[llvm-commits] [PATCH 08/11] (patch) Mips specific inline asm: constraint 'O':

[Jack Carter]

A signed 15 bit constant.

Example:

  short s_input = 7;short s_result = 0;

  // Good: value is within range.
  short s_val = 16383;
  __asm__ __volatile__(
    "addi %0,%1,%2" : "=r" (s_result)  : "r" (s_input), "O" (s_val));
  printf ("mips_addi(%d,%d) = %d\n", s_input, s_val, s_result);

  // Good: value is still within range.
  short s_val = -16383;
  __asm__ __volatile__(
    "addi %0,%1,%2" : "=r" (s_result)  : "r" (s_input), "O" (s_val));
  printf ("mips_addi(%d,%d) = %d\n", s_input, s_val, s_result);

  // Bad: value is out of range. llc should produce an error
  short s_val = 16384;
  __asm__ __volatile__(
    "addi %0,%1,%2" : "=r" (s_result)  : "r" (s_input), "O" (s_val));
  printf ("mips_addi(%d,%d) = %d\n", s_input, s_val, s_result);
---
 lib/Target/Mips/MipsISelLowering.cpp         |   11 +++++++++++
 test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll |   13 +++++++++++++
 test/CodeGen/Mips/inlineasm_constraint.ll    |    6 ++++++
 3 files changed, 30 insertions(+), 0 deletions(-)
 create mode 100644 test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll

-------------- next part --------------
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 83203ee..4d1d7ad 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -2931,6 +2931,7 @@ 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;
@@ -3034,6 +3035,16 @@ 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 0000000..40c8cb7
--- /dev/null
+++ b/test/CodeGen/Mips/inlineasm-cnstrnt-bad-O.ll
@@ -0,0 +1,13 @@
+;XFAIL:
+;
+;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 
+
+define i32 @main() nounwind {
+entry:
+  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 06ca721..cb02dd1 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
 }