MIPS: Improve Lsa/Dlsa implementations.

src/mips64/macro-assembler-mips64.h

Index: src/mips64/macro-assembler-mips64.h
diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index 097f46012a42417c565a1f7ef9feedbafc0c8eb7..216f4b996f2503dc9503c3cde7ebeca5020f47b9 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -677,6 +677,9 @@ class MacroAssembler: public Assembler {
 #undef DEFINE_INSTRUCTION2
 #undef DEFINE_INSTRUCTION3
 
+  // Load Scaled Address instructions. Parameter sa (shift argument) must be
+  // between [1, 31] (inclusive). On pre-r6 architectures the scratch register
+  // may be clobbered.
   void Lsa(Register rd, Register rs, Register rt, uint8_t sa,
            Register scratch = at);
   void Dlsa(Register rd, Register rs, Register rt, uint8_t sa,
@@ -1954,7 +1957,7 @@ void MacroAssembler::GenerateSwitchTable(Register index, size_t case_count,
       nop();
     }
     addiupc(at, 5);
-    dlsa(at, at, index, kPointerSizeLog2);
+    Dlsa(at, at, index, kPointerSizeLog2);
     ld(at, MemOperand(at));
   } else {
     Label here;