; ; Here all the branches we unswitch are exiting from the inner loop. ; That means we should not be getting exponential behavior on inner-loop ; unswitch. In fact there should be just a single version of inner-loop, ; with possibly some outer loop copies. ; ; There should be just a single copy of each loop when strictest mutiplier ; candidates formula (unscaled candidates == 0) is enforced: ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \ ; RUN: -passes='loop(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1 ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \ ; RUN: -passes='loop(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1 ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \ ; RUN: -passes='loop-mssa(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1 ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \ ; RUN: -passes='loop-mssa(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1 ; ; When we relax the candidates part of a multiplier formula ; (unscaled candidates == 2) we start getting some unswitches in outer loops, ; which leads to siblings multiplier kicking in. ; ; The tests below also run licm, because it is needed to hoist out ; loop-invariant freeze instructions, which otherwise may block further ; unswitching. ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=1 \ ; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \ ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV1 ; ; NB: sort -b is essential here and below, otherwise blanks might lead to different ; order depending on locale. ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \ ; RUN: -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=2 \ ; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \ ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV2 ; ; With disabled cost-multiplier we get maximal possible amount of unswitches. ; ; RUN: opt < %s -enable-unswitch-cost-multiplier=false \ ; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \ ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-MAX ; ; Single loop nest, not unswitched ; LOOP1: Loop at depth 1 containing: ; LOOP1-NOT: Loop at depth 1 containing: ; LOOP1: Loop at depth 2 containing: ; LOOP1-NOT: Loop at depth 2 containing: ; LOOP1: Loop at depth 3 containing: ; LOOP1-NOT: Loop at depth 3 containing: ; ; Half unswitched loop nests, with unscaled3 and div1 it gets less depth1 loops unswitched ; since they have more cost. ; LOOP-UNSCALE3-DIV1-COUNT-4: Loop at depth 1 containing: ; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 1 containing: ; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 2 containing: ; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 2 containing: ; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 3 containing: ; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 3 containing: ; ; Half unswitched loop nests, with unscaled3 and div2 it gets more depth1 loops unswitched ; as div2 kicks in. ; LOOP-UNSCALE3-DIV2-COUNT-6: Loop at depth 1 containing: ; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 1 containing: ; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 2 containing: ; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 2 containing: ; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 3 containing: ; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 3 containing: ; ; Maximally unswitched (copy of the outer loop per each condition) ; LOOP-MAX-COUNT-6: Loop at depth 1 containing: ; LOOP-MAX-NOT: Loop at depth 1 containing: ; LOOP-MAX-COUNT-1: Loop at depth 2 containing: ; LOOP-MAX-NOT: Loop at depth 2 containing: ; LOOP-MAX-COUNT-1: Loop at depth 3 containing: ; LOOP-MAX-NOT: Loop at depth 3 containing: declare void @bar() define void @loop_nested3_conds5(i32* %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) { entry: %addr1 = getelementptr i32, i32* %addr, i64 0 %addr2 = getelementptr i32, i32* %addr, i64 1 %addr3 = getelementptr i32, i32* %addr, i64 2 br label %outer outer: %iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch] %iv1.next = add i32 %iv1, 1 ;; skip nontrivial unswitch call void @bar() br label %middle middle: %iv2 = phi i32 [0, %outer], [%iv2.next, %middle_latch] %iv2.next = add i32 %iv2, 1 ;; skip nontrivial unswitch call void @bar() br label %loop loop: %iv3 = phi i32 [0, %middle], [%iv3.next, %loop_latch] %iv3.next = add i32 %iv3, 1 ;; skip nontrivial unswitch call void @bar() br i1 %c1, label %loop_next1_left, label %outer_latch loop_next1_left: br label %loop_next1 loop_next1_right: br label %loop_next1 loop_next1: br i1 %c2, label %loop_next2_left, label %outer_latch loop_next2_left: br label %loop_next2 loop_next2_right: br label %loop_next2 loop_next2: br i1 %c3, label %loop_next3_left, label %outer_latch loop_next3_left: br label %loop_next3 loop_next3_right: br label %loop_next3 loop_next3: br i1 %c4, label %loop_next4_left, label %outer_latch loop_next4_left: br label %loop_next4 loop_next4_right: br label %loop_next4 loop_next4: br i1 %c5, label %loop_latch_left, label %outer_latch loop_latch_left: br label %loop_latch loop_latch_right: br label %loop_latch loop_latch: store volatile i32 0, i32* %addr1 %test_loop = icmp slt i32 %iv3, 50 br i1 %test_loop, label %loop, label %middle_latch middle_latch: store volatile i32 0, i32* %addr2 %test_middle = icmp slt i32 %iv2, 50 br i1 %test_middle, label %middle, label %outer_latch outer_latch: store volatile i32 0, i32* %addr3 %test_outer = icmp slt i32 %iv1, 50 br i1 %test_outer, label %outer, label %exit exit: ret void }