forked from OSchip/llvm-project
[PGO] Do not create block count annotations when all weights are 0,
avoiding an assertion. A BB with a nonzero count, whose successor blocks all have 0 counts, could cause an assertion. Don't create any branch weights in this case. Reviewed By: xur Differential Revision: https://reviews.llvm.org/D134203
This commit is contained in:
parent
1532be98f9
commit
b43a1d1bd9
|
@ -1689,7 +1689,21 @@ void PGOUseFunc::setBranchWeights() {
|
|||
MaxCount = EdgeCount;
|
||||
EdgeCounts[SuccNum] = EdgeCount;
|
||||
}
|
||||
|
||||
if (MaxCount)
|
||||
setProfMetadata(M, TI, EdgeCounts, MaxCount);
|
||||
else {
|
||||
// A zero MaxCount can come about when we have a BB with a positive
|
||||
// count, and whose successor blocks all have 0 count. This can happen
|
||||
// when there is no exit block and the code exits via a noreturn function.
|
||||
auto &Ctx = M->getContext();
|
||||
Ctx.diagnose(DiagnosticInfoPGOProfile(
|
||||
M->getName().data(),
|
||||
Twine("Profile in ") + F.getName().str() +
|
||||
Twine(" partially ignored") +
|
||||
Twine(", possibly due to the lack of a return path."),
|
||||
DS_Warning));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
@ -440,6 +440,7 @@ bool MemOPSizeOpt::perform(MemOp MO) {
|
|||
DTU.applyUpdates(Updates);
|
||||
Updates.clear();
|
||||
|
||||
if (MaxCount)
|
||||
setProfMetadata(Func.getParent(), SI, CaseCounts, MaxCount);
|
||||
|
||||
LLVM_DEBUG(dbgs() << *BB << "\n");
|
||||
|
|
|
@ -0,0 +1,11 @@
|
|||
# IR level Instrumentation Flag
|
||||
:ir
|
||||
foo
|
||||
# Func Hash:
|
||||
146835645050580305
|
||||
# Num Counters:
|
||||
3
|
||||
# Counter Values:
|
||||
0
|
||||
1
|
||||
0
|
|
@ -0,0 +1,47 @@
|
|||
; Make sure a profile that is generated from a function without an exit node
|
||||
; does not cause an assertion. The profile consists of a non-zero count in a
|
||||
; basic block and 0 counts in all succcessor blocks. Expect a warning.
|
||||
|
||||
; RUN: llvm-profdata merge %S/Inputs/maxcountzero.proftext -o %t.profdata
|
||||
; RUN: opt < %s -passes=pgo-instr-use -pgo-instrument-entry=false -pgo-test-profile-file=%t.profdata -S 2>&1 | FileCheck %s
|
||||
|
||||
define void @bar(i32 noundef %s) {
|
||||
entry:
|
||||
%cmp = icmp sgt i32 %s, 20
|
||||
br i1 %cmp, label %if.then, label %if.end
|
||||
|
||||
if.then:
|
||||
call void @exit(i32 noundef 1)
|
||||
unreachable
|
||||
|
||||
if.end:
|
||||
ret void
|
||||
}
|
||||
|
||||
declare void @exit(i32 noundef)
|
||||
|
||||
define void @foo(i32 noundef %n) {
|
||||
entry:
|
||||
%sum = alloca i32, align 4
|
||||
store volatile i32 %n, ptr %sum, align 4
|
||||
%sum.0.sum.0. = load volatile i32, ptr %sum, align 4
|
||||
call void @bar(i32 noundef %sum.0.sum.0.)
|
||||
%cmp = icmp slt i32 %n, 10
|
||||
br i1 %cmp, label %if.then, label %if.end
|
||||
|
||||
if.then:
|
||||
%sum.0.sum.0.1 = load volatile i32, ptr %sum, align 4
|
||||
call void @bar(i32 noundef %sum.0.sum.0.1)
|
||||
br label %if.end
|
||||
|
||||
if.end:
|
||||
br label %for.cond
|
||||
|
||||
for.cond:
|
||||
%sum.0.sum.0.2 = load volatile i32, ptr %sum, align 4
|
||||
call void @bar(i32 noundef %sum.0.sum.0.2)
|
||||
br label %for.cond
|
||||
}
|
||||
|
||||
; CHECK: warning:{{.*}}Profile in foo partially ignored
|
||||
; CHECK: define
|
Loading…
Reference in New Issue