From e3f99e4360aabc84ab9d341dce7184b96ec4cd62 Mon Sep 17 00:00:00 2001
From: Jacob Lifshay <programmerjake@gmail.com>
Date: Thu, 27 Aug 2020 17:17:47 -0700
Subject: [PATCH] add subf[o][.] instructions

---
 src/instr_models.rs | 15 +++++++++++++++
 src/lib.rs          | 18 ++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/instr_models.rs b/src/instr_models.rs
index 8711e22..59ff2bb 100644
--- a/src/instr_models.rs
+++ b/src/instr_models.rs
@@ -53,6 +53,21 @@ pub fn addo(inputs: InstructionInput) -> InstructionResult {
     }
 }
 
+create_instr_variants_ov_cr!(subf, subfo, subf_, subfo_, i64);
+
+pub fn subfo(inputs: InstructionInput) -> InstructionResult {
+    let ra = inputs.ra as i64;
+    let rb = inputs.rb as i64;
+    let (result, ov) = rb.overflowing_sub(ra);
+    let result = result as u64;
+    let ov32 = (rb as i32).overflowing_sub(ra as i32).1;
+    InstructionResult {
+        rt: Some(result),
+        overflow: Some(OverflowFlags { so: ov, ov, ov32 }),
+        ..InstructionResult::default()
+    }
+}
+
 create_instr_variants_ov_cr!(divde, divdeo, divde_, divdeo_, i64);
 
 pub fn divdeo(inputs: InstructionInput) -> InstructionResult {
diff --git a/src/lib.rs b/src/lib.rs
index 98880c2..6faa451 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -423,6 +423,24 @@ instrs! {
         "addo."
     }
 
+    // subf
+    #[enumerant = SubF]
+    fn subf(ra, rb) -> (rt) {
+        "subf"
+    }
+    #[enumerant = SubFO]
+    fn subfo(ra, rb) -> (rt, ov) {
+        "subfo"
+    }
+    #[enumerant = SubF_]
+    fn subf_(ra, rb) -> (rt, cr0) {
+        "subf."
+    }
+    #[enumerant = SubFO_]
+    fn subfo_(ra, rb) -> (rt, ov, cr0) {
+        "subfo."
+    }
+
     // divde
     #[enumerant = DivDE]
     fn divde(ra, rb) -> (rt) {
-- 
2.30.2