llvm-6502/test/Transforms/SimplifyCFG/preserve-branchweights.ll
Justin Bogner bcb726dc8a Transforms: Don't create bad weights when eliminating dead cases
If we happen to eliminate every case in a switch that has branch
weights, we currently try to create metadata for the one remaining
branch, triggering an assert. Instead, we need to check that the
metadata we're trying to create is sensible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197791 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-20 08:21:30 +00:00

363 lines
7.9 KiB
LLVM

; RUN: opt -simplifycfg -S -o - < %s | FileCheck %s
declare void @helper(i32)
define void @test1(i1 %a, i1 %b) {
; CHECK-LABEL: @test1(
entry:
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !0
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test2(i1 %a, i1 %b) {
; CHECK-LABEL: @test2(
entry:
br i1 %a, label %X, label %Y, !prof !1
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !1
; CHECK-NOT: !prof
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !2
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test3(i1 %a, i1 %b) {
; CHECK-LABEL: @test3(
; CHECK-NOT: !prof
entry:
br i1 %a, label %X, label %Y, !prof !1
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test4(i1 %a, i1 %b) {
; CHECK-LABEL: @test4(
; CHECK-NOT: !prof
entry:
br i1 %a, label %X, label %Y
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
;; test5 - The case where it jumps to the default target will be removed.
define void @test5(i32 %M, i32 %N) nounwind uwtable {
entry:
switch i32 %N, label %sw2 [
i32 1, label %sw2
i32 2, label %sw.bb
i32 3, label %sw.bb1
], !prof !3
; CHECK-LABEL: @test5(
; CHECK: switch i32 %N, label %sw2 [
; CHECK: i32 3, label %sw.bb1
; CHECK: i32 2, label %sw.bb
; CHECK: ], !prof !2
sw.bb:
call void @helper(i32 0)
br label %sw.epilog
sw.bb1:
call void @helper(i32 1)
br label %sw.epilog
sw2:
call void @helper(i32 2)
br label %sw.epilog
sw.epilog:
ret void
}
;; test6 - Some cases of the second switch are pruned during optimization.
;; Then the second switch will be converted to a branch, finally, the first
;; switch and the branch will be merged into a single switch.
define void @test6(i32 %M, i32 %N) nounwind uwtable {
entry:
switch i32 %N, label %sw2 [
i32 1, label %sw2
i32 2, label %sw.bb
i32 3, label %sw.bb1
], !prof !4
; CHECK-LABEL: @test6(
; CHECK: switch i32 %N, label %sw.epilog
; CHECK: i32 3, label %sw.bb1
; CHECK: i32 2, label %sw.bb
; CHECK: i32 4, label %sw.bb5
; CHECK: ], !prof !3
sw.bb:
call void @helper(i32 0)
br label %sw.epilog
sw.bb1:
call void @helper(i32 1)
br label %sw.epilog
sw2:
;; Here "case 2" is invalidated since the default case of the first switch
;; does not include "case 2".
switch i32 %N, label %sw.epilog [
i32 2, label %sw.bb4
i32 4, label %sw.bb5
], !prof !5
sw.bb4:
call void @helper(i32 2)
br label %sw.epilog
sw.bb5:
call void @helper(i32 3)
br label %sw.epilog
sw.epilog:
ret void
}
;; This test is based on test1 but swapped the targets of the second branch.
define void @test1_swap(i1 %a, i1 %b) {
; CHECK-LABEL: @test1_swap(
entry:
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %or.cond, label %Y, label %Z, !prof !4
X:
%c = or i1 %b, false
br i1 %c, label %Y, label %Z, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test7(i1 %a, i1 %b) {
; CHECK-LABEL: @test7(
entry:
%c = or i1 %b, false
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %brmerge, label %Y, label %Z, !prof !5
X:
br i1 %c, label %Y, label %Z, !prof !6
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
; Test basic folding to a conditional branch.
define void @test8(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @test8(
entry:
%lt = icmp slt i64 %x, %y
; CHECK: br i1 %lt, label %a, label %b, !prof !6
%qux = select i1 %lt, i32 0, i32 2
switch i32 %qux, label %bees [
i32 0, label %a
i32 1, label %b
i32 2, label %b
], !prof !7
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
bees:
call void @helper(i32 2) nounwind
ret void
}
; Test edge splitting when the default target has icmp and unconditinal
; branch
define i1 @test9(i32 %x, i32 %y) nounwind {
; CHECK-LABEL: @test9(
entry:
switch i32 %x, label %bees [
i32 0, label %a
i32 1, label %end
i32 2, label %end
], !prof !7
; CHECK: switch i32 %x, label %bees [
; CHECK: i32 0, label %a
; CHECK: i32 1, label %end
; CHECK: i32 2, label %end
; CHECK: i32 92, label %end
; CHECK: ], !prof !7
a:
call void @helper(i32 0) nounwind
%reta = icmp slt i32 %x, %y
ret i1 %reta
bees:
%tmp = icmp eq i32 %x, 92
br label %end
end:
; CHECK: end:
; CHECK: %ret = phi i1 [ true, %entry ], [ false, %bees ], [ true, %entry ], [ true, %entry ]
%ret = phi i1 [ true, %entry ], [%tmp, %bees], [true, %entry]
call void @helper(i32 2) nounwind
ret i1 %ret
}
define void @test10(i32 %x) nounwind readnone ssp noredzone {
entry:
switch i32 %x, label %lor.rhs [
i32 2, label %lor.end
i32 1, label %lor.end
i32 3, label %lor.end
], !prof !7
lor.rhs:
call void @helper(i32 1) nounwind
ret void
lor.end:
call void @helper(i32 0) nounwind
ret void
; CHECK-LABEL: @test10(
; CHECK: %x.off = add i32 %x, -1
; CHECK: %switch = icmp ult i32 %x.off, 3
; CHECK: br i1 %switch, label %lor.end, label %lor.rhs, !prof !8
}
; Remove dead cases from the switch.
define void @test11(i32 %x) nounwind {
%i = shl i32 %x, 1
switch i32 %i, label %a [
i32 21, label %b
i32 24, label %c
], !prof !8
; CHECK-LABEL: @test11(
; CHECK: %cond = icmp eq i32 %i, 24
; CHECK: br i1 %cond, label %c, label %a, !prof !9
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
c:
call void @helper(i32 2) nounwind
ret void
}
;; test12 - Don't crash if the whole switch is removed
define void @test12(i32 %M, i32 %N) nounwind uwtable {
entry:
switch i32 %N, label %sw.bb [
i32 1, label %sw.bb
], !prof !9
; CHECK-LABEL: @test12(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @helper
; CHECK-NEXT: ret void
sw.bb:
call void @helper(i32 0)
br label %sw.epilog
sw.epilog:
ret void
}
;; If every case is dead, make sure they are all removed. This used to
;; crash trying to merge the metadata.
define void @test13(i32 %x) nounwind {
entry:
%i = shl i32 %x, 1
switch i32 %i, label %a [
i32 21, label %b
i32 25, label %c
], !prof !8
; CHECK-LABEL: @test13(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @helper
; CHECK-NEXT: ret void
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
c:
call void @helper(i32 2) nounwind
ret void
}
!0 = metadata !{metadata !"branch_weights", i32 3, i32 5}
!1 = metadata !{metadata !"branch_weights", i32 1, i32 1}
!2 = metadata !{metadata !"branch_weights", i32 1, i32 2}
!3 = metadata !{metadata !"branch_weights", i32 4, i32 3, i32 2, i32 1}
!4 = metadata !{metadata !"branch_weights", i32 4, i32 3, i32 2, i32 1}
!5 = metadata !{metadata !"branch_weights", i32 7, i32 6, i32 5}
!6 = metadata !{metadata !"branch_weights", i32 1, i32 3}
!7 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8, i32 7}
!8 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8}
!9 = metadata !{metadata !"branch_weights", i32 7, i32 6}
; CHECK: !0 = metadata !{metadata !"branch_weights", i32 5, i32 11}
; CHECK: !1 = metadata !{metadata !"branch_weights", i32 1, i32 5}
; CHECK: !2 = metadata !{metadata !"branch_weights", i32 7, i32 1, i32 2}
; CHECK: !3 = metadata !{metadata !"branch_weights", i32 49, i32 12, i32 24, i32 35}
; CHECK: !4 = metadata !{metadata !"branch_weights", i32 11, i32 5}
; CHECK: !5 = metadata !{metadata !"branch_weights", i32 17, i32 15}
; CHECK: !6 = metadata !{metadata !"branch_weights", i32 9, i32 7}
; CHECK: !7 = metadata !{metadata !"branch_weights", i32 17, i32 9, i32 8, i32 7, i32 17}
; CHECK: !8 = metadata !{metadata !"branch_weights", i32 24, i32 33}
; CHECK: !9 = metadata !{metadata !"branch_weights", i32 8, i32 33}
; CHECK-NOT: !9