Hi, On 2025-07-11 11:22:36 +0900, Amit Langote wrote: > On Fri, Jul 11, 2025 at 5:55 AM Andres Freund <and...@anarazel.de> wrote: > > On 2025-07-10 17:28:50 +0900, Amit Langote wrote: > > > On Thu, Jul 10, 2025 at 8:34 AM Andres Freund <and...@anarazel.de> wrote: > > > > The performance gain unsurprisingly isn't significant (but seems > > > > repeatably > > > > measureable), but it does cut out a fair bit of unnecessary code. > > > > > > > > andres@awork3:/srv/dev/build/postgres/m-dev-optimize$ size > > > > executor_nodeSeqscan.c.*o > > > > text data bss dec hex filename > > > > 3330 0 0 3330 d02 executor_nodeSeqscan.c.assume.o > > > > 3834 0 0 3834 efa executor_nodeSeqscan.c.o > > > > > > > > A 13% reduction in actual code size isn't bad for such a small change, > > > > imo. > > > > > > Yeah, that seems worthwhile. I had been a bit concerned about code > > > size growth from having four variant functions with at least some > > > duplication, so this is a nice offset. > > > > I'm rather surprised by just how much the size reduces... > > > > I built nodeSeqscan.c with -ffunction-sections and looked at the size with > > size --format=sysv: > > > > Before: > > .text.SeqRecheck 6 0 > > .rodata.str1.8 135 0 > > .text.unlikely.SeqNext 53 0 > > .text.SeqNext 178 0 > > .text.ExecSeqScanEPQ 20 0 > > .text.ExecSeqScanWithProject 289 0 > > .text.unlikely.ExecSeqScanWithQual 53 0 > > .text.ExecSeqScanWithQual 441 0 > > .text.unlikely.ExecSeqScanWithQualProject 53 0 > > .text.ExecSeqScanWithQualProject 811 0 > > .text.unlikely.ExecSeqScan 53 0 > > .text.ExecSeqScan 245 0 > > .text.ExecInitSeqScan 287 0 > > .text.ExecEndSeqScan 33 0 > > .text.ExecReScanSeqScan 63 0 > > .text.ExecSeqScanEstimate 88 0 > > .text.ExecSeqScanInitializeDSM 114 0 > > .text.ExecSeqScanReInitializeDSM 34 0 > > .text.ExecSeqScanInitializeWorker 64 0 > > > > After: > > .text.SeqRecheck 6 0 > > .rodata.str1.8 135 0 > > .text.unlikely.SeqNext 53 0 > > .text.SeqNext 178 0 > > .text.ExecSeqScanEPQ 20 0 > > .text.ExecSeqScanWithProject 209 0 > > .text.unlikely.ExecSeqScanWithQual 53 0 > > .text.ExecSeqScanWithQual 373 0 > > .text.unlikely.ExecSeqScanWithQualProject 53 0 > > .text.ExecSeqScanWithQualProject 474 0 > > .text.unlikely.ExecSeqScan 53 0 > > .text.ExecSeqScan 245 0 > > .text.ExecInitSeqScan 287 0 > > .text.ExecEndSeqScan 33 0 > > .text.ExecReScanSeqScan 63 0 > > .text.ExecSeqScanEstimate 88 0 > > .text.ExecSeqScanInitializeDSM 114 0 > > .text.ExecSeqScanReInitializeDSM 34 0 > > .text.ExecSeqScanInitializeWorker 64 0 > > > > > > I'm rather baffled that the size of ExecSeqScanWithQualProject goes from 811 > > to 474, just due to those null checks being removed... But I'll take it. > > Wow, indeed.
Thanks for reviewing. Pushed! Greetings, Andres Freund
