Bug 1072300 - IonMonkey MIPS: tests fail on MIPS (asm.js/testMathLib.js, ion/testFloat32-correctness.js, ion/testFloat32.js). r=rankov

js/src/jit/mips/CodeGenerator-mips.cpp

@@ -276,6 +276,54 @@ CodeGeneratorMIPS::visitMinMaxD(LMinMaxD *ins)
     return true;
 }
 
+bool
+CodeGeneratorMIPS::visitMinMaxF(LMinMaxF *ins)
+{
+    FloatRegister first = ToFloatRegister(ins->first());
+    FloatRegister second = ToFloatRegister(ins->second());
+    FloatRegister output = ToFloatRegister(ins->output());
+
+    MOZ_ASSERT(first == output);
+
+    Assembler::DoubleCondition cond = ins->mir()->isMax()
+                                      ? Assembler::DoubleLessThanOrEqual
+                                      : Assembler::DoubleGreaterThanOrEqual;
+    Label nan, equal, returnSecond, done;
+
+    // First or second is NaN, result is NaN.
+    masm.ma_bc1s(first, second, &nan, Assembler::DoubleUnordered, ShortJump);
+    // Make sure we handle -0 and 0 right.
+    masm.ma_bc1s(first, second, &equal, Assembler::DoubleEqual, ShortJump);
+    masm.ma_bc1s(first, second, &returnSecond, cond, ShortJump);
+    masm.ma_b(&done, ShortJump);
+
+    // Check for zero.
+    masm.bind(&equal);
+    masm.loadConstantFloat32(0.0, ScratchFloat32Reg);
+    // First wasn't 0 or -0, so just return it.
+    masm.ma_bc1s(first, ScratchFloat32Reg, &done, Assembler::DoubleNotEqualOrUnordered, ShortJump);
+
+    // So now both operands are either -0 or 0.
+    if (ins->mir()->isMax()) {
+        // -0 + -0 = -0 and -0 + 0 = 0.
+        masm.as_adds(first, first, second);
+    } else {
+        masm.as_negs(first, first);
+        masm.as_subs(first, first, second);
+        masm.as_negs(first, first);
+    }
+    masm.ma_b(&done, ShortJump);
+
+    masm.bind(&nan);
+    masm.loadConstantFloat32(GenericNaN(), output);
+    masm.ma_b(&done, ShortJump);
+    masm.bind(&returnSecond);
+    masm.as_movs(output, second);
+
+    masm.bind(&done);
+    return true;
+}
+
 bool
 CodeGeneratorMIPS::visitAbsD(LAbsD *ins)
 {

js/src/jit/mips/CodeGenerator-mips.h

@@ -162,6 +162,7 @@ class CodeGeneratorMIPS : public CodeGeneratorShared
   public:
     // Instruction visitors.
     virtual bool visitMinMaxD(LMinMaxD *ins);
+    virtual bool visitMinMaxF(LMinMaxF *ins);
     virtual bool visitAbsD(LAbsD *ins);
     virtual bool visitAbsF(LAbsF *ins);
     virtual bool visitSqrtD(LSqrtD *ins);