[llvm] r341876 - Add size remarks to MachineFunctionPass
Jessica Paquette via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 10 15:24:11 PDT 2018
Author: paquette
Date: Mon Sep 10 15:24:10 2018
New Revision: 341876
URL: http://llvm.org/viewvc/llvm-project?rev=341876&view=rev
Log:
Add size remarks to MachineFunctionPass
This adds per-function size remarks to codegen, similar to what we have in the
IR layer as of r341588. This only impacts MachineFunctionPasses.
This does the same thing, but for `MachineInstr`s instead of just
`Instructions`. After this, when a `MachineFunctionPass` modifies the number of
`MachineInstr`s in the function it ran on, you'll get a remark.
To enable this, use the size-info analysis remark as before.
Added:
llvm/trunk/test/Other/machine-size-remarks.ll
Modified:
llvm/trunk/include/llvm/CodeGen/MachineFunction.h
llvm/trunk/lib/CodeGen/MachineFunctionPass.cpp
Modified: llvm/trunk/include/llvm/CodeGen/MachineFunction.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineFunction.h?rev=341876&r1=341875&r2=341876&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineFunction.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineFunction.h Mon Sep 10 15:24:10 2018
@@ -618,6 +618,14 @@ public:
BasicBlocks.sort(comp);
}
+ /// Return the number of \p MachineInstrs in this \p MachineFunction.
+ unsigned getInstructionCount() const {
+ unsigned InstrCount = 0;
+ for (const MachineBasicBlock &MBB : BasicBlocks)
+ InstrCount += MBB.size();
+ return InstrCount;
+ }
+
//===--------------------------------------------------------------------===//
// Internal functions used to automatically number MachineBasicBlocks
Modified: llvm/trunk/lib/CodeGen/MachineFunctionPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineFunctionPass.cpp?rev=341876&r1=341875&r2=341876&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineFunctionPass.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineFunctionPass.cpp Mon Sep 10 15:24:10 2018
@@ -23,11 +23,13 @@
#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
using namespace llvm;
+using namespace ore;
Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,
const std::string &Banner) const {
@@ -57,9 +59,43 @@ bool MachineFunctionPass::runOnFunction(
llvm_unreachable("MachineFunctionProperties check failed");
}
#endif
+ // Collect the MI count of the function before the pass.
+ unsigned CountBefore, CountAfter;
+
+ // Check if the user asked for size remarks.
+ bool ShouldEmitSizeRemarks =
+ F.getParent()->shouldEmitInstrCountChangedRemark();
+
+ // If we want size remarks, collect the number of MachineInstrs in our
+ // MachineFunction before the pass runs.
+ if (ShouldEmitSizeRemarks)
+ CountBefore = MF.getInstructionCount();
bool RV = runOnMachineFunction(MF);
+ if (ShouldEmitSizeRemarks) {
+ // We wanted size remarks. Check if there was a change to the number of
+ // MachineInstrs in the module. Emit a remark if there was a change.
+ CountAfter = MF.getInstructionCount();
+ if (CountBefore != CountAfter) {
+ MachineOptimizationRemarkEmitter MORE(MF, nullptr);
+ MORE.emit([&]() {
+ int64_t Delta = static_cast<int64_t>(CountAfter) -
+ static_cast<int64_t>(CountBefore);
+ MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange",
+ MF.getFunction().getSubprogram(),
+ &MF.front());
+ R << NV("Pass", getPassName())
+ << ": Function: " << NV("Function", F.getName()) << ": "
+ << "MI Instruction count changed from "
+ << NV("MIInstrsBefore", CountBefore) << " to "
+ << NV("MIInstrsAfter", CountAfter)
+ << "; Delta: " << NV("Delta", Delta);
+ return R;
+ });
+ }
+ }
+
MFProps.set(SetProperties);
MFProps.reset(ClearedProperties);
return RV;
Added: llvm/trunk/test/Other/machine-size-remarks.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/machine-size-remarks.ll?rev=341876&view=auto
==============================================================================
--- llvm/trunk/test/Other/machine-size-remarks.ll (added)
+++ llvm/trunk/test/Other/machine-size-remarks.ll Mon Sep 10 15:24:10 2018
@@ -0,0 +1,58 @@
+; RUN: llc -mtriple x86_64---- %s -pass-remarks-analysis='size-info'\
+; RUN: -pass-remarks-output=%t.yaml -o /dev/null < %s 2> %t; \
+; RUN: cat %t %t.yaml | FileCheck %s
+
+; Make sure that machine-level size remarks work.
+; Test the following:
+; - When we create a MachineFunction (e.g, during instruction selection), it
+; has a size of 0.
+; - The initial size of the function after filling it is positive.
+; - After that, we can increase or decrease the size of the function.
+; - ... The final size must be positive.
+; - ... The delta can be negative or positive.
+
+; CHECK: remark: <unknown>:0:0: X86 DAG->DAG Instruction Selection: Function:
+; CHECK-SAME: main: MI Instruction count changed from 0
+; CHECK-SAME: to [[INIT:[1-9][0-9]*]]; Delta: [[INIT]]
+; CHECK-NEXT: remark: <unknown>:0:0: Simple Register Coalescing: Function: main:
+; CHECK-SAME: MI Instruction count changed from [[INIT]] to
+; CHECK-SAME: [[FINAL:[1-9][0-9]*]];
+; CHECK-SAME: Delta: [[DELTA:-?[1-9][0-9]*]]
+; CHECK-NEXT: --- !Analysis
+; CHECK-NEXT: Pass: size-info
+; CHECK-NEXT: Name: FunctionMISizeChange
+; CHECK-NEXT: Function: main
+; CHECK-NEXT: Args:
+; CHECK-NEXT: - Pass: 'X86 DAG->DAG Instruction Selection'
+; CHECK-NEXT: - String: ': Function: '
+; CHECK-NEXT: - Function: main
+; CHECK-NEXT: - String: ': '
+; CHECK-NEXT: - String: 'MI Instruction count changed from '
+; CHECK-NEXT: - MIInstrsBefore: '0'
+; CHECK-NEXT: - String: ' to '
+; CHECK-NEXT: - MIInstrsAfter: '[[INIT]]'
+; CHECK-NEXT: - String: '; Delta: '
+; CHECK-NEXT: - Delta: '[[INIT]]'
+; CHECK-DAG: --- !Analysis
+; CHECK-NEXT: Pass: size-info
+; CHECK-NEXT: Name: FunctionMISizeChange
+; CHECK-NEXT: Function: main
+; CHECK-NEXT: Args:
+; CHECK-NEXT: - Pass: Simple Register Coalescing
+; CHECK-NEXT: - String: ': Function: '
+; CHECK-NEXT: - Function: main
+; CHECK-NEXT: - String: ': '
+; CHECK-NEXT: - String: 'MI Instruction count changed from '
+; CHECK-NEXT: - MIInstrsBefore: '[[INIT]]'
+; CHECK-NEXT: - String: ' to '
+; CHECK-NEXT: - MIInstrsAfter: '[[FINAL]]'
+; CHECK-NEXT: - String: '; Delta: '
+; CHECK-NEXT: - Delta: '[[DELTA]]'
+define i32 @main() #0 {
+entry:
+ %retval = alloca i32, align 4
+ store i32 0, i32* %retval, align 4
+ ret i32 0
+}
+
+attributes #0 = { noinline nounwind optnone ssp uwtable }
More information about the llvm-commits
mailing list