[BPF][ProfCheck] Fix sink-min-max.ll

In bpf-check-and-opt-ir, llvm.umax and llvm.umin are lowered into
explicit comparisons/i1 bitwise operations involving select. Make sure
to mark the selects as having an explicitly unknown profile given we
cannot infer what is likely/unlikely to avoid profcheck failures.

Reviewers: yonghong-song, mtrofin, eddyz87

Pull Request: llvm/llvm-project#209682

Author: boomanaiden154

llvm/lib/Target/BPF/BPFCheckAndAdjustIR.cpp

@@ -31,6 +31,7 @@
 #include "llvm/IR/IntrinsicsBPF.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/ProfDataUtils.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
 #include "llvm/Pass.h"
@@ -293,6 +294,9 @@ static bool sinkMinMaxInBB(BasicBlock &BB,
       // x < max(a, b) -> x < a || x < b
       Replacement = Builder.CreateLogicalOr(LHS, RHS);
 
+    if (SelectInst *ReplacementInst = dyn_cast<SelectInst>(Replacement))
+      setExplicitlyUnknownBranchWeightsIfProfiled(*ReplacementInst, DEBUG_TYPE);
+
     ICmp->replaceAllUsesWith(Replacement);
 
     Instruction *ToRemove[] = {ICmp, Info.ZExt, Info.SExt, MinMax};

llvm/test/CodeGen/BPF/sink-min-max.ll

@@ -15,15 +15,15 @@
 ; @test10: check that umin belonging to the same loop is not touched
 ; @test11: check that nested loops are processed
 
-define i32 @test1(i64 %a, i64 %b, i64 %x) {
+define i32 @test1(i64 %a, i64 %b, i64 %x) !prof !0 {
 ; CHECK-LABEL: define i32 @test1(
-; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]], i64 [[X:%.*]]) {
+; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]], i64 [[X:%.*]]) !prof [[PROF0:![0-9]+]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    br label %[[LOOP:.*]]
 ; CHECK:       [[LOOP]]:
 ; CHECK-NEXT:    [[TMP0:%.*]] = icmp ult i64 [[X]], [[A]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 [[X]], [[B]]
-; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP0]], i1 [[TMP1]], i1 false
+; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP0]], i1 [[TMP1]], i1 false, !prof [[PROF1:![0-9]+]]
 ; CHECK-NEXT:    br i1 [[TMP2]], label %[[LOOP]], label %[[RET:.*]]
 ; CHECK:       [[RET]]:
 ; CHECK-NEXT:    ret i32 0
@@ -37,15 +37,15 @@ loop:
 ret: ret i32 0
 }
 
-define i32 @test2(i64 %a, i64 %b, i64 %x) {
+define i32 @test2(i64 %a, i64 %b, i64 %x) !prof !0 {
 ; CHECK-LABEL: define i32 @test2(
-; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]], i64 [[X:%.*]]) {
+; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]], i64 [[X:%.*]]) !prof [[PROF0]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    br label %[[LOOP:.*]]
 ; CHECK:       [[LOOP]]:
 ; CHECK-NEXT:    [[TMP0:%.*]] = icmp ult i64 [[X]], [[A]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 [[X]], [[B]]
-; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP0]], i1 true, i1 [[TMP1]]
+; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP0]], i1 true, i1 [[TMP1]], !prof [[PROF1]]
 ; CHECK-NEXT:    br i1 [[TMP2]], label %[[LOOP]], label %[[RET:.*]]
 ; CHECK:       [[RET]]:
 ; CHECK-NEXT:    ret i32 0
@@ -279,3 +279,9 @@ declare i32 @llvm.umin.i32(i32, i32)
 declare i32 @llvm.smin.i32(i32, i32)
 declare i32 @llvm.umax.i32(i32, i32)
 declare i32 @llvm.smax.i32(i32, i32)
+
+!0 = !{!"function_entry_count", i64 1000}
+;.
+; CHECK: [[PROF0]] = !{!"function_entry_count", i64 1000}
+; CHECK: [[PROF1]] = !{!"unknown", !"bpf-check-and-opt-ir"}
+;.

llvm/utils/profcheck-xfail.txt

@@ -1,5 +1,4 @@
 CodeGen/ARM/sjljeh-swifterror.ll
-CodeGen/BPF/sink-min-max.ll
 CodeGen/WinEH/wineh-comdat.ll
 CodeGen/WinEH/wineh-scope-statenumbering.ll
 CodeGen/WinEH/wineh-setjmp.ll