From 85e42b45ac05223882f24c17bff66b89daa0d6fc Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 20 Dec 2005 07:56:31 +0000 Subject: [PATCH] Reserve G1 for frame offset stuff and use it to handle large stack frames. For example, instead of emitting this: test: save -40112, %o6, %o6 ;; imm too large add %i6, -40016, %o0 ;; imm too large call caller nop restore %g0, %g0, %g0 retl nop emit this: test: sethi 4194264, %g1 or %g1, 848, %g1 save %o6, %g1, %o6 sethi 4194264, %g1 add %g1, %i6, %g1 add %i1, 944, %o0 call caller nop restore %g0, %g0, %g0 retl nop which doesn't cause the assembler to barf. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24880 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Sparc/SparcRegisterInfo.cpp | 44 ++++++++++++++++++---- lib/Target/Sparc/SparcRegisterInfo.td | 7 +++- lib/Target/SparcV8/SparcV8RegisterInfo.cpp | 44 ++++++++++++++++++---- lib/Target/SparcV8/SparcV8RegisterInfo.td | 7 +++- 4 files changed, 84 insertions(+), 18 deletions(-) diff --git a/lib/Target/Sparc/SparcRegisterInfo.cpp b/lib/Target/Sparc/SparcRegisterInfo.cpp index 7b258567304..49cbbc091d7 100644 --- a/lib/Target/Sparc/SparcRegisterInfo.cpp +++ b/lib/Target/Sparc/SparcRegisterInfo.cpp @@ -96,15 +96,30 @@ SparcV8RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const { int FrameIndex = MI.getOperand(i).getFrameIndex(); - // Replace frame index with a frame pointer reference - MI.SetMachineOperandReg (i, V8::I6); - // Addressable stack objects are accessed using neg. offsets from %fp MachineFunction &MF = *MI.getParent()->getParent(); int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) + MI.getOperand(i+1).getImmedValue(); - // note: Offset < 0 - MI.SetMachineOperandConst (i+1, MachineOperand::MO_SignExtendedImmed, Offset); + + // Replace frame index with a frame pointer reference. + if (Offset >= -4096 && Offset <= 4095) { + // If the offset is small enough to fit in the immediate field, directly + // encode it. + MI.SetMachineOperandReg(i, V8::I6); + MI.SetMachineOperandConst(i+1, MachineOperand::MO_SignExtendedImmed,Offset); + } else { + // Otherwise, emit a G1 = SETHI %hi(offset). FIXME: it would be better to + // scavenge a register here instead of reserving G1 all of the time. + unsigned OffHi = (unsigned)Offset >> 10U; + BuildMI(*MI.getParent(), II, V8::SETHIi, 1, V8::G1).addImm(OffHi); + // Emit G1 = G1 + I6 + BuildMI(*MI.getParent(), II, V8::ADDrr, 2, + V8::G1).addReg(V8::G1).addReg(V8::I6); + // Insert: G1+%lo(offset) into the user. + MI.SetMachineOperandReg(i, V8::I1); + MI.SetMachineOperandConst(i+1, MachineOperand::MO_SignExtendedImmed, + Offset & ((1 << 10)-1)); + } } void SparcV8RegisterInfo:: @@ -128,8 +143,23 @@ void SparcV8RegisterInfo::emitPrologue(MachineFunction &MF) const { // Round up to next doubleword boundary -- a double-word boundary // is required by the ABI. NumBytes = (NumBytes + 7) & ~7; - BuildMI(MBB, MBB.begin(), V8::SAVEri, 2, - V8::O6).addImm(-NumBytes).addReg(V8::O6); + NumBytes = -NumBytes; + + if (NumBytes >= -4096) { + BuildMI(MBB, MBB.begin(), V8::SAVEri, 2, + V8::O6).addImm(NumBytes).addReg(V8::O6); + } else { + MachineBasicBlock::iterator InsertPt = MBB.begin(); + // Emit this the hard way. This clobbers G1 which we always know is + // available here. + unsigned OffHi = (unsigned)NumBytes >> 10U; + BuildMI(MBB, InsertPt, V8::SETHIi, 1, V8::G1).addImm(OffHi); + // Emit G1 = G1 + I6 + BuildMI(MBB, InsertPt, V8::ORri, 2, V8::G1) + .addReg(V8::G1).addImm(NumBytes & ((1 << 10)-1)); + BuildMI(MBB, InsertPt, V8::SAVErr, 2, + V8::O6).addReg(V8::O6).addReg(V8::G1); + } } void SparcV8RegisterInfo::emitEpilogue(MachineFunction &MF, diff --git a/lib/Target/Sparc/SparcRegisterInfo.td b/lib/Target/Sparc/SparcRegisterInfo.td index aa79e2837ea..07012b1626f 100644 --- a/lib/Target/Sparc/SparcRegisterInfo.td +++ b/lib/Target/Sparc/SparcRegisterInfo.td @@ -84,8 +84,10 @@ def FLAGS_REGS : RegisterClass<"V8", [FlagVT], 32, [ICC, FCC]> { // def IntRegs : RegisterClass<"V8", [i32], 32, [L0, L1, L2, L3, L4, L5, L6, L7, I0, I1, I2, I3, I4, I5, - G1, O0, O1, O2, O3, O4, O5, O7, + + // FIXME: G1 reserved for now for large imm generation by frame code. + G1, // Non-allocatable regs: G2, G3, G4, // FIXME: OK for use only in // applications, not libraries. @@ -102,7 +104,8 @@ def IntRegs : RegisterClass<"V8", [i32], 32, [L0, L1, L2, L3, L4, L5, L6, L7, IntRegsClass::iterator IntRegsClass::allocation_order_end(MachineFunction &MF) const { // FIXME: These special regs should be taken out of the regclass! - return end()-10; // Don't allocate special registers + return end()-10 // Don't allocate special registers + -1; // FIXME: G1 reserved for large imm generation by frame code. } }]; } diff --git a/lib/Target/SparcV8/SparcV8RegisterInfo.cpp b/lib/Target/SparcV8/SparcV8RegisterInfo.cpp index 7b258567304..49cbbc091d7 100644 --- a/lib/Target/SparcV8/SparcV8RegisterInfo.cpp +++ b/lib/Target/SparcV8/SparcV8RegisterInfo.cpp @@ -96,15 +96,30 @@ SparcV8RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const { int FrameIndex = MI.getOperand(i).getFrameIndex(); - // Replace frame index with a frame pointer reference - MI.SetMachineOperandReg (i, V8::I6); - // Addressable stack objects are accessed using neg. offsets from %fp MachineFunction &MF = *MI.getParent()->getParent(); int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) + MI.getOperand(i+1).getImmedValue(); - // note: Offset < 0 - MI.SetMachineOperandConst (i+1, MachineOperand::MO_SignExtendedImmed, Offset); + + // Replace frame index with a frame pointer reference. + if (Offset >= -4096 && Offset <= 4095) { + // If the offset is small enough to fit in the immediate field, directly + // encode it. + MI.SetMachineOperandReg(i, V8::I6); + MI.SetMachineOperandConst(i+1, MachineOperand::MO_SignExtendedImmed,Offset); + } else { + // Otherwise, emit a G1 = SETHI %hi(offset). FIXME: it would be better to + // scavenge a register here instead of reserving G1 all of the time. + unsigned OffHi = (unsigned)Offset >> 10U; + BuildMI(*MI.getParent(), II, V8::SETHIi, 1, V8::G1).addImm(OffHi); + // Emit G1 = G1 + I6 + BuildMI(*MI.getParent(), II, V8::ADDrr, 2, + V8::G1).addReg(V8::G1).addReg(V8::I6); + // Insert: G1+%lo(offset) into the user. + MI.SetMachineOperandReg(i, V8::I1); + MI.SetMachineOperandConst(i+1, MachineOperand::MO_SignExtendedImmed, + Offset & ((1 << 10)-1)); + } } void SparcV8RegisterInfo:: @@ -128,8 +143,23 @@ void SparcV8RegisterInfo::emitPrologue(MachineFunction &MF) const { // Round up to next doubleword boundary -- a double-word boundary // is required by the ABI. NumBytes = (NumBytes + 7) & ~7; - BuildMI(MBB, MBB.begin(), V8::SAVEri, 2, - V8::O6).addImm(-NumBytes).addReg(V8::O6); + NumBytes = -NumBytes; + + if (NumBytes >= -4096) { + BuildMI(MBB, MBB.begin(), V8::SAVEri, 2, + V8::O6).addImm(NumBytes).addReg(V8::O6); + } else { + MachineBasicBlock::iterator InsertPt = MBB.begin(); + // Emit this the hard way. This clobbers G1 which we always know is + // available here. + unsigned OffHi = (unsigned)NumBytes >> 10U; + BuildMI(MBB, InsertPt, V8::SETHIi, 1, V8::G1).addImm(OffHi); + // Emit G1 = G1 + I6 + BuildMI(MBB, InsertPt, V8::ORri, 2, V8::G1) + .addReg(V8::G1).addImm(NumBytes & ((1 << 10)-1)); + BuildMI(MBB, InsertPt, V8::SAVErr, 2, + V8::O6).addReg(V8::O6).addReg(V8::G1); + } } void SparcV8RegisterInfo::emitEpilogue(MachineFunction &MF, diff --git a/lib/Target/SparcV8/SparcV8RegisterInfo.td b/lib/Target/SparcV8/SparcV8RegisterInfo.td index aa79e2837ea..07012b1626f 100644 --- a/lib/Target/SparcV8/SparcV8RegisterInfo.td +++ b/lib/Target/SparcV8/SparcV8RegisterInfo.td @@ -84,8 +84,10 @@ def FLAGS_REGS : RegisterClass<"V8", [FlagVT], 32, [ICC, FCC]> { // def IntRegs : RegisterClass<"V8", [i32], 32, [L0, L1, L2, L3, L4, L5, L6, L7, I0, I1, I2, I3, I4, I5, - G1, O0, O1, O2, O3, O4, O5, O7, + + // FIXME: G1 reserved for now for large imm generation by frame code. + G1, // Non-allocatable regs: G2, G3, G4, // FIXME: OK for use only in // applications, not libraries. @@ -102,7 +104,8 @@ def IntRegs : RegisterClass<"V8", [i32], 32, [L0, L1, L2, L3, L4, L5, L6, L7, IntRegsClass::iterator IntRegsClass::allocation_order_end(MachineFunction &MF) const { // FIXME: These special regs should be taken out of the regclass! - return end()-10; // Don't allocate special registers + return end()-10 // Don't allocate special registers + -1; // FIXME: G1 reserved for large imm generation by frame code. } }]; }