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@kode54 /README.md Secret
Created Dec 31, 2017

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Resampler, which MSVC 2017 crashes on under specific circumstances

MSVC 2017 Optimizer Crash

The included .c file will crash MSVC 2017 v15.5.2 when compiled with the following options:

cl.exe /O2 /fp:fast /c resampler.c

Neither this:

cl.exe /O2 /c resampler.c

Nor this:

cl.exe /O1 /fp:fast /c resampler.c

... make it crash. Those two combinations of settings work, while O2 plus fp:fast make it crash with an Internal Compiler Error.

#include "resampler.h"
#include <math.h>
#include <stdlib.h>
#include <string.h>
/* Copyright (C) 2004-2008 Shay Green.
Copyright (C) 2015 Christopher Snowhill. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#undef PI
#define PI 3.1415926535897932384626433832795029
enum { imp_scale = 0x7FFF };
typedef int16_t imp_t;
typedef int32_t imp_off_t; /* for max_res of 512 and impulse width of 32, end offsets must be 32 bits */
#if RESAMPLER_BITS == 16
typedef int32_t intermediate_t;
#elif RESAMPLER_BITS == 32
typedef int64_t intermediate_t;
#endif
static void gen_sinc( double rolloff, int width, double offset, double spacing, double scale,
int count, imp_t* out )
{
double const maxh = 256;
double const step = PI / maxh * spacing;
double const to_w = maxh * 2 / width;
double const pow_a_n = pow( rolloff, maxh );
double angle = (count / 2 - 1 + offset) * -step;
scale /= maxh * 2;
while ( count-- )
{
double w;
*out++ = 0;
w = angle * to_w;
if ( fabs( w ) < PI )
{
double rolloff_cos_a = rolloff * cos( angle );
double num = 1 - rolloff_cos_a -
pow_a_n * cos( maxh * angle ) +
pow_a_n * rolloff * cos( (maxh - 1) * angle );
double den = 1 - rolloff_cos_a - rolloff_cos_a + rolloff * rolloff;
double sinc = scale * num / den - scale;
out [-1] = (imp_t) (cos( w ) * sinc + sinc);
}
angle += step;
}
}
enum { width = 64 };
enum { stereo = 2 };
enum { max_res = 512 };
enum { min_width = (width < 4 ? 4 : width) };
enum { adj_width = min_width / 4 * 4 + 2 };
enum { write_offset = adj_width * stereo };
enum { buffer_size = 128 };
typedef struct _resampler
{
int width_;
int rate_;
int inptr;
int infilled;
int outptr;
int outfilled;
int latency;
imp_t const* imp;
imp_t impulses [max_res * (adj_width + 2 * (sizeof(imp_off_t) / sizeof(imp_t)))];
sample_t buffer_in[buffer_size * stereo * 2];
sample_t buffer_out[buffer_size * stereo];
} resampler;
void * resampler_create()
{
resampler *r = (resampler *) malloc(sizeof(resampler));
if (r) resampler_clear(r);
return r;
}
void * resampler_dup(void *_r)
{
resampler *r = (resampler *)_r;
resampler *t = (resampler *) malloc(sizeof(resampler));
if (r && t)
{
memcpy(t, r, sizeof(resampler));
t->imp = t->impulses + (r->imp - r->impulses);
}
else if (t)
{
resampler_clear(t);
}
return t;
}
void resampler_destroy(void *r)
{
free(r);
}
void resampler_clear(void *_r)
{
resampler * r = (resampler *)_r;
r->width_ = adj_width;
r->inptr = 0;
r->infilled = 0;
r->outptr = 0;
r->outfilled = 0;
r->latency = 0;
r->imp = r->impulses;
resampler_set_rate(r, 1.0);
}
void resampler_set_rate( void *_r, double new_factor )
{
resampler *rs = (resampler *)_r;
double const rolloff = 0.999;
double const gain = 1.0;
int step;
double fraction;
double filter;
double pos = 0.0;
imp_t* out;
int n;
/* determine number of sub-phases that yield lowest error */
double ratio_ = 0.0;
int res = -1;
{
double least_error = 2;
double pos = 0;
int r;
for ( r = 1; r <= max_res; r++ )
{
double nearest, error;
pos += new_factor;
nearest = floor( pos + 0.5 );
error = fabs( pos - nearest );
if ( error < least_error )
{
res = r;
ratio_ = nearest / res;
least_error = error;
}
}
}
rs->rate_ = ratio_;
/* how much of input is used for each output sample */
step = stereo * (int) floor( ratio_ );
fraction = fmod( ratio_, 1.0 );
filter = (ratio_ < 1.0) ? 1.0 : 1.0 / ratio_;
/*int input_per_cycle = 0;*/
out = rs->impulses;
for ( n = res; --n >= 0; )
{
int cur_step;
gen_sinc( rolloff, (int) (rs->width_ * filter + 1) & ~1, pos, filter,
(double)(imp_scale * gain * filter), (int) rs->width_, out );
out += rs->width_;
cur_step = step;
pos += fraction;
if ( pos >= 0.9999999 )
{
pos -= 1.0;
cur_step += stereo;
}
((imp_off_t*)out)[0] = (cur_step - rs->width_ * 2 + 4) * sizeof (sample_t);
((imp_off_t*)out)[1] = 2 * sizeof (imp_t) + 2 * sizeof (imp_off_t);
out += 2 * (sizeof(imp_off_t) / sizeof(imp_t));
/*input_per_cycle += cur_step;*/
}
/* last offset moves back to beginning of impulses*/
((imp_off_t*)out) [-1] -= (char*) out - (char*) rs->impulses;
rs->imp = rs->impulses;
}
int resampler_get_free(void *_r)
{
resampler *r = (resampler *)_r;
return buffer_size * stereo - r->infilled;
}
int resampler_get_min_fill(void *_r)
{
resampler *r = (resampler *)_r;
const int min_needed = write_offset + stereo;
const int latency = r->latency ? 0 : adj_width;
int min_free = min_needed - r->infilled - latency;
return min_free < 0 ? 0 : min_free;
}
void resampler_write_pair(void *_r, sample_t ls, sample_t rs)
{
resampler *r = (resampler *)_r;
if (!r->latency)
{
int i;
for (i = 0; i < adj_width / 2; ++i)
{
r->buffer_in[r->inptr + 0] = 0;
r->buffer_in[r->inptr + 1] = 0;
r->buffer_in[buffer_size * stereo + r->inptr + 0] = 0;
r->buffer_in[buffer_size * stereo + r->inptr + 1] = 0;
r->inptr = (r->inptr + stereo) % (buffer_size * stereo);
r->infilled += stereo;
}
r->latency = 1;
}
if (r->infilled < buffer_size * stereo)
{
r->buffer_in[r->inptr + 0] = ls;
r->buffer_in[r->inptr + 1] = rs;
r->buffer_in[buffer_size * stereo + r->inptr + 0] = ls;
r->buffer_in[buffer_size * stereo + r->inptr + 1] = rs;
r->inptr = (r->inptr + stereo) % (buffer_size * stereo);
r->infilled += stereo;
}
}
#ifdef _MSC_VER
#define restrict __restrict
#endif
static const sample_t * resampler_inner_loop( resampler *r, sample_t** out_,
sample_t const* out_end, sample_t const in [], int in_size )
{
in_size -= write_offset;
if ( in_size > 0 )
{
sample_t* restrict out = *out_;
sample_t const* const in_end = in + in_size;
imp_t const* imp = r->imp;
do
{
/* accumulate in extended precision*/
int pt = imp [0];
int n;
intermediate_t l = (intermediate_t)pt * (intermediate_t)(in [0]);
intermediate_t r = (intermediate_t)pt * (intermediate_t)(in [1]);
if ( out >= out_end )
break;
for ( n = (adj_width - 2) / 2; n; --n )
{
pt = imp [1];
l += (intermediate_t)pt * (intermediate_t)(in [2]);
r += (intermediate_t)pt * (intermediate_t)(in [3]);
/* pre-increment more efficient on some RISC processors*/
imp += 2;
pt = imp [0];
r += (intermediate_t)pt * (intermediate_t)(in [5]);
in += 4;
l += (intermediate_t)pt * (intermediate_t)(in [0]);
}
pt = imp [1];
l += (intermediate_t)pt * (intermediate_t)(in [2]);
r += (intermediate_t)pt * (intermediate_t)(in [3]);
/* these two "samples" after the end of the impulse give the
* proper offsets to the next input sample and next impulse */
in = (sample_t const*) ((char const*) in + ((imp_off_t*)(&imp [2]))[0]); /* some negative value */
imp = (imp_t const*) ((char const*) imp + ((imp_off_t*)(&imp [2]))[1]); /* small positive or large negative */
out [0] = (sample_t) (l >> 15);
out [1] = (sample_t) (r >> 15);
out += 2;
}
while ( in < in_end );
r->imp = imp;
*out_ = out;
}
return in;
}
#undef restrict
static int resampler_wrapper( resampler *r, sample_t out [], int* out_size,
sample_t const in [], int in_size )
{
sample_t* out_ = out;
int result = resampler_inner_loop( r, &out_, out + *out_size, in, in_size ) - in;
*out_size = out_ - out;
return result;
}
static void resampler_fill( resampler *r )
{
while (!r->outfilled && r->infilled)
{
int writepos = ( r->outptr + r->outfilled ) % (buffer_size * stereo);
int writesize = (buffer_size * stereo) - writepos;
int inread;
if ( writesize > ( buffer_size * stereo - r->outfilled ) )
writesize = buffer_size * stereo - r->outfilled;
inread = resampler_wrapper(r, &r->buffer_out[writepos], &writesize, &r->buffer_in[buffer_size * stereo + r->inptr - r->infilled], r->infilled);
r->infilled -= inread;
r->outfilled += writesize;
if (!inread)
break;
}
}
int resampler_get_avail(void *_r)
{
resampler *r = (resampler *)_r;
if (r->outfilled < stereo && r->infilled >= r->width_)
resampler_fill( r );
return r->outfilled;
}
static void resampler_read_pair_internal( resampler *r, sample_t *ls, sample_t *rs, int advance )
{
if (r->outfilled < stereo)
resampler_fill( r );
if (r->outfilled < stereo)
{
*ls = 0;
*rs = 0;
return;
}
*ls = r->buffer_out[r->outptr + 0];
*rs = r->buffer_out[r->outptr + 1];
if (advance)
{
r->outptr = (r->outptr + 2) % (buffer_size * stereo);
r->outfilled -= stereo;
}
}
void resampler_read_pair( void *_r, sample_t *ls, sample_t *rs )
{
resampler *r = (resampler *)_r;
resampler_read_pair_internal(r, ls, rs, 1);
}
void resampler_peek_pair( void *_r, sample_t *ls, sample_t *rs )
{
resampler *r = (resampler *)_r;
resampler_read_pair_internal(r, ls, rs, 0);
}
#ifndef _RESAMPLER_H_
#define _RESAMPLER_H_
/* Copyright (C) 2004-2008 Shay Green.
Copyright (C) 2015-2016 Christopher Snowhill. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#define RESAMPLER_BITS 32
#define RESAMPLER_DECORATE midi
#ifdef RESAMPLER_DECORATE
#undef PASTE
#undef EVALUATE
#define PASTE(a,b) a ## b
#define EVALUATE(a,b) PASTE(a,b)
#define resampler_create EVALUATE(RESAMPLER_DECORATE,_resampler_create)
#define resampler_dup EVALUATE(RESAMPLER_DECORATE,_resampler_dup)
#define resampler_destroy EVALUATE(RESAMPLER_DECORATE,_resampler_destroy)
#define resampler_clear EVALUATE(RESAMPLER_DECORATE,_resampler_clear)
#define resampler_set_rate EVALUATE(RESAMPLER_DECORATE,_resampler_set_rate)
#define resampler_get_free EVALUATE(RESAMPLER_DECORATE,_resampler_get_free)
#define resampler_get_min_fill EVALUATE(RESAMPLER_DECORATE,_resampler_get_min_fill)
#define resampler_write_pair EVALUATE(RESAMPLER_DECORATE,_resampler_write_pair)
#define resampler_get_avail EVALUATE(RESAMPLER_DECORATE,_resampler_get_avail)
#define resampler_read_pair EVALUATE(RESAMPLER_DECORATE,_resampler_read_pair)
#define resampler_peek_pair EVALUATE(RESAMPLER_DECORATE,_resampler_peek_pair)
#endif
#include <stdint.h>
#if RESAMPLER_BITS == 16
typedef int16_t sample_t;
#elif RESAMPLER_BITS == 32
typedef int32_t sample_t;
#else
#error Choose a bit depth!
#endif
#ifdef __cplusplus
extern "C" {
#endif
void * resampler_create();
void * resampler_dup(void *);
void resampler_destroy(void *);
void resampler_clear(void *);
void resampler_set_rate( void *, double new_factor );
int resampler_get_free(void *);
int resampler_get_min_fill(void *);
void resampler_write_pair(void *, sample_t ls, sample_t rs);
int resampler_get_avail(void *);
void resampler_read_pair( void *, sample_t *ls, sample_t *rs );
void resampler_peek_pair( void *, sample_t *ls, sample_t *rs );
#ifdef __cplusplus
}
#endif
#endif
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