[PATCH] D63706: [InlineCost] Fix bug 42084: remember negative result when computing full inline cost

[Yevgeny Rouban via Phabricator via llvm-commits]

yrouban created this revision.
yrouban added reviewers: fedor.sergeev, xbolva00, chandlerc, haicheng, eraman.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.
yrouban set the repository for this revision to rG LLVM Github Monorepo.

This is a minimal fix for the bug https://bugs.llvm.org/show_bug.cgi?id=42084 extracted from the patch D63058 <https://reviews.llvm.org/D63058>.
The rest of D63058 <https://reviews.llvm.org/D63058> could be treated as a feature.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D63706

Files:
  llvm/lib/Analysis/InlineCost.cpp
  llvm/test/Transforms/Inline/inline_negative_result.ll


Index: llvm/test/Transforms/Inline/inline_negative_result.ll
===================================================================
--- llvm/test/Transforms/Inline/inline_negative_result.ll
+++ llvm/test/Transforms/Inline/inline_negative_result.ll
@@ -1,14 +1,17 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -inline -S | FileCheck %s
+; RUN: opt < %s -inline -S -inline-remark-attribute | FileCheck %s
+; RUN: opt < %s -inline -S -inline-remark-attribute --pass-remarks-missed=inline --pass-remarks-analysis=inline --pass-remarks=inline | FileCheck %s
+; RUN: opt < %s -inline -S -inline-remark-attribute -inline-cost-full=true | FileCheck %s
+; RUN: opt < %s -inline -S -inline-remark-attribute -inline-cost-full=false | FileCheck %s
 
 ; PR42084
+; The test checks that inline remarks do not change inline decisions.
 
 define internal fastcc void @func4() {
 ; CHECK-LABEL: @func4(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br label [[FOR_COND:%.*]]
 ; CHECK:       for.cond:
-; CHECK-NEXT:    tail call void (...) @g()
+; CHECK-NEXT:    tail call void (...) @g() [[INLINE_REMARK0:#[0-9]+]]
 ; CHECK-NEXT:    br label [[FOR_COND]]
 ;
 entry:
@@ -22,7 +25,7 @@
 define internal fastcc void @func3() {
 ; CHECK-LABEL: @func3(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    tail call fastcc void @func4()
+; CHECK-NEXT:    tail call fastcc void @func4() [[INLINE_REMARK1:#[0-9]+]]
 ; CHECK-NEXT:    unreachable
 ;
 entry:
@@ -33,7 +36,7 @@
 define internal fastcc void @func2() {
 ; CHECK-LABEL: @func2(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    tail call fastcc void @func3()
+; CHECK-NEXT:    tail call fastcc void @func3() [[INLINE_REMARK1:#[0-9]+]]
 ; CHECK-NEXT:    unreachable
 ;
 entry:
@@ -44,7 +47,7 @@
 define internal fastcc void @func1() {
 ; CHECK-LABEL: @func1(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    tail call fastcc void @func2()
+; CHECK-NEXT:    tail call fastcc void @func2() [[INLINE_REMARK1:#[0-9]+]]
 ; CHECK-NEXT:    unreachable
 ;
 entry:
@@ -55,7 +58,7 @@
 define i32 @main() {
 ; CHECK-LABEL: @main(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    tail call fastcc void @func1()
+; CHECK-NEXT:    tail call fastcc void @func1() [[INLINE_REMARK1:#[0-9]+]]
 ; CHECK-NEXT:    unreachable
 ;
 entry:
@@ -64,3 +67,6 @@
 }
 
 declare void @g(...)
+
+; CHECK: attributes [[INLINE_REMARK0]] = { "inline-remark"="unavailable definition" }
+; CHECK: attributes [[INLINE_REMARK1]] = { "inline-remark"="(cost=0, threshold=0)" }
Index: llvm/lib/Analysis/InlineCost.cpp
===================================================================
--- llvm/lib/Analysis/InlineCost.cpp
+++ llvm/lib/Analysis/InlineCost.cpp
@@ -1580,6 +1580,8 @@
 InlineResult
 CallAnalyzer::analyzeBlock(BasicBlock *BB,
                            SmallPtrSetImpl<const Value *> &EphValues) {
+  bool Result = true;
+
   for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
     // FIXME: Currently, the number of instructions in a function regardless of
     // our ability to simplify them during inline to constants or dead code,
@@ -1654,11 +1656,14 @@
 
     // Check if we've passed the maximum possible threshold so we don't spin in
     // huge basic blocks that will never inline.
-    if (Cost >= Threshold && !ComputeFullInlineCost)
-      return false;
+    if (Cost >= Threshold) {
+      Result = false;
+      if (!ComputeFullInlineCost)
+        break;
+    }
   }
 
-  return true;
+  return Result;
 }
 
 /// Compute the base pointer and cumulative constant offsets for V.


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