From c330d9e0e30253ebf42eecfbdedc3c67f3d82caa Mon Sep 17 00:00:00 2001
From: Subv <subv2112@gmail.com>
Date: Mon, 18 Jul 2016 16:10:35 -0500
Subject: [PATCH] Increase the chance of generating instructions without
 conditions in the REV/REVSH/REV16 tests.

---
 tests/arm/fuzz_arm.cpp | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/tests/arm/fuzz_arm.cpp b/tests/arm/fuzz_arm.cpp
index d2834eb6..ae19305e 100644
--- a/tests/arm/fuzz_arm.cpp
+++ b/tests/arm/fuzz_arm.cpp
@@ -366,29 +366,44 @@ TEST_CASE("Fuzz ARM reversal instructions", "[JitX64]") {
         return Dynarmic::Common::Bits<0, 3>(instr) != 0b1111 && Dynarmic::Common::Bits<12, 15>(instr) != 0b1111;
     };
 
-    const std::array<InstructionGenerator, 3> reg_instructions = {
+    const std::array<InstructionGenerator, 3> rev_instructions = {
         {
-            InstructionGenerator("cccc011010111111dddd11110011mmmm", is_valid),
-            InstructionGenerator("cccc011010111111dddd11111011mmmm", is_valid),
-            InstructionGenerator("cccc011011111111dddd11111011mmmm", is_valid),
+            InstructionGenerator("0000011010111111dddd11110011mmmm", is_valid),
+            InstructionGenerator("0000011010111111dddd11111011mmmm", is_valid),
+            InstructionGenerator("0000011011111111dddd11111011mmmm", is_valid),
         }
     };
 
     SECTION("REV tests") {
-        FuzzJitArm(1, 1, 10000, [&reg_instructions]() -> u32 {
-            return reg_instructions[0].Generate();
+        FuzzJitArm(1, 1, 10000, [&rev_instructions]() -> u32 {
+            u32 cond = 0xE;
+            // Have a one-in-twenty-five chance of actually having a cond.
+            if (RandInt(1, 25) == 1) {
+                cond = RandInt<u32>(0x0, 0xD);
+            }
+            return rev_instructions[0].Generate() | (cond << 28);
         });
     }
 
     SECTION("REV16 tests") {
-        FuzzJitArm(1, 1, 10000, [&reg_instructions]() -> u32 {
-            return reg_instructions[1].Generate();
+        FuzzJitArm(1, 1, 10000, [&rev_instructions]() -> u32 {
+            u32 cond = 0xE;
+            // Have a one-in-twenty-five chance of actually having a cond.
+            if (RandInt(1, 25) == 1) {
+                cond = RandInt<u32>(0x0, 0xD);
+            }
+            return rev_instructions[1].Generate() | (cond << 28);
         });
     }
 
     SECTION("REVSH tests") {
-        FuzzJitArm(1, 1, 10000, [&reg_instructions]() -> u32 {
-            return reg_instructions[2].Generate();
+        FuzzJitArm(1, 1, 10000, [&rev_instructions]() -> u32 {
+            u32 cond = 0xE;
+            // Have a one-in-twenty-five chance of actually having a cond.
+            if (RandInt(1, 25) == 1) {
+                cond = RandInt<u32>(0x0, 0xD);
+            }
+            return rev_instructions[2].Generate() | (cond << 28);
         });
     }
 }