tree 418ef4eae96c7657793c6fcd878e0dffa1582c1b
parent 2a9a78d0eec8a3a4a75c565f552443114d476217
author Cullen Rhodes <cullen.rhodes@arm.com> 1778136214 +0100
committer GitHub <noreply@github.com> 1778136214 +0100
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[AArch64] Avoid raw_svector_ostream for SubtargetMap keys (#196003)

AArch64TargetMachine::getSubtargetImpl builds a StringMap key on every
subtarget lookup. This showed up through repeated TTI queries while
profiling sqlite on aarch64-O0-g.

Building the key directly with SmallString appends and utostr instead of
raw_svector_ostream improves compile-time.

We used to do this until 07e7168048b1.

CTMark geomean:
- stage1-aarch64-O3: -0.16%
- stage1-aarch64-O0-g: -0.18%

https://llvm-compile-time-tracker.com/compare.php?from=c9d713aa48a714d20b8502d06b9feb24829e6f22&to=e7ff83884193ee70cf3a69778b891fb729e0bcba&stat=instructions%3Au

Assisted-by: codex