Use isFunctionHotInCallGraph to set the function section prefix.

Summary: The current prefix based function layout algorithm only looks at function's entry count, which is not sufficient. A function should be grouped together if its entry count or any call edge count is hot.

Reviewers: davidxl, eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31225

llvm-svn: 298656

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/test/Transforms/CodeGenPrepare/section.ll b/llvm/test/Transforms/CodeGenPrepare/section.ll
index 795c45c220d..2c96612e1ba 100644
--- a/llvm/test/Transforms/CodeGenPrepare/section.ll
+++ b/llvm/test/Transforms/CodeGenPrepare/section.ll
@@ -5,12 +5,32 @@ target triple = "x86_64-pc-linux-gnu"
 ; This tests that hot/cold functions get correct section prefix assigned
 
 ; CHECK: hot_func{{.*}}!section_prefix ![[HOT_ID:[0-9]+]]
+; The entry is hot
 define void @hot_func() !prof !15 {
   ret void
 }
 
+; CHECK: hot_call_func{{.*}}!section_prefix ![[HOT_ID]]
+; The sum of 2 callsites are hot
+define void @hot_call_func() !prof !16 {
+  call void @hot_func(), !prof !17
+  call void @hot_func(), !prof !17
+  ret void
+}
+
+; CHECK-NOT: normal_func{{.*}}!section_prefix
+; The sum of all callsites are neither hot or cold
+define void @normal_func() !prof !16 {
+  call void @hot_func(), !prof !17
+  call void @hot_func(), !prof !18
+  call void @hot_func(), !prof !18
+  ret void
+}
+
 ; CHECK: cold_func{{.*}}!section_prefix ![[COLD_ID:[0-9]+]]
+; The entry and the callsite are both cold
 define void @cold_func() !prof !16 {
+  call void @hot_func(), !prof !18
   ret void
 }
 
@@ -33,3 +53,5 @@ define void @cold_func() !prof !16 {
 !14 = !{i32 999999, i64 1, i32 2}
 !15 = !{!"function_entry_count", i64 1000}
 !16 = !{!"function_entry_count", i64 1}
+!17 = !{!"branch_weights", i32 80}
+!18 = !{!"branch_weights", i32 1}