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Magnus pushed to branch wip/mangoiv/ci-stages at Glasgow Haskell Compiler / GHC

Commits:

098bba70

by Facundo Domínguez at 2026-09-17T14:57:41-04:00

Remove the call to hoistFlag from processCmdLineP

This call was undesirable because it was causing a reconstruction
of the list of flag processors.

Even relying on list fusion would not be sufficient because we want
to replace the list with a data structure with faster lookups to
address #25763.

The removal is done in two moves:

* We move CmdLineP to CmdLine.hs
* Then we move the effect of hoisting to processArgs via a new function
  hoistEwM

e01799c7

by Facundo Domínguez at 2026-09-17T14:57:42-04:00

Do not create duplicate flag processors for the -W flag

This makes simpler implementing the command line parser with a trie map
holding flag processors. If we were to allow duplicate flag processors
for any flag, the trie map would need to be a multimap.

3875b257

by Facundo Domínguez at 2026-09-17T14:57:42-04:00

Replace the list of flag processors with a trie map in `processArgs`

Previously `GHC.Driver.CmdLine.findArg` was called for each
command-line argument, doing a linear search on the list of flag
processors each time. This was somewhat costly as the list of flag
processor has near 2000 elements.

A lookup with a trie map is faster in general, but the speed up is
only noticeable when calling `GHC.Driver.CmdLine.processArgs` sufficient
times, so the amount of lookups piles up. This could happen in large
projects with many units each having many dependencies. If only a
module needs to be recompiled, the user still needs to wait for all of
the flag parsing to complete.

The benchmark at testsuite/tests/perf/compiler/cmdline-parser shows a
10x speed up when using the trie.

The trie map is implemented in `GHC.Data.StringTrie`.

The design is explained in Note [Processing command line argument fast]
in GHC.Driver.Session.

The commit also:
* adds two property-based tests for trie map operations,
* adds a benchmark of the command line parser, and
* renames the predicate `arg_ok` to `valid_flag_suffix` to decide what
  flag processor should be used when there are multiple matching
  prefixes on a flag.

Fixes #25763.

5236634a

by Andreas Klebinger at 2026-09-17T14:58:24-04:00

Compile Word64{Map,Set} with -O2 always.

This is the hottest code and even if we build GHC with -O0 otherwise -O2
pays off for these modules.

Fixes #27814.

c236efd5

by mangoiv at 2026-09-22T17:27:27+02:00

ci: build and test stage

Split up CI in a build and test stage:
1. in the build stage, just produce a bindist as well as running the
   stage1 tests
2. in the test stage, install the bindist, then run the testsuite with
  out of tree args

87108874
by mangoiv at 2026-09-22T17:28:50+02:00
```
ci: reorder packaging and testing stages
```

a643b245