commit 43539f74b37cb0ff112267d3f4ebab3ce4ce7dff
author Felicia Lim <flim@google.com> Fri Mar 18 08:52:05 2016 +0800
committer Koen Vos <koenvos@users.noreply.github.com> Fri Mar 18 08:52:05 2016 +0800
tree 96707319bdaa0165c88012072bf5cc116d92ee15
parent 403b1f736646fd946c3e0577c763856cc5aaee31

fix for divide by zero

silk/fixed/burg_modified_FIX.c

diff --git a/silk/fixed/burg_modified_FIX.c b/silk/fixed/burg_modified_FIX.c
index 9c35c94..53d92fa 100644
--- a/silk/fixed/burg_modified_FIX.c
+++ b/silk/fixed/burg_modified_FIX.c
@@ -219,12 +219,14 @@
             /* Max prediction gain exceeded; set reflection coefficient such that max prediction gain is exactly hit */
             tmp2 = SILK_FIX_CONST( 1, 30 ) - silk_DIV32_varQ( minInvGain_Q30, invGain_Q30, 30 );        /* Q30 */
             rc_Q31 = silk_SQRT_APPROX( tmp2 );                                                          /* Q15 */
-            /* Newton-Raphson iteration */
-            rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 );                           /* Q15 */
-            rc_Q31 = silk_LSHIFT32( rc_Q31, 16 );                                                       /* Q31 */
-            if( num < 0 ) {
-                /* Ensure adjusted reflection coefficients has the original sign */
-                rc_Q31 = -rc_Q31;
+            if( rc_Q31 > 0 ) {
+                /* Newton-Raphson iteration */
+                rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 );                       /* Q15 */
+                rc_Q31 = silk_LSHIFT32( rc_Q31, 16 );                                                   /* Q31 */
+                if( num < 0 ) {
+                    /* Ensure adjusted reflection coefficients has the original sign */
+                    rc_Q31 = -rc_Q31;
+                }
             }
             invGain_Q30 = minInvGain_Q30;
             reached_max_gain = 1;