llvm/lib/Target/Sparc/SparcSubtarget.cpp
Chris Dewhurst 2ac3a338b2 [SPARC] Fixes for hardware errata on LEON processor.
Passes to fix three hardware errata that appear on some LEON processor variants.

The instructions FSMULD, FMULS and FDIVS do not work as expected on some LEON processors. This change allows those instructions to be substituted for alternatives instruction sequences that are known to work.

These passes only run when selected individually, or as part of a processor defintion. They are not included in general SPARC processor compilations for non-LEON processors or for those LEON processors that do not have these hardware errata.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273108 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-19 11:03:28 +00:00

98 lines
3.0 KiB
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//===-- SparcSubtarget.cpp - SPARC Subtarget Information ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SPARC specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#include "SparcSubtarget.h"
#include "Sparc.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
#define DEBUG_TYPE "sparc-subtarget"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "SparcGenSubtargetInfo.inc"
void SparcSubtarget::anchor() { }
SparcSubtarget &SparcSubtarget::initializeSubtargetDependencies(StringRef CPU,
StringRef FS) {
IsV9 = false;
IsLeon = false;
V8DeprecatedInsts = false;
IsVIS = false;
HasHardQuad = false;
UsePopc = false;
UseSoftFloat = false;
// Leon features
HasLeonCasa = false;
HasUmacSmac = false;
InsertNOPLoad = false;
FixFSMULD = false;
ReplaceFMULS = false;
FixAllFDIVSQRT = false;
// Determine default and user specified characteristics
std::string CPUName = CPU;
if (CPUName.empty())
CPUName = (Is64Bit) ? "v9" : "v8";
// Parse features string.
ParseSubtargetFeatures(CPUName, FS);
// Popc is a v9-only instruction.
if (!IsV9)
UsePopc = false;
return *this;
}
SparcSubtarget::SparcSubtarget(const Triple &TT, const std::string &CPU,
const std::string &FS, const TargetMachine &TM,
bool is64Bit)
: SparcGenSubtargetInfo(TT, CPU, FS), TargetTriple(TT), Is64Bit(is64Bit),
InstrInfo(initializeSubtargetDependencies(CPU, FS)), TLInfo(TM, *this),
FrameLowering(*this) {}
int SparcSubtarget::getAdjustedFrameSize(int frameSize) const {
if (is64Bit()) {
// All 64-bit stack frames must be 16-byte aligned, and must reserve space
// for spilling the 16 window registers at %sp+BIAS..%sp+BIAS+128.
frameSize += 128;
// Frames with calls must also reserve space for 6 outgoing arguments
// whether they are used or not. LowerCall_64 takes care of that.
frameSize = alignTo(frameSize, 16);
} else {
// Emit the correct save instruction based on the number of bytes in
// the frame. Minimum stack frame size according to V8 ABI is:
// 16 words for register window spill
// 1 word for address of returned aggregate-value
// + 6 words for passing parameters on the stack
// ----------
// 23 words * 4 bytes per word = 92 bytes
frameSize += 92;
// Round up to next doubleword boundary -- a double-word boundary
// is required by the ABI.
frameSize = alignTo(frameSize, 8);
}
return frameSize;
}
bool SparcSubtarget::enableMachineScheduler() const {
return true;
}