remove inverse from f_field.h

src/include/field.h

@@ -37,21 +37,6 @@ field_isr (
     field_a_t       a,
     const field_a_t x
 );
-
-/**
- * Returns 1/x.
- * 
- * If x=0, returns 0.
- *
- * TODO: this is currently unused in Decaf, but I've left a decl
- * for it because field_inverse is different (and simpler) than
- * field_isqrt for 5-mod-8 fields.
- */
-void
-field_inverse (
-    field_a_t       a,
-    const field_a_t x
-);
     
 /**
  * Square x, n times.

src/p25519/f_field.h

@@ -23,7 +23,6 @@
 #define field_mulw           p255_mulw
 #define field_bias           p255_bias
 #define field_isr            p255_isr
-#define field_inverse        p255_inverse
 #define field_weak_reduce    p255_weak_reduce
 #define field_strong_reduce  p255_strong_reduce
 #define field_serialize      p255_serialize

src/p448/f_field.h

@@ -23,7 +23,6 @@
 #define field_mulw           p448_mulw
 #define field_bias           p448_bias
 #define field_isr            p448_isr
-#define field_inverse        p448_inverse
 #define field_weak_reduce    p448_weak_reduce
 #define field_strong_reduce  p448_strong_reduce
 #define field_serialize      p448_serialize

src/p480/f_field.h

@@ -23,7 +23,6 @@
 #define field_mulw           p480_mulw
 #define field_bias           p480_bias
 #define field_isr            p480_isr
-#define field_inverse        p480_inverse
 #define field_weak_reduce    p480_weak_reduce
 #define field_strong_reduce  p480_strong_reduce
 #define field_serialize      p480_serialize

src/p521/f_field.h

@@ -23,7 +23,6 @@
 #define field_mulw           p521_mulw
 #define field_bias           p521_bias
 #define field_isr            p521_isr
-#define field_inverse        p521_inverse
 #define field_weak_reduce    p521_weak_reduce
 #define field_strong_reduce  p521_strong_reduce
 #define field_serialize      p521_serialize