From 1ce2034e43b94abb9930fd86430c46c0bf309ed7 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Mon, 7 May 2012 05:46:48 +0000
Subject: [PATCH] Add support for the 'O' constraint.

Patch by Jack Carter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156285 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsISelLowering.cpp         | 11 +++++++++++
 test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll | 16 ++++++++++++++++
 test/CodeGen/Mips/inlineasm_constraint.ll    |  6 ++++++
 3 files changed, 33 insertions(+)
 create mode 100644 test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index ded6aa0608b..97a0ef67367 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -3044,6 +3044,7 @@ MipsTargetLowering::getSingleConstraintMatchWeight(
   case 'K': // unsigned 16 bit immediate
   case 'L': // signed 32 bit immediate where lower 16 bits are 0
   case 'N': // immediate in the range of -65535 to -1 (inclusive)
+  case 'O': // signed 15 bit immediate (+- 16383)
     if (isa<ConstantInt>(CallOperandVal))
       weight = CW_Constant;
     break;
@@ -3146,6 +3147,16 @@ void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
       }
     }
     return;
+  case 'O': // signed 15 bit immediate
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
+      EVT Type = Op.getValueType();
+      int64_t Val = C->getSExtValue();
+      if ((isInt<15>(Val))) {
+        Result = DAG.getTargetConstant(Val, Type);
+        break;
+      }
+    }
+    return;
   }
 
   if (Result.getNode()) {
diff --git a/test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll
new file mode 100644
index 00000000000..cd4431ac526
--- /dev/null
+++ b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll
@@ -0,0 +1,16 @@
+;
+;This is a negative test. The constant value given for the constraint (O).
+;signed 15 bit immediate (+- 16383).
+;Our example uses the positive value 16384.
+;
+; 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 'O'
+
+  tail call i32 asm sideeffect "addi $0,$1,$2", "=r,r,O"(i32 undef, i32 16384) nounwind
+  ret i32 0
+}
diff --git a/test/CodeGen/Mips/inlineasm_constraint.ll b/test/CodeGen/Mips/inlineasm_constraint.ll
index 06ca7219fe0..cb02dd149f4 100644
--- a/test/CodeGen/Mips/inlineasm_constraint.ll
+++ b/test/CodeGen/Mips/inlineasm_constraint.ll
@@ -39,5 +39,11 @@ entry:
 ; CHECK: #NO_APP	
   tail call i32 asm sideeffect "addi $0,$1,$2", "=r,r,N"(i32 7, i32 -3) nounwind
 
+; Now O with -3
+; CHECK: #APP
+; CHECK: addi ${{[0-9]+}},${{[0-9]+}},-3
+; CHECK: #NO_APP	
+  tail call i32 asm sideeffect "addi $0,$1,$2", "=r,r,O"(i32 7, i16 -3) nounwind
+
   ret i32 0
 }