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authordim <dim@FreeBSD.org>2014-03-21 17:53:59 +0000
committerdim <dim@FreeBSD.org>2014-03-21 17:53:59 +0000
commit9cedb8bb69b89b0f0c529937247a6a80cabdbaec (patch)
treec978f0e9ec1ab92dc8123783f30b08a7fd1e2a39 /contrib/llvm/lib/Target/R600/SIFixSGPRCopies.cpp
parent03fdc2934eb61c44c049a02b02aa974cfdd8a0eb (diff)
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MFC 261991:
Upgrade our copy of llvm/clang to 3.4 release. This version supports all of the features in the current working draft of the upcoming C++ standard, provisionally named C++1y. The code generator's performance is greatly increased, and the loop auto-vectorizer is now enabled at -Os and -O2 in addition to -O3. The PowerPC backend has made several major improvements to code generation quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ backends have all seen major feature work. Release notes for llvm and clang can be found here: <http://llvm.org/releases/3.4/docs/ReleaseNotes.html> <http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html> MFC 262121 (by emaste): Update lldb for clang/llvm 3.4 import This commit largely restores the lldb source to the upstream r196259 snapshot with the addition of threaded inferior support and a few bug fixes. Specific upstream lldb revisions restored include: SVN git 181387 779e6ac 181703 7bef4e2 182099 b31044e 182650 f2dcf35 182683 0d91b80 183862 15c1774 183929 99447a6 184177 0b2934b 184948 4dc3761 184954 007e7bc 186990 eebd175 Sponsored by: DARPA, AFRL MFC 262186 (by emaste): Fix mismerge in r262121 A break statement was lost in the merge. The error had no functional impact, but restore it to reduce the diff against upstream. MFC 262303: Pull in r197521 from upstream clang trunk (by rdivacky): Use the integrated assembler by default on FreeBSD/ppc and ppc64. Requested by: jhibbits MFC 262611: Pull in r196874 from upstream llvm trunk: Fix a crash that occurs when PWD is invalid. MCJIT needs to be able to run in hostile environments, even when PWD is invalid. There's no need to crash MCJIT in this case. The obvious fix is to simply leave MCContext's CompilationDir empty when PWD can't be determined. This way, MCJIT clients, and other clients that link with LLVM don't need a valid working directory. If we do want to guarantee valid CompilationDir, that should be done only for clients of getCompilationDir(). This is as simple as checking for an empty string. The only current use of getCompilationDir is EmitGenDwarfInfo, which won't conceivably run with an invalid working dir. However, in the purely hypothetically and untestable case that this happens, the AT_comp_dir will be omitted from the compilation_unit DIE. This should help fix assertions occurring with ports-mgmt/tinderbox, when it is using jails, and sometimes invalidates clang's current working directory. Reported by: decke MFC 262809: Pull in r203007 from upstream clang trunk: Don't produce an alias between destructors with different calling conventions. Fixes pr19007. (Please note that is an LLVM PR identifier, not a FreeBSD one.) This should fix Firefox and/or libxul crashes (due to problems with regparm/stdcall calling conventions) on i386. Reported by: multiple users on freebsd-current PR: bin/187103 MFC 263048: Repair recognition of "CC" as an alias for the C++ compiler, since it was silently broken by upstream for a Windows-specific use-case. Apparently some versions of CMake still rely on this archaic feature... Reported by: rakuco MFC 263049: Garbage collect the old way of adding the libstdc++ include directories in clang's InitHeaderSearch.cpp. This has been superseded by David Chisnall's commit in r255321. Moreover, if libc++ is used, the libstdc++ include directories should not be in the search path at all. These directories are now only used if you pass -stdlib=libstdc++.
Diffstat (limited to 'contrib/llvm/lib/Target/R600/SIFixSGPRCopies.cpp')
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diff --git a/contrib/llvm/lib/Target/R600/SIFixSGPRCopies.cpp b/contrib/llvm/lib/Target/R600/SIFixSGPRCopies.cpp
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+++ b/contrib/llvm/lib/Target/R600/SIFixSGPRCopies.cpp
@@ -0,0 +1,263 @@
+//===-- SIFixSGPRCopies.cpp - Remove potential VGPR => SGPR copies --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// Copies from VGPR to SGPR registers are illegal and the register coalescer
+/// will sometimes generate these illegal copies in situations like this:
+///
+/// Register Class <vsrc> is the union of <vgpr> and <sgpr>
+///
+/// BB0:
+/// %vreg0 <sgpr> = SCALAR_INST
+/// %vreg1 <vsrc> = COPY %vreg0 <sgpr>
+/// ...
+/// BRANCH %cond BB1, BB2
+/// BB1:
+/// %vreg2 <vgpr> = VECTOR_INST
+/// %vreg3 <vsrc> = COPY %vreg2 <vgpr>
+/// BB2:
+/// %vreg4 <vsrc> = PHI %vreg1 <vsrc>, <BB#0>, %vreg3 <vrsc>, <BB#1>
+/// %vreg5 <vgpr> = VECTOR_INST %vreg4 <vsrc>
+///
+///
+/// The coalescer will begin at BB0 and eliminate its copy, then the resulting
+/// code will look like this:
+///
+/// BB0:
+/// %vreg0 <sgpr> = SCALAR_INST
+/// ...
+/// BRANCH %cond BB1, BB2
+/// BB1:
+/// %vreg2 <vgpr> = VECTOR_INST
+/// %vreg3 <vsrc> = COPY %vreg2 <vgpr>
+/// BB2:
+/// %vreg4 <sgpr> = PHI %vreg0 <sgpr>, <BB#0>, %vreg3 <vsrc>, <BB#1>
+/// %vreg5 <vgpr> = VECTOR_INST %vreg4 <sgpr>
+///
+/// Now that the result of the PHI instruction is an SGPR, the register
+/// allocator is now forced to constrain the register class of %vreg3 to
+/// <sgpr> so we end up with final code like this:
+///
+/// BB0:
+/// %vreg0 <sgpr> = SCALAR_INST
+/// ...
+/// BRANCH %cond BB1, BB2
+/// BB1:
+/// %vreg2 <vgpr> = VECTOR_INST
+/// %vreg3 <sgpr> = COPY %vreg2 <vgpr>
+/// BB2:
+/// %vreg4 <sgpr> = PHI %vreg0 <sgpr>, <BB#0>, %vreg3 <sgpr>, <BB#1>
+/// %vreg5 <vgpr> = VECTOR_INST %vreg4 <sgpr>
+///
+/// Now this code contains an illegal copy from a VGPR to an SGPR.
+///
+/// In order to avoid this problem, this pass searches for PHI instructions
+/// which define a <vsrc> register and constrains its definition class to
+/// <vgpr> if the user of the PHI's definition register is a vector instruction.
+/// If the PHI's definition class is constrained to <vgpr> then the coalescer
+/// will be unable to perform the COPY removal from the above example which
+/// ultimately led to the creation of an illegal COPY.
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "sgpr-copies"
+#include "AMDGPU.h"
+#include "SIInstrInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+namespace {
+
+class SIFixSGPRCopies : public MachineFunctionPass {
+
+private:
+ static char ID;
+ const TargetRegisterClass *inferRegClassFromUses(const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI,
+ unsigned Reg,
+ unsigned SubReg) const;
+ const TargetRegisterClass *inferRegClassFromDef(const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI,
+ unsigned Reg,
+ unsigned SubReg) const;
+ bool isVGPRToSGPRCopy(const MachineInstr &Copy, const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI) const;
+
+public:
+ SIFixSGPRCopies(TargetMachine &tm) : MachineFunctionPass(ID) { }
+
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ const char *getPassName() const {
+ return "SI Fix SGPR copies";
+ }
+
+};
+
+} // End anonymous namespace
+
+char SIFixSGPRCopies::ID = 0;
+
+FunctionPass *llvm::createSIFixSGPRCopiesPass(TargetMachine &tm) {
+ return new SIFixSGPRCopies(tm);
+}
+
+static bool hasVGPROperands(const MachineInstr &MI, const SIRegisterInfo *TRI) {
+ const MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
+ for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
+ if (!MI.getOperand(i).isReg() ||
+ !TargetRegisterInfo::isVirtualRegister(MI.getOperand(i).getReg()))
+ continue;
+
+ if (TRI->hasVGPRs(MRI.getRegClass(MI.getOperand(i).getReg())))
+ return true;
+ }
+ return false;
+}
+
+/// This functions walks the use list of Reg until it finds an Instruction
+/// that isn't a COPY returns the register class of that instruction.
+/// \return The register defined by the first non-COPY instruction.
+const TargetRegisterClass *SIFixSGPRCopies::inferRegClassFromUses(
+ const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI,
+ unsigned Reg,
+ unsigned SubReg) const {
+ // The Reg parameter to the function must always be defined by either a PHI
+ // or a COPY, therefore it cannot be a physical register.
+ assert(TargetRegisterInfo::isVirtualRegister(Reg) &&
+ "Reg cannot be a physical register");
+
+ const TargetRegisterClass *RC = MRI.getRegClass(Reg);
+ RC = TRI->getSubRegClass(RC, SubReg);
+ for (MachineRegisterInfo::use_iterator I = MRI.use_begin(Reg),
+ E = MRI.use_end(); I != E; ++I) {
+ switch (I->getOpcode()) {
+ case AMDGPU::COPY:
+ RC = TRI->getCommonSubClass(RC, inferRegClassFromUses(TRI, MRI,
+ I->getOperand(0).getReg(),
+ I->getOperand(0).getSubReg()));
+ break;
+ }
+ }
+
+ return RC;
+}
+
+const TargetRegisterClass *SIFixSGPRCopies::inferRegClassFromDef(
+ const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI,
+ unsigned Reg,
+ unsigned SubReg) const {
+ if (!TargetRegisterInfo::isVirtualRegister(Reg)) {
+ const TargetRegisterClass *RC = TRI->getPhysRegClass(Reg);
+ return TRI->getSubRegClass(RC, SubReg);
+ }
+ MachineInstr *Def = MRI.getVRegDef(Reg);
+ if (Def->getOpcode() != AMDGPU::COPY) {
+ return TRI->getSubRegClass(MRI.getRegClass(Reg), SubReg);
+ }
+
+ return inferRegClassFromDef(TRI, MRI, Def->getOperand(1).getReg(),
+ Def->getOperand(1).getSubReg());
+}
+
+bool SIFixSGPRCopies::isVGPRToSGPRCopy(const MachineInstr &Copy,
+ const SIRegisterInfo *TRI,
+ const MachineRegisterInfo &MRI) const {
+
+ unsigned DstReg = Copy.getOperand(0).getReg();
+ unsigned SrcReg = Copy.getOperand(1).getReg();
+ unsigned SrcSubReg = Copy.getOperand(1).getSubReg();
+ const TargetRegisterClass *DstRC = MRI.getRegClass(DstReg);
+ const TargetRegisterClass *SrcRC;
+
+ if (!TargetRegisterInfo::isVirtualRegister(SrcReg) ||
+ DstRC == &AMDGPU::M0RegRegClass)
+ return false;
+
+ SrcRC = inferRegClassFromDef(TRI, MRI, SrcReg, SrcSubReg);
+ return TRI->isSGPRClass(DstRC) && TRI->hasVGPRs(SrcRC);
+}
+
+bool SIFixSGPRCopies::runOnMachineFunction(MachineFunction &MF) {
+ MachineRegisterInfo &MRI = MF.getRegInfo();
+ const SIRegisterInfo *TRI = static_cast<const SIRegisterInfo *>(
+ MF.getTarget().getRegisterInfo());
+ const SIInstrInfo *TII = static_cast<const SIInstrInfo *>(
+ MF.getTarget().getInstrInfo());
+ for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
+ BI != BE; ++BI) {
+
+ MachineBasicBlock &MBB = *BI;
+ for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
+ I != E; ++I) {
+ MachineInstr &MI = *I;
+ if (MI.getOpcode() == AMDGPU::COPY && isVGPRToSGPRCopy(MI, TRI, MRI)) {
+ DEBUG(dbgs() << "Fixing VGPR -> SGPR copy:\n");
+ DEBUG(MI.print(dbgs()));
+ TII->moveToVALU(MI);
+
+ }
+
+ switch (MI.getOpcode()) {
+ default: continue;
+ case AMDGPU::PHI: {
+ DEBUG(dbgs() << " Fixing PHI:\n");
+ DEBUG(MI.print(dbgs()));
+
+ for (unsigned i = 1; i < MI.getNumOperands(); i+=2) {
+ unsigned Reg = MI.getOperand(i).getReg();
+ const TargetRegisterClass *RC = inferRegClassFromDef(TRI, MRI, Reg,
+ MI.getOperand(0).getSubReg());
+ MRI.constrainRegClass(Reg, RC);
+ }
+ unsigned Reg = MI.getOperand(0).getReg();
+ const TargetRegisterClass *RC = inferRegClassFromUses(TRI, MRI, Reg,
+ MI.getOperand(0).getSubReg());
+ if (TRI->getCommonSubClass(RC, &AMDGPU::VReg_32RegClass)) {
+ MRI.constrainRegClass(Reg, &AMDGPU::VReg_32RegClass);
+ }
+
+ if (!TRI->isSGPRClass(MRI.getRegClass(Reg)))
+ break;
+
+ // If a PHI node defines an SGPR and any of its operands are VGPRs,
+ // then we need to move it to the VALU.
+ for (unsigned i = 1; i < MI.getNumOperands(); i+=2) {
+ unsigned Reg = MI.getOperand(i).getReg();
+ if (TRI->hasVGPRs(MRI.getRegClass(Reg))) {
+ TII->moveToVALU(MI);
+ break;
+ }
+ }
+
+ break;
+ }
+ case AMDGPU::REG_SEQUENCE: {
+ if (TRI->hasVGPRs(TII->getOpRegClass(MI, 0)) ||
+ !hasVGPROperands(MI, TRI))
+ continue;
+
+ DEBUG(dbgs() << "Fixing REG_SEQUENCE:\n");
+ DEBUG(MI.print(dbgs()));
+
+ TII->moveToVALU(MI);
+ break;
+ }
+ }
+ }
+ }
+ return false;
+}
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