Fix trellis layout to avoid mis-identify triangle.
Summary:
For the following CFG:
A->B
B->C
A->C
If there is another edge B->D, then ABC should not be considered as triangle.
Reviewers: davidxl, iteratee
Reviewed By: iteratee
Subscribers: nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D31310
llvm-svn: 298661
diff --git a/llvm/test/CodeGen/PowerPC/tail-dup-layout.ll b/llvm/test/CodeGen/PowerPC/tail-dup-layout.ll
index 12fce24..c9b5bf8 100644
--- a/llvm/test/CodeGen/PowerPC/tail-dup-layout.ll
+++ b/llvm/test/CodeGen/PowerPC/tail-dup-layout.ll
@@ -474,6 +474,51 @@
ret void
}
+; Verify that we did not mis-identify triangle trellises if it is not
+; really a triangle.
+; CHECK-LABEL: trellis_no_triangle
+; CHECK: # %entry
+; CHECK: # %b
+; CHECK: # %d
+; CHECK: # %ret
+; CHECK: # %c
+; CHECK: # %e
+define void @trellis_no_triangle(i32 %tag) {
+entry:
+ br label %a
+a:
+ call void @a()
+ call void @a()
+ %tagbits.a = and i32 %tag, 3
+ %tagbits.a.eq0 = icmp eq i32 %tagbits.a, 0
+ br i1 %tagbits.a.eq0, label %b, label %c, !prof !8 ; 98 to 2
+b:
+ call void @b()
+ call void @b()
+ %tagbits.b = and i32 %tag, 12
+ %tagbits.b.eq1 = icmp eq i32 %tagbits.b, 8
+ br i1 %tagbits.b.eq1, label %d, label %e, !prof !9 ; 97 to 1
+d:
+ call void @d()
+ call void @d()
+ %tagbits.d = and i32 %tag, 48
+ %tagbits.d.eq1 = icmp eq i32 %tagbits.d, 32
+ br i1 %tagbits.d.eq1, label %ret, label %e, !prof !10 ; 96 to 2
+c:
+ call void @c()
+ call void @c()
+ %tagbits.c = and i32 %tag, 12
+ %tagbits.c.eq0 = icmp eq i32 %tagbits.c, 0
+ br i1 %tagbits.c.eq0, label %d, label %e, !prof !2 ; 1 to 1
+e:
+ call void @e()
+ call void @e()
+ br label %ret
+ret:
+ call void @f()
+ ret void
+}
+
declare void @a()
declare void @b()
declare void @c()
@@ -492,3 +537,6 @@
!5 = !{!"branch_weights", i32 2, i32 8}
!6 = !{!"branch_weights", i32 3, i32 4}
!7 = !{!"branch_weights", i32 4, i32 2}
+!8 = !{!"branch_weights", i32 98, i32 2}
+!9 = !{!"branch_weights", i32 97, i32 1}
+!10 = !{!"branch_weights", i32 96, i32 2}