llvm-project/llvm/lib/CodeGen/TargetSubtargetInfo.cpp
Andrea Di Biagio edbf06a767 [AsmPrinter] Remove hidden flag -print-schedule.
This patch removes hidden codegen flag -print-schedule effectively reverting the
logic originally committed as r300311
(https://llvm.org/viewvc/llvm-project?view=revision&revision=300311).

Flag -print-schedule was originally introduced by r300311 to address PR32216
(https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better
testing of schedule model instruction latencies/throughputs".

These days, we can use llvm-mca to test scheduling models. So there is no longer
a need for flag -print-schedule in LLVM. The main use case for PR32216 is
now addressed by llvm-mca.
Flag -print-schedule is mainly used for debugging purposes, and it is only
actually used by x86 specific tests. We already have extensive (latency and
throughput) tests under "test/tools/llvm-mca" for X86 processor models. That
means, most (if not all) existing -print-schedule tests for X86 are redundant.

When flag -print-schedule was first added to LLVM, several files had to be
modified; a few APIs gained new arguments (see for example method
MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained
a couple of getSchedInfoStr() methods.

Method getSchedInfoStr() had to originally work for both MCInst and
MachineInstr. The original implmentation of getSchedInfoStr() introduced a
subtle layering violation (reported as PR37160 and then fixed/worked-around by
r330615).
In retrospect, that new API could have been designed more optimally. We can
always query MCSchedModel to get the latency and throughput. More importantly,
the "sched-info" string should not have been generated by the subtarget.
Note, r317782 fixed an issue where "print-schedule" didn't work very well in the
presence of inline assembly. That commit is also reverted by this change.

Differential Revision: https://reviews.llvm.org/D57244

llvm-svn: 353043
2019-02-04 12:51:26 +00:00

62 lines
1.8 KiB
C++

//===- TargetSubtargetInfo.cpp - General Target Information ----------------==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file This file describes the general parts of a Subtarget.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/TargetSubtargetInfo.h"
using namespace llvm;
TargetSubtargetInfo::TargetSubtargetInfo(
const Triple &TT, StringRef CPU, StringRef FS,
ArrayRef<SubtargetFeatureKV> PF, ArrayRef<SubtargetFeatureKV> PD,
const SubtargetInfoKV *ProcSched, const MCWriteProcResEntry *WPR,
const MCWriteLatencyEntry *WL, const MCReadAdvanceEntry *RA,
const InstrStage *IS, const unsigned *OC, const unsigned *FP)
: MCSubtargetInfo(TT, CPU, FS, PF, PD, ProcSched, WPR, WL, RA, IS, OC, FP) {
}
TargetSubtargetInfo::~TargetSubtargetInfo() = default;
bool TargetSubtargetInfo::enableAtomicExpand() const {
return true;
}
bool TargetSubtargetInfo::enableIndirectBrExpand() const {
return false;
}
bool TargetSubtargetInfo::enableMachineScheduler() const {
return false;
}
bool TargetSubtargetInfo::enableJoinGlobalCopies() const {
return enableMachineScheduler();
}
bool TargetSubtargetInfo::enableRALocalReassignment(
CodeGenOpt::Level OptLevel) const {
return true;
}
bool TargetSubtargetInfo::enableAdvancedRASplitCost() const {
return false;
}
bool TargetSubtargetInfo::enablePostRAScheduler() const {
return getSchedModel().PostRAScheduler;
}
bool TargetSubtargetInfo::useAA() const {
return false;
}
void TargetSubtargetInfo::mirFileLoaded(MachineFunction &MF) const { }