From a8f4056f794b1e20ca2ea558e2dbd85d0002e95b Mon Sep 17 00:00:00 2001
From: Richard Allen <rsaxvc@gmail.com>
Date: Tue, 10 Jan 2023 00:55:10 -0600
Subject: [PATCH] use 32-bit bitreversal loop index (#81)

With GCC 8.3.1:
arm_bitreversal_16 - saves 1 instruction
arm_bitreversal_64 - saves 5 instructions
---
 Source/TransformFunctions/arm_bitreversal2.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Source/TransformFunctions/arm_bitreversal2.c b/Source/TransformFunctions/arm_bitreversal2.c
index 77fac1f8..faefbb08 100644
--- a/Source/TransformFunctions/arm_bitreversal2.c
+++ b/Source/TransformFunctions/arm_bitreversal2.c
@@ -43,7 +43,8 @@ void arm_bitreversal_64(
   const uint16_t bitRevLen,
   const uint16_t *pBitRevTab)
 {
-  uint64_t a, b, i, tmp;
+  uint64_t a, b, tmp;
+  uint32_t i;
 
   for (i = 0; i < bitRevLen; )
   {
@@ -112,7 +113,8 @@ void arm_bitreversal_16(
   const uint16_t bitRevLen,
   const uint16_t *pBitRevTab)
 {
-  uint16_t a, b, i, tmp;
+  uint16_t a, b, tmp;
+  uint32_t i;
 
   for (i = 0; i < bitRevLen; )
   {