From f2a6a1756bd3d3e284410c001ee997c4d12a260b Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sat, 18 Feb 2023 10:27:08 -0700
Subject: [PATCH] Sema: fix for loops with comptime-known int ranges

---
 src/Sema.zig          |  6 +++++-
 test/behavior/for.zig | 12 ++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/Sema.zig b/src/Sema.zig
index fde9072d71..980aee720b 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -3924,7 +3924,11 @@ fn zirForLen(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.
         const object_ty = sema.typeOf(object);
         // Each arg could be an indexable, or a range, in which case the length
         // is passed directly as an integer.
-        const arg_len = if (object_ty.zigTypeTag() == .Int) object else l: {
+        const is_int = switch (object_ty.zigTypeTag()) {
+            .Int, .ComptimeInt => true,
+            else => false,
+        };
+        const arg_len = if (is_int) object else l: {
             try checkIndexable(sema, block, src, object_ty);
             if (!object_ty.indexableHasLen()) continue;
 
diff --git a/test/behavior/for.zig b/test/behavior/for.zig
index c9ae2f4461..20788f7269 100644
--- a/test/behavior/for.zig
+++ b/test/behavior/for.zig
@@ -249,3 +249,15 @@ test "for loop with else branch" {
         try expect(q == 4);
     }
 }
+
+test "count over fixed range" {
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+
+    var sum: usize = 0;
+    for (0..6) |i| {
+        sum += i;
+    }
+
+    try expect(sum == 15);
+}