[GlobalISel][InstructionSelect] Switching over root LLTs, perf patch 10

This patch continues a series of patches started by r332907 (reapplied
as r332917).

In this commit we introduce new matching opcode for the MatchTable:
GIM_SwitchType, similar to GIM_SwitchOpcode, and use it to switch over
LLTs of def operands of root instructions on the 2nd level of the
MatchTable within GIM_SwitchOpcode's cases.

This is expected to decrease time GlobalISel spends in its
InstructionSelect pass by about 6.5% for an -O0 build as measured on
sqlite3-amalgamation (http://sqlite.org/download.html) targeting
AArch64 (cross-compile on x86).

Reviewers: qcolombet, dsanders, bogner, aemerson, javed.absar

Reviewed By: qcolombet

Subscribers: rovka, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D44700

llvm-svn: 333146

1 files changed, 10 insertions, 1 deletions

diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index dbfecf7d393..ad461f59256 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -4153,6 +4153,8 @@ void GroupMatcher::optimize() {
   }
   GlobalISelEmitter::optimizeRules<GroupMatcher>(Matchers, MatcherStorage)
       .swap(Matchers);
+  GlobalISelEmitter::optimizeRules<SwitchMatcher>(Matchers, MatcherStorage)
+      .swap(Matchers);
 }
 
 void GlobalISelEmitter::run(raw_ostream &OS) {
@@ -4641,7 +4643,7 @@ void GroupMatcher::emit(MatchTable &Table) {
 }
 
 bool SwitchMatcher::isSupportedPredicateType(const PredicateMatcher &P) {
-  return isa<InstructionOpcodeMatcher>(P);
+  return isa<InstructionOpcodeMatcher>(P) || isa<LLTOperandMatcher>(P);
 }
 
 bool SwitchMatcher::candidateConditionMatches(
@@ -4717,6 +4719,13 @@ void SwitchMatcher::emitPredicateSpecificOpcodes(const PredicateMatcher &P,
           << MatchTable::IntValue(Condition->getInsnVarID());
     return;
   }
+  if (const auto *Condition = dyn_cast<LLTOperandMatcher>(&P)) {
+    Table << MatchTable::Opcode("GIM_SwitchType") << MatchTable::Comment("MI")
+          << MatchTable::IntValue(Condition->getInsnVarID())
+          << MatchTable::Comment("Op")
+          << MatchTable::IntValue(Condition->getOpIdx());
+    return;
+  }
 
   llvm_unreachable("emitPredicateSpecificOpcodes is broken: can not handle a "
                    "predicate type that is claimed to be supported");