diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index 49feac0..4c1a39d 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -118,3 +118,13 @@
 
 #define __diag_ignore_all(option, comment) \
 	__diag_clang(13, ignore, option)
+
+/*
+ * clang has horrible behavior with "g" or "rm" constraints for asm
+ * inputs, turning them into something worse than "m". Avoid using
+ * constraints with multiple possible uses (but "ir" seems to be ok):
+ *
+ *	https://github.com/llvm/llvm-project/issues/20571
+ */
+#define ASM_INPUT_G "ir"
+#define ASM_INPUT_RM "r"
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 8f82363..f82bdac 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -391,6 +391,15 @@ struct ftrace_likely_data {
 #define asm_goto_output(x...) asm volatile goto(x)
 #endif
 
+/*
+ * Clang has trouble with constraints with multiple
+ * alternative behaviors (mainly "g" and "rm").
+ */
+#ifndef ASM_INPUT_G
+  #define ASM_INPUT_G "g"
+  #define ASM_INPUT_RM "rm"
+#endif
+
 #ifdef CONFIG_CC_HAS_ASM_INLINE
 #define asm_inline asm __inline
 #else