Handle 'a' modifier on inline assembly operands.
This is part of the fix for pr4521.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75201 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index 5559a5e..834ce6f 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -907,8 +907,13 @@
     
     switch (ExtraCode[0]) {
     default: return true;  // Unknown modifier.
-    case 'a': // Don't print "#" before a global var name or constant.
-    case 'c': // Don't print "$" before a global var name or constant.
+    case 'a': // Print as a memory address.
+      if (MI->getOperand(OpNum).isReg()) {
+        O << "[" << TRI->getAsmName(MI->getOperand(OpNum).getReg()) << "]";
+        return false;
+      }
+      // Fallthrough
+    case 'c': // Don't print "#" before an immediate operand.
       printOperand(MI, OpNum, "no_hash");
       return false;
     case 'P': // Print a VFP double precision register.
diff --git a/test/CodeGen/ARM/2009-07-09-asm-p-constraint.ll b/test/CodeGen/ARM/2009-07-09-asm-p-constraint.ll
new file mode 100644
index 0000000..ea502cd
--- /dev/null
+++ b/test/CodeGen/ARM/2009-07-09-asm-p-constraint.ll
@@ -0,0 +1,7 @@
+; RUN: llvm-as < %s | llc -march=arm -mattr=+v6
+
+define void @test(i8* %x) nounwind {
+entry:
+	call void asm sideeffect "pld\09${0:a}", "r,~{cc}"(i8* %x) nounwind
+	ret void
+}