Revert "work around llvm failing to lower memcpy"

This reverts commit acf70439551fc3f49b2d292ff93ee519901cdf42.

Fixed as of ec768b7fa2f9c7dea6b92651bef59a7eea3299f2.
This commit is contained in:
Alex Rønne Petersen 2025-01-18 12:45:27 +01:00
parent 9758371419
commit 515c97065a
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@ -9,36 +9,12 @@ comptime {
}
}
const llvm_cannot_lower = switch (builtin.cpu.arch) {
.arm, .armeb, .thumb, .thumbeb => builtin.zig_backend == .stage2_llvm,
else => false,
};
fn memcpy(noalias opt_dest: ?[*]u8, noalias opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
if (llvm_cannot_lower) {
for (0..len) |i| opt_dest.?[i] = opt_src.?[i];
return opt_dest;
} else {
return memmove(opt_dest, opt_src, len);
}
return memmove(opt_dest, opt_src, len);
}
/// A port of https://github.com/facebook/folly/blob/1c8bc50e88804e2a7361a57cd9b551dd10f6c5fd/folly/memcpy.S
fn memmove(opt_dest: ?[*]u8, opt_src: ?[*]const u8, len: usize) callconv(.C) ?[*]u8 {
if (llvm_cannot_lower) {
if (@intFromPtr(opt_dest) < @intFromPtr(opt_src)) {
for (0..len) |i| opt_dest.?[i] = opt_src.?[i];
return opt_dest;
} else {
var index = len;
while (index != 0) {
index -= 1;
opt_dest.?[index] = opt_src.?[index];
}
return opt_dest;
}
}
// a port of https://github.com/facebook/folly/blob/1c8bc50e88804e2a7361a57cd9b551dd10f6c5fd/folly/memcpy.S
if (len == 0) {
@branchHint(.unlikely);
return opt_dest;