zig

commit f0a4bb6bd15b8a605e450af3359fe1622302463a (tree)
parent 147beec7da5f3eb3a858037b806ad8b1b66bfffc
Author: mlugg <mlugg@mlugg.co.uk>
Date:   Mon, 26 Feb 2024 15:11:38 +0000

AstGen: avoid unnecessary coercion instructions

Coercions such as `@as(usize, 0)` can be trivially elided by matching
these cases and translating to fixed InternPool indices.

Diffstat:
M
lib/std/zig/AstGen.zig
 | 
22
++++++++++++++++++++--

1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/lib/std/zig/AstGen.zig b/lib/std/zig/AstGen.zig
@@ -10874,6 +10874,7 @@ fn rvalueInner(
             const as_comptime_int = @as(u64, @intFromEnum(Zir.Inst.Ref.comptime_int_type)) << 32;
             const as_bool = @as(u64, @intFromEnum(Zir.Inst.Ref.bool_type)) << 32;
             const as_usize = @as(u64, @intFromEnum(Zir.Inst.Ref.usize_type)) << 32;
+            const as_u8 = @as(u64, @intFromEnum(Zir.Inst.Ref.u8_type)) << 32;
             const as_void = @as(u64, @intFromEnum(Zir.Inst.Ref.void_type)) << 32;
             switch ((@as(u64, @intFromEnum(ty_inst)) << 32) | @as(u64, @intFromEnum(result))) {
                 as_ty | @intFromEnum(Zir.Inst.Ref.u1_type),
@@ -10939,13 +10940,30 @@ fn rvalueInner(
                 as_ty | @intFromEnum(Zir.Inst.Ref.empty_struct_type),
                 as_comptime_int | @intFromEnum(Zir.Inst.Ref.zero),
                 as_comptime_int | @intFromEnum(Zir.Inst.Ref.one),
-                as_bool | @intFromEnum(Zir.Inst.Ref.bool_true),
-                as_bool | @intFromEnum(Zir.Inst.Ref.bool_false),
+                as_comptime_int | @intFromEnum(Zir.Inst.Ref.negative_one),
                 as_usize | @intFromEnum(Zir.Inst.Ref.zero_usize),
                 as_usize | @intFromEnum(Zir.Inst.Ref.one_usize),
+                as_u8 | @intFromEnum(Zir.Inst.Ref.zero_u8),
+                as_u8 | @intFromEnum(Zir.Inst.Ref.one_u8),
+                as_u8 | @intFromEnum(Zir.Inst.Ref.four_u8),
+                as_bool | @intFromEnum(Zir.Inst.Ref.bool_true),
+                as_bool | @intFromEnum(Zir.Inst.Ref.bool_false),
                 as_void | @intFromEnum(Zir.Inst.Ref.void_value),
                 => return result, // type of result is already correct
 
+                as_usize | @intFromEnum(Zir.Inst.Ref.zero) => return .zero_usize,
+                as_u8 | @intFromEnum(Zir.Inst.Ref.zero) => return .zero_u8,
+                as_usize | @intFromEnum(Zir.Inst.Ref.one) => return .one_usize,
+                as_u8 | @intFromEnum(Zir.Inst.Ref.one) => return .one_u8,
+                as_comptime_int | @intFromEnum(Zir.Inst.Ref.zero_usize) => return .zero,
+                as_u8 | @intFromEnum(Zir.Inst.Ref.zero_usize) => return .zero_u8,
+                as_comptime_int | @intFromEnum(Zir.Inst.Ref.one_usize) => return .one,
+                as_u8 | @intFromEnum(Zir.Inst.Ref.one_usize) => return .one_u8,
+                as_comptime_int | @intFromEnum(Zir.Inst.Ref.zero_u8) => return .zero,
+                as_usize | @intFromEnum(Zir.Inst.Ref.zero_u8) => return .zero_usize,
+                as_comptime_int | @intFromEnum(Zir.Inst.Ref.one_u8) => return .one,
+                as_usize | @intFromEnum(Zir.Inst.Ref.one_u8) => return .one_usize,
+
                 // Need an explicit type coercion instruction.
                 else => return gz.addPlNode(ri.zirTag(), src_node, Zir.Inst.As{
                     .dest_type = ty_inst,