forked from OSchip/llvm-project
139 lines
4.0 KiB
LLVM
139 lines
4.0 KiB
LLVM
; Checks whether dead loops with multiple exits can be eliminated.
|
|
; Note that we loop simplify and LCSSA over the test cases to make sure the
|
|
; critical components remain after those passes and are visible to the loop
|
|
; deletion pass.
|
|
;
|
|
; RUN: opt < %s -loop-simplify -lcssa -S | FileCheck %s --check-prefixes=CHECK,BEFORE
|
|
; RUN: opt < %s -loop-deletion -S | FileCheck %s --check-prefixes=CHECK,AFTER
|
|
;
|
|
; RUN: opt < %s -passes=no-op-loop -S | FileCheck %s --check-prefixes=CHECK,BEFORE
|
|
; RUN: opt < %s -passes=loop-deletion -S | FileCheck %s --check-prefixes=CHECK,AFTER
|
|
|
|
|
|
define void @foo(i64 %n, i64 %m) nounwind {
|
|
; CHECK-LABEL: @foo(
|
|
|
|
entry:
|
|
br label %bb
|
|
; CHECK: entry:
|
|
; BEFORE-NEXT: br label %bb
|
|
; AFTER-NEXT: br label %return
|
|
|
|
bb:
|
|
%x.0 = phi i64 [ 0, %entry ], [ %t0, %bb2 ]
|
|
%t0 = add i64 %x.0, 1
|
|
%t1 = icmp slt i64 %x.0, %n
|
|
br i1 %t1, label %bb2, label %return
|
|
; BEFORE: bb:
|
|
; BEFORE: br i1 {{.*}}, label %bb2, label %return
|
|
; AFTER-NOT: bb:
|
|
; AFTER-NOT: br
|
|
|
|
bb2:
|
|
%t2 = icmp slt i64 %x.0, %m
|
|
br i1 %t1, label %bb, label %return
|
|
; BEFORE: bb2:
|
|
; BEFORE: br i1 {{.*}}, label %bb, label %return
|
|
; AFTER-NOT: bb2:
|
|
; AFTER-NOT: br
|
|
|
|
return:
|
|
ret void
|
|
; CHECK: return:
|
|
; CHECK-NEXT: ret void
|
|
}
|
|
|
|
define i64 @bar(i64 %n, i64 %m, i64 %maybe_zero) nounwind {
|
|
; CHECK-LABEL: @bar(
|
|
|
|
entry:
|
|
br label %bb
|
|
; CHECK: entry:
|
|
; BEFORE-NEXT: br label %bb
|
|
; AFTER-NEXT: br label %return
|
|
|
|
bb:
|
|
%x.0 = phi i64 [ 0, %entry ], [ %t0, %bb3 ]
|
|
%t0 = add i64 %x.0, 1
|
|
%t1 = icmp slt i64 %x.0, %n
|
|
br i1 %t1, label %bb2, label %return
|
|
; BEFORE: bb:
|
|
; BEFORE: br i1 {{.*}}, label %bb2, label %return
|
|
; AFTER-NOT: bb:
|
|
; AFTER-NOT: br
|
|
|
|
bb2:
|
|
%t2 = icmp slt i64 %x.0, %m
|
|
; This unused division prevents unifying this loop exit path with others
|
|
; because it can be deleted but cannot be hoisted.
|
|
%unused1 = udiv i64 42, %maybe_zero
|
|
br i1 %t2, label %bb3, label %return
|
|
; BEFORE: bb2:
|
|
; BEFORE: br i1 {{.*}}, label %bb3, label %return
|
|
; AFTER-NOT: bb2:
|
|
; AFTER-NOT: br
|
|
|
|
bb3:
|
|
%t3 = icmp slt i64 %x.0, %m
|
|
; This unused division prevents unifying this loop exit path with others
|
|
; because it can be deleted but cannot be hoisted.
|
|
%unused2 = sdiv i64 42, %maybe_zero
|
|
br i1 %t3, label %bb, label %return
|
|
; BEFORE: bb3:
|
|
; BEFORE: br i1 {{.*}}, label %bb, label %return
|
|
; AFTER-NOT: bb3:
|
|
; AFTER-NOT: br
|
|
|
|
return:
|
|
%x.lcssa = phi i64 [ 10, %bb ], [ 10, %bb2 ], [ 10, %bb3 ]
|
|
ret i64 %x.lcssa
|
|
; CHECK: return:
|
|
; BEFORE-NEXT: %[[X:.*]] = phi i64 [ 10, %bb ], [ 10, %bb2 ], [ 10, %bb3 ]
|
|
; AFTER-NEXT: %[[X:.*]] = phi i64 [ 10, %entry ]
|
|
; CHECK-NEXT: ret i64 %[[X]]
|
|
}
|
|
|
|
; This function has a loop which looks like @bar's but that cannot be deleted
|
|
; because which path we exit through determines which value is selected.
|
|
define i64 @baz(i64 %n, i64 %m, i64 %maybe_zero) nounwind {
|
|
; CHECK-LABEL: @baz(
|
|
|
|
entry:
|
|
br label %bb
|
|
; CHECK: entry:
|
|
; CHECK-NEXT: br label %bb
|
|
|
|
bb:
|
|
%x.0 = phi i64 [ 0, %entry ], [ %t0, %bb3 ]
|
|
%t0 = add i64 %x.0, 1
|
|
%t1 = icmp slt i64 %x.0, %n
|
|
br i1 %t1, label %bb2, label %return
|
|
; CHECK: bb:
|
|
; CHECK: br i1 {{.*}}, label %bb2, label %return
|
|
|
|
bb2:
|
|
%t2 = icmp slt i64 %x.0, %m
|
|
; This unused division prevents unifying this loop exit path with others
|
|
; because it can be deleted but cannot be hoisted.
|
|
%unused1 = udiv i64 42, %maybe_zero
|
|
br i1 %t2, label %bb3, label %return
|
|
; CHECK: bb2:
|
|
; CHECK: br i1 {{.*}}, label %bb3, label %return
|
|
|
|
bb3:
|
|
%t3 = icmp slt i64 %x.0, %m
|
|
; This unused division prevents unifying this loop exit path with others
|
|
; because it can be deleted but cannot be hoisted.
|
|
%unused2 = sdiv i64 42, %maybe_zero
|
|
br i1 %t3, label %bb, label %return
|
|
; CHECK: bb3:
|
|
; CHECK: br i1 {{.*}}, label %bb, label %return
|
|
|
|
return:
|
|
%x.lcssa = phi i64 [ 12, %bb ], [ 10, %bb2 ], [ 10, %bb3 ]
|
|
ret i64 %x.lcssa
|
|
; CHECK: return:
|
|
; CHECK-NEXT: %[[X:.*]] = phi i64 [ 12, %bb ], [ 10, %bb2 ], [ 10, %bb3 ]
|
|
; CHECK-NEXT: ret i64 %[[X]]
|
|
}
|