From 5286cb1a467bb489d00819060c045ca6216472cb Mon Sep 17 00:00:00 2001
From: Daniel Pouzzner <douzzer@wolfssl.com>
Date: Thu, 26 Nov 2020 00:27:50 -0600
Subject: [PATCH] optimize domain check in wolfcrypt/src/integer.c and
 wolfcrypt/src/tfm.c.

---
 wolfcrypt/src/integer.c | 8 ++++----
 wolfcrypt/src/tfm.c     | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/wolfcrypt/src/integer.c b/wolfcrypt/src/integer.c
index fa13dfda5..12f4d7c1f 100644
--- a/wolfcrypt/src/integer.c
+++ b/wolfcrypt/src/integer.c
@@ -562,10 +562,10 @@ void mp_rshb (mp_int *c, int x)
     mp_digit r, rr;
     mp_digit D = x;
 
-    /* shifting by a negative number not supported */
-    if (x < 0) return;
-    /* shifting by zero changes nothing */
-    if (x == 0) return;
+    /* shifting by a negative number not supported, and shifting by
+     * zero changes nothing.
+     */
+    if (x <= 0) return;
 
     /* shift digits first if needed */
     if (x >= DIGIT_BIT) {
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
index 56fb5993e..9eedd30d7 100644
--- a/wolfcrypt/src/tfm.c
+++ b/wolfcrypt/src/tfm.c
@@ -3903,10 +3903,10 @@ void fp_rshb(fp_int *c, int x)
     fp_digit r, rr;
     fp_digit D = x;
 
-    /* shifting by a negative number not supported */
-    if (x < 0) return;
-    /* shifting by zero changes nothing */
-    if (x == 0) return;
+    /* shifting by a negative number not supported, and shifting by
+     * zero changes nothing.
+     */
+    if (x <= 0) return;
 
     /* shift digits first if needed */
     if (x >= DIGIT_BIT) {