[AsmPrinter] hoist %a output template to base class for ARM+Aarch64

Summary:
X86 is quite complicated; so I intend to leave it as is. ARM+Aarch64 do
basically the same thing (Aarch64 did not correctly handle immediates,
ARM has a test llvm/test/CodeGen/ARM/2009-04-06-AsmModifier.ll that uses
%a with an immediate) for a flag that should be target independent
anyways.

Reviewers: echristo, peter.smith

Reviewed By: echristo

Subscribers: javed.absar, eraman, kristof.beyls, hiraditya, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60841

llvm-svn: 358618

1 files changed, 11 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index b18bd2ca426..60be9451f4b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -601,7 +601,8 @@ void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
 
 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
 /// instruction, using the specified assembler variant.  Targets should
-/// override this to format as appropriate.
+/// override this to format as appropriate for machine specific ExtraCodes
+/// or when the arch-independent handling would be too complex otherwise.
 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                                  const char *ExtraCode, raw_ostream &O) {
   // Does this asm operand have a single letter operand modifier?
@@ -613,18 +614,24 @@ bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
     switch (ExtraCode[0]) {
     default:
       return true;  // Unknown modifier.
+    case 'a': // Print as memory address.
+      if (MO.isReg()) {
+        PrintAsmMemoryOperand(MI, OpNo, nullptr, O);
+        return false;
+      }
+      LLVM_FALLTHROUGH; // GCC allows '%a' to behave like '%c' with immediates.
     case 'c': // Substitute immediate value without immediate syntax
-      if (MO.getType() != MachineOperand::MO_Immediate)
+      if (!MO.isImm())
         return true;
       O << MO.getImm();
       return false;
     case 'n':  // Negate the immediate constant.
-      if (MO.getType() != MachineOperand::MO_Immediate)
+      if (!MO.isImm())
         return true;
       O << -MO.getImm();
       return false;
     case 's':  // The GCC deprecated s modifier
-      if (MO.getType() != MachineOperand::MO_Immediate)
+      if (!MO.isImm())
         return true;
       O << ((32 - MO.getImm()) & 31);
       return false;