From 28ebdf1a02eb26f1fc539991e97b41510bfd031f Mon Sep 17 00:00:00 2001
From: Daniel Sanders <daniel_l_sanders@apple.com>
Date: Tue, 16 Jun 2020 13:41:38 -0700
Subject: [PATCH] [gicombiner] Allow generated CombinerHelpers to have
 additional arguments

Summary:
This allows combiners to delegate to other helpers or depend
on additional information. It's not great as an overall
solution though as callers must provide the argument on every call, even for
static data like an additional helper. Another patch will follow to
support additional members of the generated combiner.

Reviewers: aditya_nandakumar, bogner, aemerson, paquette, volkan, arsenm

Reviewed By: aditya_nandakumar

Subscribers: wdng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81862
---
 .../include/llvm/Target/GlobalISel/Combine.td |  8 ++++++++
 llvm/utils/TableGen/GICombinerEmitter.cpp     | 19 ++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/llvm/include/llvm/Target/GlobalISel/Combine.td b/llvm/include/llvm/Target/GlobalISel/Combine.td
index b41185133d770..7803ce1b51abd 100644
--- a/llvm/include/llvm/Target/GlobalISel/Combine.td
+++ b/llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -27,6 +27,11 @@ class GICombineGroup<list<GICombine> rules> : GICombine {
   let Rules = rules;
 }
 
+class GICombinerHelperArg<string type, string name> {
+  string Type = type;
+  string Name = name;
+}
+
 // Declares a combiner helper class
 class GICombinerHelper<string classname, list<GICombine> rules>
     : GICombineGroup<rules> {
@@ -35,6 +40,9 @@ class GICombinerHelper<string classname, list<GICombine> rules>
   // The name of a run-time compiler option that will be generated to disable
   // specific rules within this combiner.
   string DisableRuleOption = ?;
+  // Any additional arguments that should be appended to the tryCombine*().
+  list<GICombinerHelperArg> AdditionalArguments =
+      [GICombinerHelperArg<"CombinerHelper &", "Helper">];
 }
 class GICombineRule<dag defs, dag match, dag apply> : GICombine {
   /// Defines the external interface of the match rule. This includes:
diff --git a/llvm/utils/TableGen/GICombinerEmitter.cpp b/llvm/utils/TableGen/GICombinerEmitter.cpp
index 8c70ed157a587..761ca4b52614d 100644
--- a/llvm/utils/TableGen/GICombinerEmitter.cpp
+++ b/llvm/utils/TableGen/GICombinerEmitter.cpp
@@ -841,6 +841,13 @@ void GICombinerEmitter::generateCodeForTree(raw_ostream &OS,
     OS << Indent << "return false;\n";
 }
 
+static void emitAdditionalHelperMethodArguments(raw_ostream &OS,
+                                                Record *Combiner) {
+  for (Record *Arg : Combiner->getValueAsListOfDefs("AdditionalArguments"))
+    OS << ",\n    " << Arg->getValueAsString("Type")
+       << Arg->getValueAsString("Name");
+}
+
 void GICombinerEmitter::run(raw_ostream &OS) {
   gatherRules(Rules, Combiner->getValueAsListOfDefs("Rules"));
   if (StopAfterParse) {
@@ -901,9 +908,10 @@ void GICombinerEmitter::run(raw_ostream &OS) {
      << "  bool tryCombineAll(\n"
      << "    GISelChangeObserver &Observer,\n"
      << "    MachineInstr &MI,\n"
-     << "    MachineIRBuilder &B,\n"
-     << "    CombinerHelper &Helper) const;\n"
-     << "};\n\n";
+     << "    MachineIRBuilder &B";
+  emitAdditionalHelperMethodArguments(OS, Combiner);
+  OS << ") const;\n";
+  OS << "};\n\n";
 
   emitNameMatcher(OS);
 
@@ -958,8 +966,9 @@ void GICombinerEmitter::run(raw_ostream &OS) {
   OS << "bool " << getClassName() << "::tryCombineAll(\n"
      << "    GISelChangeObserver &Observer,\n"
      << "    MachineInstr &MI,\n"
-     << "    MachineIRBuilder &B,\n"
-     << "    CombinerHelper &Helper) const {\n"
+     << "    MachineIRBuilder &B";
+  emitAdditionalHelperMethodArguments(OS, Combiner);
+  OS << ") const {\n"
      << "  MachineBasicBlock *MBB = MI.getParent();\n"
      << "  MachineFunction *MF = MBB->getParent();\n"
      << "  MachineRegisterInfo &MRI = MF->getRegInfo();\n"