llvm/lib/Target/PowerPC/PPCSubtarget.cpp
Chris Lattner 57fc62c8d2 Another step forward in PPC64 JIT support: we now no-longer need stubs
emitted for external globals in PPC64-JIT-PIC mode (which is good because
we didn't handle them before!).

This also fixes a bug handling the picbase delta, which we would get wrong
in some cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32451 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-11 23:22:45 +00:00

139 lines
4.4 KiB
C++

//===- PowerPCSubtarget.cpp - PPC Subtarget Information -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Nate Begeman and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PPC specific subclass of TargetSubtarget.
//
//===----------------------------------------------------------------------===//
#include "PPCSubtarget.h"
#include "PPC.h"
#include "llvm/Module.h"
#include "llvm/Target/TargetMachine.h"
#include "PPCGenSubtarget.inc"
using namespace llvm;
#if defined(__APPLE__)
#include <mach/mach.h>
#include <mach/mach_host.h>
#include <mach/host_info.h>
#include <mach/machine.h>
/// GetCurrentPowerPCFeatures - Returns the current CPUs features.
static const char *GetCurrentPowerPCCPU() {
host_basic_info_data_t hostInfo;
mach_msg_type_number_t infoCount;
infoCount = HOST_BASIC_INFO_COUNT;
host_info(mach_host_self(), HOST_BASIC_INFO, (host_info_t)&hostInfo,
&infoCount);
if (hostInfo.cpu_type != CPU_TYPE_POWERPC) return "generic";
switch(hostInfo.cpu_subtype) {
case CPU_SUBTYPE_POWERPC_601: return "601";
case CPU_SUBTYPE_POWERPC_602: return "602";
case CPU_SUBTYPE_POWERPC_603: return "603";
case CPU_SUBTYPE_POWERPC_603e: return "603e";
case CPU_SUBTYPE_POWERPC_603ev: return "603ev";
case CPU_SUBTYPE_POWERPC_604: return "604";
case CPU_SUBTYPE_POWERPC_604e: return "604e";
case CPU_SUBTYPE_POWERPC_620: return "620";
case CPU_SUBTYPE_POWERPC_750: return "750";
case CPU_SUBTYPE_POWERPC_7400: return "7400";
case CPU_SUBTYPE_POWERPC_7450: return "7450";
case CPU_SUBTYPE_POWERPC_970: return "970";
default: ;
}
return "generic";
}
#endif
PPCSubtarget::PPCSubtarget(const TargetMachine &tm, const Module &M,
const std::string &FS, bool is64Bit)
: TM(tm)
, StackAlignment(16)
, IsGigaProcessor(false)
, Has64BitSupport(false)
, Use64BitRegs(false)
, IsPPC64(is64Bit)
, HasAltivec(false)
, HasFSQRT(false)
, HasSTFIWX(false)
, IsDarwin(false)
, HasLazyResolverStubs(false) {
// Determine default and user specified characteristics
std::string CPU = "generic";
#if defined(__APPLE__)
CPU = GetCurrentPowerPCCPU();
#endif
// Parse features string.
ParseSubtargetFeatures(FS, CPU);
// If we are generating code for ppc64, verify that options make sense.
if (is64Bit) {
if (!has64BitSupport()) {
cerr << "PPC: Generation of 64-bit code for a 32-bit processor "
<< "requested. Ignoring 32-bit processor feature.\n";
Has64BitSupport = true;
}
// Silently force 64-bit register use on ppc64.
Use64BitRegs = true;
}
// If the user requested use of 64-bit regs, but the cpu selected doesn't
// support it, warn and ignore.
if (use64BitRegs() && !has64BitSupport()) {
cerr << "PPC: 64-bit registers requested on CPU without support. "
<< "Disabling 64-bit register use.\n";
Use64BitRegs = false;
}
// Set the boolean corresponding to the current target triple, or the default
// if one cannot be determined, to true.
const std::string& TT = M.getTargetTriple();
if (TT.length() > 5) {
IsDarwin = TT.find("-darwin") != std::string::npos;
} else if (TT.empty()) {
#if defined(__APPLE__)
IsDarwin = true;
#endif
}
// Set up darwin-specific properties.
if (IsDarwin) {
HasLazyResolverStubs = true;
}
}
/// SetJITMode - This is called to inform the subtarget info that we are
/// producing code for the JIT.
void PPCSubtarget::SetJITMode() {
// JIT mode doesn't want lazy resolver stubs, it knows exactly where
// everything is. This matters for PPC64, which codegens in PIC mode without
// stubs.
HasLazyResolverStubs = false;
}
/// hasLazyResolverStub - Return true if accesses to the specified global have
/// to go through a dyld lazy resolution stub. This means that an extra load
/// is required to get the address of the global.
bool PPCSubtarget::hasLazyResolverStub(const GlobalValue *GV) const {
// We never hae stubs if HasLazyResolverStubs=false or if in static mode.
if (!HasLazyResolverStubs || TM.getRelocationModel() == Reloc::Static)
return false;
return GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
(GV->isExternal() && !GV->hasNotBeenReadFromBytecode());
}