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[SimpleLoopUnswitch] adding cost multiplier to cap exponential unswitch with
We need to control exponential behavior of loop-unswitch so we do not get run-away compilation. Suggested solution is to introduce a multiplier for an unswitch cost that makes cost prohibitive as soon as there are too many candidates and too many sibling loops (meaning we have already started duplicating loops by unswitching). It does solve the currently known problem with compile-time degradation (PR 39544). Tests are built on top of a recently implemented CHECK-COUNT-<num> FileCheck directives. Reviewed By: chandlerc, mkazantsev Differential Revision: https://reviews.llvm.org/D54223 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347097 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Fedor Sergeev
@@ -0,0 +1,139 @@
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;
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; There should be just a single copy of each loop when strictest mutiplier
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; candidates formula (unscaled candidates == 0) is enforced:
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
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;
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;
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; When we relax the candidates part of a multiplier formula
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; (unscaled candidates == 4) we start getting some unswitches,
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; which leads to siblings multiplier kicking in.
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=4 -unswitch-siblings-toplevel-div=1 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-UNSCALE4-DIV1
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;
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; NB: sort -b is essential here and below, otherwise blanks might lead to different
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; order depending on locale.
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=4 -unswitch-siblings-toplevel-div=2 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-UNSCALE4-DIV2
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;
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;
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; Get
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; 2^(num conds) == 2^5 = 32
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; loop nests when cost multiplier is disabled:
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=false \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP32
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;
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; Single loop nest, not unswitched
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; LOOP1: Loop at depth 1 containing:
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; LOOP1: Loop at depth 2 containing:
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; LOOP1: Loop at depth 3 containing:
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; LOOP1-NOT: Loop at depth {{[0-9]+}} containing:
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;
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; Half unswitched loop nests, with unscaled4 and div1 it gets less depth1 loops unswitched
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; since they have more cost.
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; LOOP-UNSCALE4-DIV1-COUNT-6: Loop at depth 1 containing:
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; LOOP-UNSCALE4-DIV1-COUNT-19: Loop at depth 2 containing:
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; LOOP-UNSCALE4-DIV1-COUNT-29: Loop at depth 3 containing:
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; LOOP-UNSCALE4-DIV1-NOT: Loop at depth {{[0-9]+}} containing:
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;
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; Half unswitched loop nests, with unscaled4 and div2 it gets more depth1 loops unswitched
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; as div2 kicks in.
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; LOOP-UNSCALE4-DIV2-COUNT-11: Loop at depth 1 containing:
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; LOOP-UNSCALE4-DIV2-COUNT-22: Loop at depth 2 containing:
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; LOOP-UNSCALE4-DIV2-COUNT-29: Loop at depth 3 containing:
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; LOOP-UNSCALE4-DIV2-NOT: Loop at depth {{[0-9]+}} containing:
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;
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; 32 loop nests, fully unswitched
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; LOOP32-COUNT-32: Loop at depth 1 containing:
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; LOOP32-COUNT-32: Loop at depth 2 containing:
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; LOOP32-COUNT-32: Loop at depth 3 containing:
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; LOOP32-NOT: Loop at depth {{[0-9]+}} containing:
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declare void @bar()
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define void @loop_nested3_conds5(i32* %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) {
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entry:
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%addr1 = getelementptr i32, i32* %addr, i64 0
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%addr2 = getelementptr i32, i32* %addr, i64 1
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%addr3 = getelementptr i32, i32* %addr, i64 2
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br label %outer
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outer:
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%iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch]
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%iv1.next = add i32 %iv1, 1
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;; skip nontrivial unswitch
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call void @bar()
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br label %middle
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middle:
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%iv2 = phi i32 [0, %outer], [%iv2.next, %middle_latch]
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%iv2.next = add i32 %iv2, 1
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;; skip nontrivial unswitch
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call void @bar()
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br label %loop
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loop:
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%iv3 = phi i32 [0, %middle], [%iv3.next, %loop_latch]
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%iv3.next = add i32 %iv3, 1
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;; skip nontrivial unswitch
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call void @bar()
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br i1 %c1, label %loop_next1_left, label %loop_next1_right
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loop_next1_left:
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br label %loop_next1
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loop_next1_right:
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br label %loop_next1
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loop_next1:
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br i1 %c2, label %loop_next2_left, label %loop_next2_right
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loop_next2_left:
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br label %loop_next2
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loop_next2_right:
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br label %loop_next2
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loop_next2:
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br i1 %c3, label %loop_next3_left, label %loop_next3_right
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loop_next3_left:
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br label %loop_next3
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loop_next3_right:
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br label %loop_next3
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loop_next3:
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br i1 %c4, label %loop_next4_left, label %loop_next4_right
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loop_next4_left:
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br label %loop_next4
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loop_next4_right:
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br label %loop_next4
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loop_next4:
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br i1 %c5, label %loop_latch_left, label %loop_latch_right
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loop_latch_left:
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br label %loop_latch
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loop_latch_right:
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br label %loop_latch
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loop_latch:
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store volatile i32 0, i32* %addr1
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%test_loop = icmp slt i32 %iv3, 50
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br i1 %test_loop, label %loop, label %middle_latch
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middle_latch:
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store volatile i32 0, i32* %addr2
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%test_middle = icmp slt i32 %iv2, 50
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br i1 %test_middle, label %middle, label %outer_latch
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outer_latch:
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store volatile i32 0, i32* %addr3
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%test_outer = icmp slt i32 %iv1, 50
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br i1 %test_outer, label %outer, label %exit
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exit:
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ret void
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}
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@@ -0,0 +1,149 @@
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;
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; Here all the branches we unswitch are exiting from the inner loop.
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; That means we should not be getting exponential behavior on inner-loop
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; unswitch. In fact there should be just a single version of inner-loop,
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; with possibly some outer loop copies.
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;
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; There should be just a single copy of each loop when strictest mutiplier
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; candidates formula (unscaled candidates == 0) is enforced:
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
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;
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;
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; When we relax the candidates part of a multiplier formula
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; (unscaled candidates == 2) we start getting some unswitches in outer loops,
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; which leads to siblings multiplier kicking in.
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=1 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV1
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;
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; NB: sort -b is essential here and below, otherwise blanks might lead to different
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; order depending on locale.
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
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; RUN: -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=2 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV2
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;
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; With disabled cost-multiplier we get maximal possible amount of unswitches.
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=false \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
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; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-MAX
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;
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; Single loop nest, not unswitched
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; LOOP1: Loop at depth 1 containing:
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; LOOP1-NOT: Loop at depth 1 containing:
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; LOOP1: Loop at depth 2 containing:
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; LOOP1-NOT: Loop at depth 2 containing:
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; LOOP1: Loop at depth 3 containing:
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; LOOP1-NOT: Loop at depth 3 containing:
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;
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; Half unswitched loop nests, with unscaled3 and div1 it gets less depth1 loops unswitched
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; since they have more cost.
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; LOOP-UNSCALE3-DIV1-COUNT-4: Loop at depth 1 containing:
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; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 1 containing:
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; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 2 containing:
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; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 2 containing:
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; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 3 containing:
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; LOOP-UNSCALE3-DIV1-NOT: Loop at depth 3 containing:
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;
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; Half unswitched loop nests, with unscaled3 and div2 it gets more depth1 loops unswitched
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; as div2 kicks in.
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; LOOP-UNSCALE3-DIV2-COUNT-6: Loop at depth 1 containing:
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; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 1 containing:
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; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 2 containing:
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; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 2 containing:
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; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 3 containing:
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; LOOP-UNSCALE3-DIV2-NOT: Loop at depth 3 containing:
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;
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; Maximally unswitched (copy of the outer loop per each condition)
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; LOOP-MAX-COUNT-6: Loop at depth 1 containing:
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; LOOP-MAX-NOT: Loop at depth 1 containing:
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; LOOP-MAX-COUNT-1: Loop at depth 2 containing:
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; LOOP-MAX-NOT: Loop at depth 2 containing:
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; LOOP-MAX-COUNT-1: Loop at depth 3 containing:
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; LOOP-MAX-NOT: Loop at depth 3 containing:
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declare void @bar()
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define void @loop_nested3_conds5(i32* %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) {
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entry:
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%addr1 = getelementptr i32, i32* %addr, i64 0
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%addr2 = getelementptr i32, i32* %addr, i64 1
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%addr3 = getelementptr i32, i32* %addr, i64 2
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br label %outer
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outer:
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%iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch]
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%iv1.next = add i32 %iv1, 1
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;; skip nontrivial unswitch
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call void @bar()
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br label %middle
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middle:
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%iv2 = phi i32 [0, %outer], [%iv2.next, %middle_latch]
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%iv2.next = add i32 %iv2, 1
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;; skip nontrivial unswitch
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call void @bar()
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br label %loop
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loop:
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%iv3 = phi i32 [0, %middle], [%iv3.next, %loop_latch]
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%iv3.next = add i32 %iv3, 1
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;; skip nontrivial unswitch
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call void @bar()
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br i1 %c1, label %loop_next1_left, label %outer_latch
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loop_next1_left:
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br label %loop_next1
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loop_next1_right:
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br label %loop_next1
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loop_next1:
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br i1 %c2, label %loop_next2_left, label %outer_latch
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loop_next2_left:
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br label %loop_next2
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loop_next2_right:
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br label %loop_next2
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loop_next2:
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br i1 %c3, label %loop_next3_left, label %outer_latch
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loop_next3_left:
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br label %loop_next3
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loop_next3_right:
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br label %loop_next3
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loop_next3:
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br i1 %c4, label %loop_next4_left, label %outer_latch
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loop_next4_left:
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br label %loop_next4
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loop_next4_right:
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br label %loop_next4
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loop_next4:
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br i1 %c5, label %loop_latch_left, label %outer_latch
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loop_latch_left:
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br label %loop_latch
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loop_latch_right:
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br label %loop_latch
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loop_latch:
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store volatile i32 0, i32* %addr1
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%test_loop = icmp slt i32 %iv3, 50
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br i1 %test_loop, label %loop, label %middle_latch
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middle_latch:
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store volatile i32 0, i32* %addr2
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%test_middle = icmp slt i32 %iv2, 50
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br i1 %test_middle, label %middle, label %outer_latch
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outer_latch:
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store volatile i32 0, i32* %addr3
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%test_outer = icmp slt i32 %iv1, 50
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br i1 %test_outer, label %outer, label %exit
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exit:
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ret void
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}
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@@ -0,0 +1,80 @@
|
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;
|
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; There should be just a single copy of loop when strictest mutiplier candidates
|
||||
; formula (unscaled candidates == 0) is enforced:
|
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;
|
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
|
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
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; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=8 \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
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;
|
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; With relaxed candidates multiplier (unscaled candidates == 8) we should allow
|
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; some unswitches to happen until siblings multiplier starts kicking in:
|
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;
|
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
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; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=1 \
|
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP5
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;
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; With relaxed candidates multiplier (unscaled candidates == 8) and with relaxed
|
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; siblings multiplier for top-level loops (toplevel-div == 8) we should get
|
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; 2^(num conds) == 2^5 == 32
|
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; copies of the loop:
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;
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
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; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=8 \
|
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP32
|
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;
|
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; Similarly get
|
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; 2^(num conds) == 2^5 == 32
|
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; copies of the loop when cost multiplier is disabled:
|
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;
|
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; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=false \
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; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP32
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;
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;
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; Single loop, not unswitched
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; LOOP1: Loop at depth 1 containing:
|
||||
; LOOP1-NOT: Loop at depth 1 containing:
|
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|
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; 5 loops, unswitched 4 times
|
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; LOOP5-COUNT-5: Loop at depth 1 containing:
|
||||
; LOOP5-NOT: Loop at depth 1 containing:
|
||||
|
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; 32 loops, fully unswitched
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; LOOP32-COUNT-32: Loop at depth 1 containing:
|
||||
; LOOP32-NOT: Loop at depth 1 containing:
|
||||
|
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define void @loop_simple5(i32* %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) {
|
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entry:
|
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br label %loop
|
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loop:
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%iv = phi i32 [0, %entry], [%iv.next, %loop_latch]
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%iv.next = add i32 %iv, 1
|
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br i1 %c1, label %loop_next1, label %loop_next1_right
|
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loop_next1_right:
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br label %loop_next1
|
||||
loop_next1:
|
||||
br i1 %c2, label %loop_next2, label %loop_next2_right
|
||||
loop_next2_right:
|
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br label %loop_next2
|
||||
loop_next2:
|
||||
br i1 %c3, label %loop_next3, label %loop_next3_right
|
||||
loop_next3_right:
|
||||
br label %loop_next3
|
||||
loop_next3:
|
||||
br i1 %c4, label %loop_next4, label %loop_next4_right
|
||||
loop_next4_right:
|
||||
br label %loop_next4
|
||||
loop_next4:
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||||
br i1 %c5, label %loop_latch, label %loop_latch_right
|
||||
loop_latch_right:
|
||||
br label %loop_latch
|
||||
loop_latch:
|
||||
store volatile i32 0, i32* %addr
|
||||
%test_loop = icmp slt i32 %iv, 50
|
||||
br i1 %test_loop, label %loop, label %exit
|
||||
exit:
|
||||
ret void
|
||||
}
|
||||
@@ -0,0 +1,56 @@
|
||||
;
|
||||
; Here all the branches are exiting ones. Checking that we dont have
|
||||
; exponential behavior with any kind of controlling heuristics here.
|
||||
;
|
||||
; There we should have just a single loop.
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=8 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=1 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=8 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=false \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
;
|
||||
; Single loop, not unswitched
|
||||
; LOOP1: Loop at depth 1 containing:
|
||||
; LOOP1-NOT: Loop at depth 1 containing:
|
||||
|
||||
declare void @bar()
|
||||
|
||||
define void @loop_simple5(i32* %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) {
|
||||
entry:
|
||||
br label %loop
|
||||
loop:
|
||||
%iv = phi i32 [0, %entry], [%iv.next, %loop_latch]
|
||||
%iv.next = add i32 %iv, 1
|
||||
;; disabling trivial unswitch
|
||||
call void @bar()
|
||||
br i1 %c1, label %loop_next1, label %exit
|
||||
loop_next1:
|
||||
br i1 %c2, label %loop_next2, label %exit
|
||||
loop_next2:
|
||||
br i1 %c3, label %loop_next3, label %exit
|
||||
loop_next3:
|
||||
br i1 %c4, label %loop_next4, label %exit
|
||||
loop_next4:
|
||||
br i1 %c5, label %loop_latch, label %exit
|
||||
loop_latch:
|
||||
store volatile i32 0, i32* %addr
|
||||
%test_loop = icmp slt i32 %iv, 50
|
||||
br i1 %test_loop, label %loop, label %exit
|
||||
exit:
|
||||
ret void
|
||||
}
|
||||
@@ -0,0 +1,118 @@
|
||||
;
|
||||
; Here we have 5-way unswitchable switch with each successor also having an unswitchable
|
||||
; exiting branch in it. If we start unswitching those branches we start duplicating the
|
||||
; whole switch. This can easily lead to exponential behavior w/o proper control.
|
||||
; On a real-life testcase there was 16-way switch and that took forever to compile w/o
|
||||
; a cost control.
|
||||
;
|
||||
;
|
||||
; When we use the stricted multiplier candidates formula (unscaled candidates == 0)
|
||||
; we should be getting just a single loop.
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
|
||||
;
|
||||
;
|
||||
; With relaxed candidates multiplier (unscaled candidates == 8) we should allow
|
||||
; some unswitches to happen until siblings multiplier starts kicking in:
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=1 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
|
||||
; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-RELAX
|
||||
;
|
||||
; With relaxed candidates multiplier (unscaled candidates == 8) and with relaxed
|
||||
; siblings multiplier for top-level loops (toplevel-div == 8) we should get
|
||||
; considerably more copies of the loop (especially top-level ones).
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=true \
|
||||
; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=8 \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
|
||||
; RUN: sort -b | FileCheck %s --check-prefixes=LOOP-RELAX2
|
||||
;
|
||||
; We get hundreds of copies of the loop when cost multiplier is disabled:
|
||||
;
|
||||
; RUN: opt < %s -enable-nontrivial-unswitch -enable-unswitch-cost-multiplier=false \
|
||||
; RUN: -passes='loop(unswitch),print<loops>' -disable-output 2>&1 | \
|
||||
; RUN: sort -b | 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:
|
||||
;
|
||||
; Somewhat relaxed restrictions on candidates:
|
||||
; LOOP-RELAX-COUNT-5: Loop at depth 1 containing:
|
||||
; LOOP-RELAX-NOT: Loop at depth 1 containing:
|
||||
; LOOP-RELAX-COUNT-32: Loop at depth 2 containing:
|
||||
; LOOP-RELAX-NOT: Loop at depth 2 containing:
|
||||
;
|
||||
; Even more relaxed restrictions on candidates and siblings.
|
||||
; LOOP-RELAX2-COUNT-11: Loop at depth 1 containing:
|
||||
; LOOP-RELAX2-NOT: Loop at depth 1 containing:
|
||||
; LOOP-RELAX2-COUNT-40: Loop at depth 2 containing:
|
||||
; LOOP-RELAX-NOT: Loop at depth 2 containing:
|
||||
;
|
||||
; Unswitched as much as it could (with multiplier disabled).
|
||||
; LOOP-MAX-COUNT-56: Loop at depth 1 containing:
|
||||
; LOOP-MAX-NOT: Loop at depth 1 containing:
|
||||
; LOOP-MAX-COUNT-111: Loop at depth 2 containing:
|
||||
; LOOP-MAX-NOT: Loop at depth 2 containing:
|
||||
|
||||
define i32 @loop_switch(i32* %addr, i32 %c1, i32 %c2) {
|
||||
entry:
|
||||
%addr1 = getelementptr i32, i32* %addr, i64 0
|
||||
%addr2 = getelementptr i32, i32* %addr, i64 1
|
||||
%check0 = icmp eq i32 %c2, 0
|
||||
%check1 = icmp eq i32 %c2, 31
|
||||
%check2 = icmp eq i32 %c2, 32
|
||||
%check3 = icmp eq i32 %c2, 33
|
||||
%check4 = icmp eq i32 %c2, 34
|
||||
br label %outer_loop
|
||||
|
||||
outer_loop:
|
||||
%iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch]
|
||||
%iv1.next = add i32 %iv1, 1
|
||||
br label %inner_loop
|
||||
inner_loop:
|
||||
%iv2 = phi i32 [0, %outer_loop], [%iv2.next, %inner_latch]
|
||||
%iv2.next = add i32 %iv2, 1
|
||||
switch i32 %c1, label %inner_latch [
|
||||
i32 0, label %case0
|
||||
i32 1, label %case1
|
||||
i32 2, label %case2
|
||||
i32 3, label %case3
|
||||
i32 4, label %case4
|
||||
]
|
||||
|
||||
case4:
|
||||
br i1 %check4, label %exit, label %inner_latch
|
||||
case3:
|
||||
br i1 %check3, label %exit, label %inner_latch
|
||||
case2:
|
||||
br i1 %check2, label %exit, label %inner_latch
|
||||
case1:
|
||||
br i1 %check1, label %exit, label %inner_latch
|
||||
case0:
|
||||
br i1 %check0, label %exit, label %inner_latch
|
||||
|
||||
inner_latch:
|
||||
store volatile i32 0, i32* %addr1
|
||||
%test_inner = icmp slt i32 %iv2, 50
|
||||
br i1 %test_inner, label %inner_loop, label %outer_latch
|
||||
|
||||
outer_latch:
|
||||
store volatile i32 0, i32* %addr2
|
||||
%test_outer = icmp slt i32 %iv1, 50
|
||||
br i1 %test_outer, label %outer_loop, label %exit
|
||||
|
||||
exit: ; preds = %bci_0
|
||||
ret i32 1
|
||||
}
|
||||
Reference in New Issue
Block a user