1 files changed, 45 insertions, 13 deletions
diff --git a/src/arch/x86/isa/insts/general_purpose/string/store_string.py b/src/arch/x86/isa/insts/general_purpose/string/store_string.py
index 08a126c1f..a8655cf96 100644
--- a/src/arch/x86/isa/insts/general_purpose/string/store_string.py
+++ b/src/arch/x86/isa/insts/general_purpose/string/store_string.py
@@ -53,16 +53,48 @@
 #
 # Authors: Gabe Black
 
-microcode = ""
-#let {{
-#    class STOS(Inst):
-#	"Add 0 0 0"
-#    class STOSB(Inst):
-#	"Add 0 0 0"
-#    class STOSW(Inst):
-#	"Add 0 0 0"
-#    class STOSD(Inst):
-#	"Add 0 0 0"
-#    class STOSQ(Inst):
-#	"Add 0 0 0"
-#}};
+microcode = '''
+def macroop STOS_M {
+    # Find the constant we need to either add or subtract from rdi
+    ruflag t0, 10
+    movi t3, t3, dsz, flags=(CEZF,), dataSize=asz
+    subi t4, t0, dsz, dataSize=asz
+    mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
+
+    st rax, es, [1, t0, rdi]
+
+    add rdi, rdi, t3, dataSize=asz
+};
+
+def macroop STOS_E_M {
+    # Find the constant we need to either add or subtract from rdi
+    ruflag t0, 10
+    movi t3, t3, dsz, flags=(CEZF,), dataSize=asz
+    subi t4, t0, dsz, dataSize=asz
+    mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
+
+topOfLoop:
+    st rax, es, [1, t0, rdi]
+
+    subi rcx, rcx, 1, flags=(EZF,), dataSize=asz
+    add rdi, rdi, t3, dataSize=asz
+    bri t0, label("topOfLoop"), flags=(CSTRZnEZF,)
+    fault "NoFault"
+};
+
+def macroop STOS_N_M {
+    # Find the constant we need to either add or subtract from rdi
+    ruflag t0, 10
+    movi t3, t3, dsz, flags=(CEZF,), dataSize=asz
+    subi t4, t0, dsz, dataSize=asz
+    mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
+
+topOfLoop:
+    st rax, es, [1, t0, rdi]
+
+    subi rcx, rcx, 1, flags=(EZF,), dataSize=asz
+    add rdi, rdi, t3, dataSize=asz
+    bri t0, label("topOfLoop"), flags=(CSTRnZnEZF,)
+    fault "NoFault"
+};
+'''