Put two hot silk arrays on real stack (iram)

Speeds up decoding of 16kbps test file by 16.7MHz on H300.

Change-Id: I39c90e3b423ae8e2ee5c2b88c5dcec8d48807f77

2 files changed, 10 insertions, 6 deletions

diff --git a/lib/rbcodec/codecs/libopus/silk/decode_core.c b/lib/rbcodec/codecs/libopus/silk/decode_core.c
index 693c9faacf..b298389f07 100644
--- a/lib/rbcodec/codecs/libopus/silk/decode_core.c
+++ b/lib/rbcodec/codecs/libopus/silk/decode_core.c
@@ -49,7 +49,7 @@ void silk_decode_core(
     opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
     opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14;
     VARDECL( opus_int32, res_Q14 );
-    VARDECL( opus_int32, sLPC_Q14 );
+/*    VARDECL( opus_int32, sLPC_Q14 ); */
     SAVE_STACK;
 
     silk_assert( psDec->prev_gain_Q16 != 0 );
@@ -57,7 +57,8 @@ void silk_decode_core(
     ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
     ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
     ALLOC( res_Q14, psDec->subfr_length, opus_int32 );
-    ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 );
+/*    ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 ); */
+    opus_int32 sLPC_Q14[psDec->subfr_length + MAX_LPC_ORDER]; /* worst case is 80 + 16 */
 
     offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
 
diff --git a/lib/rbcodec/codecs/libopus/silk/resampler_private_IIR_FIR.c b/lib/rbcodec/codecs/libopus/silk/resampler_private_IIR_FIR.c
index 04246257e7..ce9aff0907 100644
--- a/lib/rbcodec/codecs/libopus/silk/resampler_private_IIR_FIR.c
+++ b/lib/rbcodec/codecs/libopus/silk/resampler_private_IIR_FIR.c
@@ -72,10 +72,13 @@ void silk_resampler_private_IIR_FIR(
     silk_resampler_state_struct *S = (silk_resampler_state_struct *)SS;
     opus_int32 nSamplesIn;
     opus_int32 max_index_Q16, index_increment_Q16;
-    VARDECL( opus_int16, buf );
-    SAVE_STACK;
+/*    VARDECL( opus_int16, buf );
+    SAVE_STACK; */
 
-    ALLOC( buf, 2 * S->batchSize + RESAMPLER_ORDER_FIR_12, opus_int16 );
+/*    ALLOC( buf, 2 * S->batchSize + RESAMPLER_ORDER_FIR_12, opus_int16 ); */
+
+    /* worst case = 2*16*10+8 = 328 * 2 = 656bytes */
+    opus_int16 buf[2 * S->batchSize + RESAMPLER_ORDER_FIR_12];
 
     /* Copy buffered samples to start of buffer */
     silk_memcpy( buf, S->sFIR.i16, RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
@@ -103,5 +106,5 @@ void silk_resampler_private_IIR_FIR(
 
     /* Copy last part of filtered signal to the state for the next call */
     silk_memcpy( S->sFIR.i16, &buf[ nSamplesIn << 1 ], RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
-    RESTORE_STACK;
+/*    RESTORE_STACK; */
 }