Use movw+movt in ARMFastISel::ARMMaterializeGV.
This eliminates a lot of constant pool entries for -O0 builds of code
with many global variable accesses.
This speeds up -O0 codegen of consumer-typeset by 2x because the
constant island pass no longer has to look at thousands of constant pool
entries.
<rdar://problem/10629774>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147712 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 7ce5099..56e3d49 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -617,40 +617,61 @@
// TODO: Need more magic for ARM PIC.
if (!isThumb2 && (RelocM == Reloc::PIC_)) return 0;
- // MachineConstantPool wants an explicit alignment.
- unsigned Align = TD.getPrefTypeAlignment(GV->getType());
- if (Align == 0) {
- // TODO: Figure out if this is correct.
- Align = TD.getTypeAllocSize(GV->getType());
- }
-
- // Grab index.
- unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 : (Subtarget->isThumb() ? 4 : 8);
- unsigned Id = AFI->createPICLabelUId();
- ARMConstantPoolValue *CPV = ARMConstantPoolConstant::Create(GV, Id,
- ARMCP::CPValue,
- PCAdj);
- unsigned Idx = MCP.getConstantPoolIndex(CPV, Align);
-
- // Load value.
- MachineInstrBuilder MIB;
unsigned DestReg = createResultReg(TLI.getRegClassFor(VT));
- if (isThumb2) {
- unsigned Opc = (RelocM != Reloc::PIC_) ? ARM::t2LDRpci : ARM::t2LDRpci_pic;
- MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), DestReg)
- .addConstantPoolIndex(Idx);
- if (RelocM == Reloc::PIC_)
- MIB.addImm(Id);
+
+ // Use movw+movt when possible, it avoids constant pool entries.
+ if (Subtarget->isTargetDarwin() && Subtarget->useMovt()) {
+ unsigned Opc;
+ switch (RelocM) {
+ case Reloc::PIC_:
+ Opc = isThumb2 ? ARM::t2MOV_ga_pcrel : ARM::MOV_ga_pcrel;
+ break;
+ case Reloc::DynamicNoPIC:
+ Opc = isThumb2 ? ARM::t2MOV_ga_dyn : ARM::MOV_ga_dyn;
+ break;
+ default:
+ Opc = isThumb2 ? ARM::t2MOVi32imm : ARM::MOVi32imm;
+ break;
+ }
+ AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc),
+ DestReg).addGlobalAddress(GV));
} else {
- // The extra immediate is for addrmode2.
- MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(ARM::LDRcp),
- DestReg)
- .addConstantPoolIndex(Idx)
- .addImm(0);
+ // MachineConstantPool wants an explicit alignment.
+ unsigned Align = TD.getPrefTypeAlignment(GV->getType());
+ if (Align == 0) {
+ // TODO: Figure out if this is correct.
+ Align = TD.getTypeAllocSize(GV->getType());
+ }
+
+ // Grab index.
+ unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 :
+ (Subtarget->isThumb() ? 4 : 8);
+ unsigned Id = AFI->createPICLabelUId();
+ ARMConstantPoolValue *CPV = ARMConstantPoolConstant::Create(GV, Id,
+ ARMCP::CPValue,
+ PCAdj);
+ unsigned Idx = MCP.getConstantPoolIndex(CPV, Align);
+
+ // Load value.
+ MachineInstrBuilder MIB;
+ if (isThumb2) {
+ unsigned Opc = (RelocM!=Reloc::PIC_) ? ARM::t2LDRpci : ARM::t2LDRpci_pic;
+ MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), DestReg)
+ .addConstantPoolIndex(Idx);
+ if (RelocM == Reloc::PIC_)
+ MIB.addImm(Id);
+ } else {
+ // The extra immediate is for addrmode2.
+ MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(ARM::LDRcp),
+ DestReg)
+ .addConstantPoolIndex(Idx)
+ .addImm(0);
+ }
+ AddOptionalDefs(MIB);
}
- AddOptionalDefs(MIB);
if (Subtarget->GVIsIndirectSymbol(GV, RelocM)) {
+ MachineInstrBuilder MIB;
unsigned NewDestReg = createResultReg(TLI.getRegClassFor(VT));
if (isThumb2)
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,