| Message ID | 20110414133453.GA18805@intel.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Apr 14, 2011 at 3:34 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: > We have > > static unsigned int > get_decl_align_unit (tree decl) > { > unsigned int align = LOCAL_DECL_ALIGNMENT (decl); > return align / BITS_PER_UNIT; > } > > LOCAL_DECL_ALIGNMENT may increase alignment for local variable. But it is > never saved. DECL_ALIGN (decl) returns the old alignment. This patch > updates DECL_ALIGN if needed. OK for trunk if there are no regressions? A get_* function does not seem like a good place to do such things. Why does it matter that DECL_ALIGN is updated? > Thanks. > > H.J. > --- > 2011-04-14 H.J. Lu <hongjiu.lu@intel.com> > > PR middle-end/48608 > * cfgexpand.c (get_decl_align_unit): Update DECL_ALIGN if needed. > > diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c > index cc1382f..e79d50c 100644 > --- a/gcc/cfgexpand.c > +++ b/gcc/cfgexpand.c > @@ -212,6 +212,8 @@ static unsigned int > get_decl_align_unit (tree decl) > { > unsigned int align = LOCAL_DECL_ALIGNMENT (decl); > + if (align > DECL_ALIGN (decl)) > + DECL_ALIGN (decl) = align; > return align / BITS_PER_UNIT; > } > >
On Thu, Apr 14, 2011 at 6:57 AM, Richard Guenther <richard.guenther@gmail.com> wrote: > On Thu, Apr 14, 2011 at 3:34 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: >> We have >> >> static unsigned int >> get_decl_align_unit (tree decl) >> { >> unsigned int align = LOCAL_DECL_ALIGNMENT (decl); >> return align / BITS_PER_UNIT; >> } >> >> LOCAL_DECL_ALIGNMENT may increase alignment for local variable. But it is >> never saved. DECL_ALIGN (decl) returns the old alignment. This patch >> updates DECL_ALIGN if needed. OK for trunk if there are no regressions? > > A get_* function does not seem like a good place to do such things. Any suggestion to how to do it properly? I can rename get_decl_align_unit to align_local_variable. > Why does it matter that DECL_ALIGN is updated? > My port needs accurate alignment information on local variables.
On Thu, Apr 14, 2011 at 4:01 PM, H.J. Lu <hjl.tools@gmail.com> wrote: > On Thu, Apr 14, 2011 at 6:57 AM, Richard Guenther > <richard.guenther@gmail.com> wrote: >> On Thu, Apr 14, 2011 at 3:34 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: >>> We have >>> >>> static unsigned int >>> get_decl_align_unit (tree decl) >>> { >>> unsigned int align = LOCAL_DECL_ALIGNMENT (decl); >>> return align / BITS_PER_UNIT; >>> } >>> >>> LOCAL_DECL_ALIGNMENT may increase alignment for local variable. But it is >>> never saved. DECL_ALIGN (decl) returns the old alignment. This patch >>> updates DECL_ALIGN if needed. OK for trunk if there are no regressions? >> >> A get_* function does not seem like a good place to do such things. > > Any suggestion to how to do it properly? I can rename > get_decl_align_unit to align_local_variable. That works for me. >> Why does it matter that DECL_ALIGN is updated? >> > > My port needs accurate alignment information on local variables. I see. Richard. > -- > H.J. >
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index cc1382f..e79d50c 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -212,6 +212,8 @@ static unsigned int get_decl_align_unit (tree decl) { unsigned int align = LOCAL_DECL_ALIGNMENT (decl); + if (align > DECL_ALIGN (decl)) + DECL_ALIGN (decl) = align; return align / BITS_PER_UNIT; }
We have static unsigned int get_decl_align_unit (tree decl) { unsigned int align = LOCAL_DECL_ALIGNMENT (decl); return align / BITS_PER_UNIT; } LOCAL_DECL_ALIGNMENT may increase alignment for local variable. But it is never saved. DECL_ALIGN (decl) returns the old alignment. This patch updates DECL_ALIGN if needed. OK for trunk if there are no regressions? Thanks. H.J. --- 2011-04-14 H.J. Lu <hongjiu.lu@intel.com> PR middle-end/48608 * cfgexpand.c (get_decl_align_unit): Update DECL_ALIGN if needed.