Partially implement "POP"

--HG--
extra : convert_revision : ba454579a6a82ce4924102a633e5758fb2a30b2d

src/arch/x86/isa/decoder/one_byte_opcodes.isa

@@ -179,7 +179,7 @@
             0x3: pop_rBX();
             0x4: pop_rSP();
             0x5: pop_rBP();
-            0x6: pop_rSI();
+            0x6: Inst::POP(rSI);
             0x7: pop_rDI();
         }
         0x0C: decode OPCODE_OP_BOTTOM3 {

src/arch/x86/isa/insts/data_transfer/stack_operations.py

@@ -53,7 +53,12 @@
 #
 # Authors: Gabe Black
 
-microcode = ""
+microcode = '''
+def macroop POP {
+    # There needs to be a load here to actually "pop" the data
+    addi "INTREG_RSP", "INTREG_RSP", "env.dataSize"
+};
+'''
 #let {{
 #    class POP(Inst):
 #	"GenFault ${new UnimpInstFault}"