Revert debugging checks from SincResampler; no crashes found.

media/base/sinc_resampler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Initial input buffer layout, dividing into regions r0_ to r4_ (note: r0_, r3_
 // and r4_ will move after the first load):
 //
 // |----------------|-----------------------------------------|----------------|
 //
 //                                        request_frames_
@@ skipping 63 matching lines @@
 // |virtual_source_idx_|, etc.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include "media/base/sinc_resampler.h"
 
 #include <cmath>
 #include <limits>
 
-#include "base/debug/alias.h"
 #include "base/logging.h"
 #include "build/build_config.h"
 
 #if defined(ARCH_CPU_X86_FAMILY)
 #include <xmmintrin.h>
 #define CONVOLVE_FUNC Convolve_SSE
 #elif defined(ARCH_CPU_ARM_FAMILY) && defined(USE_NEON)
 #include <arm_neon.h>
 #define CONVOLVE_FUNC Convolve_NEON
 #else
@@ skipping 95 matching lines @@
       kernel_pre_sinc_storage_[idx] = pre_sinc;
 
       // Compute Blackman window, matching the offset of the sinc().
       const float x = (i - subsample_offset) / kKernelSize;
       const float window = static_cast<float>(kA0 - kA1 * cos(2.0 * M_PI * x) +
           kA2 * cos(4.0 * M_PI * x));
       kernel_window_storage_[idx] = window;
 
       // Compute the sinc with offset, then window the sinc() function and store
       // at the correct offset.
-      kernel_storage_[idx] = static_cast<float>(window *
-          ((pre_sinc == 0) ?
-              sinc_scale_factor :
-              (sin(sinc_scale_factor * pre_sinc) / pre_sinc)));
+      kernel_storage_[idx] = static_cast<float>(
+          window * (pre_sinc ? sin(sinc_scale_factor * pre_sinc) / pre_sinc
+                             : sinc_scale_factor));
     }
   }
 }
 
 void SincResampler::SetRatio(double io_sample_rate_ratio) {
   if (fabs(io_sample_rate_ratio_ - io_sample_rate_ratio) <
       std::numeric_limits<double>::epsilon()) {
     return;
   }
 
   io_sample_rate_ratio_ = io_sample_rate_ratio;
   chunk_size_ = CalculateChunkSize(block_size_, io_sample_rate_ratio_);
 
   // Optimize reinitialization by reusing values which are independent of
   // |sinc_scale_factor|.  Provides a 3x speedup.
   const double sinc_scale_factor = SincScaleFactor(io_sample_rate_ratio_);
   for (int offset_idx = 0; offset_idx <= kKernelOffsetCount; ++offset_idx) {
     for (int i = 0; i < kKernelSize; ++i) {
       const int idx = i + offset_idx * kKernelSize;
       const float window = kernel_window_storage_[idx];
       const float pre_sinc = kernel_pre_sinc_storage_[idx];
 
-      kernel_storage_[idx] = static_cast<float>(window *
-          ((pre_sinc == 0) ?
-              sinc_scale_factor :
-              (sin(sinc_scale_factor * pre_sinc) / pre_sinc)));
+      kernel_storage_[idx] = static_cast<float>(
+          window * (pre_sinc ? sin(sinc_scale_factor * pre_sinc) / pre_sinc
+                             : sinc_scale_factor));
     }
   }
 }
 
 void SincResampler::Resample(int frames, float* destination) {
   int remaining_frames = frames;
 
   // Step (1) -- Prime the input buffer at the start of the input stream.
   if (!buffer_primed_ && remaining_frames) {
     read_cb_.Run(request_frames_, r0_);
     buffer_primed_ = true;
   }
 
-  // TODO(dalecurtis): Temporary debugging for http://crbug.com/663814
-  const double starting_idx = virtual_source_idx_;
-  CHECK(!std::isnan(virtual_source_idx_));
-
-  // Step (2) -- Resample!  const what we can outside of the loop for speed.  It
-  // actually has an impact on ARM performance.  See inner loop comment below.
-  const double current_io_ratio = io_sample_rate_ratio_;
-  const float* const kernel_ptr = kernel_storage_.get();
+  // Step (2) -- Resample!
   while (remaining_frames) {
-    // Note: The loop construct here can severely impact performance on ARM
-    // or when built with clang.  See https://codereview.chromium.org/18566009/
-    int source_idx = static_cast<int>(virtual_source_idx_);
-    // TODO(dalecurtis): Temporary debugging for http://crbug.com/663814
-    CHECK_GE(source_idx, 0);
-    while (source_idx < block_size_) {
+    while (virtual_source_idx_ < block_size_) {
       // |virtual_source_idx_| lies in between two kernel offsets so figure out
       // what they are.
-      const double subsample_remainder = virtual_source_idx_ - source_idx;
-
+      const int source_idx = static_cast<int>(virtual_source_idx_);
       const double virtual_offset_idx =
-          subsample_remainder * kKernelOffsetCount;
+          (virtual_source_idx_ - source_idx) * kKernelOffsetCount;
       const int offset_idx = static_cast<int>(virtual_offset_idx);
 
       // We'll compute "convolutions" for the two kernels which straddle
       // |virtual_source_idx_|.
-      const float* const k1 = kernel_ptr + offset_idx * kKernelSize;
-      const float* const k2 = k1 + kKernelSize;
+      const float* k1 = kernel_storage_.get() + offset_idx * kKernelSize;
+      const float* k2 = k1 + kKernelSize;
 
       // Ensure |k1|, |k2| are 16-byte aligned for SIMD usage.  Should always be
       // true so long as kKernelSize is a multiple of 16.
       DCHECK_EQ(0u, reinterpret_cast<uintptr_t>(k1) & 0x0F);
       DCHECK_EQ(0u, reinterpret_cast<uintptr_t>(k2) & 0x0F);
 
       // Initialize input pointer based on quantized |virtual_source_idx_|.
-      const float* const input_ptr = r1_ + source_idx;
+      const float* input_ptr = r1_ + source_idx;
 
       // Figure out how much to weight each kernel's "convolution".
       const double kernel_interpolation_factor =
           virtual_offset_idx - offset_idx;
-      *destination++ = CONVOLVE_FUNC(
-          input_ptr, k1, k2, kernel_interpolation_factor);
+      *destination++ =
+          CONVOLVE_FUNC(input_ptr, k1, k2, kernel_interpolation_factor);
 
       // Advance the virtual index.
-      virtual_source_idx_ += current_io_ratio;
-      source_idx = static_cast<int>(virtual_source_idx_);
-
-      // TODO(dalecurtis): Temporary debugging for http://crbug.com/663814
-      base::debug::Alias(&starting_idx);
-      CHECK(!std::isnan(virtual_source_idx_));
-      CHECK_GE(source_idx, 0);
+      virtual_source_idx_ += io_sample_rate_ratio_;
       if (!--remaining_frames)
         return;
     }
 
     // Wrap back around to the start.
     DCHECK_GE(virtual_source_idx_, block_size_);
     virtual_source_idx_ -= block_size_;
 
-    // TODO(dalecurtis): Temporary debugging for http://crbug.com/663814
-    base::debug::Alias(&starting_idx);
-    CHECK(!std::isnan(virtual_source_idx_));
-
     // Step (3) -- Copy r3_, r4_ to r1_, r2_.
     // This wraps the last input frames back to the start of the buffer.
     memcpy(r1_, r3_, sizeof(*input_buffer_.get()) * kKernelSize);
 
     // Step (4) -- Reinitialize regions if necessary.
     if (r0_ == r2_)
       UpdateRegions(true);
 
     // Step (5) -- Refresh the buffer with more input.
     read_cb_.Run(request_frames_, r0_);
@@ skipping 10 matching lines @@
 
 void SincResampler::Flush() {
   virtual_source_idx_ = 0;
   buffer_primed_ = false;
   memset(input_buffer_.get(), 0,
          sizeof(*input_buffer_.get()) * input_buffer_size_);
   UpdateRegions(false);
 }
 
 double SincResampler::BufferedFrames() const {
-  if (buffer_primed_) {
-    return request_frames_ - virtual_source_idx_;
-  } else {
-    return 0.0;
-  }
+  return buffer_primed_ ? request_frames_ - virtual_source_idx_ : 0;
 }
 
 float SincResampler::Convolve_C(const float* input_ptr, const float* k1,
                                 const float* k2,
                                 double kernel_interpolation_factor) {
   float sum1 = 0;
   float sum2 = 0;
 
   // Generate a single output sample.  Unrolling this loop hurt performance in
   // local testing.
@@ skipping 70 matching lines @@
       vmulq_f32(m_sums1, vmovq_n_f32(1.0 - kernel_interpolation_factor)),
       m_sums2, vmovq_n_f32(kernel_interpolation_factor));
 
   // Sum components together.
   float32x2_t m_half = vadd_f32(vget_high_f32(m_sums1), vget_low_f32(m_sums1));
   return vget_lane_f32(vpadd_f32(m_half, m_half), 0);
 }
 #endif
 
 }  // namespace media