> On 1/28/07, Richard Guenther <[EMAIL PROTECTED]> wrote: > >On 1/28/07, tbp <[EMAIL PROTECTED]> wrote: > >> objdump -wdrfC --no-show-raw-insn $1|perl -pe 's/^\s+\w+:\s+//'|perl > >> -ne 'printf "%4d\n", hex($1) if /sub\s+\$(0x\w+),%esp/'|sort -r| head > >> -n 10 > >> > >> msvc:2196 2100 1772 1692 1688 1444 1428 1312 1308 1160 > >> icc: 2412 2280 2172 2044 1928 1848 1820 1588 1428 1396 > >> gcc: 2604 2596 2412 2076 2028 1932 1900 1756 1720 1132 > > > >It would have been nice to tell us what the particular columns in > >this table mean - now we have to decrypt objdump params and > >perl postprocessing ourselves. > I should have known better than to post on a sunday morning. Sorry. > That's the sorted 10 largest stack allocations in binaries produced by > each compiler (presuming most everything falls in place). > Each time i verify codegen for a function across all 3, gcc always has > the largest frame by a substantial amount (on ia32). And that's what > that rigorous table is trying to demonstrate ;) > > Basically i'm wondering if a stack frame shrinking pass [ ] is > possible, [ ] makes no sense, [ ] has been done, [ ] is planed etc...
Actually we do have one stack frame shrinking pass already. It depends on where the bloat is comming from - we can pack (with some limitations) memory used by structures/arrays used by different inline functions or lexical blocks. We don't do any packing of spilled registers nor shring wrapping other compilers sometimes implement. Honza > > >(If you are interested in stack size related to inlining you may want > >to tune --param large-stack-frame and --param large-stack-frame-growth). > Recently g++ 4.3 has started to complain about "warning: inlining > failed in call to 'xxx': --param large-stack-frame-growth limit > reached [-Winline]. Bumping said large-function-growth by an ungodly > amount did the trick. But it was the sure sign inlining was being > fixed. > There's much less need to babysit it, thanks a lot to whomever wrote > those patches.
