--- a/lib/std/math/exp2.zig     Tue Dec 08 00:07:14 2020 -0700
+++ b/lib/std/math/exp2.zig     Tue Dec 08 16:00:26 2020 -0500
@@ -95,7 +95,7 @@
     uf -= redux;

     const z: f64 = x - uf;
-    var r: f64 = exp2ft[i_0];
+    var r: f64 = exp2ft[@truncate(c_uint, i_0)];
     const t: f64 = r * z;
     r = r + t * (P1 + z * P2) + t * (z * z) * (P3 + z * P4);
     return @floatCast(f32, r * uk);
@@ -418,8 +418,8 @@

     // r = exp2(y) = exp2t[i_0] * p(z - eps[i])
     var z = x - uf;
-    const t = exp2dt[2 * i_0];
-    z -= exp2dt[2 * i_0 + 1];
+    const t = exp2dt[2 * @truncate(c_uint, i_0)];
+    z -= exp2dt[2 * @truncate(c_uint, i_0) + 1];
     const r = t + t * z * (P1 + z * (P2 + z * (P3 + z * (P4 + z * P5))));

     return math.scalbn(r, ik);
diff -r f5790902119e lib/std/special/compiler_rt.zig
--- a/lib/std/special/compiler_rt.zig   Tue Dec 08 00:07:14 2020 -0700
+++ b/lib/std/special/compiler_rt.zig   Tue Dec 08 16:00:26 2020 -0500
@@ -317,7 +317,8 @@
     @export(@import("compiler_rt/mulodi4.zig").__mulodi4, .{ .name = "__mulodi4", .linkage = linkage });
 }

-pub usingnamespace @import("compiler_rt/atomics.zig");
+// Temporarily removed to get this working
+// pub usingnamespace @import("compiler_rt/atomics.zig");

 // Avoid dragging in the runtime safety mechanisms into this .o file,
 // unless we're trying to test this file.
nathan@stalagmite:~/zig/zig/build$ locate crt0.S
nathan@stalagmite:~/zig/zig/build$ hg diff
diff -r f5790902119e lib/std/math/exp2.zig
--- a/lib/std/math/exp2.zig     Tue Dec 08 00:07:14 2020 -0700
+++ b/lib/std/math/exp2.zig     Tue Dec 08 16:24:19 2020 -0500
@@ -95,7 +95,7 @@
     uf -= redux;

     const z: f64 = x - uf;
-    var r: f64 = exp2ft[i_0];
+    var r: f64 = exp2ft[@truncate(c_uint, i_0)];
     const t: f64 = r * z;
     r = r + t * (P1 + z * P2) + t * (z * z) * (P3 + z * P4);
     return @floatCast(f32, r * uk);
@@ -418,8 +418,8 @@

     // r = exp2(y) = exp2t[i_0] * p(z - eps[i])
     var z = x - uf;
-    const t = exp2dt[2 * i_0];
-    z -= exp2dt[2 * i_0 + 1];
+    const t = exp2dt[2 * @truncate(c_uint, i_0)];
+    z -= exp2dt[2 * @truncate(c_uint, i_0) + 1];
     const r = t + t * z * (P1 + z * (P2 + z * (P3 + z * (P4 + z * P5))));

     return math.scalbn(r, ik);
diff -r f5790902119e lib/std/special/compiler_rt.zig
--- a/lib/std/special/compiler_rt.zig   Tue Dec 08 00:07:14 2020 -0700
+++ b/lib/std/special/compiler_rt.zig   Tue Dec 08 16:24:19 2020 -0500
@@ -317,7 +317,8 @@
     @export(@import("compiler_rt/mulodi4.zig").__mulodi4, .{ .name = "__mulodi4", .linkage = linkage });
 }

-pub usingnamespace @import("compiler_rt/atomics.zig");
+// Temporarily removed to get this working
+// pub usingnamespace @import("compiler_rt/atomics.zig");

 // Avoid dragging in the runtime safety mechanisms into this .o file,
 // unless we're trying to test this file.