shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

Add minimum count threshold for indirect call promotion (#145282)

Browse Source 
Allow users to set the minimum absolute count for indirect call promotion. This is primarily meant to be control indirect call promotion for synthetic vp metadata introduced in #141164 for use by MemProf.
This commit is contained in:
Snehasish Kumar 2025-06-26 12:10:59 -07:00 committed by GitHub
parent 4308292d1e
commit 70233c61d6
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 23 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
llvm/lib/Analysis/IndirectCallPromotionAnalysis.cpp
View File

@ -31,12 +31,18 @@ static cl::opt<unsigned> ICPRemainingPercentThreshold(
// The percent threshold for the direct-call target (this call site vs the
// total call count) for it to be considered as the promotion target.
static cl::opt<unsigned>
static cl::opt<uint64_t>
ICPTotalPercentThreshold("icp-total-percent-threshold", cl::init(5),
cl::Hidden,
cl::desc("The percentage threshold against total "
"count for the promotion"));
// Set the minimum absolute count threshold for indirect call promotion.
// Candidates with counts below this threshold will not be promoted.
static cl::opt<unsigned> ICPMinimumCountThreshold(
"icp-minimum-count-threshold", cl::init(0), cl::Hidden,
cl::desc("Minimum absolute count for promotion candidate"));
// Set the maximum number of targets to promote for a single indirect-call
// callsite.
static cl::opt<unsigned>
@ -51,7 +57,8 @@ cl::opt<unsigned> MaxNumVTableAnnotations(
bool ICallPromotionAnalysis::isPromotionProfitable(uint64_t Count,
uint64_t TotalCount,
uint64_t RemainingCount) {
return Count * 100 >= ICPRemainingPercentThreshold * RemainingCount &&
return Count >= ICPMinimumCountThreshold &&
Count * 100 >= ICPRemainingPercentThreshold * RemainingCount &&
Count * 100 >= ICPTotalPercentThreshold * TotalCount;
}

14
llvm/test/Transforms/PGOProfile/indirect_call_promotion.ll
View File

@ -1,6 +1,10 @@
; RUN: opt < %s -passes=pgo-icall-prom -S -icp-total-percent-threshold=50 | FileCheck %s --check-prefix=ICALL-PROM
; RUN: opt < %s -passes=pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-remaining-percent-threshold=0 -icp-total-percent-threshold=0 -icp-max-prom=4 2>&1 | FileCheck %s --check-prefix=PASS-REMARK
; RUN: opt < %s -passes=pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-remaining-percent-threshold=0 -icp-total-percent-threshold=20 -icp-max-prom=4 2>&1 | FileCheck %s --check-prefix=PASS2-REMARK
; Test minimum count threshold - should prevent func1 promotion (count 10 < threshold 15)
; RUN: opt < %s -passes=pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-minimum-count-threshold=15 -icp-remaining-percent-threshold=0 -icp-total-percent-threshold=0 -icp-max-prom=4 2>&1 | FileCheck %s --check-prefix=MIN-COUNT-15
; Test edge case - threshold exactly at count value
; RUN: opt < %s -passes=pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-minimum-count-threshold=10 -icp-remaining-percent-threshold=0 -icp-total-percent-threshold=0 -icp-max-prom=4 2>&1 | FileCheck %s --check-prefix=MIN-COUNT-10
; PASS-REMARK: remark: <unknown>:0:0: Promote indirect call to func4 with count 1030 out of 1600
; PASS-REMARK: remark: <unknown>:0:0: Promote indirect call to func2 with count 410 out of 570
@ -12,6 +16,16 @@
; PASS2-REMARK-NOT: remark: <unknown>:0:0: Promote indirect call to func3
; PASS2-REMARK-NOT: remark: <unknown>:0:0: Promote indirect call to func1
; MIN-COUNT-15: remark: <unknown>:0:0: Promote indirect call to func4 with count 1030 out of 1600
; MIN-COUNT-15: remark: <unknown>:0:0: Promote indirect call to func2 with count 410 out of 570
; MIN-COUNT-15: remark: <unknown>:0:0: Promote indirect call to func3 with count 150 out of 160
; MIN-COUNT-15-NOT: remark: <unknown>:0:0: Promote indirect call to func1
; MIN-COUNT-10: remark: <unknown>:0:0: Promote indirect call to func4 with count 1030 out of 1600
; MIN-COUNT-10: remark: <unknown>:0:0: Promote indirect call to func2 with count 410 out of 570
; MIN-COUNT-10: remark: <unknown>:0:0: Promote indirect call to func3 with count 150 out of 160
; MIN-COUNT-10: remark: <unknown>:0:0: Promote indirect call to func1 with count 10 out of 10
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"