- Stop simplifycfg from duplicating "ret" instructions into unconditional

  branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
  allocation is done.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124462 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 38 insertions, 15 deletions

diff --git a/test/Transforms/SimplifyCFG/MagicPointer.ll b/test/Transforms/SimplifyCFG/MagicPointer.ll
index 54e5b14880..93b9a276ea 100644
--- a/test/Transforms/SimplifyCFG/MagicPointer.ll
+++ b/test/Transforms/SimplifyCFG/MagicPointer.ll
@@ -8,7 +8,6 @@
 ; CHECK: i64 2, label
 ; CHECK: i64 3, label
 ; CHECK: i64 4, label
-; CHECK-NOT: br
 ; CHECK: }
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
diff --git a/test/Transforms/SimplifyCFG/basictest.ll b/test/Transforms/SimplifyCFG/basictest.ll
index b485f6ab05..052e10667d 100644
--- a/test/Transforms/SimplifyCFG/basictest.ll
+++ b/test/Transforms/SimplifyCFG/basictest.ll
@@ -25,16 +25,6 @@ define void @test3(i1 %T) {
 }
 
 
-define void @test4() {
-  br label %return
-return:
-  ret void
-; CHECK: @test4
-; CHECK-NEXT: ret void
-}
-@test4g = global i8* blockaddress(@test4, %return)
-
-
 ; PR5795
 define void @test5(i32 %A) {
   switch i32 %A, label %return [
diff --git a/test/Transforms/SimplifyCFG/switch_create.ll b/test/Transforms/SimplifyCFG/switch_create.ll
index da7f65a6ca..4e199bc859 100644
--- a/test/Transforms/SimplifyCFG/switch_create.ll
+++ b/test/Transforms/SimplifyCFG/switch_create.ll
@@ -147,7 +147,7 @@ UnifiedReturnBlock:             ; preds = %shortcirc_done.4, %shortcirc_next.4
 ; CHECK:       i32 16, label %UnifiedReturnBlock
 ; CHECK:       i32 17, label %UnifiedReturnBlock
 ; CHECK:       i32 18, label %UnifiedReturnBlock
-; CHECK:       i32 19, label %switch.edge
+; CHECK:       i32 19, label %UnifiedReturnBlock
 ; CHECK:     ]
 }
 
@@ -441,3 +441,29 @@ if.end:
 ; CHECK-NOT: switch
 ; CHECK: ret void
 }
+
+; PR8675
+; rdar://5134905
+define zeroext i1 @test16(i32 %x) nounwind {
+entry:
+; CHECK: @test16
+; CHECK: switch i32 %x, label %lor.rhs [
+; CHECK:   i32 1, label %lor.end
+; CHECK:   i32 2, label %lor.end
+; CHECK:   i32 3, label %lor.end
+; CHECK: ]
+  %cmp.i = icmp eq i32 %x, 1
+  br i1 %cmp.i, label %lor.end, label %lor.lhs.false
+
+lor.lhs.false:
+  %cmp.i2 = icmp eq i32 %x, 2
+  br i1 %cmp.i2, label %lor.end, label %lor.rhs
+
+lor.rhs:
+  %cmp.i1 = icmp eq i32 %x, 3
+  br label %lor.end
+
+lor.end:
+  %0 = phi i1 [ true, %lor.lhs.false ], [ true, %entry ], [ %cmp.i1, %lor.rhs ]
+  ret i1 %0
+}
diff --git a/test/Transforms/SimplifyCFG/switch_formation.dbg.ll b/test/Transforms/SimplifyCFG/switch_formation.dbg.ll
index f1c820ec43..357ffb60e1 100644
--- a/test/Transforms/SimplifyCFG/switch_formation.dbg.ll
+++ b/test/Transforms/SimplifyCFG/switch_formation.dbg.ll
@@ -1,5 +1,4 @@
-; RUN: opt < %s -simplifycfg -S | not grep br
-
+; RUN: opt < %s -simplifycfg -S | FileCheck %s
 
         %llvm.dbg.anchor.type = type { i32, i32 }
         %llvm.dbg.compile_unit.type = type { i32, { }*, i32, i8*, i8*, i8*, i1, i1, i8* }
@@ -13,7 +12,16 @@
 
 declare void @llvm.dbg.stoppoint(i32, i32, { }*) nounwind
 
-define i1 @_ZN4llvm11SetCondInst7classofEPKNS_11InstructionE({ i32, i32 }* %I) {
+define i1 @t({ i32, i32 }* %I) {
+; CHECK: t
+; CHECK:  switch i32 %tmp.2.i, label %shortcirc_next.4 [
+; CHECK:    i32 14, label %UnifiedReturnBlock
+; CHECK:    i32 15, label %UnifiedReturnBlock
+; CHECK:    i32 16, label %UnifiedReturnBlock
+; CHECK:    i32 17, label %UnifiedReturnBlock
+; CHECK:    i32 18, label %UnifiedReturnBlock
+; CHECK:    i32 19, label %UnifiedReturnBlock
+; CHECK:  ]
 entry:
         %tmp.1.i = getelementptr { i32, i32 }* %I, i64 0, i32 1         ; <i32*> [#uses=1]
         %tmp.2.i = load i32* %tmp.1.i           ; <i32> [#uses=6]