Index: llvm/lib/CodeGen/MachineOutliner.cpp =================================================================== --- llvm/lib/CodeGen/MachineOutliner.cpp +++ llvm/lib/CodeGen/MachineOutliner.cpp @@ -96,6 +96,12 @@ cl::desc("Enable the machine outliner on linkonceodr functions"), cl::init(false)); +// Set the number of times to repeatedly apply outlining. +// Defaults to 1, but more repetitions can save additional size. +static cl::opt + NumRepeat("outline-repeat-count", cl::Hidden, + cl::desc("The number of times to apply outlining"), cl::init(1)); + namespace { /// Represents an undefined index in the suffix tree. @@ -841,6 +847,9 @@ /// linkonceodr linkage. bool OutlineFromLinkOnceODRs = false; + /// The current repeat number of machine outlining. + unsigned OutlineRepeatedNum = 0; + /// Set to true if the outliner should run on all functions in the module /// considered safe for outlining. /// Set to true by default for compatibility with llc's -run-pass option. @@ -899,9 +908,12 @@ InstructionMapper &Mapper, unsigned Name); - /// Calls 'doOutline()'. + /// Calls runOnceOnModule NumRepeat times bool runOnModule(Module &M) override; + /// Calls 'doOutline()'. + bool runOnceOnModule(Module &M, unsigned Iter); + /// Construct a suffix tree on the instructions in \p M and outline repeated /// strings from that tree. bool doOutline(Module &M, unsigned &OutlinedFunctionNum); @@ -1098,7 +1110,13 @@ // Create the function name. This should be unique. // FIXME: We should have a better naming scheme. This should be stable, // regardless of changes to the outliner's cost model/traversal order. - std::string FunctionName = ("OUTLINED_FUNCTION_" + Twine(Name)).str(); + std::string FunctionName; + if (OutlineRepeatedNum > 0) + FunctionName = ("OUTLINED_FUNCTION_" + Twine(OutlineRepeatedNum + 1) + "_" + + Twine(Name)) + .str(); + else + FunctionName = ("OUTLINED_FUNCTION_" + Twine(Name)).str(); // Create the function using an IR-level function. LLVMContext &C = M.getContext(); @@ -1415,12 +1433,14 @@ } } -bool MachineOutliner::runOnModule(Module &M) { +bool MachineOutliner::runOnceOnModule(Module &M, unsigned Iter) { // Check if there's anything in the module. If it's empty, then there's // nothing to outline. if (M.empty()) return false; + OutlineRepeatedNum = Iter; + // Number to append to the current outlined function. unsigned OutlinedFunctionNum = 0; @@ -1484,3 +1504,24 @@ return OutlinedSomething; } + +// Apply machine outlining for NumRepeat times. +bool MachineOutliner::runOnModule(Module &M) { + unsigned NumRepeats = NumRepeat; + if (NumRepeats < 1) + report_fatal_error("Expect NumRepeats for machine outlining " + "is equal or greater than 1!\n"); + + bool Changed = false; + for (unsigned I = 0; I < NumRepeats; I++) { + if (!runOnceOnModule(M, I)) { + LLVM_DEBUG(dbgs() << "Stopped outlining at iteration " << I + << " because no changes were found.\n";); + return Changed; + } + Changed = true; + } + LLVM_DEBUG(dbgs() << "Stopped outlining because iteration " << I + << " >= " << NumRepeats << "\n";); + return Changed; +} Index: llvm/test/CodeGen/AArch64/machine-outliner-iterative.mir =================================================================== --- /dev/null +++ llvm/test/CodeGen/AArch64/machine-outliner-iterative.mir @@ -0,0 +1,130 @@ +# RUN: llc -mtriple=aarch64--- -run-pass=prologepilog -run-pass=machine-outliner -outline-repeat-count=2 -verify-machineinstrs %s -o - | FileCheck %s + +# Example of Repeated Instruction Sequence - Iterative Machine Outlining +# +#; define void @"$s12"(...) { define i64 @"$s5” (...) { define void @"$s13"(...) { +# ... ... ... +# %8 = load i1, i1* %7 %8 = load i1, i1* %7 +# %9 = load i4, i4*, %6 %9 = load i4, i4*, %6 %9 = load i4, i4*, %6 +# store i4 %9, i4* %5 store i4 %9, i4* %5 store i4 %9, i4* %5 +# ... ... ... +# } } } +# +# After machine outliner (1st time) +# +# define void @"$s12"(...) { define i64 @"$s5” (...) { define void @"$s13"(...) { +# ... ... ... +# %8 = load i1, i1* %7 %8 = load i1, i1* %7 +# call void @outlined_function_1_1 call void @outlined_function_1_1 call void @outlined_function_1_1 +# ... ... ... +# } } } +# +# After machine outliner (2nd time) +# +# define void @"$s12"(...) { define i64 @"$s5” (...) { define void @"$s13"(...) { +# ... ... ... +# call void @outlined_function_2_1 call void @outlined_function_1_1 call void @outlined_function_2_1 +# ... ... ... +# } } } +# +# Check whether machine outliner can further find the outlining opportunity after machine +# outlining has performed. +# +--- | + target triple = "aarch64-apple-darwin" + + %0 = type { %1*, i64 } + %1 = type { i64 } + %2 = type <{ %0, %3, %6 }> + %3 = type <{ %4, %4, %4, %4 }> + %4 = type <{ %5 }> + %5 = type <{ double }> + %6 = type <{ %7 }> + %7 = type <{ %8 }> + %8 = type <{ %9* }> + %9 = type opaque + %10 = type <{ %0, %6 }> + + declare void @widget(%0*) local_unnamed_addr + + declare void @foo(i8*, [24 x i8]*, i64, i8*) local_unnamed_addr + + define void @baz.14 (%2* %tmp37) optsize minsize noredzone { + ret void + } + + define void @baz.15 (%2* %tmp38, %10* %tmp11) optsize minsize noredzone { + ret void + } + + define void @baz.16 (%2* %tmp39) optsize minsize noredzone { + ret void + } +... +--- +name: baz.14 +tracksRegLiveness: true +body: | + bb.0: + liveins: $x0 + + renamable $x19 = COPY $x0 + renamable $x0 = nuw ADDXri $x0, 48, 0 + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x1 = ADDXri $sp, 0, 0 + dead $w2 = MOVi32imm 33, implicit-def $x2 + $x3 = COPY $xzr + BL @foo, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit killed $x1, implicit killed $x2, implicit killed $x3, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x0 = COPY killed renamable $x19 + BL @widget, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + RET_ReallyLR + +... +--- +name: baz.15 +stack: +body: | + bb.0: + liveins: $x0, $x1 + + renamable $x19 = COPY $x0 + renamable $x0 = nuw ADDXri killed renamable $x1, 16, 0 + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x1 = ADDXri $sp, 0, 0 + dead $w2 = MOVi32imm 33, implicit-def $x2 + $x3 = COPY $xzr + BL @foo, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit $x1, implicit killed $x2, implicit killed $x3, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x0 = COPY killed renamable $x19 + BL @widget, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + RET_ReallyLR + +... +--- +name: baz.16 +tracksRegLiveness: true +body: | + bb.0: + liveins: $x0 + + renamable $x19 = COPY $x0 + renamable $x0 = nuw ADDXri $x0, 48, 0 + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x1 = ADDXri $sp, 0, 0 + dead $w2 = MOVi32imm 33, implicit-def $x2 + $x3 = COPY $xzr + BL @foo, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit killed $x1, implicit killed $x2, implicit killed $x3, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp + $x0 = COPY killed renamable $x19 + BL @widget, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp + ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp + RET_ReallyLR + +... +# CHECK: [[OUTLINED:OUTLINED_FUNCTION_2_[0-9]+]]