[clang] fe30370 - Reland "[AlwaysInliner] Enable call site inlining to make flatten attribute working again (#53360)"

[Dávid Bolvanský via cfe-commits]

Author: Dávid Bolvanský
Date: 2022-01-26T01:11:06+01:00
New Revision: fe30370b007e7efa1bd1f39a3189b27ae4e5fcbe

URL: https://github.com/llvm/llvm-project/commit/fe30370b007e7efa1bd1f39a3189b27ae4e5fcbe
DIFF: https://github.com/llvm/llvm-project/commit/fe30370b007e7efa1bd1f39a3189b27ae4e5fcbe.diff

LOG: Reland "[AlwaysInliner] Enable call site inlining to make flatten attribute working again (#53360)"

Added: 
    

Modified: 
    clang/test/CodeGen/flatten.c
    clang/test/CodeGenCXX/flatten.cpp
    llvm/lib/Transforms/IPO/AlwaysInliner.cpp
    llvm/test/Transforms/Inline/always-inline.ll

Removed: 
    


################################################################################
diff  --git a/clang/test/CodeGen/flatten.c b/clang/test/CodeGen/flatten.c
index 287d4f2a46b65..4e762223de486 100644
--- a/clang/test/CodeGen/flatten.c
+++ b/clang/test/CodeGen/flatten.c
@@ -1,9 +1,3 @@
-// UNSUPPORTED: experimental-new-pass-manager
-// Currently, 
diff erent code seems to be intentionally generated under the new
-// PM since we alwaysinline functions and not callsites under new PM.
-// Under new PM, f() will not be inlined from g() since f is not marked as
-// alwaysinline.
-
 // RUN: %clang_cc1 -triple=x86_64-linux-gnu %s -emit-llvm -o - | FileCheck %s
 
 void f(void) {}

diff  --git a/clang/test/CodeGenCXX/flatten.cpp b/clang/test/CodeGenCXX/flatten.cpp
index 7a6484591aaa0..e988d6d726dd7 100644
--- a/clang/test/CodeGenCXX/flatten.cpp
+++ b/clang/test/CodeGenCXX/flatten.cpp
@@ -1,7 +1,3 @@
-// UNSUPPORTED: experimental-new-pass-manager
-// See the comment for CodeGen/flatten.c on why this is unsupported with the new
-// PM.
-
 // RUN: %clang_cc1 -triple=x86_64-linux-gnu -std=c++11 %s -emit-llvm -o - | FileCheck %s
 
 void f(void) {}

diff  --git a/llvm/lib/Transforms/IPO/AlwaysInliner.cpp b/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
index 7acc9b266ad82..a6d9ce1033f3c 100644
--- a/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
+++ b/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
@@ -54,13 +54,13 @@ PreservedAnalyses AlwaysInlinerPass::run(Module &M,
     if (F.isPresplitCoroutine())
       continue;
 
-    if (!F.isDeclaration() && F.hasFnAttribute(Attribute::AlwaysInline) &&
-        isInlineViable(F).isSuccess()) {
+    if (!F.isDeclaration() && isInlineViable(F).isSuccess()) {
       Calls.clear();
 
       for (User *U : F.users())
         if (auto *CB = dyn_cast<CallBase>(U))
-          if (CB->getCalledFunction() == &F)
+          if (CB->getCalledFunction() == &F &&
+              CB->hasFnAttr(Attribute::AlwaysInline))
             Calls.insert(CB);
 
       for (CallBase *CB : Calls) {
@@ -92,10 +92,12 @@ PreservedAnalyses AlwaysInlinerPass::run(Module &M,
         Changed = true;
       }
 
-      // Remember to try and delete this function afterward. This both avoids
-      // re-walking the rest of the module and avoids dealing with any iterator
-      // invalidation issues while deleting functions.
-      InlinedFunctions.push_back(&F);
+      if (F.hasFnAttribute(Attribute::AlwaysInline)) {
+        // Remember to try and delete this function afterward. This both avoids
+        // re-walking the rest of the module and avoids dealing with any
+        // iterator invalidation issues while deleting functions.
+        InlinedFunctions.push_back(&F);
+      }
     }
   }
 

diff  --git a/llvm/test/Transforms/Inline/always-inline.ll b/llvm/test/Transforms/Inline/always-inline.ll
index 0fcf956199c46..f947bdbd87347 100644
--- a/llvm/test/Transforms/Inline/always-inline.ll
+++ b/llvm/test/Transforms/Inline/always-inline.ll
@@ -1,14 +1,11 @@
-; RUN: opt < %s -inline-threshold=0 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CALL
+; RUN: opt < %s -inline-threshold=0 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK
 ;
 ; Ensure the threshold has no impact on these decisions.
-; RUN: opt < %s -inline-threshold=20000000 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CALL
-; RUN: opt < %s -inline-threshold=-20000000 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CALL
+; RUN: opt < %s -inline-threshold=20000000 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK
+; RUN: opt < %s -inline-threshold=-20000000 -always-inline -enable-new-pm=0 -S | FileCheck %s --check-prefix=CHECK
 ;
 ; The new pass manager doesn't re-use any threshold based infrastructure for
-; the always inliner, but test that we get the correct result. The new PM
-; always inliner also doesn't support inlining call-site alwaysinline
-; annotations. It isn't clear that this is a reasonable use case for
-; 'alwaysinline'.
+; the always inliner, but test that we get the correct result.
 ; RUN: opt < %s -inline-threshold=0 -passes=always-inline -S | FileCheck %s --check-prefix=CHECK
 ; RUN: opt < %s -inline-threshold=20000000 -passes=always-inline -S | FileCheck %s --check-prefix=CHECK
 ; RUN: opt < %s -inline-threshold=-20000000 -passes=always-inline -S | FileCheck %s --check-prefix=CHECK
@@ -146,10 +143,9 @@ define i32 @inner7() {
   ret i32 1
 }
 define i32 @outer7() {
-; CHECK-CALL-LABEL: @outer7(
-; CHECK-CALL-NOT: call
-; CHECK-CALL: ret
-
+; CHECK-LABEL: @outer7(
+; CHECK-NOT: call
+; CHECK: ret
    %r = call i32 @inner7() alwaysinline
    ret i32 %r
 }