diff options
| -rw-r--r-- | lib/CodeGen/SelectionDAG/FastISel.cpp | 8 | ||||
| -rw-r--r-- | lib/Target/X86/X86FastISel.cpp | 19 | ||||
| -rw-r--r-- | test/CodeGen/X86/fast-isel-branch_weights.ll | 19 |
3 files changed, 41 insertions, 5 deletions
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp index 21fcbd6161..f7da4d546d 100644 --- a/lib/CodeGen/SelectionDAG/FastISel.cpp +++ b/lib/CodeGen/SelectionDAG/FastISel.cpp @@ -42,6 +42,7 @@ #include "llvm/CodeGen/FastISel.h" #include "llvm/ADT/Optional.h" #include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/BranchProbabilityInfo.h" #include "llvm/Analysis/Loads.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/FunctionLoweringInfo.h" @@ -981,7 +982,6 @@ FastISel::SelectInstruction(const Instruction *I) { /// the CFG. void FastISel::FastEmitBranch(MachineBasicBlock *MSucc, DebugLoc DbgLoc) { - if (FuncInfo.MBB->getBasicBlock()->size() > 1 && FuncInfo.MBB->isLayoutSuccessor(MSucc)) { // For more accurate line information if this is the only instruction @@ -992,7 +992,11 @@ FastISel::FastEmitBranch(MachineBasicBlock *MSucc, DebugLoc DbgLoc) { TII.InsertBranch(*FuncInfo.MBB, MSucc, nullptr, SmallVector<MachineOperand, 0>(), DbgLoc); } - FuncInfo.MBB->addSuccessor(MSucc); + uint32_t BranchWeight = 0; + if (FuncInfo.BPI) + BranchWeight = FuncInfo.BPI->getEdgeWeight(FuncInfo.MBB->getBasicBlock(), + MSucc->getBasicBlock()); + FuncInfo.MBB->addSuccessor(MSucc, BranchWeight); } /// SelectFNeg - Emit an FNeg operation. diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp index e8f8805ee1..e041b504af 100644 --- a/lib/Target/X86/X86FastISel.cpp +++ b/lib/Target/X86/X86FastISel.cpp @@ -20,6 +20,7 @@ #include "X86RegisterInfo.h" #include "X86Subtarget.h" #include "X86TargetMachine.h" +#include "llvm/Analysis/BranchProbabilityInfo.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/FastISel.h" #include "llvm/CodeGen/FunctionLoweringInfo.h" @@ -1206,7 +1207,11 @@ bool X86FastISel::X86SelectBranch(const Instruction *I) { } FastEmitBranch(FalseMBB, DbgLoc); - FuncInfo.MBB->addSuccessor(TrueMBB); + uint32_t BranchWeight = 0; + if (FuncInfo.BPI) + BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), + TrueMBB->getBasicBlock()); + FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } } else if (TruncInst *TI = dyn_cast<TruncInst>(BI->getCondition())) { @@ -1238,7 +1243,11 @@ bool X86FastISel::X86SelectBranch(const Instruction *I) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(JmpOpc)) .addMBB(TrueMBB); FastEmitBranch(FalseMBB, DbgLoc); - FuncInfo.MBB->addSuccessor(TrueMBB); + uint32_t BranchWeight = 0; + if (FuncInfo.BPI) + BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), + TrueMBB->getBasicBlock()); + FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } } @@ -1255,7 +1264,11 @@ bool X86FastISel::X86SelectBranch(const Instruction *I) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JNE_4)) .addMBB(TrueMBB); FastEmitBranch(FalseMBB, DbgLoc); - FuncInfo.MBB->addSuccessor(TrueMBB); + uint32_t BranchWeight = 0; + if (FuncInfo.BPI) + BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(), + TrueMBB->getBasicBlock()); + FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight); return true; } diff --git a/test/CodeGen/X86/fast-isel-branch_weights.ll b/test/CodeGen/X86/fast-isel-branch_weights.ll new file mode 100644 index 0000000000..bc41395e1e --- /dev/null +++ b/test/CodeGen/X86/fast-isel-branch_weights.ll @@ -0,0 +1,19 @@ +; RUN: llc < %s -mtriple=x86_64-apple-darwin10 | FileCheck %s +; RUN: llc < %s -fast-isel -fast-isel-abort -mtriple=x86_64-apple-darwin10 | FileCheck %s + +; Test if the BBs are reordred according to their branch weights. +define i64 @branch_weights_test(i64 %a, i64 %b) { +; CHECK-LABEL: branch_weights_test +; CHECK-LABEL: success +; CHECK-LABEL: fail + %1 = icmp ult i64 %a, %b + br i1 %1, label %fail, label %success, !prof !0 + +fail: + ret i64 -1 + +success: + ret i64 0 +} + +!0 = metadata !{metadata !"branch_weights", i32 0, i32 2147483647} |