RFR: 8324433: Introduce a way to determine if an expression is evaluated as a constant by the Jit compiler [v4]

Quan Anh Mai qamai at openjdk.org
Tue Jan 23 16:51:50 UTC 2024


> Hi,
> 
> This patch introduces `JitCompiler::isConstantExpression` which can be used to statically determine whether an expression has been constant-folded by the Jit compiler, leading to more constant-folding opportunities. For example, it can be used in `MemorySessionImpl::checkValidStateRaw` to eliminate the lifetime check on global sessions without imposing additional branches on other non-global sessions. This is inspired by `std::is_constant_evaluated` in C++.
> 
> Please kindly give your opinion as well as your reviews, thanks very much.

Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:

  address reviews: rename to isCompileConstant, remove duplication, revert unnecessary changes

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/17527/files
  - new: https://git.openjdk.org/jdk/pull/17527/files/31403d6f..18f7d482

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17527&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17527&range=02-03

  Stats: 92 lines in 8 files changed: 10 ins; 13 del; 69 mod
  Patch: https://git.openjdk.org/jdk/pull/17527.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17527/head:pull/17527

PR: https://git.openjdk.org/jdk/pull/17527


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