diff --git a/core/tiny_alloc_fast.inc.h b/core/tiny_alloc_fast.inc.h
index 2f9f09a6..1d31a004 100644
--- a/core/tiny_alloc_fast.inc.h
+++ b/core/tiny_alloc_fast.inc.h
@@ -417,7 +417,8 @@ static inline void* tiny_alloc_fast_pop(int class_idx) {
 #endif
 
     // Phase 1: Try array stack (FastCache) first for hottest tiny classes (C0–C3)
-    if (__builtin_expect(g_fastcache_enable && class_idx <= 3, 1)) {
+    // Phase 7-Step4: Use config macro for dead code elimination in PGO mode
+    if (__builtin_expect(TINY_FRONT_FASTCACHE_ENABLED && class_idx <= 3, 1)) {
         void* fc = fastcache_pop(class_idx);
         if (__builtin_expect(fc != NULL, 1)) {
             // Frontend FastCache hit (already tracked by g_front_fc_hit)
@@ -752,7 +753,8 @@ static inline void* tiny_alloc_fast(size_t size) {
     }
 #endif
 
-    if (__builtin_expect(ultra_slim_mode_enabled(), 0)) {
+    // Phase 7-Step4: Use config macro for dead code elimination in PGO mode
+    if (__builtin_expect(TINY_FRONT_ULTRA_SLIM_ENABLED, 0)) {
         return ultra_slim_alloc_with_refill(size);
     }
     // ========== End Phase 19-2: Ultra SLIM ==========
@@ -804,7 +806,8 @@ static inline void* tiny_alloc_fast(size_t size) {
     void* ptr = NULL;
 
     // Front-V2: TLS magazine front (A/B, default OFF)
-    if (__builtin_expect(tiny_heap_v2_enabled() && front_prune_heapv2_enabled() && class_idx <= 3, 0)) {
+    // Phase 7-Step4: Use config macro for dead code elimination in PGO mode
+    if (__builtin_expect(TINY_FRONT_HEAP_V2_ENABLED && front_prune_heapv2_enabled() && class_idx <= 3, 0)) {
         void* hv2 = tiny_heap_v2_alloc_by_class(class_idx);
         if (hv2) {
             front_metrics_heapv2_hit(class_idx);