From 7b29966a9334623b8ffebb1e6332408c9c07d6b5 Mon Sep 17 00:00:00 2001
From: Teresa Johnson <tejohnson@google.com>
Date: Thu, 11 May 2017 23:18:05 +0000
Subject: Restrict call metadata based hotness detection to Sample PGO mode

Summary:
Don't use the metadata on call instructions for determining hotness
unless we are in sample PGO mode, where it is needed because profile
counts are not accurate. In instrumentation mode this is not necessary
and does more harm than good when calls have VP metadata that hasn't
been properly scaled after transformations or dropped after constant
prop based devirtualization (both should be fixed, but we don't need
to do this in the first place for instrumentation PGO).

This required adjusting a number of tests to distinguish between sample
and instrumentation PGO handling, and to add in profile summary metadata
so that getProfileCount can get the summary.

Reviewers: davidxl, danielcdh

Subscribers: aemerson, rengolin, mehdi_amini, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D32877

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302844 91177308-0d34-0410-b5e6-96231b3b80d8
---
 ...o-function-summary-callgraph-profile-summary.ll |   2 +-
 ...ion-summary-callgraph-sample-profile-summary.ll | 121 +++++++++++++++++++++
 2 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100644 test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll

(limited to 'test/Bitcode')

diff --git a/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll b/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
index 982bb5cb7e5..b64d5bd52bf 100644
--- a/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
+++ b/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
@@ -29,7 +29,7 @@
 ; CHECK-NEXT:    <VERSION
 ; CHECK-NEXT:    <VALUE_GUID op0=25 op1=123/>
 ; op4=hot1 op6=cold op8=hot2 op10=hot4 op12=none1 op14=hot3 op16=none2 op18=none3 op20=123
-; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op4=1 op5=3 op6=5 op7=1 op8=2 op9=3 op10=4 op11=3 op12=6 op13=2 op14=3 op15=3 op16=7 op17=2 op18=8 op19=2 op20=25 op21=3/>
+; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op4=1 op5=3 op6=5 op7=1 op8=2 op9=3 op10=4 op11=1 op12=6 op13=2 op14=3 op15=3 op16=7 op17=2 op18=8 op19=2 op20=25 op21=3/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; CHECK: <STRTAB_BLOCK
diff --git a/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll b/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll
new file mode 100644
index 00000000000..875f397646a
--- /dev/null
+++ b/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll
@@ -0,0 +1,121 @@
+; Test to check the callgraph in summary when there is PGO
+; RUN: opt -module-summary %s -o %t.o
+; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
+; RUN: opt -module-summary %p/Inputs/thinlto-function-summary-callgraph-profile-summary.ll -o %t2.o
+; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
+; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
+
+
+; CHECK: <SOURCE_FILENAME
+; "hot_function"
+; CHECK-NEXT: <FUNCTION op0=0 op1=12
+; "hot1"
+; CHECK-NEXT: <FUNCTION op0=12 op1=4
+; "hot2"
+; CHECK-NEXT: <FUNCTION op0=16 op1=4
+; "hot3"
+; CHECK-NEXT: <FUNCTION op0=20 op1=4
+; "hot4"
+; CHECK-NEXT: <FUNCTION op0=24 op1=4
+; "cold"
+; CHECK-NEXT: <FUNCTION op0=28 op1=4
+; "none1"
+; CHECK-NEXT: <FUNCTION op0=32 op1=5
+; "none2"
+; CHECK-NEXT: <FUNCTION op0=37 op1=5
+; "none3"
+; CHECK-NEXT: <FUNCTION op0=42 op1=5
+; CHECK-LABEL:       <GLOBALVAL_SUMMARY_BLOCK
+; CHECK-NEXT:    <VERSION
+; CHECK-NEXT:    <VALUE_GUID op0=25 op1=123/>
+; op4=hot1 op6=cold op8=hot2 op10=hot4 op12=none1 op14=hot3 op16=none2 op18=none3 op20=123
+; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op4=1 op5=3 op6=5 op7=1 op8=2 op9=3 op10=4 op11=3 op12=6 op13=2 op14=3 op15=3 op16=7 op17=2 op18=8 op19=2 op20=25 op21=3/>
+; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+
+; CHECK: <STRTAB_BLOCK
+; CHECK-NEXT: blob data = 'hot_functionhot1hot2hot3hot4coldnone1none2none3'
+
+; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <VERSION
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <VALUE_GUID
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <COMBINED_PROFILE {{.*}} op5=[[HOT1:.*]] op6=3 op7=[[COLD:.*]] op8=1 op9=[[HOT2:.*]] op10=3 op11=[[NONE1:.*]] op12=2 op13=[[HOT3:.*]] op14=3 op15=[[NONE2:.*]] op16=2 op17=[[NONE3:.*]] op18=2/>
+; COMBINED_NEXT:    <COMBINED abbrevid=
+; COMBINED_NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+
+
+; ModuleID = 'thinlto-function-summary-callgraph.ll'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; This function have high profile count, so entry block is hot.
+define void @hot_function(i1 %a, i1 %a2) !prof !20 {
+entry:
+    call void @hot1()
+    br i1 %a, label %Cold, label %Hot, !prof !41
+Cold:           ; 1/1000 goes here
+  call void @cold()
+  call void @hot2()
+  call void @hot4(), !prof !15
+  call void @none1()
+  br label %exit
+Hot:            ; 999/1000 goes here
+  call void @hot2()
+  call void @hot3()
+  br i1 %a2, label %None1, label %None2, !prof !42
+None1:          ; half goes here
+  call void @none1()
+  call void @none2()
+  br label %exit
+None2:          ; half goes here
+  call void @none3()
+  br label %exit
+exit:
+  ret void
+}
+
+declare void @hot1() #1
+declare void @hot2() #1
+declare void @hot3() #1
+declare void @hot4() #1
+declare void @cold() #1
+declare void @none1() #1
+declare void @none2() #1
+declare void @none3() #1
+
+
+!41 = !{!"branch_weights", i32 1, i32 1000}
+!42 = !{!"branch_weights", i32 1, i32 1}
+
+
+
+!llvm.module.flags = !{!1}
+!20 = !{!"function_entry_count", i64 110, i64 123}
+
+!1 = !{i32 1, !"ProfileSummary", !2}
+!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
+!3 = !{!"ProfileFormat", !"SampleProfile"}
+!4 = !{!"TotalCount", i64 10000}
+!5 = !{!"MaxCount", i64 10}
+!6 = !{!"MaxInternalCount", i64 1}
+!7 = !{!"MaxFunctionCount", i64 1000}
+!8 = !{!"NumCounts", i64 3}
+!9 = !{!"NumFunctions", i64 3}
+!10 = !{!"DetailedSummary", !11}
+!11 = !{!12, !13, !14}
+!12 = !{i32 10000, i64 100, i32 1}
+!13 = !{i32 999000, i64 100, i32 1}
+!14 = !{i32 999999, i64 1, i32 2}
+!15 = !{!"branch_weights", i32 100}
-- 
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