From 0cbea0ce2dece50c3b2befc86ff6e5d2e1f0ed27 Mon Sep 17 00:00:00 2001
From: Loser Cheems <losercheems@gmail.com>
Date: Mon, 23 Jun 2025 13:51:57 +0800
Subject: [PATCH] Adds conditional softcap switch macro

Introduces a new SOFTCAP_SWITCH macro that can be conditionally disabled
via the FLASHATTENTION_DISABLE_SOFTCAP preprocessor flag.

When the flag is defined, the macro forces the condition to false,
effectively disabling softcap functionality. Otherwise, it defaults
to the standard BOOL_SWITCH behavior.
---
 csrc/src/static_switch.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/csrc/src/static_switch.h b/csrc/src/static_switch.h
index d912812..00322bd 100644
--- a/csrc/src/static_switch.h
+++ b/csrc/src/static_switch.h
@@ -46,6 +46,16 @@
   #define EVENK_SWITCH BOOL_SWITCH
 #endif
 
+#ifdef FLASHATTENTION_DISABLE_SOFTCAP
+  #define SOFTCAP_SWITCH(COND, CONST_NAME, ...)   \
+  [&] {                                         \
+    constexpr static bool CONST_NAME = false;    \
+    return __VA_ARGS__();                       \
+  }()
+#else
+  #define SOFTCAP_SWITCH BOOL_SWITCH
+#endif
+
 #define FP16_SWITCH(COND, ...)               \
   [&] {                                      \
     if (COND) {                              \