From 19a2bfeeeac4274bbeca7f8757a2ee73bdf03895 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Fri, 28 Jan 2022 18:04:15 -0500
Subject: [PATCH] Abstract out verify logic for fe_set_int

---
 src/field.h            | 7 +++++--
 src/field_10x26_impl.h | 8 +-------
 src/field_5x52_impl.h  | 8 +-------
 src/field_impl.h       | 9 +++++++++
 4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/src/field.h b/src/field.h
index 8db62a92eb..e841f14ee0 100644
--- a/src/field.h
+++ b/src/field.h
@@ -80,6 +80,7 @@ static const secp256k1_fe secp256k1_const_beta = SECP256K1_FE_CONST(
 #  define secp256k1_fe_normalize_var secp256k1_fe_impl_normalize_var
 #  define secp256k1_fe_normalizes_to_zero secp256k1_fe_impl_normalizes_to_zero
 #  define secp256k1_fe_normalizes_to_zero_var secp256k1_fe_impl_normalizes_to_zero_var
+#  define secp256k1_fe_set_int secp256k1_fe_impl_set_int
 #endif /* !defined(VERIFY) */
 
 /** Normalize a field element.
@@ -115,8 +116,10 @@ static int secp256k1_fe_normalizes_to_zero(const secp256k1_fe *r);
  */
 static int secp256k1_fe_normalizes_to_zero_var(const secp256k1_fe *r);
 
-/** Set a field element equal to a small (not greater than 0x7FFF), non-negative integer.
- *  Resulting field element is normalized; it has magnitude 0 if a == 0, and magnitude 1 otherwise.
+/** Set a field element to an integer in range [0,0x7FFF].
+ *
+ * On input, r does not need to be initialized, a must be in [0,0x7FFF].
+ * On output, r represents value a, is normalized and has magnitude (a!=0).
  */
 static void secp256k1_fe_set_int(secp256k1_fe *r, int a);
 
diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h
index e107bee8a8..70be960f8a 100644
--- a/src/field_10x26_impl.h
+++ b/src/field_10x26_impl.h
@@ -264,15 +264,9 @@ static int secp256k1_fe_impl_normalizes_to_zero_var(const secp256k1_fe *r) {
     return (z0 == 0) | (z1 == 0x3FFFFFFUL);
 }
 
-SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe *r, int a) {
-    VERIFY_CHECK(0 <= a && a <= 0x7FFF);
+SECP256K1_INLINE static void secp256k1_fe_impl_set_int(secp256k1_fe *r, int a) {
     r->n[0] = a;
     r->n[1] = r->n[2] = r->n[3] = r->n[4] = r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
-#ifdef VERIFY
-    r->magnitude = (a != 0);
-    r->normalized = 1;
-    secp256k1_fe_verify(r);
-#endif
 }
 
 SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe *a) {
diff --git a/src/field_5x52_impl.h b/src/field_5x52_impl.h
index 1a8960ff1e..c735257f53 100644
--- a/src/field_5x52_impl.h
+++ b/src/field_5x52_impl.h
@@ -210,15 +210,9 @@ static int secp256k1_fe_impl_normalizes_to_zero_var(const secp256k1_fe *r) {
     return (z0 == 0) | (z1 == 0xFFFFFFFFFFFFFULL);
 }
 
-SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe *r, int a) {
-    VERIFY_CHECK(0 <= a && a <= 0x7FFF);
+SECP256K1_INLINE static void secp256k1_fe_impl_set_int(secp256k1_fe *r, int a) {
     r->n[0] = a;
     r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
-#ifdef VERIFY
-    r->magnitude = (a != 0);
-    r->normalized = 1;
-    secp256k1_fe_verify(r);
-#endif
 }
 
 SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe *a) {
diff --git a/src/field_impl.h b/src/field_impl.h
index ae54693859..0083aabc8d 100644
--- a/src/field_impl.h
+++ b/src/field_impl.h
@@ -185,6 +185,15 @@ SECP256K1_INLINE static int secp256k1_fe_normalizes_to_zero_var(const secp256k1_
     secp256k1_fe_verify(r);
     return secp256k1_fe_impl_normalizes_to_zero_var(r);
 }
+
+static void secp256k1_fe_impl_set_int(secp256k1_fe *r, int a);
+SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe *r, int a) {
+    VERIFY_CHECK(0 <= a && a <= 0x7FFF);
+    secp256k1_fe_impl_set_int(r, a);
+    r->magnitude = (a != 0);
+    r->normalized = 1;
+    secp256k1_fe_verify(r);
+}
 #endif /* defined(VERIFY) */
 
 #endif /* SECP256K1_FIELD_IMPL_H */