+all of whom have explicitly granted such permission.
+
+This file previously contained text expressing a belief that most of
+the files covered by the above exception were sufficiently trivial not
+to be subject to copyright, resulting in confusion over whether it
+negated the permissions granted in the license. In the spirit of
+permissive licensing, and of not having licensing issues being an
+obstacle to adoption, that text has been removed.

crates/compiler/builtins/bitcode/src/libc/musl/README.md

@@ -0,0 +1,2 @@
+This set of files all come from [musl libc](https://musl.libc.org/).
+Roc just directly uses a few of them instead of depending on musl libc fully.

crates/compiler/builtins/bitcode/src/libc/musl/memcpy.zig

@@ -0,0 +1,35 @@
+const builtin = @import("builtin");
+const arch = builtin.cpu.arch;
+
+comptime {
+    switch (arch) {
+        .x86_64 => {
+            asm (
+                \\ .global musl_memcpy;
+                \\ musl_memcpy:
+                \\     mov %rdi,%rax
+                \\     cmp $8,%rdx
+                \\     jc 1f
+                \\     test $7,%edi
+                \\     jz 1f
+                \\ 2:  movsb
+                \\     dec %rdx
+                \\     test $7,%edi
+                \\     jnz 2b
+                \\ 1:  mov %rdx,%rcx
+                \\     shr $3,%rcx
+                \\     rep
+                \\     movsq
+                \\     and $7,%edx
+                \\     jz 1f
+                \\ 2:  movsb
+                \\     dec %edx
+                \\     jnz 2b
+                \\ 1:  ret
+            );
+        },
+        else => unreachable,
+    }
+}
+
+pub extern fn musl_memcpy(noalias dest: [*]u8, noalias src: [*]const u8, len: usize) callconv(.C) [*]u8;