| Message ID | alpine.LNX.2.00.1305230956120.24881@zhemvz.fhfr.qr |
|---|---|
| State | New |
| Headers | show |
On Thu, May 23, 2013 at 09:58:50AM +0200, Richard Biener wrote: > 2013-05-23 Richard Biener <rguenther@suse.de> > > PR rtl-optimization/57341 > * ira.c (validate_equiv_mem_from_store): Use anti_dependence > instead of true_dependence. > > * gcc.dg/torture/pr57341.c: New testcase. Ok, thanks. Jakub
Index: gcc/ira.c =================================================================== --- gcc/ira.c (revision 199199) +++ gcc/ira.c (working copy) @@ -2520,7 +2520,7 @@ validate_equiv_mem_from_store (rtx dest, if ((REG_P (dest) && reg_overlap_mentioned_p (dest, equiv_mem)) || (MEM_P (dest) - && true_dependence (dest, VOIDmode, equiv_mem))) + && anti_dependence (equiv_mem, dest))) equiv_mem_modified = 1; }
When trying to figure out whether it can re-materialize a memory load before the use in <read> ... = equiv_mem; <write> dest = ...; <use> IRA manages to get alias queries wrong by using true_dependence (which is for read-after-write) instead of anti_dependence as it wants to test whether the write invalidates equiv_mem. Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk? Ok for the 4.8 branch at this point? Thanks, Richard. 2013-05-23 Richard Biener <rguenther@suse.de> PR rtl-optimization/57341 * ira.c (validate_equiv_mem_from_store): Use anti_dependence instead of true_dependence. * gcc.dg/torture/pr57341.c: New testcase. Index: gcc/testsuite/gcc.dg/torture/pr57341.c =================================================================== *** gcc/testsuite/gcc.dg/torture/pr57341.c (revision 0) --- gcc/testsuite/gcc.dg/torture/pr57341.c (revision 0) *************** *** 0 **** --- 1,22 ---- + /* { dg-do run } */ + /* { dg-additional-options "-msse" { target sse2_runtime } } */ + + int a, d; + int *b = &a, **c; + int + main () + { + int e; + { + int f[4]; + for (d = 0; d < 4; d++) + f[d] = 1; + e = f[1]; + } + int *g[28] = { }; + *b = e; + c = &g[0]; + if (a != 1) + __builtin_abort (); + return 0; + }