commit 46a649dac63d58bf3d53ad714357b10cf2ce08b4
author Sean Risser <srisser@google.com> Mon Aug 30 15:44:33 2021 -0400
committer swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com <swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Sep 01 15:56:24 2021 +0000
tree 686a9741f06ea84f65037a20670ded7d278cfe8c
parent b75ca3758a8091cd6a4053b5ac2bd097e864bf1e

Minimize usage of global constructors in Reactor

A few const bools are easily replaced with constexprs. Other global
constructors are left as is for now.

llvm_shutdown_obj is necessary for cleaning up LLVM at program exit and
is necessarily used every time SwiftShader is invoked.

We could replace CPUID::SSE4_1 with a call to a singleton function.
However, I believe this increases code complexity for little benefit.
Because it's a bool, there's no deconstructor associated with it, it's
cleaned up when global memory is deallocated.

Bug: b/175073772
Change-Id: I25635fda0878e30668cbfc6982877b5d2d924789
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/56708
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Sean Risser <srisser@google.com>
Commit-Queue: Sean Risser <srisser@google.com>

src/Reactor/SubzeroReactor.cpp

diff --git a/src/Reactor/SubzeroReactor.cpp b/src/Reactor/SubzeroReactor.cpp
index db23dc5..e87eb76 100644
--- a/src/Reactor/SubzeroReactor.cpp
+++ b/src/Reactor/SubzeroReactor.cpp
@@ -165,7 +165,7 @@
 
 // Wrapper for calls on C functions with Ice types
 template<typename Return, typename... CArgs, typename... RArgs>
-Ice::Variable *Call(Ice::Cfg *function, Ice::CfgNode *basicBlock, Return(fptr)(CArgs...), RArgs &&...args)
+Ice::Variable *Call(Ice::Cfg *function, Ice::CfgNode *basicBlock, Return(fptr)(CArgs...), RArgs &&... args)
 {
 	static_assert(sizeof...(CArgs) == sizeof...(RArgs), "Expected number of args don't match");
 
@@ -309,7 +309,7 @@
 #endif
 	}
 
-	static bool detectARM()
+	constexpr static bool detectARM()
 	{
 #if defined(__arm__) || defined(__aarch64__)
 		return true;
@@ -334,10 +334,10 @@
 	}
 };
 
-const bool CPUID::ARM = CPUID::detectARM();
+constexpr bool CPUID::ARM = CPUID::detectARM();
 const bool CPUID::SSE4_1 = CPUID::detectSSE4_1();
-const bool emulateIntrinsics = false;
-const bool emulateMismatchedBitCast = CPUID::ARM;
+constexpr bool emulateIntrinsics = false;
+constexpr bool emulateMismatchedBitCast = CPUID::ARM;
 
 constexpr bool subzeroDumpEnabled = false;
 constexpr bool subzeroEmitTextAsm = false;