[llvm-commits] [PATCH 07/11] (patch) Mips specific inline asm: constraint 'N'

[Jack Carter]

A constant in the range of -65535 to -1 inclusive.

Example:

  int i_input = 7; int i_result = 0;

  // Good: i_val falls in the correct range
  int i_val = -3;
  __asm__ __volatile__(
    "addi %0,%1,%2" : "=r" (i_result) : "r" (i_input), "N" (i_val));

  // Bad: llc should produce an error
  int i_val = 3;
  __asm__ __volatile__(
    "addi %0,%1,%2" : "=r" (i_result) : "r" (i_input), "N" (i_val));
---
 lib/Target/Mips/MipsISelLowering.cpp         |   11 +++++++++++
 test/CodeGen/Mips/inlineasm-cnstrnt-bad-N.ll |   15 +++++++++++++++
 test/CodeGen/Mips/inlineasm_constraint.ll    |    6 ++++++
 3 files changed, 32 insertions(+), 0 deletions(-)
 create mode 100644 test/CodeGen/Mips/inlineasm-cnstrnt-bad-N.ll

-------------- next part --------------
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index a2c69b7..83203ee 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -2930,6 +2930,7 @@ MipsTargetLowering::getSingleConstraintMatchWeight(
   case 'J': // integer zero
   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)
     if (isa<ConstantInt>(CallOperandVal))
       weight = CW_Constant;
     break;
@@ -3023,6 +3024,16 @@ void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
       }
     }
     return;
+  case 'N': // immediate in the range of -65535 to -1 (inclusive)
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
+      EVT Type = Op.getValueType();
+      int64_t Val = C->getSExtValue();
+      if ((Val >= -65535) && (Val <= -1)) {
+        Result = DAG.getTargetConstant(Val, Type);
+        break;
+      }
+    }
+    return;
   }
 
   if (Result.getNode()) {
diff --git a/test/CodeGen/Mips/inlineasm-cnstrnt-bad-N.ll b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-N.ll
new file mode 100644
index 0000000..1ffbe70
--- /dev/null
+++ b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-N.ll
@@ -0,0 +1,15 @@
+ 
+;XFAIL:
+;
+;This is a negative test. The constant value given for the constraint (N).
+;immediate in the range of -65535 to -1 (inclusive).
+;Our example uses the positive value 3.
+;
+; RUN: not llc -march=mipsel < %s 
+
+define i32 @main() nounwind {
+entry:
+  tail call i32 asm sideeffect "addi $0,$1,$2", "=r,r,N"(i32 7, i32 3) nounwind
+  ret i32 0
+}
+
diff --git a/test/CodeGen/Mips/inlineasm_constraint.ll b/test/CodeGen/Mips/inlineasm_constraint.ll
index 34d0657..06ca721 100644
--- a/test/CodeGen/Mips/inlineasm_constraint.ll
+++ b/test/CodeGen/Mips/inlineasm_constraint.ll
@@ -33,5 +33,11 @@ entry:
 ; CHECK: #NO_APP	
   tail call i32 asm sideeffect "add $0,$1,$3\0A\09", "=r,r,L,r"(i32 7, i32 1048576, i32 0) nounwind
 
+; Now N 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,N"(i32 7, i32 -3) nounwind
+
   ret i32 0
 }