Commit 867ab50575b89de123c852aa74b481966f00d8eb | zig

author	Mick Sayson <mick@sayson.com> 2026-07-13 15:41:54-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2026-08-04 18:13:01-07:00
log	867ab50575b89de123c852aa74b481966f00d8eb
tree	e9943b71b2ec4a12a8a7292a6fca5a059b5ed062
parent	5d2ad0b021f1926f09039827077bf1bd55f83df7

fix compiler crash on mem.doNotOptimize on SPIR-V

1 files changed, 22 insertions(+), 11 deletions(-)

lib
- std
  - mem.zig

lib/std/mem.zig+22-11

 @@ -4810,21 +4810,32 @@ pub fn doNotOptimizeAway(val: anytype) void {
         return;
     }
-    const max_gp_register_bits = @bitSizeOf(c_long);
     switch (@typeInfo(@TypeOf(val))) {
         .void, .null, .comptime_int, .comptime_float => return,
         .@"enum" => doNotOptimizeAway(@backingInt(val)),
         .bool => doNotOptimizeAway(@intFromBool(val)),
-        .int => |int| if (int.bits <= max_gp_register_bits) {
+        .int => |int| {
-            const val2 = @as(
+            // SPIR-V targets do not have registers per se, they have values
-                @Int(int.signedness, @max(8, std.math.ceilPowerOfTwoAssert(u16, int.bits))),
+            // tied to IDs that can be passed to valid instructions. Some
-                val,
+            // SPIR-V targets do not define c_long, so we just allow any sized
-            );
+            // integer on these targets
-            asm volatile (""
+            const val_fits_in_gp_register = builtin.target.cpu.arch.isSpirV() or fits: {
-                :
+                const max_gp_register_bits = @bitSizeOf(c_long);
-                : [_] "r" (val2),
+                break :fits int.bits <= max_gp_register_bits;
-            );
+            };
-        } else doNotOptimizeAway(&val),
+            if (val_fits_in_gp_register) {
+                const val2 = @as(
+                    @Int(int.signedness, @max(8, std.math.ceilPowerOfTwoAssert(u16, int.bits))),
+                    val,
+                );
+                asm volatile (""
+                    :
+                    : [_] "r" (val2),
+                );
+            } else {
+                doNotOptimizeAway(&val);
+            }
+        },
         .float => |float| switch (float.bits) {
             else => comptime unreachable,
             16, 80, 128 => doNotOptimizeAway(&val),