From 489ec2dcb684ca262ed91a0cd11632359d8e31fb Mon Sep 17 00:00:00 2001
From: lizzie <lizzie@eden-emu.dev>
Date: Wed, 27 Aug 2025 12:12:32 +0200
Subject: [PATCH] [jit] Disable fastmem (by default) on FreeBSD, Solaris and
 OpenBSD due to subpar timings of SIGSEGV (#319)

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/319
Reviewed-by: Shinmegumi <shinmegumi@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>
---
 src/core/arm/dynarmic/arm_dynarmic_32.cpp | 20 +++++++++++++-------
 src/core/arm/dynarmic/arm_dynarmic_64.cpp | 20 +++++++++++++-------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/src/core/arm/dynarmic/arm_dynarmic_32.cpp b/src/core/arm/dynarmic/arm_dynarmic_32.cpp
index db159388bf..798623a5fa 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_32.cpp
+++ b/src/core/arm/dynarmic/arm_dynarmic_32.cpp
@@ -269,8 +269,13 @@ std::shared_ptr<Dynarmic::A32::Jit> ArmDynarmic32::MakeJit(Common::PageTable* pa
             config.check_halt_on_memory_access = true;
         }
     } else {
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__sun__)
+        config.fastmem_pointer = std::nullopt;
+        config.fastmem_exclusive_access = false;
+#endif
+        switch (Settings::values.cpu_accuracy.GetValue()) {
         // Unsafe optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Unsafe) {
+        case Settings::CpuAccuracy::Unsafe:
             config.unsafe_optimizations = true;
             if (Settings::values.cpuopt_unsafe_unfuse_fma) {
                 config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_UnfuseFMA;
@@ -287,21 +292,22 @@ std::shared_ptr<Dynarmic::A32::Jit> ArmDynarmic32::MakeJit(Common::PageTable* pa
             if (Settings::values.cpuopt_unsafe_ignore_global_monitor) {
                 config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_IgnoreGlobalMonitor;
             }
-        }
-
+            break;
         // Curated optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Auto) {
+        case Settings::CpuAccuracy::Auto:
             config.unsafe_optimizations = true;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_UnfuseFMA;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_IgnoreStandardFPCRValue;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_InaccurateNaN;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_IgnoreGlobalMonitor;
-        }
-
+            break;
         // Paranoia mode for debugging optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Paranoid) {
+        case Settings::CpuAccuracy::Paranoid:
             config.unsafe_optimizations = false;
             config.optimizations = Dynarmic::no_optimizations;
+            break;
+        default:
+            break;
         }
     }
 
diff --git a/src/core/arm/dynarmic/arm_dynarmic_64.cpp b/src/core/arm/dynarmic/arm_dynarmic_64.cpp
index dcff0ddf3f..7b59ce2633 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_64.cpp
+++ b/src/core/arm/dynarmic/arm_dynarmic_64.cpp
@@ -327,8 +327,13 @@ std::shared_ptr<Dynarmic::A64::Jit> ArmDynarmic64::MakeJit(Common::PageTable* pa
             config.check_halt_on_memory_access = true;
         }
     } else {
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__sun__)
+        config.fastmem_pointer = std::nullopt;
+        config.fastmem_exclusive_access = false;
+#endif
         // Unsafe optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Unsafe) {
+        switch(Settings::values.cpu_accuracy.GetValue()) {
+        case Settings::CpuAccuracy::Unsafe:
             config.unsafe_optimizations = true;
             if (Settings::values.cpuopt_unsafe_unfuse_fma) {
                 config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_UnfuseFMA;
@@ -345,20 +350,21 @@ std::shared_ptr<Dynarmic::A64::Jit> ArmDynarmic64::MakeJit(Common::PageTable* pa
             if (Settings::values.cpuopt_unsafe_ignore_global_monitor) {
                 config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_IgnoreGlobalMonitor;
             }
-        }
-
+            break;
         // Curated optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Auto) {
+        case Settings::CpuAccuracy::Auto:
             config.unsafe_optimizations = true;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_UnfuseFMA;
             config.fastmem_address_space_bits = 64;
             config.optimizations |= Dynarmic::OptimizationFlag::Unsafe_IgnoreGlobalMonitor;
-        }
-
+            break;
         // Paranoia mode for debugging optimizations
-        if (Settings::values.cpu_accuracy.GetValue() == Settings::CpuAccuracy::Paranoid) {
+        case Settings::CpuAccuracy::Paranoid:
             config.unsafe_optimizations = false;
             config.optimizations = Dynarmic::no_optimizations;
+            break;
+        default:
+            break;
         }
     }