[llvm] [InlineCost] Disable cost-benefit when sample based PGO is used (PR #86626)

[Xiangyang Guo via llvm-commits]

https://github.com/helloguo created https://github.com/llvm/llvm-project/pull/86626

#66457 makes InlineCost to use cost-benefit by default, which causes 0.4-0.5% performance regression on multiple internal workloads. See discussions https://github.com/llvm/llvm-project/pull/66457. This pull request reverts it. 

>From c01f19cbdc09203e9da5e5f58622a0c7f0c42cf0 Mon Sep 17 00:00:00 2001
From: helloguo <helloguo at meta.com>
Date: Mon, 25 Mar 2024 22:03:41 -0700
Subject: [PATCH] Revert "Reland [InlineCost] Enable the cost benefit analysis
 for Sample PGO (#66457)"

This reverts commit 954979d681339c2f44e38e669d67b9183a5cf92d.
---
 llvm/lib/Analysis/InlineCost.cpp                      | 2 +-
 llvm/test/Transforms/SampleProfile/remarks-hotness.ll | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
index e55eaa55f8e947..c75460f44c1d9f 100644
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -800,7 +800,7 @@ class InlineCostCallAnalyzer final : public CallAnalyzer {
         return false;
     } else {
       // Otherwise, require instrumentation profile.
-      if (!(PSI->hasInstrumentationProfile() || PSI->hasSampleProfile()))
+      if (!PSI->hasInstrumentationProfile())
         return false;
     }
 
diff --git a/llvm/test/Transforms/SampleProfile/remarks-hotness.ll b/llvm/test/Transforms/SampleProfile/remarks-hotness.ll
index b90b21e9e3c582..36fb3c58181703 100644
--- a/llvm/test/Transforms/SampleProfile/remarks-hotness.ll
+++ b/llvm/test/Transforms/SampleProfile/remarks-hotness.ll
@@ -24,7 +24,7 @@
 
 ; YAML-PASS:      --- !Passed
 ; YAML-PASS-NEXT: Pass:            inline
-; YAML-PASS-NEXT: Name:            AlwaysInline
+; YAML-PASS-NEXT: Name:            Inlined
 ; YAML-PASS-NEXT: DebugLoc:        { File: remarks-hotness.cpp, Line: 10, Column: 10 }
 ; YAML-PASS-NEXT: Function:        _Z7caller1v
 ; YAML-PASS-NEXT: Hotness:         401
@@ -36,7 +36,7 @@
 ; YAML-MISS-NEXT: Function:        _Z7caller2v
 ; YAML-MISS-NEXT: Hotness:         2
 
-; CHECK-RPASS: '_Z7callee1v' inlined into '_Z7caller1v' with (cost=always): benefit over cost at callsite _Z7caller1v:1:10; (hotness: 401)
+; CHECK-RPASS: '_Z7callee1v' inlined into '_Z7caller1v' with (cost=-30, threshold=4500) at callsite _Z7caller1v:1:10; (hotness: 401)
 ; CHECK-RPASS-NOT: '_Z7callee2v' not inlined into '_Z7caller2v' because it should never be inlined (cost=never): noinline function attribute (hotness: 2)
 
 ; ModuleID = 'remarks-hotness.cpp'