http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902
--- Comment #11 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
OK I'm down to one function from ./libavcodec/flacdec.c:
208 __attribute__ ((optimize(0)))
209 static int decode_residuals(FLACContext *s, int32_t *decoded, int
pred_order)
210 {
211 int i, tmp, partition, method_type, rice_order;
212 int rice_bits, rice_esc;
213 int samples;
214
215 method_type = get_bits(&s->gb, 2);
216 if (method_type > 1) {
217 av_log(s->avctx, AV_LOG_ERROR, "illegal residual coding method
%d\n",
218 method_type);
219 return AVERROR_INVALIDDATA;
220 }
221
222 rice_order = get_bits(&s->gb, 4);
223
224 samples= s->blocksize >> rice_order;
225 if (samples << rice_order != s->blocksize) {
226 av_log(s->avctx, AV_LOG_ERROR, "invalid rice order: %i blocksize
%i\n",
227 rice_order, s->blocksize);
228 return AVERROR_INVALIDDATA;
229 }
230
231 if (pred_order > samples) {
232 av_log(s->avctx, AV_LOG_ERROR, "invalid predictor order: %i >
%i\n",
233 pred_order, samples);
234 return AVERROR_INVALIDDATA;
235 }
236
237 rice_bits = 4 + method_type;
238 rice_esc = (1 << rice_bits) - 1;
239
240 decoded += pred_order;
241 i= pred_order;
242 for (partition = 0; partition < (1 << rice_order); partition++) {
243 tmp = get_bits(&s->gb, rice_bits);
244 if (tmp == rice_esc) {
245 tmp = get_bits(&s->gb, 5);
246 for (; i < samples; i++)
247 *decoded++ = get_sbits_long(&s->gb, tmp);
248 } else {
249 for (; i < samples; i++) {
250 *decoded++ = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
251 }
252 }
253 i= 0;
254 }
255
256 return 0;
257 }
258
Without __attribute__ ((optimize(0))) it gets miscompiled.
