Pass edges weights to MachineBasicBlock::addSuccessor in TailDuplicatePass to

preserve branch probability information.

<rdar://problem/15893208>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201245 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 52 insertions, 0 deletions

diff --git a/test/CodeGen/ARM/taildup-branch-weight.ll b/test/CodeGen/ARM/taildup-branch-weight.ll
new file mode 100644
index 0000000000..80bbc8c323
--- /dev/null
+++ b/test/CodeGen/ARM/taildup-branch-weight.ll
@@ -0,0 +1,52 @@
+; RUN: llc < %s -march=arm -print-machineinstrs=tailduplication -tail-dup-size=100 -enable-tail-merge=false -disable-cgp -o /dev/null 2>&1 | FileCheck %s
+
+; CHECK: Machine code for function test0:
+; CHECK: Successors according to CFG: BB#1(4) BB#2(124)
+
+define void @test0(i32 %a, i32 %b, i32* %c, i32* %d) {
+entry:
+  store i32 3, i32* %d
+  br label %B1
+
+B2:
+  store i32 2, i32* %c
+  br label %B4
+
+B3:
+  store i32 2, i32* %c
+  br label %B4
+
+B1:
+  store i32 1, i32* %d
+  %test0 = icmp slt i32 %a, %b
+  br i1 %test0, label %B2, label %B3, !prof !0
+
+B4:
+  ret void
+}
+
+!0 = metadata !{metadata !"branch_weights", i32 4, i32 124}
+
+; CHECK: Machine code for function test1:
+; CHECK: Successors according to CFG: BB#1(8) BB#2(248)
+
+@g0 = common global i32 0, align 4
+
+define void @test1(i32 %a, i32 %b, i32* %c, i32* %d, i32* %e) {
+
+  %test0 = icmp slt i32 %a, %b
+  br i1 %test0, label %B1, label %B2, !prof !1
+
+B1:
+  br label %B3
+
+B2:
+  store i32 2, i32* %c
+  br label %B3
+
+B3:
+  store i32 3, i32* %e
+  ret void
+}
+
+!1 = metadata !{metadata !"branch_weights", i32 248, i32 8}