zig

commit 26fac15f485e89dc7106256e1aa79184c1761efd (tree)
parent d019229c2c3432c9053594eb140b255c3be9ebeb
Author: Jacob Young <jacobly0@users.noreply.github.com>
Date:   Wed, 31 May 2023 00:42:24 -0400

math.big.int: fix ctz of zero

Diffstat:
M
lib/std/math/big/int.zig
 | 
4
++--
M
src/value.zig
 | 
4
++--

2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/lib/std/math/big/int.zig b/lib/std/math/big/int.zig
@@ -2512,7 +2512,7 @@ pub const Const = struct {
         return total_limb_lz + bits - total_limb_bits;
     }
 
-    pub fn ctz(a: Const) Limb {
+    pub fn ctz(a: Const, bits: Limb) Limb {
         // Limbs are stored in little-endian order.
         var result: Limb = 0;
         for (a.limbs) |limb| {
@@ -2520,7 +2520,7 @@ pub const Const = struct {
             result += limb_tz;
             if (limb_tz != @sizeOf(Limb) * 8) break;
         }
-        return result;
+        return @min(result, bits);
     }
 };
 
diff --git a/src/value.zig b/src/value.zig
@@ -1216,10 +1216,10 @@ pub const Value = struct {
         return bigint.clz(ty.intInfo(mod).bits);
     }
 
-    pub fn ctz(val: Value, _: Type, mod: *Module) u64 {
+    pub fn ctz(val: Value, ty: Type, mod: *Module) u64 {
         var bigint_buf: BigIntSpace = undefined;
         const bigint = val.toBigInt(&bigint_buf, mod);
-        return bigint.ctz();
+        return bigint.ctz(ty.intInfo(mod).bits);
     }
 
     pub fn popCount(val: Value, ty: Type, mod: *Module) u64 {