Compilation failure on latest mater for target AVR25 (ATTiny13A MCU)

[seletskiy]

Zig Version

0.14.0-dev.1632+d83a3f174

Steps to Reproduce and Observed Behavior

Minimal case to repro:

• build.zig.zon

  .{
      .name = "tmp.CsP3FWngBQ",
      .version = "0.0.0",
      .paths = .{
          "build.zig",
          "build.zig.zon",
          "src",
      },
  }

• build.zig

  const std = @import("std");
  
  pub fn build(b: *std.Build) void {
      const target = b.resolveTargetQuery(std.Target.Query{
          .cpu_arch = .avr,
          .cpu_model = .{ .explicit = &std.Target.avr.cpu.attiny13a },
          .os_tag = .freestanding,
          .abi = .none,
      });
  
      const optimize = std.builtin.OptimizeMode.ReleaseSmall;
  
      const exe = b.addExecutable(.{
          .name = "tmp.CsP3FWngBQ",
          .root_source_file = b.path("src/main.zig"),
          .target = target,
          .optimize = optimize,
      });
  
      b.installArtifact(exe);
  }

• src/main.zig

  pub export fn _start() void {}

zig build output:

install
└─ install tmp.CsP3FWngBQ
   └─ zig build-exe tmp.CsP3FWngBQ ReleaseSmall avr-freestanding-none failure
error: error: <unknown>:0: out of range branch target (expected an integer in the range -4096 to 4095)

Expected Behavior

Code compiles successfully. Confirmed to work on 0.13.0.

[alexrp]

Haven't looked closely at this yet, but my suspicion would be that this is fixed by llvm/llvm-project#109124.

[alexrp]

Seems like llvm/llvm-project#118015 might resolve this.

[Patryk27]

Note that there's also a follow-up pull request - llvm/llvm-project#121498.

[Patryk27]

Status: there's a backport ready, but it won't be accepted, because LLVM 20 is already on its way - if you want, you can pull it manually to Zig:

llvm/llvm-project#125081