| Message ID | 1369839046.3473.7.camel@gnopaine |
|---|---|
| State | New |
| Headers | show |
On Wed, May 29, 2013 at 4:50 PM, Bill Schmidt <wschmidt@linux.vnet.ibm.com> wrote: > Hi, > > Prior to adding conditional candidates to SLSR, the size of the > increment vector was bounded by the number of related candidates, and > the vector was malloc'd to be that size. With conditional candidates, > there can be an additional increment for each related PHI operand, > causing potential overflow and heap corruption. This patch removes the > no longer valid assumption and allocates a fixed-size vector. > > Bootstrap and regtest in progress on powerpc64-linux-gnu. Ok for trunk > if everything checks out? Ok with referencing the PR in the changelog and adding the testcase. Thanks, Richard. > Thanks, > Bill > > > 2013-05-29 Bill Schmidt <wschmidt@linux.vnet.ibm.com> > > * gimple-ssa-strength-reduction.c (analyze_candidates_and_replace): > Don't limit size of incr_vec to number of candidates. > > > Index: gcc/gimple-ssa-strength-reduction.c > =================================================================== > --- gcc/gimple-ssa-strength-reduction.c (revision 199406) > +++ gcc/gimple-ssa-strength-reduction.c (working copy) > @@ -3361,7 +3361,6 @@ analyze_candidates_and_replace (void) > less expensive to calculate than the replaced statements. */ > else > { > - int length; > enum machine_mode mode; > bool speed; > > @@ -3372,14 +3371,11 @@ analyze_candidates_and_replace (void) > > /* If all candidates have already been replaced under other > interpretations, nothing remains to be done. */ > - length = count_candidates (c); > - if (!length) > + if (!count_candidates (c)) > continue; > - if (length > MAX_INCR_VEC_LEN) > - length = MAX_INCR_VEC_LEN; > > /* Construct an array of increments for this candidate chain. */ > - incr_vec = XNEWVEC (incr_info, length); > + incr_vec = XNEWVEC (incr_info, MAX_INCR_VEC_LEN); > incr_vec_len = 0; > record_increments (c); > > >
Index: gcc/gimple-ssa-strength-reduction.c =================================================================== --- gcc/gimple-ssa-strength-reduction.c (revision 199406) +++ gcc/gimple-ssa-strength-reduction.c (working copy) @@ -3361,7 +3361,6 @@ analyze_candidates_and_replace (void) less expensive to calculate than the replaced statements. */ else { - int length; enum machine_mode mode; bool speed; @@ -3372,14 +3371,11 @@ analyze_candidates_and_replace (void) /* If all candidates have already been replaced under other interpretations, nothing remains to be done. */ - length = count_candidates (c); - if (!length) + if (!count_candidates (c)) continue; - if (length > MAX_INCR_VEC_LEN) - length = MAX_INCR_VEC_LEN; /* Construct an array of increments for this candidate chain. */ - incr_vec = XNEWVEC (incr_info, length); + incr_vec = XNEWVEC (incr_info, MAX_INCR_VEC_LEN); incr_vec_len = 0; record_increments (c);