MIPS: [turbofan] Improve code generation for unordered comparisons.

src/compiler/mips/code-generator-mips.cc

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index 792abef24f40777d65de5c93e2dac1ca7de7c3f9..598bf6ea62d190e94f555307e98f5da71cb5a0a5 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -203,6 +203,67 @@ class OutOfLineCeil FINAL : public OutOfLineRound {
       : OutOfLineRound(gen, result) {}
 };
 
+
+Condition FlagsConditionToConditionCmp(FlagsCondition condition) {
+  switch (condition) {
+    case kEqual:
+      return eq;
+    case kNotEqual:
+      return ne;
+    case kSignedLessThan:
+      return lt;
+    case kSignedGreaterThanOrEqual:
+      return ge;
+    case kSignedLessThanOrEqual:
+      return le;
+    case kSignedGreaterThan:
+      return gt;
+    case kUnsignedLessThan:
+      return lo;
+    case kUnsignedGreaterThanOrEqual:
+      return hs;
+    case kUnsignedLessThanOrEqual:
+      return ls;
+    case kUnsignedGreaterThan:
+      return hi;
+    case kUnorderedEqual:
+    case kUnorderedNotEqual:
+      break;
+    default:
+      break;
+  }
+  UNREACHABLE();
+  return kNoCondition;
+}
+
+
+Condition FlagsConditionToConditionTst(FlagsCondition condition) {
+  switch (condition) {
+    case kNotEqual:
+      return ne;
+    case kEqual:
+      return eq;
+    default:
+      break;
+  }
+  UNREACHABLE();
+  return kNoCondition;
+}
+
+
+Condition FlagsConditionToConditionOvf(FlagsCondition condition) {
+  switch (condition) {
+    case kOverflow:
+      return lt;
+    case kNotOverflow:
+      return ge;
+    default:
+      break;
+  }
+  UNREACHABLE();
+  return kNoCondition;
+}
+
 }  // namespace
 
 
@@ -646,72 +707,18 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
   //    not separated by other instructions.
 
   if (instr->arch_opcode() == kMipsTst) {
-    switch (branch->condition) {
-      case kNotEqual:
-        cc = ne;
-        break;
-      case kEqual:
-        cc = eq;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsTst, branch->condition);
-        break;
-    }
+    cc = FlagsConditionToConditionTst(branch->condition);
     __ And(at, i.InputRegister(0), i.InputOperand(1));
     __ Branch(tlabel, cc, at, Operand(zero_reg));
 
   } else if (instr->arch_opcode() == kMipsAddOvf ||
              instr->arch_opcode() == kMipsSubOvf) {
     // kMipsAddOvf, SubOvf emit negative result to 'kCompareReg' on overflow.
-    switch (branch->condition) {
-      case kOverflow:
-        cc = lt;
-        break;
-      case kNotOverflow:
-        cc = ge;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsAddOvf, branch->condition);
-        break;
-    }
+    cc = FlagsConditionToConditionOvf(branch->condition);
     __ Branch(tlabel, cc, kCompareReg, Operand(zero_reg));
 
   } else if (instr->arch_opcode() == kMipsCmp) {
-    switch (branch->condition) {
-      case kEqual:
-        cc = eq;
-        break;
-      case kNotEqual:
-        cc = ne;
-        break;
-      case kSignedLessThan:
-        cc = lt;
-        break;
-      case kSignedGreaterThanOrEqual:
-        cc = ge;
-        break;
-      case kSignedLessThanOrEqual:
-        cc = le;
-        break;
-      case kSignedGreaterThan:
-        cc = gt;
-        break;
-      case kUnsignedLessThan:
-        cc = lo;
-        break;
-      case kUnsignedGreaterThanOrEqual:
-        cc = hs;
-        break;
-      case kUnsignedLessThanOrEqual:
-        cc = ls;
-        break;
-      case kUnsignedGreaterThan:
-        cc = hi;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsCmp, branch->condition);
-        break;
-    }
+    cc = FlagsConditionToConditionCmp(branch->condition);
     __ Branch(tlabel, cc, i.InputRegister(0), i.InputOperand(1));
 
     if (!branch->fallthru) __ Branch(flabel);  // no fallthru to flabel.
@@ -721,24 +728,24 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
     // even if we have to unfold BranchF macro.
     Label* nan = flabel;
     switch (branch->condition) {
-      case kUnorderedEqual:
+      case kEqual:
         cc = eq;
         break;
-      case kUnorderedNotEqual:
+      case kNotEqual:
         cc = ne;
         nan = tlabel;
         break;
-      case kUnorderedLessThan:
+      case kUnsignedLessThan:
         cc = lt;
         break;
-      case kUnorderedGreaterThanOrEqual:
+      case kUnsignedGreaterThanOrEqual:
         cc = ge;
         nan = tlabel;
         break;
-      case kUnorderedLessThanOrEqual:
+      case kUnsignedLessThanOrEqual:
         cc = le;
         break;
-      case kUnorderedGreaterThan:
+      case kUnsignedGreaterThan:
         cc = gt;
         nan = tlabel;
         break;
@@ -788,17 +795,7 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
   // TODO(plind): Add CHECK() to ensure that test/cmp and this branch were
   //    not separated by other instructions.
   if (instr->arch_opcode() == kMipsTst) {
-    switch (condition) {
-      case kNotEqual:
-        cc = ne;
-        break;
-      case kEqual:
-        cc = eq;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsTst, condition);
-        break;
-    }
+    cc = FlagsConditionToConditionTst(condition);
     __ And(at, i.InputRegister(0), i.InputOperand(1));
     __ Branch(USE_DELAY_SLOT, &done, cc, at, Operand(zero_reg));
     __ li(result, Operand(1));  // In delay slot.
@@ -806,17 +803,7 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
   } else if (instr->arch_opcode() == kMipsAddOvf ||
              instr->arch_opcode() == kMipsSubOvf) {
     // kMipsAddOvf, SubOvf emits negative result to 'kCompareReg' on overflow.
-    switch (condition) {
-      case kOverflow:
-        cc = lt;
-        break;
-      case kNotOverflow:
-        cc = ge;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsAddOvf, condition);
-        break;
-    }
+    cc = FlagsConditionToConditionOvf(condition);
     __ Branch(USE_DELAY_SLOT, &done, cc, kCompareReg, Operand(zero_reg));
     __ li(result, Operand(1));  // In delay slot.
 
@@ -824,41 +811,7 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
   } else if (instr->arch_opcode() == kMipsCmp) {
     Register left = i.InputRegister(0);
     Operand right = i.InputOperand(1);
-    switch (condition) {
-      case kEqual:
-        cc = eq;
-        break;
-      case kNotEqual:
-        cc = ne;
-        break;
-      case kSignedLessThan:
-        cc = lt;
-        break;
-      case kSignedGreaterThanOrEqual:
-        cc = ge;
-        break;
-      case kSignedLessThanOrEqual:
-        cc = le;
-        break;
-      case kSignedGreaterThan:
-        cc = gt;
-        break;
-      case kUnsignedLessThan:
-        cc = lo;
-        break;
-      case kUnsignedGreaterThanOrEqual:
-        cc = hs;
-        break;
-      case kUnsignedLessThanOrEqual:
-        cc = ls;
-        break;
-      case kUnsignedGreaterThan:
-        cc = hi;
-        break;
-      default:
-        UNSUPPORTED_COND(kMipsCmp, condition);
-        break;
-    }
+    cc = FlagsConditionToConditionCmp(condition);
     __ Branch(USE_DELAY_SLOT, &done, cc, left, right);
     __ li(result, Operand(1));  // In delay slot.
 
@@ -870,30 +823,30 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
     FPURegister dummy1 = f0;
     FPURegister dummy2 = f2;
     switch (condition) {
-      case kUnorderedEqual:
+      case kEqual:
         // TODO(plind):  improve the NaN testing throughout this function.
         __ BranchF(NULL, &false_value, kNoCondition, dummy1, dummy2);
         cc = eq;
         break;
-      case kUnorderedNotEqual:
+      case kNotEqual:
         __ BranchF(USE_DELAY_SLOT, NULL, &done, kNoCondition, dummy1, dummy2);
         __ li(result, Operand(1));  // In delay slot - returns 1 on NaN.
         cc = ne;
         break;
-      case kUnorderedLessThan:
+      case kUnsignedLessThan:
         __ BranchF(NULL, &false_value, kNoCondition, dummy1, dummy2);
         cc = lt;
         break;
-      case kUnorderedGreaterThanOrEqual:
+      case kUnsignedGreaterThanOrEqual:
         __ BranchF(USE_DELAY_SLOT, NULL, &done, kNoCondition, dummy1, dummy2);
         __ li(result, Operand(1));  // In delay slot - returns 1 on NaN.
         cc = ge;
         break;
-      case kUnorderedLessThanOrEqual:
+      case kUnsignedLessThanOrEqual:
         __ BranchF(NULL, &false_value, kNoCondition, dummy1, dummy2);
         cc = le;
         break;
-      case kUnorderedGreaterThan:
+      case kUnsignedGreaterThan:
         __ BranchF(USE_DELAY_SLOT, NULL, &done, kNoCondition, dummy1, dummy2);
         __ li(result, Operand(1));  // In delay slot - returns 1 on NaN.
         cc = gt;