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[FunctionSpecialization] Fix profile count preserving logic #157939

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Merged
merged 5 commits into from
Sep 11, 2025
Merged

[FunctionSpecialization] Fix profile count preserving logic #157939

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7c4211f
[FunctionSpecialization] Fix profile count preserving logic
alanzhao1 Sep 10, 2025
146ff7f
undo accidental reverted change
alanzhao1 Sep 10, 2025
16fd512
make the test expectations more consistent
alanzhao1 Sep 10, 2025
5511d80
check second call to foo.specialized.2
alanzhao1 Sep 11, 2025
1b0914a
remove FunctionSpecialization from profcheck-xfail.txt
alanzhao1 Sep 11, 2025
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4 changes: 2 additions & 2 deletions llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -802,8 +802,8 @@ bool FunctionSpecializer::run() {
if (std::optional<llvm::Function::ProfileCount> MaybeOriginalCount =
S.F->getEntryCount()) {
uint64_t OriginalCount = MaybeOriginalCount->getCount();
if (OriginalCount >= CallCount) {
S.F->setEntryCount(OriginalCount - CallCount);
if (OriginalCount >= *Count) {
S.F->setEntryCount(OriginalCount - *Count);
} else {
// This should generally not happen as that would mean there are
// more computed calls to the function than what was recorded.
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23 changes: 14 additions & 9 deletions llvm/test/Transforms/FunctionSpecialization/profile-counts.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -13,23 +13,28 @@ entry:

; CHECK: if.then:
; CHECK: call i32 @foo.specialized.1(i32 %x, ptr @A)
; CHECK: call i32 @foo.specialized.2(i32 %y, ptr @B)
if.then:
%call = call i32 @foo(i32 %x, ptr @A)
%call1 = call i32 @foo(i32 %y, ptr @B)
%call2 = call i32 @foo(i32 %y, ptr @B)
%add = add i32 %call, %call1
%add1 = add i32 %add, %call2
br label %return

; CHECK: if.else:
; CHECK: call i32 @foo.specialized.2(i32 %y, ptr @B)
if.else:
%call1 = call i32 @foo(i32 %y, ptr @B)
%call3 = call i32 @foo(i32 %y, ptr @B)
br label %return

; CHECK: return:
; CHECK: %call2 = call i32 @foo(i32 %x, ptr %z)
; CHECK: call i32 @foo(i32 %x, ptr %z)
return:
%retval.0 = phi i32 [ %call, %if.then ], [ %call1, %if.else ]
%call2 = call i32 @foo(i32 %x, ptr %z);
%add = add i32 %retval.0, %call2
ret i32 %add
%retval.0 = phi i32 [ %add1, %if.then ], [ %call3, %if.else ]
%call4 = call i32 @foo(i32 %x, ptr %z);
%add2 = add i32 %retval.0, %call4
ret i32 %add2
}

; CHECK: define internal i32 @foo(i32 %x, ptr %b) !prof ![[FOO_UNSPEC_PROF:[0-9]]]
Expand All @@ -44,9 +49,9 @@ entry:

; CHECK: ![[BAR_PROF]] = !{!"function_entry_count", i64 1000}
; CHECK: ![[BRANCH_PROF]] = !{!"branch_weights", i32 1, i32 3}
; CHECK: ![[FOO_UNSPEC_PROF]] = !{!"function_entry_count", i64 234}
; CHECK: ![[FOO_UNSPEC_PROF]] = !{!"function_entry_count", i64 500}
; CHECK: ![[FOO_SPEC_1_PROF]] = !{!"function_entry_count", i64 250}
; CHECK: ![[FOO_SPEC_2_PROF]] = !{!"function_entry_count", i64 750}
; CHECK: ![[FOO_SPEC_2_PROF]] = !{!"function_entry_count", i64 1250}
!0 = !{!"function_entry_count", i64 1000}
!1 = !{!"branch_weights", i32 1, i32 3}
!2 = !{!"function_entry_count", i64 1234}
!2 = !{!"function_entry_count", i64 2000}