Distribute the weight on the edge from switch to default statement to edges generated...

Currently, when edge weights are assigned to edges that are created when lowering switch statement, the weight on the edge to default statement (let's call it "default weight" here) is not considered. We need to distribute this weight properly. However, without value profiling, we have no idea how to distribute it. In this patch, I applied the heuristic that this weight is evenly distributed to successors.

For example, given a switch statement with cases 1,2,3,5,10,11,20, and every edge from switch to each successor has weight 10. If there is a binary search tree built to test if n < 10, then its two out-edges will have weight 4x10+10/2 = 45 and 3x10 + 10/2 = 35 respectively (currently they are 40 and 30 without considering the default weight). Each distribution (which is 5 here) will be stored in each SwitchWorkListItem for further distribution.

There are some exceptions:

For a jump table header which doesn't have any edge to default statement, we don't distribute the default weight to it.
For a bit test header which covers a contiguous range and hence has no edges to default statement, we don't distribute the default weight to it.
When the branch checks a single value or a contiguous range with no edge to default statement, we don't distribute the default weight to it.
In other cases, the default weight is evenly distributed to successors.

Differential Revision: http://reviews.llvm.org/D12418

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246522 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c958f7d..50f8c16 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1924,8 +1924,7 @@ void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
 
   MachineBasicBlock* MBB = B.Cases[0].ThisBB;
 
-  uint32_t DefaultWeight = getEdgeWeight(SwitchBB, B.Default);
-  addSuccessorWithWeight(SwitchBB, B.Default, DefaultWeight);
+  addSuccessorWithWeight(SwitchBB, B.Default, B.DefaultWeight);
   addSuccessorWithWeight(SwitchBB, MBB, B.Weight);
 
   SDValue BrRange = DAG.getNode(ISD::BRCOND, dl,
@@ -8037,7 +8036,8 @@ void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
   }
 
   // Compute total weight.
-  uint32_t UnhandledWeights = 0;
+  uint32_t DefaultWeight = W.DefaultWeight;
+  uint32_t UnhandledWeights = DefaultWeight;
   for (CaseClusterIt I = W.FirstCluster; I <= W.LastCluster; ++I) {
     UnhandledWeights += I->Weight;
     assert(UnhandledWeights >= I->Weight && "Weight overflow!");
@@ -8067,14 +8067,24 @@ void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
         MachineBasicBlock *JumpMBB = JT->MBB;
         CurMF->insert(BBI, JumpMBB);
 
-        // Collect the sum of weights of outgoing edges from JumpMBB, which will
-        // be the edge weight on CurMBB->JumpMBB.
-        uint32_t JumpWeight = 0;
-        for (auto Succ : JumpMBB->successors())
-          JumpWeight += getEdgeWeight(JumpMBB, Succ);
-        uint32_t FallthruWeight = getEdgeWeight(CurMBB, Fallthrough);
+        uint32_t JumpWeight = I->Weight;
+        uint32_t FallthroughWeight = UnhandledWeights;
+
+        // If Fallthrough is a target of the jump table, we evenly distribute
+        // the weight on the edge to Fallthrough to successors of CurMBB.
+        // Also update the weight on the edge from JumpMBB to Fallthrough.
+        for (MachineBasicBlock::succ_iterator SI = JumpMBB->succ_begin(),
+                                              SE = JumpMBB->succ_end();
+             SI != SE; ++SI) {
+          if (*SI == Fallthrough) {
+            JumpWeight += DefaultWeight / 2;
+            FallthroughWeight -= DefaultWeight / 2;
+            JumpMBB->setSuccWeight(SI, DefaultWeight / 2);
+            break;
+          }
+        }
 
-        addSuccessorWithWeight(CurMBB, Fallthrough, FallthruWeight);
+        addSuccessorWithWeight(CurMBB, Fallthrough, FallthroughWeight);
         addSuccessorWithWeight(CurMBB, JumpMBB, JumpWeight);
 
         // The jump table header will be inserted in our current block, do the
@@ -8101,8 +8111,17 @@ void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
         BTB->Parent = CurMBB;
         BTB->Default = Fallthrough;
 
-        // If we're in the right place, emit the bit test header header right now.
-        if (CurMBB ==SwitchMBB) {
+        BTB->DefaultWeight = UnhandledWeights;
+        // If the cases in bit test don't form a contiguous range, we evenly
+        // distribute the weight on the edge to Fallthrough to two successors
+        // of CurMBB.
+        if (!BTB->ContiguousRange) {
+          BTB->Weight += DefaultWeight / 2;
+          BTB->DefaultWeight -= DefaultWeight / 2;
+        }
+
+        // If we're in the right place, emit the bit test header right now.
+        if (CurMBB == SwitchMBB) {
           visitBitTestHeader(*BTB, SwitchMBB);
           BTB->Emitted = true;
         }
@@ -8167,8 +8186,8 @@ void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
   // Mehlhorn "Nearly Optimal Binary Search Trees" (1975).
   CaseClusterIt LastLeft = W.FirstCluster;
   CaseClusterIt FirstRight = W.LastCluster;
-  uint32_t LeftWeight = LastLeft->Weight;
-  uint32_t RightWeight = FirstRight->Weight;
+  uint32_t LeftWeight = LastLeft->Weight + W.DefaultWeight / 2;
+  uint32_t RightWeight = FirstRight->Weight + W.DefaultWeight / 2;
 
   // Move LastLeft and FirstRight towards each other from opposite directions to
   // find a partitioning of the clusters which balances the weight on both
@@ -8254,7 +8273,8 @@ void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
   } else {
     LeftMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
     FuncInfo.MF->insert(BBI, LeftMBB);
-    WorkList.push_back({LeftMBB, FirstLeft, LastLeft, W.GE, Pivot});
+    WorkList.push_back(
+        {LeftMBB, FirstLeft, LastLeft, W.GE, Pivot, W.DefaultWeight / 2});
     // Put Cond in a virtual register to make it available from the new blocks.
     ExportFromCurrentBlock(Cond);
   }
@@ -8269,7 +8289,8 @@ void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
   } else {
     RightMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
     FuncInfo.MF->insert(BBI, RightMBB);
-    WorkList.push_back({RightMBB, FirstRight, LastRight, Pivot, W.LT});
+    WorkList.push_back(
+        {RightMBB, FirstRight, LastRight, Pivot, W.LT, W.DefaultWeight / 2});
     // Put Cond in a virtual register to make it available from the new blocks.
     ExportFromCurrentBlock(Cond);
   }
@@ -8370,7 +8391,8 @@ void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) {
   SwitchWorkList WorkList;
   CaseClusterIt First = Clusters.begin();
   CaseClusterIt Last = Clusters.end() - 1;
-  WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr});
+  uint32_t DefaultWeight = getEdgeWeight(SwitchMBB, DefaultMBB);
+  WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr, DefaultWeight});
 
   while (!WorkList.empty()) {
     SwitchWorkListItem W = WorkList.back();

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 537d8e0..3b97d46 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -288,7 +288,7 @@ private:
                  BitTestInfo C, uint32_t W)
         : First(F), Range(R), SValue(SV), Reg(Rg), RegVT(RgVT), Emitted(E),
           ContiguousRange(CR), Parent(P), Default(D), Cases(std::move(C)),
-          Weight(W) {}
+          Weight(W), DefaultWeight(0) {}
     APInt First;
     APInt Range;
     const Value *SValue;
@@ -300,6 +300,7 @@ private:
     MachineBasicBlock *Default;
     BitTestInfo Cases;
     uint32_t Weight;
+    uint32_t DefaultWeight;
   };
 
   /// Minimum jump table density, in percent.
@@ -341,6 +342,7 @@ private:
     CaseClusterIt LastCluster;
     const ConstantInt *GE;
     const ConstantInt *LT;
+    uint32_t DefaultWeight;
   };
   typedef SmallVector<SwitchWorkListItem, 4> SwitchWorkList;
 

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 2c5c168..7e2bbae 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1490,9 +1490,7 @@ SelectionDAGISel::FinishBasicBlock() {
       CodeGenAndEmitDAG();
     }
 
-    uint32_t UnhandledWeight = 0;
-    for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j)
-      UnhandledWeight += SDB->BitTestCases[i].Cases[j].ExtraWeight;
+    uint32_t UnhandledWeight = SDB->BitTestCases[i].Weight;
 
     for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) {
       UnhandledWeight -= SDB->BitTestCases[i].Cases[j].ExtraWeight;

diff --git a/test/CodeGen/AArch64/aarch64-deferred-spilling.ll b/test/CodeGen/AArch64/aarch64-deferred-spilling.ll
index ff280c7..f38925a 100644 (file)
--- a/test/CodeGen/AArch64/aarch64-deferred-spilling.ll
+++ b/test/CodeGen/AArch64/aarch64-deferred-spilling.ll
@@ -7,9 +7,9 @@
 ;
 ; CHECK: // %if.then.120
 ;
-; REGULAR: str w22, [sp, #[[OFFSET:[0-9]+]]] // 4-byte Folded Spill
-; Check that w22 wouldn't need to be spilled since it is never reused.
-; REGULAR-NOT: {{[wx]}}22{{,?}}
+; REGULAR: str w21, [sp, #[[OFFSET:[0-9]+]]] // 4-byte Folded Spill
+; Check that w21 wouldn't need to be spilled since it is never reused.
+; REGULAR-NOT: {{[wx]}}21{{,?}}
 ;
 ; Check that w22 is used to carry a value through the call.
 ; DEFERRED-NOT: str {{[wx]}}22,
@@ -22,8 +22,8 @@
 ; DEFERRED: mov {{[wx][0-9]+}}, {{[wx]}}22
 ; DEFERRED-NOT: ldr {{[wx]}}22,
 ;
-; REGULAR-NOT: {{[wx]}}22{{,?}}
-; REGUAL: ldr w22, [sp, #[[OFFSET]]] // 4-byte Folded Reload
+; REGULAR-NOT: {{[wx]}}21{{,?}}
+; REGULAR: ldr w21, [sp, #[[OFFSET]]] // 4-byte Folded Reload
 ;
 ; End of the basic block we are interested in.
 ; CHECK:        b

diff --git a/test/CodeGen/ARM/jump-table-islands.ll b/test/CodeGen/ARM/jump-table-islands.ll
index 03d5a7d..6b4f174 100644 (file)
--- a/test/CodeGen/ARM/jump-table-islands.ll
+++ b/test/CodeGen/ARM/jump-table-islands.ll
@@ -13,7 +13,7 @@ define %BigInt @test_moved_jumptable(i1 %tst, i32 %sw, %BigInt %l) {
 ; CHECK:   .long LBB{{[0-9]+_[0-9]+}}-[[JUMP_TABLE]]
 
 ; CHECK: [[SKIP_TABLE]]:
-; CHECK:   add pc, lr, {{r[0-9]+}}
+; CHECK:   add pc, {{r[0-9]+}}, {{r[0-9]+}}
   br i1 %tst, label %simple, label %complex
 
 simple:

diff --git a/test/CodeGen/Generic/MachineBranchProb.ll b/test/CodeGen/Generic/MachineBranchProb.ll
index 8288e45..b11d369 100644 (file)
--- a/test/CodeGen/Generic/MachineBranchProb.ll
+++ b/test/CodeGen/Generic/MachineBranchProb.ll
@@ -16,9 +16,9 @@ entry:
     i64 5, label %sw.bb1
   ], !prof !0
 ; CHECK: BB#0: derived from LLVM BB %entry
-; CHECK: Successors according to CFG: BB#2(64) BB#4(14)
+; CHECK: Successors according to CFG: BB#2(64) BB#4(21)
 ; CHECK: BB#4: derived from LLVM BB %entry
-; CHECK: Successors according to CFG: BB#1(10) BB#5(4)
+; CHECK: Successors according to CFG: BB#1(10) BB#5(11)
 ; CHECK: BB#5: derived from LLVM BB %entry
 ; CHECK: Successors according to CFG: BB#1(4) BB#3(7)
 

diff --git a/test/CodeGen/Thumb2/v8_IT_3.ll b/test/CodeGen/Thumb2/v8_IT_3.ll
index 3ccee5f..78b51a0 100644 (file)
--- a/test/CodeGen/Thumb2/v8_IT_3.ll
+++ b/test/CodeGen/Thumb2/v8_IT_3.ll
@@ -35,7 +35,7 @@ bb:
   br i1 %tmp4, label %bb1, label %bb8
 
 bb1:
-; CHECK: %bb6
+; CHECK: %entry
 ; CHECK: it    eq
 ; CHECK-NEXT: ldreq
 ; CHECK-NEXT: it       eq
@@ -54,8 +54,9 @@ bb1:
 bb4:
 ; CHECK-PIC: cmp
 ; CHECK-PIC: cmp
+; CHECK-PIC: cmp
 ; CHECK-PIC-NEXT: bne
-; CHECK-PIC-NEXT: %bb4
+; CHECK-PIC: %bb6
 ; CHECK-PIC-NEXT: movs
 ; CHECK-PIC-NEXT: add
 ; CHECK-PIC-NEXT: pop

diff --git a/test/CodeGen/Thumb2/v8_IT_5.ll b/test/CodeGen/Thumb2/v8_IT_5.ll
index 78b80d7..08df9e6 100644 (file)
--- a/test/CodeGen/Thumb2/v8_IT_5.ll
+++ b/test/CodeGen/Thumb2/v8_IT_5.ll
@@ -7,9 +7,11 @@
 ; CHECK-NEXT: %if.else163
 ; CHECK-NEXT: mov.w
 ; CHECK-NEXT: b
+; CHECK: [[JUMPTARGET]]:{{.*}}%if.else173
+; CHECK-NEXT: mov.w
+; CHECK-NEXT: pop
 ; CHECK-NEXT: %if.else145
 ; CHECK-NEXT: mov.w
-; CHECK: [[JUMPTARGET]]:{{.*}}%if.else173
 
 %struct.hc = type { i32, i32, i32, i32 }
 

diff --git a/test/CodeGen/X86/2006-10-19-SwitchUnnecessaryBranching.ll b/test/CodeGen/X86/2006-10-19-SwitchUnnecessaryBranching.ll
index dd67064..332816e 100644 (file)
--- a/test/CodeGen/X86/2006-10-19-SwitchUnnecessaryBranching.ll
+++ b/test/CodeGen/X86/2006-10-19-SwitchUnnecessaryBranching.ll
@@ -6,8 +6,8 @@
 define i32 @test(i32 %argc, i8** %argv) nounwind {
 entry:
 ; CHECK: cmpl  $2
-; CHECK-NEXT: jne
-; CHECK-NEXT: %bb2
+; CHECK-NEXT: je
+; CHECK-NEXT: %entry
 
        switch i32 %argc, label %UnifiedReturnBlock [
                 i32 1, label %bb

diff --git a/test/CodeGen/X86/switch-bt.ll b/test/CodeGen/X86/switch-bt.ll
index 2cf3aaf..6a2cbe1 100644 (file)
--- a/test/CodeGen/X86/switch-bt.ll
+++ b/test/CodeGen/X86/switch-bt.ll
@@ -5,7 +5,7 @@
 
 ;      CHECK: movabsq $2305843009482129440, %r
 ; CHECK-NEXT: btq %rax, %r
-; CHECK-NEXT: jae
+; CHECK-NEXT: jb
 ;     CHECK: movl  $671088640, %e
 ; CHECK-NEXT: btq %rax, %r
 ; CHECK-NEXT: jae
@@ -145,13 +145,13 @@ sw.epilog:
 ; CHECK: cmpl $10
 ; CHECK: je
 ; CHECK: cmpl $20
+; CHECK: je
+; CHECK: cmpl $30
 ; CHECK: jne
 ; CHECK: cmpl $40
 ; CHECK: je
 ; CHECK: cmpl $50
-; CHECK: jne
-; CHECK: cmpl $30
-; CHECK: jne
+; CHECK: je
 ; CHECK: cmpl $60
 ; CHECK: jne
 }

diff --git a/test/CodeGen/X86/switch-edge-weight.ll b/test/CodeGen/X86/switch-edge-weight.ll
index c4cba43..27f15a7 100644 (file)
--- a/test/CodeGen/X86/switch-edge-weight.ll
+++ b/test/CodeGen/X86/switch-edge-weight.ll
@@ -1,19 +1,20 @@
 ; RUN: llc -march=x86-64 -print-machineinstrs=expand-isel-pseudos %s -o /dev/null 2>&1 | FileCheck %s
 
+declare void @foo(i32)
 
 ; CHECK-LABEL: test
 
 define void @test(i32 %x) nounwind {
 entry:
   switch i32 %x, label %sw.default [
-    i32 54, label %sw.bb
-    i32 55, label %sw.bb
-    i32 56, label %sw.bb
-    i32 58, label %sw.bb
-    i32 67, label %sw.bb
-    i32 68, label %sw.bb
-    i32 134, label %sw.bb
-    i32 140, label %sw.bb
+    i32 1, label %sw.bb
+    i32 155, label %sw.bb
+    i32 156, label %sw.bb
+    i32 157, label %sw.bb
+    i32 158, label %sw.bb
+    i32 159, label %sw.bb
+    i32 1134, label %sw.bb
+    i32 1140, label %sw.bb
   ], !prof !1
 
 sw.bb:
@@ -30,12 +31,199 @@ sw.epilog:
 ; Check if weights are correctly assigned to edges generated from switch
 ; statement.
 ;
+; CHECK: BB#0:
+; BB#0 to BB#4: [0, 1133] (65 = 60 + 5)
+; BB#0 to BB#5: [1134, UINT32_MAX] (25 = 20 + 5)
+; CHECK: Successors according to CFG: BB#4(65) BB#5(25)
+;
 ; CHECK: BB#4:
-; CHECK: Successors according to CFG: BB#1(10) BB#6(10)
+; BB#4 to BB#1: [155, 159] (50)
+; BB#4 to BB#5: [0, 1133] - [155, 159] (15 = 10 + 5)
+; CHECK: Successors according to CFG: BB#1(50) BB#7(15)
+;
+; CHECK: BB#5:
+; BB#5 to BB#1: {1140} (10)
+; BB#5 to BB#6: [1134, UINT32_MAX] - {1140} (15 = 10 + 5)
+; CHECK: Successors according to CFG: BB#1(10) BB#6(15)
+;
 ; CHECK: BB#6:
-; CHECK: Successors according to CFG: BB#1(10) BB#2(10)
+; BB#6 to BB#1: {1134} (10)
+; BB#6 to BB#2: [1134, UINT32_MAX] - {1134, 1140} (5)
+; CHECK: Successors according to CFG: BB#1(10) BB#2(5)
 }
 
-declare void @foo(i32)
+; CHECK-LABEL: test2
+
+define void @test2(i32 %x) nounwind {
+entry:
+
+; In this switch statement, there is an edge from jump table to default
+; statement.
+
+  switch i32 %x, label %sw.default [
+    i32 1, label %sw.bb
+    i32 10, label %sw.bb2
+    i32 11, label %sw.bb3
+    i32 12, label %sw.bb4
+    i32 13, label %sw.bb5
+    i32 14, label %sw.bb5
+  ], !prof !3
+
+sw.bb:
+  call void @foo(i32 0)
+  br label %sw.epilog
+
+sw.bb2:
+  call void @foo(i32 2)
+  br label %sw.epilog
+
+sw.bb3:
+  call void @foo(i32 3)
+  br label %sw.epilog
+
+sw.bb4:
+  call void @foo(i32 4)
+  br label %sw.epilog
+
+sw.bb5:
+  call void @foo(i32 5)
+  br label %sw.epilog
+
+sw.default:
+  call void @foo(i32 1)
+  br label %sw.epilog
+
+sw.epilog:
+  ret void
+
+; Check if weights are correctly assigned to edges generated from switch
+; statement.
+;
+; CHECK: BB#0:
+; BB#0 to BB#6: {0} + [15, UINT32_MAX] (5)
+; BB#0 to BB#8: [1, 14] (jump table) (65 = 60 + 5)
+; CHECK: Successors according to CFG: BB#6(5) BB#8(65)
+;
+; CHECK: BB#8:
+; BB#8 to BB#1: {1} (10)
+; BB#8 to BB#6: [2, 9] (5)
+; BB#8 to BB#2: {10} (10)
+; BB#8 to BB#3: {11} (10)
+; BB#8 to BB#4: {12} (10)
+; BB#8 to BB#5: {13, 14} (20)
+; CHECK: Successors according to CFG: BB#1(10) BB#6(5) BB#2(10) BB#3(10) BB#4(10) BB#5(20)
+}
+
+; CHECK-LABEL: test3
+
+define void @test3(i32 %x) nounwind {
+entry:
+
+; In this switch statement, there is no edge from jump table to default
+; statement.
+
+  switch i32 %x, label %sw.default [
+    i32 10, label %sw.bb
+    i32 11, label %sw.bb2
+    i32 12, label %sw.bb3
+    i32 13, label %sw.bb4
+    i32 14, label %sw.bb5
+  ], !prof !2
+
+sw.bb:
+  call void @foo(i32 0)
+  br label %sw.epilog
+
+sw.bb2:
+  call void @foo(i32 2)
+  br label %sw.epilog
+
+sw.bb3:
+  call void @foo(i32 3)
+  br label %sw.epilog
+
+sw.bb4:
+  call void @foo(i32 4)
+  br label %sw.epilog
+
+sw.bb5:
+  call void @foo(i32 5)
+  br label %sw.epilog
+
+sw.default:
+  call void @foo(i32 1)
+  br label %sw.epilog
+
+sw.epilog:
+  ret void
+
+; Check if weights are correctly assigned to edges generated from switch
+; statement.
+;
+; CHECK: BB#0:
+; BB#0 to BB#6: [0, 9] + [15, UINT32_MAX] {10}
+; BB#0 to BB#8: [10, 14] (jump table) (50)
+; CHECK: Successors according to CFG: BB#6(10) BB#8(50)
+;
+; CHECK: BB#8:
+; BB#8 to BB#1: {10} (10)
+; BB#8 to BB#2: {11} (10)
+; BB#8 to BB#3: {12} (10)
+; BB#8 to BB#4: {13} (10)
+; BB#8 to BB#5: {14} (10)
+; CHECK: Successors according to CFG: BB#1(10) BB#2(10) BB#3(10) BB#4(10) BB#5(10)
+}
+
+; CHECK-LABEL: test4
+
+define void @test4(i32 %x) nounwind {
+entry:
+
+; In this switch statement, there is no edge from bit test to default basic
+; block.
+
+  switch i32 %x, label %sw.default [
+    i32 1, label %sw.bb
+    i32 111, label %sw.bb2
+    i32 112, label %sw.bb3
+    i32 113, label %sw.bb3
+    i32 114, label %sw.bb2
+    i32 115, label %sw.bb2
+  ], !prof !3
+
+sw.bb:
+  call void @foo(i32 0)
+  br label %sw.epilog
+
+sw.bb2:
+  call void @foo(i32 2)
+  br label %sw.epilog
+
+sw.bb3:
+  call void @foo(i32 3)
+  br label %sw.epilog
+
+sw.default:
+  call void @foo(i32 1)
+  br label %sw.epilog
+
+sw.epilog:
+  ret void
+
+; Check if weights are correctly assigned to edges generated from switch
+; statement.
+;
+; CHECK: BB#0:
+; BB#0 to BB#6: [0, 110] + [116, UINT32_MAX] (20)
+; BB#0 to BB#7: [111, 115] (bit test) (50)
+; CHECK: Successors according to CFG: BB#6(20) BB#7(50)
+;
+; CHECK: BB#7:
+; BB#7 to BB#2: {111, 114, 115} (30)
+; BB#7 to BB#3: {112, 113} (20)
+; CHECK: Successors according to CFG: BB#2(30) BB#3(20)
+}
 
 !1 = !{!"branch_weights", i32 10, i32 10, i32 10, i32 10, i32 10, i32 10, i32 10, i32 10, i32 10} 
+!2 = !{!"branch_weights", i32 10, i32 10, i32 10, i32 10, i32 10, i32 10} 
+!3 = !{!"branch_weights", i32 10, i32 10, i32 10, i32 10, i32 10, i32 10, i32 10} 

diff --git a/test/CodeGen/X86/switch-order-weight.ll b/test/CodeGen/X86/switch-order-weight.ll
index 207e0b3..8c0c1a7 100644 (file)
--- a/test/CodeGen/X86/switch-order-weight.ll
+++ b/test/CodeGen/X86/switch-order-weight.ll
@@ -13,8 +13,8 @@ entry:
 ; CHECK-LABEL: test1:
 ; CHECK-NOT: unr
 ; CHECK: cmpl $10
-; CHECK: bar
 ; CHECK: cmpl $20
+; CHECK: bar
 
 if.then:
   tail call void @unr(i32 23) noreturn nounwind

diff --git a/test/CodeGen/X86/switch.ll b/test/CodeGen/X86/switch.ll
index fdb148a..4658734 100644 (file)
--- a/test/CodeGen/X86/switch.ll
+++ b/test/CodeGen/X86/switch.ll
@@ -51,7 +51,7 @@ return: ret void
 ; CHECK-LABEL: simple_ranges
 ; CHECK: leal -100
 ; CHECK: cmpl $4
-; CHECK: jae
+; CHECK: jb
 ; CHECK: cmpl $3
 ; CHECK: ja