diff --git a/lib/CodeGen/MachineBlockPlacement.cpp b/lib/CodeGen/MachineBlockPlacement.cpp index cd948e24a6b..774df81b4d5 100644 --- a/lib/CodeGen/MachineBlockPlacement.cpp +++ b/lib/CodeGen/MachineBlockPlacement.cpp @@ -39,6 +39,7 @@ #include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/Support/Allocator.h" +#include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetLowering.h" @@ -52,6 +53,11 @@ STATISTIC(CondBranchTakenFreq, STATISTIC(UncondBranchTakenFreq, "Potential frequency of taking unconditional branches"); +static cl::opt AlignAllBlock("align-all-blocks", + cl::desc("Force the alignment of all " + "blocks in the function."), + cl::init(0), cl::Hidden); + namespace { class BlockChain; /// \brief Type for our function-wide basic block -> block chain mapping. @@ -1083,6 +1089,14 @@ bool MachineBlockPlacement::runOnMachineFunction(MachineFunction &F) { TLI = F.getTarget().getTargetLowering(); assert(BlockToChain.empty()); + if (AlignAllBlock) { + // Align all of the blocks in the function to a specific alignment. + for (MachineFunction::iterator FI = F.begin(), FE = F.end(); + FI != FE; ++FI) + FI->setAlignment(AlignAllBlock); + return true; + } + buildCFGChains(F); BlockToChain.clear(); diff --git a/test/CodeGen/X86/code_placement_align_all.ll b/test/CodeGen/X86/code_placement_align_all.ll new file mode 100644 index 00000000000..2a36a3a3af5 --- /dev/null +++ b/test/CodeGen/X86/code_placement_align_all.ll @@ -0,0 +1,22 @@ +; RUN: llc -march=x86 -align-all-blocks=16 < %s | FileCheck %s + +;CHECK: foo +;CHECK: .align 16, 0x90 +;CHECK: .align 16, 0x90 +;CHECK: .align 16, 0x90 +;CHECK: ret +define i32 @foo(i32 %t, i32 %l) nounwind readnone ssp uwtable { + %1 = icmp eq i32 %t, 0 + br i1 %1, label %4, label %2 + +;