[gicombiner] Add the run-time rule disable option

Summary:
Each generated helper can be configured to generate an option that disables
rules in that helper. This can be used to bisect rulesets.

The disable bits are stored in a SparseVector as this is very cheap for the
common case where nothing is disabled. It gets more expensive the more rules
are disabled but you're generally doing that for debug purposes where
performance is less of a concern.

Depends on D68426

Reviewers: volkan, bogner

Reviewed By: volkan

Subscribers: hiraditya, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68438

llvm-svn: 375067

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
index 644ce2e604b..b4562a5c660 100644
--- a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -27,6 +27,18 @@
 
 using namespace llvm;
 
+namespace llvm {
+cl::OptionCategory GICombinerOptionCategory(
+    "GlobalISel Combiner",
+    "Control the rules which are enabled. These options all take a comma "
+    "separated list of rules to disable and may be specified by number "
+    "or number range (e.g. 1-10)."
+#ifndef NDEBUG
+    " They may also be specified by name."
+#endif
+);
+} // end namespace llvm
+
 namespace {
 /// This class acts as the glue the joins the CombinerHelper to the overall
 /// Combine algorithm. The CombinerHelper is intended to report the