1 files changed, 144 insertions, 0 deletions
diff --git a/src/common_audio/signal_processing_library/main/source/division_operations.c b/src/common_audio/signal_processing_library/main/source/division_operations.c
new file mode 100644
index 0000000000..b143373a2f
--- /dev/null
+++ b/src/common_audio/signal_processing_library/main/source/division_operations.c
@@ -0,0 +1,144 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+/*
+ * This file contains implementations of the divisions
+ * WebRtcSpl_DivU32U16()
+ * WebRtcSpl_DivW32W16()
+ * WebRtcSpl_DivW32W16ResW16()
+ * WebRtcSpl_DivResultInQ31()
+ * WebRtcSpl_DivW32HiLow()
+ *
+ * The description header can be found in signal_processing_library.h
+ *
+ */
+
+#include "signal_processing_library.h"
+
+WebRtc_UWord32 WebRtcSpl_DivU32U16(WebRtc_UWord32 num, WebRtc_UWord16 den)
+{
+    // Guard against division with 0
+    if (den != 0)
+    {
+        return (WebRtc_UWord32)(num / den);
+    } else
+    {
+        return (WebRtc_UWord32)0xFFFFFFFF;
+    }
+}
+
+WebRtc_Word32 WebRtcSpl_DivW32W16(WebRtc_Word32 num, WebRtc_Word16 den)
+{
+    // Guard against division with 0
+    if (den != 0)
+    {
+        return (WebRtc_Word32)(num / den);
+    } else
+    {
+        return (WebRtc_Word32)0x7FFFFFFF;
+    }
+}
+
+WebRtc_Word16 WebRtcSpl_DivW32W16ResW16(WebRtc_Word32 num, WebRtc_Word16 den)
+{
+    // Guard against division with 0
+    if (den != 0)
+    {
+        return (WebRtc_Word16)(num / den);
+    } else
+    {
+        return (WebRtc_Word16)0x7FFF;
+    }
+}
+
+WebRtc_Word32 WebRtcSpl_DivResultInQ31(WebRtc_Word32 num, WebRtc_Word32 den)
+{
+    WebRtc_Word32 L_num = num;
+    WebRtc_Word32 L_den = den;
+    WebRtc_Word32 div = 0;
+    int k = 31;
+    int change_sign = 0;
+
+    if (num == 0)
+        return 0;
+
+    if (num < 0)
+    {
+        change_sign++;
+        L_num = -num;
+    }
+    if (den < 0)
+    {
+        change_sign++;
+        L_den = -den;
+    }
+    while (k--)
+    {
+        div <<= 1;
+        L_num <<= 1;
+        if (L_num >= L_den)
+        {
+            L_num -= L_den;
+            div++;
+        }
+    }
+    if (change_sign == 1)
+    {
+        div = -div;
+    }
+    return div;
+}
+
+WebRtc_Word32 WebRtcSpl_DivW32HiLow(WebRtc_Word32 num, WebRtc_Word16 den_hi,
+                                    WebRtc_Word16 den_low)
+{
+    WebRtc_Word16 approx, tmp_hi, tmp_low, num_hi, num_low;
+    WebRtc_Word32 tmpW32;
+
+    approx = (WebRtc_Word16)WebRtcSpl_DivW32W16((WebRtc_Word32)0x1FFFFFFF, den_hi);
+    // result in Q14 (Note: 3FFFFFFF = 0.5 in Q30)
+
+    // tmpW32 = 1/den = approx * (2.0 - den * approx) (in Q30)
+    tmpW32 = (WEBRTC_SPL_MUL_16_16(den_hi, approx) << 1)
+            + ((WEBRTC_SPL_MUL_16_16(den_low, approx) >> 15) << 1);
+    // tmpW32 = den * approx
+
+    tmpW32 = (WebRtc_Word32)0x7fffffffL - tmpW32; // result in Q30 (tmpW32 = 2.0-(den*approx))
+
+    // Store tmpW32 in hi and low format
+    tmp_hi = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmpW32, 16);
+    tmp_low = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32((tmpW32
+            - WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)tmp_hi, 16)), 1);
+
+    // tmpW32 = 1/den in Q29
+    tmpW32 = ((WEBRTC_SPL_MUL_16_16(tmp_hi, approx) + (WEBRTC_SPL_MUL_16_16(tmp_low, approx)
+            >> 15)) << 1);
+
+    // 1/den in hi and low format
+    tmp_hi = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmpW32, 16);
+    tmp_low = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32((tmpW32
+            - WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)tmp_hi, 16)), 1);
+
+    // Store num in hi and low format
+    num_hi = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(num, 16);
+    num_low = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32((num
+            - WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)num_hi, 16)), 1);
+
+    // num * (1/den) by 32 bit multiplication (result in Q28)
+
+    tmpW32 = (WEBRTC_SPL_MUL_16_16(num_hi, tmp_hi) + (WEBRTC_SPL_MUL_16_16(num_hi, tmp_low)
+            >> 15) + (WEBRTC_SPL_MUL_16_16(num_low, tmp_hi) >> 15));
+
+    // Put result in Q31 (convert from Q28)
+    tmpW32 = WEBRTC_SPL_LSHIFT_W32(tmpW32, 3);
+
+    return tmpW32;
+}