Files
clang-p2996/llvm/test/Transforms/Inline/inline-cold-callee.ll
Easwaran Raman 12585b0148 Improve PGO support for the new inliner
This adds the following to the new PM based inliner in PGO mode:

* Use block frequency analysis to derive callsite's profile count and use
that to adjust thresholds of hot and cold callsites.

* Incrementally update the BFI of the caller after a callee gets inlined
into it. This incremental update is only within an invocation of the run
method - BFI is not preserved across calls to run.
Update the function entry count of the callee after inlining it into a
caller.

* I've tuned the thresholds for the hot and cold callsites using a hacked
up version of the old inliner that explicitly computes BFI on a set of
internal benchmarks and spec. Once the new PM based pipeline stabilizes
(IIRC Chandler mentioned there are known issues) I'll benchmark this
again and adjust the thresholds if required.
Inliner PGO support.

Differential revision: https://reviews.llvm.org/D28331

llvm-svn: 292666
2017-01-20 22:44:04 +00:00

55 lines
1.5 KiB
LLVM

; RUN: opt < %s -inline -inlinecold-threshold=0 -S | FileCheck %s
; This tests that a cold callee gets the (lower) inlinecold-threshold even without
; Cold hint and does not get inlined because the cost exceeds the inlinecold-threshold.
; A callee with identical body does gets inlined because cost fits within the
; inline-threshold
define i32 @callee1(i32 %x) !prof !21 {
%x1 = add i32 %x, 1
%x2 = add i32 %x1, 1
%x3 = add i32 %x2, 1
call void @extern()
ret i32 %x3
}
define i32 @callee2(i32 %x) !prof !22 {
; CHECK-LABEL: @callee2(
%x1 = add i32 %x, 1
%x2 = add i32 %x1, 1
%x3 = add i32 %x2, 1
call void @extern()
ret i32 %x3
}
define i32 @caller2(i32 %y1) !prof !22 {
; CHECK-LABEL: @caller2(
; CHECK: call i32 @callee2
; CHECK-NOT: call i32 @callee1
; CHECK: ret i32 %x3.i
%y2 = call i32 @callee2(i32 %y1)
%y3 = call i32 @callee1(i32 %y2)
ret i32 %y3
}
declare void @extern()
!llvm.module.flags = !{!1}
!21 = !{!"function_entry_count", i64 100}
!22 = !{!"function_entry_count", i64 1}
!1 = !{i32 1, !"ProfileSummary", !2}
!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
!3 = !{!"ProfileFormat", !"InstrProf"}
!4 = !{!"TotalCount", i64 10000}
!5 = !{!"MaxCount", i64 1000}
!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}