diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index a74d5bd3a..a6291ccb9 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -14016,11 +14016,28 @@ void lb_generate_code(lbGenerator *gen) {
 	LLVMPassRegistryRef pass_registry = LLVMGetGlobalPassRegistry();
 
 	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(mod);
+	LLVMPassManagerRef function_pass_manager_minimal = LLVMCreateFunctionPassManagerForModule(mod);
+	LLVMPassManagerRef function_pass_manager_size = LLVMCreateFunctionPassManagerForModule(mod);
+	LLVMPassManagerRef function_pass_manager_speed = LLVMCreateFunctionPassManagerForModule(mod);
 	defer (LLVMDisposePassManager(default_function_pass_manager));
+	defer (LLVMDisposePassManager(function_pass_manager_minimal));
+	defer (LLVMDisposePassManager(function_pass_manager_size));
+	defer (LLVMDisposePassManager(function_pass_manager_speed));
 
 	LLVMInitializeFunctionPassManager(default_function_pass_manager);
+	LLVMInitializeFunctionPassManager(function_pass_manager_minimal);
+	LLVMInitializeFunctionPassManager(function_pass_manager_size);
+	LLVMInitializeFunctionPassManager(function_pass_manager_speed);
+
 	lb_populate_function_pass_manager(default_function_pass_manager, false, build_context.optimization_level);
+	lb_populate_function_pass_manager(function_pass_manager_minimal, false, 0);
+	lb_populate_function_pass_manager(function_pass_manager_size, false, 1);
+	lb_populate_function_pass_manager(function_pass_manager_speed, false, 2);
+
 	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_minimal);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_size);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_speed);
 
 
 	LLVMPassManagerRef default_function_pass_manager_without_memcpy = LLVMCreateFunctionPassManagerForModule(mod);
@@ -14330,7 +14347,25 @@ void lb_generate_code(lbGenerator *gen) {
 				if (p->flags & lbProcedureFlag_WithoutMemcpyPass) {
 					LLVMRunFunctionPassManager(default_function_pass_manager_without_memcpy, p->value);
 				} else {
-					LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
+					if (p->entity && p->entity->kind == Entity_Procedure) {
+						switch (p->entity->Procedure.optimization_mode) {
+						case ProcedureOptimizationMode_None:
+						case ProcedureOptimizationMode_Minimal:
+							LLVMRunFunctionPassManager(function_pass_manager_minimal, p->value);
+							break;
+						case ProcedureOptimizationMode_Size:
+							LLVMRunFunctionPassManager(function_pass_manager_size, p->value);
+							break;
+						case ProcedureOptimizationMode_Speed:
+							LLVMRunFunctionPassManager(function_pass_manager_speed, p->value);
+							break;
+						default:
+							LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
+							break;
+						}
+					} else {
+						LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
+					}
 				}
 			}
 		}
diff --git a/src/llvm_backend_opt.cpp b/src/llvm_backend_opt.cpp
index 5e1154af2..52cfa1808 100644
--- a/src/llvm_backend_opt.cpp
+++ b/src/llvm_backend_opt.cpp
@@ -1,11 +1,41 @@
+void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level);
+void lb_add_function_simplifcation_passes(LLVMPassManagerRef mpm, i32 optimization_level);
+void lb_populate_module_pass_manager(LLVMTargetMachineRef target_machine, LLVMPassManagerRef mpm, i32 optimization_level);
+
+void lb_basic_populate_function_pass_manager(LLVMPassManagerRef fpm) {
+	LLVMAddPromoteMemoryToRegisterPass(fpm);
+	LLVMAddMergedLoadStoreMotionPass(fpm);
+	LLVMAddConstantPropagationPass(fpm);
+	LLVMAddEarlyCSEPass(fpm);
+
+	LLVMAddConstantPropagationPass(fpm);
+	LLVMAddMergedLoadStoreMotionPass(fpm);
+	LLVMAddPromoteMemoryToRegisterPass(fpm);
+	LLVMAddCFGSimplificationPass(fpm);
+}
+
 void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level) {
 	// NOTE(bill): Treat -opt:3 as if it was -opt:2
 	// TODO(bill): Determine which opt definitions should exist in the first place
 	optimization_level = gb_clamp(optimization_level, 0, 2);
 
-	if (!ignore_memcpy_pass) {
+	if (ignore_memcpy_pass) {
+		lb_basic_populate_function_pass_manager(fpm);
+		return;
+	} else if (optimization_level == 0) {
 		LLVMAddMemCpyOptPass(fpm);
+		lb_basic_populate_function_pass_manager(fpm);
+		return;
 	}
+
+#if 1
+
+	LLVMPassManagerBuilderRef pmb = LLVMPassManagerBuilderCreate();
+	LLVMPassManagerBuilderSetOptLevel(pmb, optimization_level);
+	LLVMPassManagerBuilderSetSizeLevel(pmb, optimization_level);
+	LLVMPassManagerBuilderPopulateFunctionPassManager(pmb, fpm);
+#else
+	LLVMAddMemCpyOptPass(fpm);
 	LLVMAddPromoteMemoryToRegisterPass(fpm);
 	LLVMAddMergedLoadStoreMotionPass(fpm);
 	LLVMAddConstantPropagationPass(fpm);
@@ -16,16 +46,6 @@ void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcp
 	LLVMAddPromoteMemoryToRegisterPass(fpm);
 	LLVMAddCFGSimplificationPass(fpm);
 
-	// LLVMAddSLPVectorizePass(fpm);
-	// LLVMAddLoopVectorizePass(fpm);
-
-	// LLVMAddScalarizerPass(fpm);
-	// LLVMAddLoopIdiomPass(fpm);
-	if (optimization_level == 0) {
-		return;
-	}
-
-#if 1
 	LLVMAddSCCPPass(fpm);
 
 	LLVMAddPromoteMemoryToRegisterPass(fpm);