diff options
Diffstat (limited to 'llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll')
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll | 66 |
1 files changed, 56 insertions, 10 deletions
diff --git a/llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll b/llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll index 611ee5f..02f5bf9 100644 --- a/llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll +++ b/llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll @@ -3,14 +3,27 @@ @known_constant = internal unnamed_addr constant [9 x i32] [i32 0, i32 -1, i32 0, i32 -1, i32 5, i32 -1, i32 0, i32 -1, i32 0], align 16 ; CHECK-LABEL: @bar_prof -; CHECK: loop: -; CHECK: %mul = mul -; CHECK: %mul.1 = mul -; CHECK: %mul.2 = mul -; CHECK: %mul.3 = mul -; CHECK: br i1 %niter.ncmp.7, label %loop.end.unr-lcssa, label %loop, !prof [[PROF0:![0-9]+]] -; CHECK: loop.epil: -; CHECK: br i1 %epil.iter.cmp, label %loop.epil, label %loop.end.epilog-lcssa, !prof [[PROF1:![0-9]+]], !llvm.loop {{![0-9]+}} +; CHECK: entry: +; CHECK: br i1 %{{.*}}, label %[[LOOP_EPIL_PREHEADER:.*]], label %[[ENTRY_NEW:.*]], !prof ![[#PROF_UR_GUARD:]] +; CHECK: [[ENTRY_NEW]]: +; CHECK: br label %loop +; CHECK: loop: +; CHECK: %mul = mul +; CHECK: %mul.1 = mul +; CHECK: %mul.2 = mul +; CHECK: %mul.3 = mul +; CHECK: %mul.4 = mul +; CHECK: %mul.5 = mul +; CHECK: %mul.6 = mul +; CHECK: %mul.7 = mul +; CHECK-NOT: %mul.8 = mul +; CHECK: br i1 %{{.*}}, label %[[LOOP_END_UNR_LCSSA:.*]], label %loop, !prof ![[#PROF_UR_LATCH:]], !llvm.loop ![[#LOOP_UR_LATCH:]] +; CHECK: [[LOOP_END_UNR_LCSSA]]: +; CHECK: br i1 %{{.*}}, label %[[LOOP_EPIL_PREHEADER]], label %loop.end, !prof ![[#PROF_RM_GUARD:]] +; CHECK: [[LOOP_EPIL_PREHEADER]]: +; CHECK: br label %[[LOOP_EPIL:.*]] +; CHECK: [[LOOP_EPIL]]: +; CHECK: br i1 %{{.*}}, label %[[LOOP_EPIL]], label %[[LOOP_END_EPILOG_LCSSA:.*]], !prof ![[#PROF_RM_LATCH:]], !llvm.loop ![[#LOOP_RM_LATCH:]] define i32 @bar_prof(ptr noalias nocapture readonly %src, i64 %c) !prof !1 { entry: br label %loop @@ -60,5 +73,38 @@ loop.end: !1 = !{!"function_entry_count", i64 1} !2 = !{!"branch_weights", i32 1, i32 1000} -; CHECK: [[PROF0]] = !{!"branch_weights", i32 1, i32 124} -; CHECK: [[PROF1]] = !{!"branch_weights", i32 3, i32 1} +; Original loop probability: p = 1000/(1+1000) = 0.999000999 +; Original estimated trip count: (1+1000)/1 = 1001 +; Unroll count: 8 + +; Probability of >=7 iterations after first: p^7 = 0.993027916 =~ +; 2132511214 / (14972434 + 2132511214). +; CHECK: ![[#PROF_UR_GUARD]] = !{!"branch_weights", i32 14972434, i32 2132511214} + +; Probability of >=8 more iterations: p^8 = 0.99203588 =~ +; 2130380833 / (17102815 + 2130380833). +; CHECK: ![[#PROF_UR_LATCH]] = !{!"branch_weights", i32 17102815, i32 2130380833} + +; 1001//8 = 125 +; CHECK: ![[#LOOP_UR_LATCH]] = distinct !{![[#LOOP_UR_LATCH]], ![[#LOOP_UR_TC:]]} +; CHECK: ![[#LOOP_UR_TC]] = !{!"llvm.loop.estimated_trip_count", i32 125} + +; Probability of 1 to 7 more of 7 more remainder iterations: +; (p-p^8)/(1-p^8) = 0.874562282 =~ 1878108210 / (1878108210 + 269375438). +; CHECK: ![[#PROF_RM_GUARD]] = !{!"branch_weights", i32 1878108210, i32 269375438} + +; Frequency of first remainder iter: r1 = 1 +; Frequency of second remainder iter: r2 = r1*(p-p^7)/(1-p^7) = 0.856714143 +; Frequency of third remainder iter: r3 = r2*(p-p^6)/(1-p^6) = 0.713571429 +; Frequency of fourth remainder iter: r4 = r2*(p-p^5)/(1-p^5) = 0.570571715 +; Frequency of fifth remainder iter: r5 = r2*(p-p^4)/(1-p^4) = 0.427714858 +; Frequency of sixth remainder iter: r6 = r2*(p-p^3)/(1-p^3) = 0.285000715 +; Frequency of seventh remainder iter: r7 = r2*(p-p^2)/(1-p^2) = 0.142429143 +; Solve for loop probability that produces that frequency: f = 1/(1-p') => +; p' = 1-1/f = 1-1/(r1+r2+r3+r4+r5+r6+r7) = 0.749749875 =~ +; 1610075606 / (1610075606 + 537408042). +; CHECK: ![[#PROF_RM_LATCH]] = !{!"branch_weights", i32 1610075606, i32 537408042} + +; Remainder estimated trip count: 1001%8 = 1 +; CHECK: ![[#LOOP_RM_LATCH]] = distinct !{![[#LOOP_RM_LATCH]], ![[#LOOP_RM_TC:]], ![[#DISABLE:]]} +; CHECK: ![[#LOOP_RM_TC]] = !{!"llvm.loop.estimated_trip_count", i32 1} |