[PM] Port ArgumentPromotion to the new pass manager.

Now that the call graph supports efficient replacement of a function and
spurious reference edges, we can port ArgumentPromotion to the new pass
manager very easily.

The old PM-specific bits are sunk into callbacks that the new PM simply
doesn't use. Unlike the old PM, the new PM simply does argument
promotion and afterward does the update to LCG reflecting the promoted
function.

Differential Revision: https://reviews.llvm.org/D29580

llvm-svn: 294667

include/llvm/Transforms/IPO/ArgumentPromotion.h

@@ -0,0 +1,31 @@
+//===- ArgumentPromotion.h - Promote by-reference arguments -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_IPO_ARGUMENTPROMOTION_H
+#define LLVM_TRANSFORMS_IPO_ARGUMENTPROMOTION_H
+
+#include "llvm/Analysis/CGSCCPassManager.h"
+#include "llvm/Analysis/LazyCallGraph.h"
+
+namespace llvm {
+
+/// Argument promotion pass.
+///
+/// This pass walks the functions in each SCC and for each one tries to
+/// transform it and all of its callers to replace indirect arguments with
+/// direct (by-value) arguments.
+class ArgumentPromotionPass : public PassInfoMixin<ArgumentPromotionPass> {
+public:
+  PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
+                        LazyCallGraph &CG, CGSCCUpdateResult &UR);
+};
+
+}
+
+#endif

lib/Passes/PassBuilder.cpp

@@ -61,6 +61,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/GCOVProfiler.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
+#include "llvm/Transforms/IPO/ArgumentPromotion.h"
 #include "llvm/Transforms/IPO/ConstantMerge.h"
 #include "llvm/Transforms/IPO/CrossDSOCFI.h"
 #include "llvm/Transforms/IPO/DeadArgumentElimination.h"

lib/Passes/PassRegistry.def

@@ -85,6 +85,7 @@ CGSCC_ANALYSIS("fam-proxy", FunctionAnalysisManagerCGSCCProxy())
 #ifndef CGSCC_PASS
 #define CGSCC_PASS(NAME, CREATE_PASS)
 #endif
+CGSCC_PASS("argpromotion", ArgumentPromotionPass())
 CGSCC_PASS("invalidate<all>", InvalidateAllAnalysesPass())
 CGSCC_PASS("function-attrs", PostOrderFunctionAttrsPass())
 CGSCC_PASS("inline", InlinerPass())

lib/Transforms/IPO/ArgumentPromotion.cpp

@@ -29,7 +29,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Transforms/IPO/ArgumentPromotion.h"
 #include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Analysis/AliasAnalysis.h"
@@ -37,6 +39,7 @@
 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/Analysis/LazyCallGraph.h"
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/CFG.h"
@@ -67,9 +70,11 @@ typedef std::vector<uint64_t> IndicesVector;
 /// DoPromotion - This method actually performs the promotion of the specified
 /// arguments, and returns the new function.  At this point, we know that it's
 /// safe to do so.
-static CallGraphNode *
+static Function *
 doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
-            SmallPtrSetImpl<Argument *> &ByValArgsToTransform, CallGraph &CG) {
+            SmallPtrSetImpl<Argument *> &ByValArgsToTransform,
+            Optional<function_ref<void(CallSite OldCS, CallSite NewCS)>>
+                ReplaceCallSite) {
 
   // Start by computing a new prototype for the function, which is the same as
   // the old function, but has modified arguments.
@@ -207,9 +212,6 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
   F->getParent()->getFunctionList().insert(F->getIterator(), NF);
   NF->takeName(F);
 
-  // Get a new callgraph node for NF.
-  CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);
-
   // Loop over all of the callers of the function, transforming the call sites
   // to pass in the loaded pointers.
   //
@@ -334,8 +336,8 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
     AttributesVec.clear();
 
     // Update the callgraph to know that the callsite has been transformed.
-    CallGraphNode *CalleeNode = CG[Call->getParent()->getParent()];
-    CalleeNode->replaceCallEdge(CS, CallSite(New), NF_CGN);
+    if (ReplaceCallSite)
+      (*ReplaceCallSite)(CS, CallSite(New));
 
     if (!Call->use_empty()) {
       Call->replaceAllUsesWith(New);
@@ -463,18 +465,7 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
     std::advance(I2, ArgIndices.size());
   }
 
-  NF_CGN->stealCalledFunctionsFrom(CG[F]);
-
-  // Now that the old function is dead, delete it.  If there is a dangling
-  // reference to the CallgraphNode, just leave the dead function around for
-  // someone else to nuke.
-  CallGraphNode *CGN = CG[F];
-  if (CGN->getNumReferences() == 0)
-    delete CG.removeFunctionFromModule(CGN);
-  else
-    F->setLinkage(Function::ExternalLinkage);
-
-  return NF_CGN;
+  return NF;
 }
 
 /// AllCallersPassInValidPointerForArgument - Return true if we can prove that
@@ -818,14 +809,13 @@ static bool canPaddingBeAccessed(Argument *arg) {
 /// example, all callers are direct).  If safe to promote some arguments, it
 /// calls the DoPromotion method.
 ///
-static CallGraphNode *
-promoteArguments(CallGraphNode *CGN, CallGraph &CG,
-                 function_ref<AAResults &(Function &F)> AARGetter,
-                 unsigned MaxElements) {
-  Function *F = CGN->getFunction();
-
+static Function *
+promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter,
+                 unsigned MaxElements,
+                 Optional<function_ref<void(CallSite OldCS, CallSite NewCS)>>
+                     ReplaceCallSite) {
   // Make sure that it is local to this module.
-  if (!F || !F->hasLocalLinkage())
+  if (!F->hasLocalLinkage())
     return nullptr;
 
   // Don't promote arguments for variadic functions. Adding, removing, or
@@ -950,7 +940,52 @@ promoteArguments(CallGraphNode *CGN, CallGraph &CG,
   if (ArgsToPromote.empty() && ByValArgsToTransform.empty())
     return nullptr;
 
-  return doPromotion(F, ArgsToPromote, ByValArgsToTransform, CG);
+  return doPromotion(F, ArgsToPromote, ByValArgsToTransform, ReplaceCallSite);
+}
+
+PreservedAnalyses ArgumentPromotionPass::run(LazyCallGraph::SCC &C,
+                                             CGSCCAnalysisManager &AM,
+                                             LazyCallGraph &CG,
+                                             CGSCCUpdateResult &UR) {
+  bool Changed = false, LocalChange;
+
+  // Iterate until we stop promoting from this SCC.
+  do {
+    LocalChange = false;
+
+    for (LazyCallGraph::Node &N : C) {
+      Function &OldF = N.getFunction();
+
+      FunctionAnalysisManager &FAM =
+          AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager();
+      // FIXME: This lambda must only be used with this function. We should
+      // skip the lambda and just get the AA results directly.
+      auto AARGetter = [&](Function &F) -> AAResults & {
+        assert(&F == &OldF && "Called with an unexpected function!");
+        return FAM.getResult<AAManager>(F);
+      };
+
+      Function *NewF = promoteArguments(&OldF, AARGetter, 3u, None);
+      if (!NewF)
+        continue;
+      LocalChange = true;
+
+      // Directly substitute the functions in the call graph. Note that this
+      // requires the old function to be completely dead and completely
+      // replaced by the new function. It does no call graph updates, it merely
+      // swaps out the particular function mapped to a particular node in the
+      // graph.
+      C.getOuterRefSCC().replaceNodeFunction(N, *NewF);
+      OldF.eraseFromParent();
+    }
+
+    Changed |= LocalChange;
+  } while (LocalChange);
+
+  if (!Changed)
+    return PreservedAnalyses::all();
+
+  return PreservedAnalyses::none();
 }
 
 namespace {
@@ -1010,9 +1045,31 @@ bool ArgPromotion::runOnSCC(CallGraphSCC &SCC) {
     LocalChange = false;
     // Attempt to promote arguments from all functions in this SCC.
     for (CallGraphNode *OldNode : SCC) {
-      if (CallGraphNode *NewNode =
-              promoteArguments(OldNode, CG, AARGetter, MaxElements)) {
+      Function *OldF = OldNode->getFunction();
+      if (!OldF)
+        continue;
+
+      auto ReplaceCallSite = [&](CallSite OldCS, CallSite NewCS) {
+        Function *Caller = OldCS.getInstruction()->getParent()->getParent();
+        CallGraphNode *NewCalleeNode =
+            CG.getOrInsertFunction(NewCS.getCalledFunction());
+        CallGraphNode *CallerNode = CG[Caller];
+        CallerNode->replaceCallEdge(OldCS, NewCS, NewCalleeNode);
+      };
+
+      if (Function *NewF = promoteArguments(OldF, AARGetter, MaxElements,
+                                            {ReplaceCallSite})) {
         LocalChange = true;
+
+        // Update the call graph for the newly promoted function.
+        CallGraphNode *NewNode = CG.getOrInsertFunction(NewF);
+        NewNode->stealCalledFunctionsFrom(OldNode);
+        if (OldNode->getNumReferences() == 0)
+          delete CG.removeFunctionFromModule(OldNode);
+        else
+          OldF->setLinkage(Function::ExternalLinkage);
+
+        // And updat ethe SCC we're iterating as well.
         SCC.ReplaceNode(OldNode, NewNode);
       }
     }

test/Transforms/ArgumentPromotion/aggregate-promote.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 %T = type { i32, i32, i32, i32 }
 @G = constant %T { i32 0, i32 0, i32 17, i32 25 }

test/Transforms/ArgumentPromotion/attrs.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 %struct.ss = type { i32, i64 }
 

test/Transforms/ArgumentPromotion/byval-2.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 ; Arg promotion eliminates the struct argument.
 ; FIXME: Should it eliminate the i32* argument?

test/Transforms/ArgumentPromotion/byval.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
 

test/Transforms/ArgumentPromotion/chained.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 @G1 = constant i32 0
 @G2 = constant i32* @G1

test/Transforms/ArgumentPromotion/control-flow.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 ; Don't promote around control flow.
 define internal i32 @callee(i1 %C, i32* %P) {

test/Transforms/ArgumentPromotion/control-flow2.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 ; CHECK: load i32, i32* %A
 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

test/Transforms/ArgumentPromotion/crash.ll

@@ -1,4 +1,5 @@
 ; RUN: opt -S < %s -inline -argpromotion | FileCheck %s
+; RUN: opt -S < %s -passes=inline,argpromotion | FileCheck %s
 
 %S = type { %S* }
 

test/Transforms/ArgumentPromotion/dbg.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 declare void @sink(i32)
 

test/Transforms/ArgumentPromotion/fp80.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"

test/Transforms/ArgumentPromotion/inalloca.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %s -argpromotion -sroa -S | FileCheck %s
+; RUN: opt %s -passes='argpromotion,function(sroa)' -S | FileCheck %s
 
 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
 

test/Transforms/ArgumentPromotion/pr27568.ll

@@ -1,4 +1,5 @@
 ; RUN: opt -S -argpromotion < %s | FileCheck %s
+; RUN: opt -S -passes=argpromotion < %s | FileCheck %s
 target triple = "x86_64-pc-windows-msvc"
 
 define internal void @callee(i8*) {

test/Transforms/ArgumentPromotion/reserve-tbaa.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 ; PR17906
 ; When we promote two arguments in a single function with different types,

test/Transforms/ArgumentPromotion/sret.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-pc-windows-msvc"

test/Transforms/ArgumentPromotion/tail.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %s -argpromotion -S -o - | FileCheck %s
+; RUN: opt %s -passes=argpromotion -S -o - | FileCheck %s
 ; PR14710
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

test/Transforms/ArgumentPromotion/variadic.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -argpromotion -S | FileCheck %s
+; RUN: opt < %s -passes=argpromotion -S | FileCheck %s
 
 ; Unused arguments from variadic functions cannot be eliminated as that changes
 ; their classiciation according to the SysV amd64 ABI. Clang and other frontends