PPC: Simulator fixes for shift operations.

src/ppc/simulator-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #if V8_TARGET_ARCH_PPC
 
@@ skipping 1715 matching lines @@
 bool Simulator::ExecuteExt2_10bit(Instruction* instr) {
   bool found = true;
 
   int opcode = instr->Bits(10, 1) << 1;
   switch (opcode) {
     case SRWX: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       uint32_t rs_val = get_register(rs);
-      uintptr_t rb_val = get_register(rb);
-      intptr_t result = rs_val >> (rb_val & 0x3f);
+      uintptr_t rb_val = get_register(rb) & 0x3f;
+      intptr_t result = (rb_val > 31) ? 0 : rs_val >> rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
 #if V8_TARGET_ARCH_PPC64
     case SRDX: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       uintptr_t rs_val = get_register(rs);
-      uintptr_t rb_val = get_register(rb);
-      intptr_t result = rs_val >> (rb_val & 0x7f);
+      uintptr_t rb_val = get_register(rb) & 0x7f;
+      intptr_t result = (rb_val > 63) ? 0 : rs_val >> rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
 #endif
     case SRAW: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       int32_t rs_val = get_register(rs);
-      intptr_t rb_val = get_register(rb);
-      intptr_t result = rs_val >> (rb_val & 0x3f);
+      intptr_t rb_val = get_register(rb) & 0x3f;
+      intptr_t result = (rb_val > 31) ? rs_val >> 31 : rs_val >> rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
 #if V8_TARGET_ARCH_PPC64
     case SRAD: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       intptr_t rs_val = get_register(rs);
-      intptr_t rb_val = get_register(rb);
-      intptr_t result = rs_val >> (rb_val & 0x7f);
+      intptr_t rb_val = get_register(rb) & 0x7f;
+      intptr_t result = (rb_val > 63) ? rs_val >> 63 : rs_val >> rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
 #endif
     case SRAWIX: {
       int ra = instr->RAValue();
       int rs = instr->RSValue();
@@ skipping 356 matching lines @@
         bool setSO = (special_reg_xer_ & 0x80000000);
         SetCR0(alu_out, setSO);
       }
       break;
     }
     case SLWX: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       uint32_t rs_val = get_register(rs);
-      uintptr_t rb_val = get_register(rb);
-      uint32_t result = rs_val << (rb_val & 0x3f);
+      uintptr_t rb_val = get_register(rb) & 0x3f;
+      uint32_t result = (rb_val > 31) ? 0 : rs_val << rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
 #if V8_TARGET_ARCH_PPC64
     case SLDX: {
       int rs = instr->RSValue();
       int ra = instr->RAValue();
       int rb = instr->RBValue();
       uintptr_t rs_val = get_register(rs);
-      uintptr_t rb_val = get_register(rb);
-      uintptr_t result = rs_val << (rb_val & 0x7f);
+      uintptr_t rb_val = get_register(rb) & 0x7f;
+      uintptr_t result = (rb_val > 63) ? 0 : rs_val << rb_val;
       set_register(ra, result);
       if (instr->Bit(0)) {  // RC bit set
         SetCR0(result);
       }
       break;
     }
     case MFVSRD: {
       DCHECK(!instr->Bit(0));
       int frt = instr->RTValue();
       int ra = instr->RAValue();
@@ skipping 1947 matching lines @@
   uintptr_t* stack_slot = reinterpret_cast<uintptr_t*>(current_sp);
   uintptr_t address = *stack_slot;
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // USE_SIMULATOR
 #endif  // V8_TARGET_ARCH_PPC