From e5076d484b2f530e2e2422fb06c268970b53b055 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Mon, 7 May 2012 03:13:42 +0000
Subject: [PATCH] Support the 'J' constraint.

Patch by Jack Carter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156280 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsISelLowering.cpp         | 11 +++++++++++
 test/CodeGen/Mips/inlineasm-cnstrnt-bad-J.ll | 16 ++++++++++++++++
 test/CodeGen/Mips/inlineasm_constraint.ll    |  6 ++++++
 3 files changed, 33 insertions(+)
 create mode 100644 test/CodeGen/Mips/inlineasm-cnstrnt-bad-J.ll

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 13665ee89a9..97332cf00d1 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -3040,6 +3040,7 @@ MipsTargetLowering::getSingleConstraintMatchWeight(
       weight = CW_Register;
     break;
   case 'I': // signed 16 bit immediate
+  case 'J': // integer zero
     if (isa<ConstantInt>(CallOperandVal))
       weight = CW_Constant;
     break;
@@ -3102,6 +3103,16 @@ void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
       }
     }
     return;
+  case 'J': // integer zero
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
+      EVT Type = Op.getValueType();
+      int64_t Val = C->getZExtValue();
+      if (Val == 0) {
+        Result = DAG.getTargetConstant(0, Type);
+        break;
+      }
+    }
+    return;
   }
 
   if (Result.getNode()) {
diff --git a/test/CodeGen/Mips/inlineasm-cnstrnt-bad-J.ll b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-J.ll
new file mode 100644
index 00000000000..1fdf672fe19
--- /dev/null
+++ b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-J.ll
@@ -0,0 +1,16 @@
+;
+;This is a negative test. The constant value given for the constraint (J)
+;is non-zero (3).
+;
+; RUN: not llc -march=mipsel < %s  2> %t
+; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
+
+define i32 @main() nounwind {
+entry:
+
+;CHECK-ERRORS:	error: invalid operand for inline asm constraint 'J'
+
+  tail call i32 asm "addi $0,$1,$2", "=r,r,J"(i32 1024, i32 3) nounwind
+  ret i32 0
+}
+
diff --git a/test/CodeGen/Mips/inlineasm_constraint.ll b/test/CodeGen/Mips/inlineasm_constraint.ll
index e2fbaa772ef..f053e0e2766 100644
--- a/test/CodeGen/Mips/inlineasm_constraint.ll
+++ b/test/CodeGen/Mips/inlineasm_constraint.ll
@@ -15,6 +15,12 @@ entry:
 ; CHECK: #NO_APP
    tail call i32 asm sideeffect "addi $0,$1,$2", "=r,r,I"(i32 7, i32 -3) nounwind
 
+; Now J with 0
+; CHECK: #APP
+; CHECK: addi ${{[0-9]+}},${{[0-9]+}},0
+; CHECK: #NO_APP
+  tail call i32 asm sideeffect "addi $0,$1,$2\0A\09 ", "=r,r,J"(i32 7, i16 0) nounwind
+
   ret i32 0
 }