[PowerPC] Support operand modifier 'x' in inline asm

gcc uses operand modifier 'x' in inline asm for VSX registers.
Without this modifier, instructions which use VSX numbering for their
operands are printed as VMX registers. This patch adds support for the
operand modifier 'x'.

Differential Revision: https://reviews.llvm.org/D52244

llvm-svn: 342882

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index a9da64cc216..34c58b27cc1 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -279,6 +279,21 @@ bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
       if (MI->getOperand(OpNo).isImm())
         O << "i";
       return false;
+    case 'x':
+      if(!MI->getOperand(OpNo).isReg())
+        return true;
+      // This operand uses VSX numbering.
+      // If the operand is a VMX register, convert it to a VSX register.
+      unsigned Reg = MI->getOperand(OpNo).getReg();
+      if (PPCInstrInfo::isVRRegister(Reg))
+        Reg = PPC::VSX32 + (Reg - PPC::V0);
+      else if (PPCInstrInfo::isVFRegister(Reg))
+        Reg = PPC::VSX32 + (Reg - PPC::VF0);
+      const char *RegName;
+      RegName = PPCInstPrinter::getRegisterName(Reg);
+      RegName = stripRegisterPrefix(RegName);
+      O << RegName;
+      return false;
     }
   }