Reduce inlining in deeply-nested cases

This adds a new heuristic, controllable via two new flags to
better tune inlining behaviour.

The new flags are -funfolding-case-threshold and
-funfolding-case-scaling which are document both
in the user guide and in
Note [Avoid inlining into deeply nested cases].

Co-authored-by: Andreas Klebinger <klebinger.andreas@gmx.at>

2 files changed, 8 insertions, 19 deletions

diff --git a/testsuite/tests/dependent/should_compile/all.T b/testsuite/tests/dependent/should_compile/all.T
index cf5c76d380..a368edd128 100644
--- a/testsuite/tests/dependent/should_compile/all.T
+++ b/testsuite/tests/dependent/should_compile/all.T
@@ -10,14 +10,18 @@ test('RaeBlogPost', normal, compile, [''])
 test('mkGADTVars', normal, compile, [''])
 test('TypeLevelVec',normal,compile, [''])
 test('T9632', normal, compile, [''])
-# The dynamic-paper test fails in the profasm way if we don't increase
+
+# dynamic-paper used to run out of simplfier ticks because of
+# infinite inlining, but the new case-depth mechanism cuts that off,
+# so it now compiles fine.
+#
+# Historical notes: The dynamic-paper test fails in the profasm way if we don't increase
 # the simplifier tick limit. If we do, we run out of stack
 # space. If we increase the stack size enough with -K,
 # we run out of simplifier ticks again. This is
 # discussed in #11330.
-test('dynamic-paper',
-     expect_broken_for(11330, ['profasm']),
-     compile_fail, [''])
+test('dynamic-paper', normal, compile, [''])
+
 test('T11311', normal, compile, [''])
 test('T11405', normal, compile, [''])
 test('T11241', normal, compile, [''])
diff --git a/testsuite/tests/dependent/should_compile/dynamic-paper.stderr b/testsuite/tests/dependent/should_compile/dynamic-paper.stderr
deleted file mode 100644
index b05335047f..0000000000
--- a/testsuite/tests/dependent/should_compile/dynamic-paper.stderr
+++ /dev/null
@@ -1,15 +0,0 @@
-Simplifier ticks exhausted
-  When trying UnfoldingDone delta1
-  To increase the limit, use -fsimpl-tick-factor=N (default 100).
-   
-  If you need to increase the limit substantially, please file a
-  bug report and indicate the factor you needed.
-   
-  If GHC was unable to complete compilation even with a very large factor
-  (a thousand or more), please consult the "Known bugs or infelicities"
-  section in the Users Guide before filing a report. There are a
-  few situations unlikely to occur in practical programs for which
-  simplifier non-termination has been judged acceptable.
-   
-  To see detailed counts use -ddump-simpl-stats
-  Total ticks: 140801