[AlwaysInliner] Respect noinline call site attribute

[xbolva00]

Summary

always_inline foo() { }

bar () {

noinline foo();
}

We should prefer call site attribute over attribute on decl. This is fix for AlwaysInliner, similar fix is needed for normal Inliner (follow up).

Related to https://reviews.llvm.org/D119061

[xbolva00]

Added one more test for noinline / alwaysinline combo.

llvm/lib/Transforms/IPO/AlwaysInliner.cpp

-//===- InlineAlways.cpp - Code to inline always_inline functions ----------===//
+//===- AlwaysInliner.cpp - Code to inline always_inline functions ----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements a custom inliner that handles only functions that
for (Function &F : M) {
     if (F.isPresplitCoroutine())
       continue;
 
     if (!F.isDeclaration() && isInlineViable(F).isSuccess()) {
       Calls.clear();
 
       for (User *U : F.users())
         if (auto *CB = dyn_cast<CallBase>(U))
-          if (CB->getCalledFunction() == &F &&
-              CB->hasFnAttr(Attribute::AlwaysInline))
+          if (CB->getCalledFunction() == &F) {
+            if (F.hasFnAttribute(Attribute::AlwaysInline)) {
+              // Avoid inlining if noinline call site attribute.
+              if (!CB->isNoInline())
+                Calls.insert(CB);
+            } else if (CB->hasFnAttr(Attribute::AlwaysInline)) {
+              // Ok, alwaysinline call site attribute.
               Calls.insert(CB);
+            }
+          }
 
       for (CallBase *CB : Calls) {
         Function *Caller = CB->getCaller();
         OptimizationRemarkEmitter ORE(Caller);
         auto OIC = shouldInline(
             *CB,
             [&](CallBase &CB) {
               return InlineCost::getAlways("always inline attribute");
InlineCost AlwaysInlinerLegacyPass::getInlineCost(CallBase &CB) {
 
   // FIXME: We shouldn't even get here for declarations.
   if (Callee->isDeclaration())
     return InlineCost::getNever("no definition");
 
   if (!CB.hasFnAttr(Attribute::AlwaysInline))
     return InlineCost::getNever("no alwaysinline attribute");
 
+  if (Callee->hasFnAttribute(Attribute::AlwaysInline) && CB.isNoInline())
+    return InlineCost::getNever("noinline call site attribute");
+
   auto IsViable = isInlineViable(*Callee);
   if (!IsViable.isSuccess())
     return InlineCost::getNever(IsViable.getFailureReason());
 
   return InlineCost::getAlways("always inliner");
 }

llvm/test/Transforms/Inline/always-inline.ll

; CHECK: define void @inner14
   ret void
 }
 
 define void @outer14() {
 ; CHECK: call void @inner14
   call void @inner14()
   ret void
 }
+
+define internal i32 @inner15() {
+; CHECK: @inner15(
+  ret i32 1
+}
+
+define i32 @outer15() {
+; CHECK-LABEL: @outer15(
+; CHECK: call
+
+   %r = call i32 @inner15() noinline
+   ret i32 %r
+}
+
+define internal i32 @inner16() alwaysinline {
+; CHECK: @inner16(
+  ret i32 1
+}
+
+define i32 @outer16() {
+; CHECK-LABEL: @outer16(
+; CHECK: call
+
+   %r = call i32 @inner16() noinline
+   ret i32 %r
+}
+
+define i32 @inner17() alwaysinline {
+; CHECK: @inner17(
+  ret i32 1
+}
+
+define i32 @outer17() {
+; CHECK-LABEL: @outer17(
+; CHECK: call
+
+   %r = call i32 @inner17() noinline
+   ret i32 %r
+}
+
+define i32 @inner18() noinline {
+; CHECK: @inner18(
+  ret i32 1
+}
+
+define i32 @outer18() {
+; CHECK-LABEL: @outer18(
+; CHECK-NOT: call
+; CHECK: ret
+
+   %r = call i32 @inner18() alwaysinline
+
+   ret i32 %r
+}