| Message ID | 20190124192808.GR30353@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Improve x86 address delegitimization (PR debug/89006) | expand |
On Thu, Jan 24, 2019 at 8:28 PM Jakub Jelinek <jakub@redhat.com> wrote: > > Hi! > > As the following testcase shows, during var-tracking we can end trying to > delegitimize e.g. (plus:SI (unspec:SI ... UNSPEC_SET_GOT) > (const:SI (unspec:SI (symbol_ref:SI ...) UNSPEC_GOTOFF)). The code is > prepared to handle PIC register + UNSPEC_GOTOFF, delegitimizing that > to the underlying SYMBOL_REF, but we can end up with the UNSPEC_SET_GOT > instead of the %ebx etc. register, because in the RTL that register > is initialized to that UNSPEC_SET_GOT. > > The following patch handles it like the pic register; the > ix86_pic_register_p function is used only in the delegitimization hook. > > Bootstrapped/regtested on x86_64-linux and i686-linux, the patch removed > all 170 non-delegitimized UNSPEC messages from x86_64-linux bootstrap and > 142 out of 144 non-delegitimized UNSPEC messages from i686-linux bootstrap, > ok for trunk? > > 2019-01-24 Jakub Jelinek <jakub@redhat.com> > > PR debug/89006 > * config/i386/i386.c (ix86_pic_register_p): Return true for > UNSPEC_SET_GOT too. > > * g++.dg/debug/pr89006.C: New test. LGTM. Thanks, Uros. > --- gcc/config/i386/i386.c.jj 2019-01-22 23:26:46.668212957 +0100 > +++ gcc/config/i386/i386.c 2019-01-24 11:51:40.050801078 +0100 > @@ -16972,6 +16972,8 @@ ix86_pic_register_p (rtx x) > if (GET_CODE (x) == VALUE && CSELIB_VAL_PTR (x)) > return (pic_offset_table_rtx > && rtx_equal_for_cselib_p (x, pic_offset_table_rtx)); > + else if (GET_CODE (x) == UNSPEC && XINT (x, 1) == UNSPEC_SET_GOT) > + return true; > else if (!REG_P (x)) > return false; > else if (pic_offset_table_rtx) > --- gcc/testsuite/g++.dg/debug/pr89006.C.jj 2019-01-24 12:18:59.119838677 +0100 > +++ gcc/testsuite/g++.dg/debug/pr89006.C 2019-01-24 12:16:56.642859109 +0100 > @@ -0,0 +1,20 @@ > +// PR debug/89006 > +// { dg-do compile } > +// { dg-options "-O2 -g -w" } > +// { dg-additional-options "-fPIC" { target fpic } } > +// { dg-bogus "non-delegitimized UNSPEC UNSPEC_SET_GOT" "" { target { i?86-*-* x86_64-*-* } } 0 } > + > +struct A { A (bool); }; > + > +static void > +foo (const char *x) > +{ > + new A (x); > +} > + > +void > +bar () > +{ > + foo ("foo"); > + foo ("bar"); > +} > > Jakub
--- gcc/config/i386/i386.c.jj 2019-01-22 23:26:46.668212957 +0100 +++ gcc/config/i386/i386.c 2019-01-24 11:51:40.050801078 +0100 @@ -16972,6 +16972,8 @@ ix86_pic_register_p (rtx x) if (GET_CODE (x) == VALUE && CSELIB_VAL_PTR (x)) return (pic_offset_table_rtx && rtx_equal_for_cselib_p (x, pic_offset_table_rtx)); + else if (GET_CODE (x) == UNSPEC && XINT (x, 1) == UNSPEC_SET_GOT) + return true; else if (!REG_P (x)) return false; else if (pic_offset_table_rtx) --- gcc/testsuite/g++.dg/debug/pr89006.C.jj 2019-01-24 12:18:59.119838677 +0100 +++ gcc/testsuite/g++.dg/debug/pr89006.C 2019-01-24 12:16:56.642859109 +0100 @@ -0,0 +1,20 @@ +// PR debug/89006 +// { dg-do compile } +// { dg-options "-O2 -g -w" } +// { dg-additional-options "-fPIC" { target fpic } } +// { dg-bogus "non-delegitimized UNSPEC UNSPEC_SET_GOT" "" { target { i?86-*-* x86_64-*-* } } 0 } + +struct A { A (bool); }; + +static void +foo (const char *x) +{ + new A (x); +} + +void +bar () +{ + foo ("foo"); + foo ("bar"); +}