[CodeGen] Do the Simple Early Return in block-placement pass to optimize the blocks

Summary:

In `block-placement` pass, it will create some patterns for unconditional we can do the simple early retrun.
But the `early-ret` pass is before `block-placement`, we don't want to run it again.
This patch is to do the simple early return to optimize the blocks at the last of `block-placement`.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D63972

llvm-svn: 368565

1 files changed, 4 insertions, 8 deletions

diff --git a/llvm/test/CodeGen/PowerPC/block-placement.mir b/llvm/test/CodeGen/PowerPC/block-placement.mir
index 9406e13b354..e413e3db2d5 100644
--- a/llvm/test/CodeGen/PowerPC/block-placement.mir
+++ b/llvm/test/CodeGen/PowerPC/block-placement.mir
@@ -209,14 +209,10 @@ body:             |
     BLR8 implicit $lr8, implicit $rm, implicit killed $x3
 
   ; CHECK:      bb.5.if.else.i:
-  ; CHECK:        successors: %bb.11(0x80000000)
-  ; CHECK:        B %bb.11
+  ; CHECK-NEXT:   renamable $x3 = LI8 1
+  ; CHECK-NEXT:   BLR8 implicit $lr8, implicit $rm, implicit killed $x3
 
   ; CHECK:      bb.8.while.body.i (align 4):
-  ; CHECK:        successors: %bb.11(0x04000000), %bb.9(0x7c000000)
-  ; CHECK:        BCC 76, killed renamable $cr0, %bb.11
-
-  ; CHECK:      bb.11:
-  ; CHECK:        renamable $x3 = LI8 1
-  ; CHECK-NEXT:   BLR8 implicit $lr8, implicit $rm, implicit killed $x3
+  ; CHECK:        successors: %bb.5(0x04000000), %bb.9(0x7c000000)
+  ; CHECK:        BCC 76, killed renamable $cr0, %bb.5
 ...