unable to build zig with x86 backend using ReleaseFast optimization mode

[andrewrk]

1b0b46a

$ ./zig2 build --zig-lib-dir lib -Doptimize=ReleaseFast -Dstrip -Dno-langref -Dno-autodocs
zig build-exe zig ReleaseFast native: error: error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m256 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none
error(x86_64_encoder): no encoding found for: none mov m128 r64 none none

zig build-exe zig ReleaseFast native: error: the following command failed with 9 compilation errors:
/home/andy/Downloads/zig/zig2 build-exe --stack 33554432 /home/andy/Downloads/zig/src/main.zig -fstrip -OReleaseFast --cache-dir /home/andy/Downloads/zig/zig-cache --global-cache-dir /home/andy/.cache/zig --name zig --mod aro::/home/andy/Downloads/zig/deps/aro/lib.zig --mod build_options::/home/andy/Downloads/zig/zig-cache/c/b0a3e19e067b3b3c4957215274d0ade5/options.zig --deps aro,build_options --zig-lib-dir /home/andy/Downloads/zig/lib --listen=- 
Build Summary: 2/5 steps succeeded; 1 failed (disable with --summary none)
install transitive failure
└─ install zig transitive failure
 └─ zig build-exe zig ReleaseFast native 9 errors
deps/aro/Attribute.zig:1281:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn applyAligned(attr: Attribute, p: *Parser, ty: Type, tag: ?Diagnostics.Tag) !void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:224:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn validateExtendedIdentifier(p: *Parser) !bool {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:7617:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn parseNumberEscape(p: *Parser, tok: TokenIndex, base: u8, slice: []const u8, i: *usize) !u8 {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:7634:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn parseUnicodeEscape(p: *Parser, tok: TokenIndex, count: u8, slice: []const u8, i: *usize) !void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Attribute.zig:922:5: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
pub fn initArguments(tag: Tag, name_tok: TokenIndex) Arguments {
~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:4240:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn labeledStmt(p: *Parser) Error!?NodeIndex {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Attribute.zig:223:5: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
pub fn diagnoseAlignment(attr: Tag, arguments: *Arguments, arg_idx: u32, val: Value, ty: Type, comp: *Compilation) ?Diagnostics.Message {
~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:358:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn errOverflow(p: *Parser, op_tok: TokenIndex, res: Result) !void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
deps/aro/Parser.zig:7212:1: error: CodeGen failed to find a viable instruction. This is a bug in the Zig compiler.
fn checkArrayBounds(p: *Parser, index: Result, array: Result, tok: TokenIndex) !void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

target CPU and OS info:

pub const cpu: std.Target.Cpu = .{
 .arch = .x86_64,
 .model = &std.Target.x86.cpu.skylake,
 .features = std.Target.x86.featureSet(&[_]std.Target.x86.Feature{
 .@"64bit",
 .adx,
 .aes,
 .allow_light_256_bit,
 .avx,
 .avx2,
 .bmi,
 .bmi2,
 .clflushopt,
 .cmov,
 .crc32,
 .cx16,
 .cx8,
 .ermsb,
 .f16c,
 .false_deps_popcnt,
 .fast_15bytenop,
 .fast_gather,
 .fast_scalar_fsqrt,
 .fast_shld_rotate,
 .fast_variable_crosslane_shuffle,
 .fast_variable_perlane_shuffle,
 .fast_vector_fsqrt,
 .fma,
 .fsgsbase,
 .fxsr,
 .idivq_to_divl,
 .invpcid,
 .lzcnt,
 .macrofusion,
 .mmx,
 .movbe,
 .no_bypass_delay_blend,
 .no_bypass_delay_mov,
 .no_bypass_delay_shuffle,
 .nopl,
 .pclmul,
 .popcnt,
 .prfchw,
 .rdrnd,
 .rdseed,
 .sahf,
 .sgx,
 .slow_3ops_lea,
 .sse,
 .sse2,
 .sse3,
 .sse4_1,
 .sse4_2,
 .ssse3,
 .vzeroupper,
 .x87,
 .xsave,
 .xsavec,
 .xsaveopt,
 .xsaves,
 }),
};
pub const os = std.Target.Os{
 .tag = .linux,
 .version_range = .{ .linux = .{
 .range = .{
 .min = .{
 .major = 6,
 .minor = 1,
 .patch = 53,
 },
 .max = .{
 .major = 6,
 .minor = 1,
 .patch = 53,
 },
 },
 .glibc = .{
 .major = 2,
 .minor = 36,
 .patch = 0,
 },
 }},
};

[jacobly0]

I see your backend assert and raise you a new Module assert.

diff --git a/src/Module.zig b/src/Module.zig
index eda4624bd0..d53393ba61 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -6382,6 +6382,12 @@ pub const UnionLayout = struct {
 };
 
 pub fn getUnionLayout(mod: *Module, u: InternPool.UnionType) UnionLayout {
+ const layout = mod.getUnionLayoutInner(u);
+ assert(layout.abi_align.check(layout.abi_size));
+ return layout;
+}
+
+fn getUnionLayoutInner(mod: *Module, u: InternPool.UnionType) UnionLayout {
 const ip = &mod.intern_pool;
 assert(u.haveLayout(ip));
 var most_aligned_field: u32 = undefined;

The first time I hit this assert is on this result, which I can't make heads or tails of (yes alignments are being displayed correctly as their tag name, not integer value):

(Module.UnionLayout) layout = {
 abi_size = 7
 abi_align = 8
 most_aligned_field = 1
 most_aligned_field_size = 56
 biggest_field = 1
 payload_size = 56
 payload_align = 8
 tag_align = 1
 tag_size = 1
 padding = 7
}