From ed3c266e2d782ffe2857402f6fb3cee339a0f447 Mon Sep 17 00:00:00 2001
From: "Kartik K. Agaram" <vc@akkartik.com>
Date: Thu, 12 Oct 2017 22:28:06 -0700
Subject: 4044

subx: now starting on subtraction instructions.
---
 subx/010core.cc |  3 +--
 subx/011add.cc  | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

(limited to 'subx')

diff --git a/subx/010core.cc b/subx/010core.cc
index b59f745e..058cc065 100644
--- a/subx/010core.cc
+++ b/subx/010core.cc
@@ -83,7 +83,7 @@ End_of_program = 0;
 +load: 4 -> 0c
 +load: 5 -> 0d
 +run: add imm32 0x0d0c0b0a to reg EAX
-+reg: storing 0x0d0c0b0a in reg EAX
++run: storing 0x0d0c0b0a
 
 :(code)
 // helper for tests: load a program into memory from a textual representation
@@ -107,7 +107,6 @@ void run_one_instruction() {
     int32_t arg2 = imm32();
     trace(2, "run") << "add imm32 0x" << HEXWORD << arg2 << " to reg EAX" << end();
     BINARY_ARITHMETIC_OP(+, Reg[EAX].i, arg2);
-    trace(98, "reg") << "storing 0x" << HEXWORD << Reg[EAX].i << " in reg EAX" << end();
     break;
   }
   // End Single-Byte Opcodes
diff --git a/subx/011add.cc b/subx/011add.cc
index 0d2eef31..5fe3523b 100644
--- a/subx/011add.cc
+++ b/subx/011add.cc
@@ -118,3 +118,20 @@ case 0x03: {  // add r/m32 to r32
   BINARY_ARITHMETIC_OP(+, Reg[arg1].i, *arg2);
   break;
 }
+
+//:
+
+:(scenario sub_imm32_from_eax)
+% Reg[EAX].i = 0x0d0c0baa;
+# op  ModR/M  SIB   displacement  immediate
+  2d                              0a 0b 0c 0d  # subtract 0x0d0c0b0a from EAX (reg 0)
++run: subtract imm32 0x0d0c0b0a from reg EAX
++run: storing 0x000000a0
+
+:(before "End Single-Byte Opcodes")
+case 0x2d: {  // subtract imm32 from EAX
+  int32_t arg2 = imm32();
+  trace(2, "run") << "subtract imm32 0x" << HEXWORD << arg2 << " from reg EAX" << end();
+  BINARY_ARITHMETIC_OP(-, Reg[EAX].i, arg2);
+  break;
+}
-- 
cgit 1.4.1-2-gfad0