PPC/s390: Check for overflow when SubI IntMin

src/crankshaft/s390/lithium-codegen-s390.cc

Index: src/crankshaft/s390/lithium-codegen-s390.cc
diff --git a/src/crankshaft/s390/lithium-codegen-s390.cc b/src/crankshaft/s390/lithium-codegen-s390.cc
index bbc8f839451389c73bc629f623f4447938815768..0cdcc34f31f31a268075580fa3fdc1375281768c 100644
--- a/src/crankshaft/s390/lithium-codegen-s390.cc
+++ b/src/crankshaft/s390/lithium-codegen-s390.cc
@@ -1682,10 +1682,17 @@ void LCodeGen::DoSubI(LSubI* instr) {
 #endif
 
   if (right->IsConstantOperand()) {
-    if (!isInteger || !checkOverflow)
+    if (!isInteger || !checkOverflow) {
       __ SubP(ToRegister(result), ToRegister(left), ToOperand(right));
-    else
-      __ Sub32(ToRegister(result), ToRegister(left), ToOperand(right));
+    } else {
+      // -(MinInt) will overflow
+      if (ToInteger32(LConstantOperand::cast(right)) == kMinInt) {
+        __ Load(scratch0(), ToOperand(right));
+        __ Sub32(ToRegister(result), ToRegister(left), scratch0());
+      } else {
+        __ Sub32(ToRegister(result), ToRegister(left), ToOperand(right));
+      }
+    }
   } else if (right->IsRegister()) {
     if (!isInteger)
       __ SubP(ToRegister(result), ToRegister(left), ToRegister(right));