From f5916976e9057177100badee7b7388bd7ba76ac3 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 12 Oct 2011 23:37:36 +0000 Subject: Add MachineInstr::getRegClassConstraint(). Most instructions have some requirements for their register operands. Usually, this is expressed as register class constraints in the MCInstrDesc, but for inline assembly the constraints are encoded in the flag words. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141835 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineInstr.cpp | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'lib/CodeGen/MachineInstr.cpp') diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp index 965c6c5bca..0ef1ef603b 100644 --- a/lib/CodeGen/MachineInstr.cpp +++ b/lib/CodeGen/MachineInstr.cpp @@ -854,6 +854,39 @@ int MachineInstr::findInlineAsmFlagIdx(unsigned OpIdx, return -1; } +const TargetRegisterClass* +MachineInstr::getRegClassConstraint(unsigned OpIdx, + const TargetInstrInfo *TII, + const TargetRegisterInfo *TRI) const { + // Most opcodes have fixed constraints in their MCInstrDesc. + if (!isInlineAsm()) + return TII->getRegClass(getDesc(), OpIdx, TRI); + + if (!getOperand(OpIdx).isReg()) + return NULL; + + // For tied uses on inline asm, get the constraint from the def. + unsigned DefIdx; + if (getOperand(OpIdx).isUse() && isRegTiedToDefOperand(OpIdx, &DefIdx)) + OpIdx = DefIdx; + + // Inline asm stores register class constraints in the flag word. + int FlagIdx = findInlineAsmFlagIdx(OpIdx); + if (FlagIdx < 0) + return NULL; + + unsigned Flag = getOperand(FlagIdx).getImm(); + unsigned RCID; + if (InlineAsm::hasRegClassConstraint(Flag, RCID)) + return TRI->getRegClass(RCID); + + // Assume that all registers in a memory operand are pointers. + if (InlineAsm::getKind(Flag) == InlineAsm::Kind_Mem) + return TRI->getPointerRegClass(); + + return NULL; +} + /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of /// the specific register or -1 if it is not found. It further tightens /// the search criteria to a use that kills the register if isKill is true. -- cgit v1.2.3-18-g5258