On January 16, 2020 6:08:49 AM GMT+01:00, apin...@marvell.com wrote: >From: Andrew Pinski <apin...@marvell.com> > >In struct _dep, there is an implicit padding of 4bits. This >bit-field padding is uninitialized when init_dep_1 is being called. >This means we access uninitialized memory but never use it for >anything. Adding an unused bit-field field and initializing it >in init_dep_1 will improve code generation also as we initialize >the whole 32bits now rather than just part of it. > >OK? Bootstrapped and tested on x86_64-linux-gnu.
OK. Richard. >Thanks, >Andrew Pinski > >ChangeLog: >* sched-int.h (_dep): Add unused bit-field field for the padding. >* sched-deps.c (init_dep_1): Init unused field. > >Change-Id: I27000323e728f8a73189426e0b9a98c5235b8c55 >--- > gcc/sched-deps.c | 1 + > gcc/sched-int.h | 2 ++ > 2 files changed, 3 insertions(+) > >diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c >index 9182aba5588..331af5ffdb3 100644 >--- a/gcc/sched-deps.c >+++ b/gcc/sched-deps.c >@@ -101,6 +101,7 @@ init_dep_1 (dep_t dep, rtx_insn *pro, rtx_insn >*con, enum reg_note type, ds_t ds > DEP_NONREG (dep) = 0; > DEP_MULTIPLE (dep) = 0; > DEP_REPLACE (dep) = NULL; >+ dep->unused = 0; > } > > /* Init DEP with the arguments. >diff --git a/gcc/sched-int.h b/gcc/sched-int.h >index 833b552a340..a847f876e65 100644 >--- a/gcc/sched-int.h >+++ b/gcc/sched-int.h >@@ -238,6 +238,8 @@ struct _dep >/* Cached cost of the dependency. Make sure to update UNKNOWN_DEP_COST > when changing the size of this field. */ > int cost:20; >+ >+ unsigned unused:4; > }; > > #define UNKNOWN_DEP_COST ((int) ((unsigned int) -1 << 19))
