zig

commit 4e623e11101dc7f900580772393c3d7855634291 (tree)
parent 2f1303d0dbdb1447997f6e692073f609319af4c9
Author: Motiejus <motiejus@jakstys.lt>
Date:   Sat,  7 Mar 2026 09:24:32 +0000

sema: add comptime float folding to zirMinMax

When both @min/@max operands are comptime-known floats (IP_KEY_FLOAT),
fold the result at compile time. Result type is the wider of the two
float types, or comptime_float if both are comptime_float.

Ported from Sema.zig analyzeMinMax → Value.numberMin/Max.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Diffstat:
M
stage0/sema.c
 | 
27
+++++++++++++++++++++++++++

1 file changed, 27 insertions(+), 0 deletions(-)
diff --git a/stage0/sema.c b/stage0/sema.c
@@ -10253,6 +10253,33 @@ static AirInstRef zirMinMax(Sema* sema, SemaBlock* block, uint32_t inst) {
             result_ty = semaTypeOf(sema, min_rhs);
         return internComptimeInt(sema, result_ty, r_lo, r_hi, r_neg);
     }
+
+    // Comptime folding for float operands.
+    // Ported from Sema.zig analyzeMinMax → Value.numberMin/Max for floats.
+    if (AIR_REF_IS_IP(min_lhs) && AIR_REF_IS_IP(min_rhs)) {
+        InternPoolKey lk = ipIndexToKey(sema->ip, AIR_REF_TO_IP(min_lhs));
+        InternPoolKey rk = ipIndexToKey(sema->ip, AIR_REF_TO_IP(min_rhs));
+        if (lk.tag == IP_KEY_FLOAT && rk.tag == IP_KEY_FLOAT) {
+            double lv = lk.data.float_val.val;
+            double rv = rk.data.float_val.val;
+            double result_val
+                = is_max ? (lv > rv ? lv : rv) : (lv < rv ? lv : rv);
+            TypeIndex result_ty = (floatBits(lk.data.float_val.ty)
+                                      >= floatBits(rk.data.float_val.ty))
+                ? lk.data.float_val.ty
+                : rk.data.float_val.ty;
+            if (lk.data.float_val.ty == IP_INDEX_COMPTIME_FLOAT_TYPE
+                && rk.data.float_val.ty == IP_INDEX_COMPTIME_FLOAT_TYPE)
+                result_ty = IP_INDEX_COMPTIME_FLOAT_TYPE;
+            InternPoolKey key;
+            memset(&key, 0, sizeof(key));
+            key.tag = IP_KEY_FLOAT;
+            key.data.float_val.ty = result_ty;
+            key.data.float_val.val = result_val;
+            return AIR_REF_FROM_IP(ipIntern(sema->ip, key));
+        }
+    }
+
     TypeIndex peer_ty = resolvePeerTypes(sema, min_lhs, min_rhs);
     AirInstRef c_lhs = semaCoerce(sema, block, peer_ty, min_lhs);
     AirInstRef c_rhs = semaCoerce(sema, block, peer_ty, min_rhs);