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llvm-mirror/test/Transforms/PlaceSafepoints/finite-loops.ll
Philip Reames fe3f4cccba [PlaceSafepoints] Adjust enablement logic to default to off and be GC configurable per GC
Previously, this pass ran over every function in the Module if added to the pass order.  With this change, it runs only over those with a GC attribute where the GC explicitly opts in.  A GC can also choose which of entry safepoint polls, backedge safepoint polls, and call safepoints it wants.  I hope to get these exposed as checks on the GCStrategy at some point, but for now, the checks are manual string comparisons.

llvm-svn: 230097
2015-02-21 00:09:09 +00:00

81 lines
1.7 KiB
LLVM

; Tests to ensure that we are not placing backedge safepoints in
; loops which are clearly finite.
;; RUN: opt %s -place-safepoints -S | FileCheck %s
; A simple counted loop with trivially known range
define void @test1(i32) gc "statepoint-example" {
; CHECK-LABEL: test1
; CHECK-LABEL: entry
; CHECK: statepoint
; CHECK-LABEL: loop
; CHECK-NOT: statepoint
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: statepoint
; CHECK-LABEL: loop
; CHECK-NOT: statepoint
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: statepoint
; CHECK-LABEL: loop
; CHECK-NOT: statepoint
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
}
; 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
}