executeScopConditionally: Introduce special exiting block

When introducing separate control flow for the original and optimized code we
introduce now a special 'ExitingBlock':

      \   /
    EnteringBB
        |
    SplitBlock---------\
   _____|_____         |
  /  EntryBB  \    StartBlock
  |  (region) |        |
  \_ExitingBB_/   ExitingBlock
        |              |
    MergeBlock---------/
        |
      ExitBB
      /    \

This 'ExitingBlock' contains code such as the final_reloads for scalars, which
previously were just added to whichever statement/loop_exit/branch-merge block
had been generated last. Having an explicit basic block makes it easier to
find these constructs when looking at the CFG.

llvm-svn: 255107

17 files changed, 38 insertions, 27 deletions

diff --git a/polly/lib/CodeGen/Utils.cpp b/polly/lib/CodeGen/Utils.cpp
index dd6b162ccb0..743a0cceec0 100644
--- a/polly/lib/CodeGen/Utils.cpp
+++ b/polly/lib/CodeGen/Utils.cpp
@@ -141,17 +141,23 @@ BasicBlock *polly::executeScopConditionally(Scop &S, Pass *P, Value *RTC) {
   //      ExitBB     //
   //      /    \     //
 
-  // Create the start block.
+  // Create the start and exiting block.
   Function *F = SplitBlock->getParent();
   BasicBlock *StartBlock =
       BasicBlock::Create(F->getContext(), "polly.start", F);
+  BasicBlock *ExitingBlock =
+      BasicBlock::Create(F->getContext(), "polly.exiting", F);
   SplitBlock->getTerminator()->eraseFromParent();
   Builder.SetInsertPoint(SplitBlock);
   Builder.CreateCondBr(RTC, StartBlock, R.getEntry());
-  if (Loop *L = LI.getLoopFor(SplitBlock))
+  if (Loop *L = LI.getLoopFor(SplitBlock)) {
     L->addBasicBlockToLoop(StartBlock, LI);
+    L->addBasicBlockToLoop(ExitingBlock, LI);
+  }
   DT.addNewBlock(StartBlock, SplitBlock);
+  DT.addNewBlock(ExitingBlock, StartBlock);
   RI.setRegionFor(StartBlock, RI.getRegionFor(SplitBlock));
+  RI.setRegionFor(ExitingBlock, RI.getRegionFor(SplitBlock));
 
   //      \   /                    //
   //    EnteringBB                 //
@@ -159,16 +165,21 @@ BasicBlock *polly::executeScopConditionally(Scop &S, Pass *P, Value *RTC) {
   //    SplitBlock---------\       //
   //   _____|_____         |       //
   //  /  EntryBB  \    StartBlock  //
-  //  |  (region) |                //
-  //  \_ExitingBB_/                //
+  //  |  (region) |        |       //
+  //  \_ExitingBB_/   ExitingBlock //
   //        |                      //
   //    MergeBlock                 //
   //        |                      //
   //      ExitBB                   //
   //      /    \                   //
 
-  // Connect start block to the join block.
+  // Connect start block to exiting block.
   Builder.SetInsertPoint(StartBlock);
+  Builder.CreateBr(ExitingBlock);
+  DT.changeImmediateDominator(ExitingBlock, StartBlock);
+
+  // Connect exiting block to join block.
+  Builder.SetInsertPoint(ExitingBlock);
   Builder.CreateBr(MergeBlock);
   DT.changeImmediateDominator(MergeBlock, SplitBlock);
 
@@ -179,7 +190,7 @@ BasicBlock *polly::executeScopConditionally(Scop &S, Pass *P, Value *RTC) {
   //   _____|_____         |       //
   //  /  EntryBB  \    StartBlock  //
   //  |  (region) |        |       //
-  //  \_ExitingBB_/        |       //
+  //  \_ExitingBB_/   ExitingBlock //
   //        |              |       //
   //    MergeBlock---------/       //
   //        |                      //
diff --git a/polly/test/Isl/CodeGen/OpenMP/single_loop.ll b/polly/test/Isl/CodeGen/OpenMP/single_loop.ll
index 454e815ec49..f43d1c395a3 100644
--- a/polly/test/Isl/CodeGen/OpenMP/single_loop.ll
+++ b/polly/test/Isl/CodeGen/OpenMP/single_loop.ll
@@ -39,7 +39,7 @@
 ; IR-NEXT:   call void @GOMP_parallel_end()
 ; IR-NEXT:   %1 = bitcast {}* %polly.par.userContext to i8*
 ; IR-NEXT:   call void @llvm.lifetime.end(i64 8, i8* %1)
-; IR-NEXT:   br label %polly.merge_new_and_old
+; IR-NEXT:   br label %polly.exiting
 
 ; IR: define internal void @single_parallel_loop_polly_subfn(i8* %polly.par.userContext) #2
 ; IR-LABEL: polly.par.setup:
diff --git a/polly/test/Isl/CodeGen/invariant_load_escaping.ll b/polly/test/Isl/CodeGen/invariant_load_escaping.ll
index 5afa1a6bc80..56918bfa54d 100644
--- a/polly/test/Isl/CodeGen/invariant_load_escaping.ll
+++ b/polly/test/Isl/CodeGen/invariant_load_escaping.ll
@@ -21,7 +21,7 @@
 ; CHECK:   store i32 %polly.access.B.load, i32* %tmp.preload.s2a
 ;
 ; CHECK: polly.merge_new_and_old:
-; CHECK:   %tmp.merge = phi i32 [ %tmp.final_reload, %polly.loop_exit ], [ %tmp, %do.cond ]
+; CHECK:   %tmp.merge = phi i32 [ %tmp.final_reload, %polly.exiting ], [ %tmp, %do.cond ]
 ; CHECK:   br label %do.end
 ;
 ; CHECK: do.end:
diff --git a/polly/test/Isl/CodeGen/out-of-scop-phi-node-use.ll b/polly/test/Isl/CodeGen/out-of-scop-phi-node-use.ll
index 1c5780985f2..65d6090560e 100644
--- a/polly/test/Isl/CodeGen/out-of-scop-phi-node-use.ll
+++ b/polly/test/Isl/CodeGen/out-of-scop-phi-node-use.ll
@@ -4,12 +4,12 @@ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK-NEXT: %_s.sroa.343.0.ph5161118.ph.merge = phi i32 [ %_s.sroa.343.0.ph5161118.ph.final_reload, %polly.stmt.polly.merge_new_and_old.exit ], [ %_s.sroa.343.0.ph516.lcssa2357, %for.cond.981.region_exiting ]
+; CHECK-NEXT: %_s.sroa.343.0.ph5161118.ph.merge = phi i32 [ %_s.sroa.343.0.ph5161118.ph.final_reload, %polly.exiting ], [ %_s.sroa.343.0.ph516.lcssa2357, %for.cond.981.region_exiting ]
 
 ; CHECK-LABEL: for.cond.981:
 ; CHECK-NEXT:  %_s.sroa.343.0.ph5161118 = phi i32 [ undef, %for.cond ], [ %_s.sroa.343.0.ph5161118.ph.merge, %polly.merge_new_and_old ]
 
-; CHECK-LABEL: polly.stmt.polly.merge_new_and_old.exit:
+; CHECK-LABEL: polly.exiting:
 ; CHECK-NEXT: %_s.sroa.343.0.ph5161118.ph.final_reload = load i32, i32* %_s.sroa.343.0.ph5161118.s2a
 
 ; Function Attrs: nounwind uwtable
diff --git a/polly/test/Isl/CodeGen/phi-defined-before-scop.ll b/polly/test/Isl/CodeGen/phi-defined-before-scop.ll
index f684dcca63b..1567117946e 100644
--- a/polly/test/Isl/CodeGen/phi-defined-before-scop.ll
+++ b/polly/test/Isl/CodeGen/phi-defined-before-scop.ll
@@ -1,7 +1,7 @@
 ; RUN: opt %loadPolly -polly-codegen -S < %s | FileCheck %s
 
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK-NEXT: %tmp7.ph.merge = phi %struct.wibble* [ %tmp7.ph.final_reload, %polly.stmt.bb5 ], [ %tmp7.ph, %bb6.region_exiting ]
+; CHECK-NEXT: %tmp7.ph.merge = phi %struct.wibble* [ %tmp7.ph.final_reload, %polly.exiting ], [ %tmp7.ph, %bb6.region_exiting ]
 
 ; CHECK-LABEL: polly.stmt.bb3:
 ; CHECK-NEXT: %tmp2.s2a.reload = load %struct.wibble*, %struct.wibble** %tmp2.s2a
diff --git a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_2.ll b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_2.ll
index ab71ae3a286..939b8a79fa9 100644
--- a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_2.ll
+++ b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_2.ll
@@ -7,12 +7,12 @@
 ; CHECK-NOT:   %eps1.addr.0.ph.s2a = alloca double
 ;
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK:          %eps1.addr.0.ph.merge = phi double [ %eps1.addr.0.ph.final_reload, %polly.stmt.if.end.47.region_exiting.exit ], [ %eps1.addr.0.ph, %if.end.47.region_exiting ]
+; CHECK:          %eps1.addr.0.ph.merge = phi double [ %eps1.addr.0.ph.final_reload, %polly.exiting ], [ %eps1.addr.0.ph, %if.end.47.region_exiting ]
 ;
 ; CHECK-LABEL: polly.start:
 ; CHECK-NEXT:    store double %eps1, double* %eps1.s2a
 ;
-; CHECK-LABEL: polly.stmt.if.end.47.region_exiting.exit:
+; CHECK-LABEL: polly.exiting:
 ; CHECK-NEXT:     %eps1.addr.0.ph.final_reload = load double, double* %eps1.addr.0.s2a
 ;
 define void @dbisect(double* %c, double* %b, double %eps1, double* %eps2) {
diff --git a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_3.ll b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_3.ll
index 138d204f762..45a765b9035 100644
--- a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_3.ll
+++ b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_3.ll
@@ -4,7 +4,7 @@
 ; produce the PHI node in the exit we are looking for.
 ;
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK-NEXT:     %n2ptr.2.ph.merge = phi i8* [ %n2ptr.2.ph.final_reload, %polly.merge ], [ %n2ptr.2.ph, %if.end.45.region_exiting ]
+; CHECK-NEXT:     %n2ptr.2.ph.merge = phi i8* [ %n2ptr.2.ph.final_reload, %polly.exiting ], [ %n2ptr.2.ph, %if.end.45.region_exiting ]
 ;
 ; CHECK-LABEL: if.end.45:
 ; CHECK-NEXT:     %n2ptr.2 = phi i8* [ %add.ptr25, %entry ], [ %add.ptr25, %while.cond.preheader ], [ %n2ptr.2.ph.merge, %polly.merge_new_and_old ]
diff --git a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_5.ll b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_5.ll
index 03ad2f4ebf9..bbf62e4f620 100644
--- a/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_5.ll
+++ b/polly/test/Isl/CodeGen/phi_in_exit_early_lnt_failure_5.ll
@@ -4,7 +4,7 @@
 ; produce the PHI node in the exit we are looking for.
 ;
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK-NEXT:    %eps1.addr.0.ph.merge = phi double [ %eps1.addr.0.ph.final_reload, %polly.stmt.if.end.47.region_exiting.exit ], [ %eps1.addr.0.ph, %if.end.47.region_exiting ]
+; CHECK-NEXT:    %eps1.addr.0.ph.merge = phi double [ %eps1.addr.0.ph.final_reload, %polly.exiting ], [ %eps1.addr.0.ph, %if.end.47.region_exiting ]
 ; CHECK-NEXT:      br label %if.end.47
 ;
 ; CHECK-LABEL: if.end.47:
diff --git a/polly/test/Isl/CodeGen/phi_loop_carried_float.ll b/polly/test/Isl/CodeGen/phi_loop_carried_float.ll
index f191279ae2c..cfcdb58d7df 100644
--- a/polly/test/Isl/CodeGen/phi_loop_carried_float.ll
+++ b/polly/test/Isl/CodeGen/phi_loop_carried_float.ll
@@ -20,7 +20,7 @@
 ; CHECK-NEXT:    sext
 ; CHECK-NEXT:    store float 0.000000e+00, float* %tmp.0.phiops
 
-; CHECK-LABEL: polly.merge2:
+; CHECK-LABEL: polly.exiting:
 ; CHECK-NEXT:    br label %polly.merge_new_and_old
 
 ; CHECK-LABEL: polly.stmt.bb1{{[0-9]*}}:
diff --git a/polly/test/Isl/CodeGen/phi_loop_carried_float_escape.ll b/polly/test/Isl/CodeGen/phi_loop_carried_float_escape.ll
index 11d3697202a..cce111282e9 100644
--- a/polly/test/Isl/CodeGen/phi_loop_carried_float_escape.ll
+++ b/polly/test/Isl/CodeGen/phi_loop_carried_float_escape.ll
@@ -12,14 +12,14 @@
 ;    }
 
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK-NEXT:    %tmp.0.merge = phi float [ %tmp.0.final_reload, %polly.merge2 ], [ %tmp.0, %bb8 ]
+; CHECK-NEXT:    %tmp.0.merge = phi float [ %tmp.0.final_reload, %polly.exiting ], [ %tmp.0, %bb8 ]
 ; CHECK-NEXT:    br label %exit
 
 ; CHECK-LABEL: polly.start:
 ; CHECK-NEXT:    sext
 ; CHECK-NEXT:    store float 0.000000e+00, float* %tmp.0.phiops
 
-; CHECK-LABEL: polly.merge2:
+; CHECK-LABEL: polly.exiting:
 ; CHECK-NEXT:    %tmp.0.final_reload = load float, float* %tmp.0.s2a
 ; CHECK-NEXT:    br label %polly.merge_new_and_old
 
diff --git a/polly/test/Isl/CodeGen/phi_scalar_simple_1.ll b/polly/test/Isl/CodeGen/phi_scalar_simple_1.ll
index 3e1623d0537..c39b24f7caf 100644
--- a/polly/test/Isl/CodeGen/phi_scalar_simple_1.ll
+++ b/polly/test/Isl/CodeGen/phi_scalar_simple_1.ll
@@ -22,7 +22,7 @@ entry:
   br label %for.cond
 
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK:         %x.addr.0.merge = phi i32 [ %x.addr.0.final_reload, %polly.merge ], [ %x.addr.0, %for.cond ]
+; CHECK:         %x.addr.0.merge = phi i32 [ %x.addr.0.final_reload, %polly.exiting ], [ %x.addr.0, %for.cond ]
 ; CHECK:         ret i32 %x.addr.0.merge
 
 ; CHECK-LABEL: polly.start:
diff --git a/polly/test/Isl/CodeGen/phi_scalar_simple_2.ll b/polly/test/Isl/CodeGen/phi_scalar_simple_2.ll
index 6d69cb68642..f0812fea1f3 100644
--- a/polly/test/Isl/CodeGen/phi_scalar_simple_2.ll
+++ b/polly/test/Isl/CodeGen/phi_scalar_simple_2.ll
@@ -24,7 +24,7 @@ entry:
   br label %for.cond
 
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK:         %x.addr.0.merge = phi i32 [ %x.addr.0.final_reload, %polly.merge21 ], [ %x.addr.0, %for.cond ]
+; CHECK:         %x.addr.0.merge = phi i32 [ %x.addr.0.final_reload, %polly.exiting ], [ %x.addr.0, %for.cond ]
 ; CHECK:         ret i32 %x.addr.0.merge
 
 ; CHECK-LABEL: polly.start:
diff --git a/polly/test/Isl/CodeGen/phi_with_multi_exiting_edges_2.ll b/polly/test/Isl/CodeGen/phi_with_multi_exiting_edges_2.ll
index bffb329b7b1..dd02de10865 100644
--- a/polly/test/Isl/CodeGen/phi_with_multi_exiting_edges_2.ll
+++ b/polly/test/Isl/CodeGen/phi_with_multi_exiting_edges_2.ll
@@ -1,7 +1,7 @@
 ; RUN: opt %loadPolly -polly-codegen -S < %s | FileCheck %s
 ;
 ; CHECK: polly.merge_new_and_old:
-; CHECK:   %result.ph.merge = phi float [ %result.ph.final_reload, %polly.merge ], [ %result.ph, %next.region_exiting ]
+; CHECK:   %result.ph.merge = phi float [ %result.ph.final_reload, %polly.exiting ], [ %result.ph, %next.region_exiting ]
 ; CHECK:   br label %next
 ;
 ; CHECK: next:
diff --git a/polly/test/Isl/CodeGen/phi_with_one_exit_edge.ll b/polly/test/Isl/CodeGen/phi_with_one_exit_edge.ll
index f4a0500b962..129e0ffbdb6 100644
--- a/polly/test/Isl/CodeGen/phi_with_one_exit_edge.ll
+++ b/polly/test/Isl/CodeGen/phi_with_one_exit_edge.ll
@@ -2,7 +2,7 @@
 ;
 ;
 ; CHECK: polly.merge_new_and_old:
-; CHECK:   %sumA.merge = phi float [ %sumA.final_reload, %polly.loop_exit ], [ %sumA, %loopA ]
+; CHECK:   %sumA.merge = phi float [ %sumA.final_reload, %polly.exiting ], [ %sumA, %loopA ]
 ; CHECK:   br label %next
 ;
 ; CHECK: next:
diff --git a/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_escaping.ll b/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_escaping.ll
index cb9ac0a4382..f74efa90fcd 100644
--- a/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_escaping.ll
+++ b/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_escaping.ll
@@ -50,8 +50,8 @@
 ; CODEGEN:   store float %.load12, float* %S.b.preload.s2a
 ;
 ; CODEGEN:     polly.merge_new_and_old:
-; CODEGEN-DAG:   %S.b.merge = phi float [ %S.b.final_reload, %polly.loop_exit ], [ %S.b, %do.cond ]
-; CODEGEN-DAG:   %S.a.merge = phi i32 [ %S.a.final_reload, %polly.loop_exit ], [ %S.a, %do.cond ]
+; CODEGEN-DAG:   %S.b.merge = phi float [ %S.b.final_reload, %polly.exiting ], [ %S.b, %do.cond ]
+; CODEGEN-DAG:   %S.a.merge = phi i32 [ %S.a.final_reload, %polly.exiting ], [ %S.a, %do.cond ]
 ;
 ; CODEGEN: do.end:
 ; CODEGEN:   %conv3 = sitofp i32 %S.a.merge to float
diff --git a/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_same_pointer_escaping.ll b/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_same_pointer_escaping.ll
index 8213fb4afd3..fa5a4aab772 100644
--- a/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_same_pointer_escaping.ll
+++ b/polly/test/ScopInfo/invariant_load_access_classes_different_base_type_same_pointer_escaping.ll
@@ -40,8 +40,8 @@
 ; CODEGEN:   store float %U.load1, float* %U.f.preload.s2a
 ;
 ; CODEGEN:     polly.merge_new_and_old:
-; CODEGEN-DAG:   %U.f.merge = phi float [ %U.f.final_reload, %polly.loop_exit ], [ %U.f, %do.cond ]
-; CODEGEN-DAG:   %U.i.merge = phi i32 [ %5, %polly.loop_exit ], [ %U.i, %do.cond ]
+; CODEGEN-DAG:   %U.f.merge = phi float [ %U.f.final_reload, %polly.exiting ], [ %U.f, %do.cond ]
+; CODEGEN-DAG:   %U.i.merge = phi i32 [ %5, %polly.exiting ], [ %U.i, %do.cond ]
 ;
 ; CODEGEN: polly.loop_exit:
 ; CODEGEN-DAG:   %U.f.final_reload = load float, float* %U.f.preload.s2a
diff --git a/polly/test/ScopInfo/out-of-scop-use-in-region-entry-phi-node-nonaffine-subregion.ll b/polly/test/ScopInfo/out-of-scop-use-in-region-entry-phi-node-nonaffine-subregion.ll
index 66a15bef510..224da09a989 100755
--- a/polly/test/ScopInfo/out-of-scop-use-in-region-entry-phi-node-nonaffine-subregion.ll
+++ b/polly/test/ScopInfo/out-of-scop-use-in-region-entry-phi-node-nonaffine-subregion.ll
@@ -7,7 +7,7 @@
 ; CHECK:         %loop_carried.ph = phi float [ %newval.merge, %backedge ], [ undef, %entry ]
 ;
 ; CHECK-LABEL: polly.merge_new_and_old:
-; CHECK:         %newval.merge = phi float [ %newval.final_reload, %polly.stmt.polly.merge_new_and_old.exit ], [ %newval, %subregion_exit.region_exiting ]
+; CHECK:         %newval.merge = phi float [ %newval.final_reload, %polly.exiting ], [ %newval, %subregion_exit.region_exiting ]
 ;
 ; CHECK-LABEL: polly.start:
 ; CHECK:         store float %loop_carried.ph, float* %loop_carried.phiops