Mercurial > hg > CbC > CbC_llvm
view llvm/test/Transforms/PlaceSafepoints/finite-loops.ll @ 201:a96fbbdf2d0f
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author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Fri, 04 Jun 2021 21:07:06 +0900 |
parents | 1d019706d866 |
children | 2e18cbf3894f |
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; Tests to ensure that we are not placing backedge safepoints in ; loops which are clearly finite. ;; RUN: opt < %s -place-safepoints -spp-counted-loop-trip-width=32 -S | FileCheck %s ;; RUN: opt < %s -place-safepoints -spp-counted-loop-trip-width=64 -S | FileCheck %s -check-prefix=COUNTED-64 ; A simple counted loop with trivially known range define void @test1(i32) gc "statepoint-example" { ; CHECK-LABEL: test1 ; CHECK-LABEL: entry ; CHECK: call void @do_safepoint ; CHECK-LABEL: loop ; CHECK-NOT: call void @do_safepoint ; CHECK-LABEL: exit entry: br label %loop loop: %counter = phi i32 [ 0 , %entry ], [ %counter.inc , %loop ] %counter.inc = add i32 %counter, 1 %counter.cmp = icmp slt i32 %counter.inc, 16 br i1 %counter.cmp, label %loop, label %exit exit: ret void } ; The same counted loop, but with an unknown early exit define void @test2(i32) gc "statepoint-example" { ; CHECK-LABEL: test2 ; CHECK-LABEL: entry ; CHECK: call void @do_safepoint ; CHECK-LABEL: loop ; CHECK-NOT: call void @do_safepoint ; CHECK-LABEL: exit entry: br label %loop loop: %counter = phi i32 [ 0 , %entry ], [ %counter.inc , %continue ] %counter.inc = add i32 %counter, 1 %counter.cmp = icmp slt i32 %counter.inc, 16 br i1 undef, label %continue, label %exit continue: br i1 %counter.cmp, label %loop, label %exit exit: ret void } ; The range is a 8 bit value and we can't overflow define void @test3(i8 %upper) gc "statepoint-example" { ; CHECK-LABEL: test3 ; CHECK-LABEL: entry ; CHECK: call void @do_safepoint ; CHECK-LABEL: loop ; CHECK-NOT: call void @do_safepoint ; CHECK-LABEL: exit entry: br label %loop loop: %counter = phi i8 [ 0 , %entry ], [ %counter.inc , %loop ] %counter.inc = add nsw i8 %counter, 1 %counter.cmp = icmp slt i8 %counter.inc, %upper br i1 %counter.cmp, label %loop, label %exit exit: ret void } ; The range is a 64 bit value define void @test4(i64 %upper) gc "statepoint-example" { ; CHECK-LABEL: test4 ; CHECK-LABEL: entry ; CHECK: call void @do_safepoint ; CHECK-LABEL: loop ; CHECK: call void @do_safepoint ; CHECK-LABEL: exit ; COUNTED-64-LABEL: test4 ; COUNTED-64-LABEL: entry ; COUNTED-64: call void @do_safepoint ; COUNTED-64-LABEL: loop ; COUNTED-64-NOT: call void @do_safepoint ; COUNTED-64-LABEL: exit entry: br label %loop loop: %counter = phi i64 [ 0 , %entry ], [ %counter.inc , %loop ] %counter.inc = add i64 %counter, 1 %counter.cmp = icmp slt i64 %counter.inc, %upper br i1 %counter.cmp, label %loop, label %exit exit: ret void } ; This loop can run infinitely (for %upper == INT64_MAX) so it needs a ; safepoint. define void @test5(i64 %upper) gc "statepoint-example" { ; CHECK-LABEL: test5 ; CHECK-LABEL: entry ; CHECK: call void @do_safepoint ; CHECK-LABEL: loop ; CHECK: call void @do_safepoint ; CHECK-LABEL: exit ; COUNTED-64-LABEL: test5 ; COUNTED-64-LABEL: entry ; COUNTED-64: call void @do_safepoint ; COUNTED-64-LABEL: loop ; COUNTED-64: call void @do_safepoint ; COUNTED-64-LABEL: exit entry: br label %loop loop: %counter = phi i64 [ 0 , %entry ], [ %counter.inc , %loop ] %counter.inc = add i64 %counter, 1 %counter.cmp = icmp sle i64 %counter.inc, %upper br i1 %counter.cmp, label %loop, label %exit exit: ret void } ; This function is inlined when inserting a poll. declare void @do_safepoint() define void @gc.safepoint_poll() { ; CHECK-LABEL: gc.safepoint_poll entry: call void @do_safepoint() ret void }