From: Alexander Traud <pabstraud@compuserve.com>
Date: Sat, 6 Jan 2018 11:01:00 +0000 (+0100)
Subject: codec_gsm: Avoid shifting a negative signed value.
X-Git-Tag: 13.20.0-rc1~114^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e60135efd40314f7139f8906bb0fbe7b264a059e;p=thirdparty%2Fasterisk.git

codec_gsm: Avoid shifting a negative signed value.

clang 5.0 warned about this.

ASTERISK-27558

Change-Id: Icc452ecb0d86bbeba78dae768cc472ec540699df
---

diff --git a/codecs/gsm/src/short_term.c b/codecs/gsm/src/short_term.c
index 4172d322c6..d22d276ba7 100644
--- a/codecs/gsm/src/short_term.c
+++ b/codecs/gsm/src/short_term.c
@@ -55,21 +55,21 @@ static void Decoding_of_the_coded_Log_Area_Ratios P2((LARc,LARpp),
 	 */
 
 #undef	STEP
-#define	STEP( B, MIC, INVA )	\
+#define	STEP( B_TIMES_TWO, MIC, INVA )	\
 		temp1    = GSM_ADD( *LARc++, MIC ) << 10;	\
-		temp1    = GSM_SUB( temp1, B << 1 );		\
+		temp1    = GSM_SUB( temp1, B_TIMES_TWO );	\
 		temp1    = (word)GSM_MULT_R( INVA, temp1 );		\
 		*LARpp++ = GSM_ADD( temp1, temp1 );
 
 	STEP(      0,  -32,  13107 );
 	STEP(      0,  -32,  13107 );
-	STEP(   2048,  -16,  13107 );
-	STEP(  -2560,  -16,  13107 );
+	STEP(   4096,  -16,  13107 );
+	STEP(  -5120,  -16,  13107 );
 
-	STEP(     94,   -8,  19223 );
-	STEP(  -1792,   -8,  17476 );
-	STEP(   -341,   -4,  31454 );
-	STEP(  -1144,   -4,  29708 );
+	STEP(    188,   -8,  19223 );
+	STEP(  -3584,   -8,  17476 );
+	STEP(   -682,   -4,  31454 );
+	STEP(  -2288,   -4,  29708 );
 
 	/* NOTE: the addition of *MIC is used to restore
 	 * 	 the sign of *LARc.