Pull in r199786 from upstream llvm trunk (by Venkatraman Govindaraju):

  [Sparc] Add support for inline assembly constraints which specify registers by their aliases.

Introduced here: http://svnweb.freebsd.org/changeset/base/262261

Index: lib/Target/Sparc/SparcISelLowering.cpp
===================================================================
--- lib/Target/Sparc/SparcISelLowering.cpp
+++ lib/Target/Sparc/SparcISelLowering.cpp
@@ -2992,6 +2992,26 @@ SparcTargetLowering::getRegForInlineAsmConstraint(
     case 'r':
       return std::make_pair(0U, &SP::IntRegsRegClass);
     }
+  } else  if (!Constraint.empty() && Constraint.size() <= 5
+              && Constraint[0] == '{' && *(Constraint.end()-1) == '}') {
+    // constraint = '{r<d>}'
+    // Remove the braces from around the name.
+    StringRef name(Constraint.data()+1, Constraint.size()-2);
+    // Handle register aliases:
+    //       r0-r7   -> g0-g7
+    //       r8-r15  -> o0-o7
+    //       r16-r23 -> l0-l7
+    //       r24-r31 -> i0-i7
+    uint64_t intVal = 0;
+    if (name.substr(0, 1).equals("r")
+        && !name.substr(1).getAsInteger(10, intVal) && intVal <= 31) {
+      const char regTypes[] = { 'g', 'o', 'l', 'i' };
+      char regType = regTypes[intVal/8];
+      char regIdx = '0' + (intVal % 8);
+      char tmp[] = { '{', regType, regIdx, '}', 0 };
+      std::string newConstraint = std::string(tmp);
+      return TargetLowering::getRegForInlineAsmConstraint(newConstraint, VT);
+    }
   }
 
   return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
Index: test/CodeGen/SPARC/inlineasm.ll
===================================================================
--- test/CodeGen/SPARC/inlineasm.ll
+++ test/CodeGen/SPARC/inlineasm.ll
@@ -33,3 +33,13 @@ entry:
   %0 = tail call i32 asm sideeffect "add $1, $2, $0", "=r,r,rI"(i32 %a, i32 10000)
   ret i32 %0
 }
+
+; CHECK-LABEL: test_constraint_reg
+; CHECK:       ldda [%o1] 43, %g2
+; CHECK:       ldda [%o1] 43, %g3
+define void @test_constraint_reg(i32 %s, i32* %ptr) {
+entry:
+  %0 = tail call i64 asm sideeffect "ldda [$1] $2, $0", "={r2},r,n"(i32* %ptr, i32 43)
+  %1 = tail call i64 asm sideeffect "ldda [$1] $2, $0", "={g3},r,n"(i32* %ptr, i32 43)
+  ret void
+}