Hoist signal page lookup outside fence

vchuravy · vchuravy · commit c76459cc0fb4 · 2021-07-23T11:40:57.000+02:00
diff --git a/src/cgutils.cpp b/src/cgutils.cpp
@@ -3451,8 +3451,9 @@ static Value *emit_defer_signal(jl_codectx_t &ctx)
 static void emit_safepoint(jl_codectx_t &ctx)
 {
     ctx.builder.CreateCall(prepare_call(gcroot_flush_func));
+    Value* signal_page = get_current_signal_page(ctx);
     emit_signal_fence(ctx);
-    ctx.builder.CreateLoad(T_size, get_current_signal_page(ctx), true);
+    ctx.builder.CreateLoad(T_size, signal_page, true);
     emit_signal_fence(ctx);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -3451,8 +3451,9 @@ static Value *emit_defer_signal(jl_codectx_t &ctx)`
`3451`	`3451`	`static void emit_safepoint(jl_codectx_t &ctx)`
`3452`	`3452`	`{`
`3453`	`3453`	`ctx.builder.CreateCall(prepare_call(gcroot_flush_func));`
	`3454`	`+ Value* signal_page = get_current_signal_page(ctx);`
`3454`	`3455`	`emit_signal_fence(ctx);`
`3455`		`- ctx.builder.CreateLoad(T_size, get_current_signal_page(ctx), true);`
	`3456`	`+ ctx.builder.CreateLoad(T_size, signal_page, true);`
`3456`	`3457`	`emit_signal_fence(ctx);`
`3457`	`3458`	`}`
`3458`	`3459`