Merge pull request #8060 from DrDeano/feature/add-mcpu-to-target-options

Add CPU feature check to standardTargetOptions

2 files changed, 62 insertions, 11 deletions

diff --git a/lib/std/build.zig b/lib/std/build.zig
index 12c98271d5..2b8ad8839a 100644
--- a/lib/std/build.zig
+++ b/lib/std/build.zig
@@ -637,7 +637,7 @@ pub const Builder = struct {
             "target",
             "The CPU architecture, OS, and ABI to build for",
         );
-        const mcpu = self.option([]const u8, "cpu", "Target CPU");
+        const mcpu = self.option([]const u8, "cpu", "Target CPU features to add or subtract");
 
         const triple = maybe_triple orelse return args.default_target;
 
@@ -699,20 +699,64 @@ pub const Builder = struct {
 
         if (args.whitelist) |list| whitelist_check: {
             // Make sure it's a match of one of the list.
+            var mismatch_triple = true;
+            var mismatch_cpu_features = true;
+            var whitelist_item = CrossTarget{};
             for (list) |t| {
+                mismatch_cpu_features = true;
+                mismatch_triple = true;
+
                 const t_triple = t.zigTriple(self.allocator) catch unreachable;
                 if (mem.eql(u8, t_triple, selected_canonicalized_triple)) {
-                    break :whitelist_check;
+                    mismatch_triple = false;
+                    whitelist_item = t;
+                    if (t.getCpuFeatures().isSuperSetOf(selected_target.getCpuFeatures())) {
+                        mismatch_cpu_features = false;
+                        break :whitelist_check;
+                    } else {
+                        break;
+                    }
                 }
             }
-            warn("Chosen target '{s}' does not match one of the supported targets:\n", .{
-                selected_canonicalized_triple,
-            });
-            for (list) |t| {
-                const t_triple = t.zigTriple(self.allocator) catch unreachable;
-                warn(" {s}\n", .{t_triple});
+            if (mismatch_triple) {
+                warn("Chosen target '{s}' does not match one of the supported targets:\n", .{
+                    selected_canonicalized_triple,
+                });
+                for (list) |t| {
+                    const t_triple = t.zigTriple(self.allocator) catch unreachable;
+                    warn(" {s}\n", .{t_triple});
+                }
+                warn("\n", .{});
+            } else {
+                assert(mismatch_cpu_features);
+                const whitelist_cpu = whitelist_item.getCpu();
+                const selected_cpu = selected_target.getCpu();
+                warn("Chosen CPU model '{s}' does not match one of the supported targets:\n", .{
+                    selected_cpu.model.name,
+                });
+                warn("  Supported feature Set: ", .{});
+                const all_features = whitelist_cpu.arch.allFeaturesList();
+                var populated_cpu_features = whitelist_cpu.model.features;
+                populated_cpu_features.populateDependencies(all_features);
+                for (all_features) |feature, i_usize| {
+                    const i = @intCast(std.Target.Cpu.Feature.Set.Index, i_usize);
+                    const in_cpu_set = populated_cpu_features.isEnabled(i);
+                    if (in_cpu_set) {
+                        warn("{s} ", .{feature.name});
+                    }
+                }
+                warn("\n", .{});
+                warn("  Remove: ", .{});
+                for (all_features) |feature, i_usize| {
+                    const i = @intCast(std.Target.Cpu.Feature.Set.Index, i_usize);
+                    const in_cpu_set = populated_cpu_features.isEnabled(i);
+                    const in_actual_set = selected_cpu.features.isEnabled(i);
+                    if (in_actual_set and !in_cpu_set) {
+                        warn("{s} ", .{feature.name});
+                    }
+                }
+                warn("\n", .{});
             }
-            warn("\n", .{});
             self.markInvalidUserInput();
             return args.default_target;
         }
diff --git a/lib/std/target.zig b/lib/std/target.zig
index 3fd5cd5f94..faebe665ab 100644
--- a/lib/std/target.zig
+++ b/lib/std/target.zig
@@ -664,8 +664,15 @@ pub const Target = struct {
                     return @ptrCast(*const [byte_count]u8, &set.ints);
                 }
 
-                pub fn eql(set: Set, other: Set) bool {
-                    return mem.eql(usize, &set.ints, &other.ints);
+                pub fn eql(set: Set, other_set: Set) bool {
+                    return mem.eql(usize, &set.ints, &other_set.ints);
+                }
+
+                pub fn isSuperSetOf(set: Set, other_set: Set) bool {
+                    const V = std.meta.Vector(usize_count, usize);
+                    const set_v: V = set.ints;
+                    const other_v: V = other_set.ints;
+                    return @reduce(.And, (set_v & other_v) == other_v);
                 }
             };