S390X: Prevent upper 32bit corruption in 32bit ops

src/compiler/s390/code-generator-s390.cc

Index: src/compiler/s390/code-generator-s390.cc
diff --git a/src/compiler/s390/code-generator-s390.cc b/src/compiler/s390/code-generator-s390.cc
index dfe390aa62bda7e33eb958eafe9f6d3f274de495..8d928d7531c29981bce0ade9e370dfdb0db8cf0c 100644
--- a/src/compiler/s390/code-generator-s390.cc
+++ b/src/compiler/s390/code-generator-s390.cc
@@ -808,7 +808,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     case kS390_ShiftLeft32:
       if (HasRegisterInput(instr, 1)) {
-        if (i.OutputRegister().is(i.InputRegister(1))) {
+        if (i.OutputRegister().is(i.InputRegister(1)) &&

[JoranSiu, 2016/05/02 18:22:22]

ShiftLeft masm shoudl really handle all of these cases.  It at least has a check
for DISTINCT_OPS.  Can we fix it there instead?

+            !CpuFeatures::IsSupported(DISTINCT_OPS)) {
           __ LoadRR(kScratchReg, i.InputRegister(1));
           __ ShiftLeft(i.OutputRegister(), i.InputRegister(0), kScratchReg);
         } else {
@@ -828,7 +829,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #endif
     case kS390_ShiftRight32:
       if (HasRegisterInput(instr, 1)) {
-        if (i.OutputRegister().is(i.InputRegister(1))) {
+        if (i.OutputRegister().is(i.InputRegister(1)) &&
+            !CpuFeatures::IsSupported(DISTINCT_OPS)) {
           __ LoadRR(kScratchReg, i.InputRegister(1));
           __ ShiftRight(i.OutputRegister(), i.InputRegister(0), kScratchReg);
         } else {
@@ -848,7 +850,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #endif
     case kS390_ShiftRightArith32:
       if (HasRegisterInput(instr, 1)) {
-        if (i.OutputRegister().is(i.InputRegister(1))) {
+        if (i.OutputRegister().is(i.InputRegister(1)) &&
+            !CpuFeatures::IsSupported(DISTINCT_OPS)) {
           __ LoadRR(kScratchReg, i.InputRegister(1));
           __ ShiftRightArith(i.OutputRegister(), i.InputRegister(0),
                              kScratchReg);
@@ -858,6 +861,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       } else {
         ASSEMBLE_BINOP(ShiftRightArith, ShiftRightArith);
       }
+#if V8_TARGET_ARCH_S390X
+      __ lgfr(i.OutputRegister(), i.OutputRegister());
+#endif
       break;
 #if V8_TARGET_ARCH_S390X
     case kS390_ShiftRightArith64:
@@ -1093,12 +1099,20 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kS390_MulHigh32:
       __ LoadRR(r1, i.InputRegister(0));
       __ mr_z(r0, i.InputRegister(1));
+#if V8_TARGET_ARCH_S390X

[JoranSiu, 2016/05/02 18:22:22]

We should introduce a Load_ExtendSrc() in masm so we don't have so many #if
S390X's sprinkled through our code.

+      __ lgfr(i.OutputRegister(), r0);
+#else
       __ LoadRR(i.OutputRegister(), r0);
+#endif
       break;
     case kS390_MulHighU32:
       __ LoadRR(r1, i.InputRegister(0));
       __ mlr(r0, i.InputRegister(1));
+#if V8_TARGET_ARCH_S390X
+      __ lgfr(i.OutputRegister(), r0);
+#else
       __ LoadRR(i.OutputRegister(), r0);
+#endif
       break;
     case kS390_MulFloat:
       // Ensure we don't clobber right
@@ -1131,7 +1145,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ LoadRR(r0, i.InputRegister(0));
       __ srda(r0, Operand(32));
       __ dr(r0, i.InputRegister(1));
-      __ ltr(i.OutputRegister(), r1);
+#if V8_TARGET_ARCH_S390X

[JoranSiu, 2016/05/02 18:22:22]

I believe this is the same as : LoadAndTestP_ExtendSrc

+      __ ltgfr(i.OutputRegister(), r1);  // Copy R1: Quotient to output
+#else
+      __ ltr(i.OutputRegister(), r1);  // Copy R1: Quotient to output
+#endif
       break;
 #if V8_TARGET_ARCH_S390X
     case kS390_DivU64:
@@ -1145,7 +1163,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ LoadRR(r0, i.InputRegister(0));
       __ srdl(r0, Operand(32));
       __ dlr(r0, i.InputRegister(1));  // R0:R1: Dividend
+#if V8_TARGET_ARCH_S390X
+      __ ltgfr(i.OutputRegister(), r1);
+#else
       __ ltr(i.OutputRegister(), r1);  // Copy R1: Quotient to output
+#endif
       break;
 
     case kS390_DivFloat: