| Message ID | 20181211164357.GZ12380@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Fix cleanup_auto_inc_dec on x86 (PR rtl-optimization/88416) | expand |
On 12/11/18 9:43 AM, Jakub Jelinek wrote: > Hi! > > As mentioned in the PR, x86 (maybe a couple of other targets) isn't an > AUTO_INC_DEC target, it doesn't have REG_INC notes nor wants the generic > code to synthetize any pre/post inc/dec/modify, but does support push/pop > patterns that use those RTL codes. > > If unlucky enough, as on the following testcase, we can end up with trying > to propagate such pre/post inc/dec into a DEBUG_INSN, which is invalid. > > As cleanup_auto_inc_dec calls copy_rtx which is pretty much the same > function as cleanup_auto_inc_dec in the way how it performs deep copy of the > RTX, except that cleanup_auto_inc_dec also handles the pre/post > inc/dec/modify, I think the easiest fix is just to remove the special case, > it shouldn't make it any slower on !AUTO_INC_DEC targets. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2018-12-11 Jakub Jelinek <jakub@redhat.com> > > PR rtl-optimization/88416 > * valtrack.c (cleanup_auto_inc_dec): Handle pre/post-inc/dec/modify > even if !AUTO_INC_DEC. > > * gcc.target/i386/pr88416.c: New test. OK jeff
--- gcc/valtrack.c.jj 2018-01-04 00:43:16.100702765 +0100 +++ gcc/valtrack.c 2018-12-11 15:39:05.746898166 +0100 @@ -56,8 +56,6 @@ static rtx cleanup_auto_inc_dec (rtx src, machine_mode mem_mode ATTRIBUTE_UNUSED) { rtx x = src; - if (!AUTO_INC_DEC) - return copy_rtx (x); const RTX_CODE code = GET_CODE (x); int i; --- gcc/testsuite/gcc.target/i386/pr88416.c.jj 2018-12-11 15:41:44.552308649 +0100 +++ gcc/testsuite/gcc.target/i386/pr88416.c 2018-12-11 15:41:36.977432165 +0100 @@ -0,0 +1,5 @@ +/* PR rtl-optimization/88416 */ +/* { dg-do compile } */ +/* { dg-options "-O1 -fvar-tracking-assignments -fno-forward-propagate --param max-cse-insns=1" } */ + +#include "writeeflags-1.c"