Add the ability to call directly through a register.

Simplify some code a little using it.
JesseStutler · Feb 1, 2021 · 6336627 · 6336627
1 parent 05f356f
commit 6336627
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Showing 2 changed files with 8 additions and 14 deletions.
diff --git a/lib/compiler-singlepass/src/codegen_x64.rs b/lib/compiler-singlepass/src/codegen_x64.rs
@@ -5674,13 +5674,7 @@ impl<'a> FuncGen<'a> {
                 );
                 self.emit_call_sysv(
                     |this| {
-                        let label = this.assembler.get_label();
-                        let after = this.assembler.get_label();
-                        this.assembler.emit_jmp(Condition::None, after);
-                        this.assembler.emit_label(label);
-                        this.assembler.emit_host_redirection(GPR::RAX);
-                        this.assembler.emit_label(after);
-                        this.assembler.emit_call_label(label);
+                        this.assembler.emit_call_register(GPR::RAX);
                     },
                     // [vmctx, memory_index]
                     iter::once(Location::Imm32(memory_index.index() as u32)),
@@ -5719,13 +5713,7 @@ impl<'a> FuncGen<'a> {
 
                 self.emit_call_sysv(
                     |this| {
-                        let label = this.assembler.get_label();
-                        let after = this.assembler.get_label();
-                        this.assembler.emit_jmp(Condition::None, after);
-                        this.assembler.emit_label(label);
-                        this.assembler.emit_host_redirection(GPR::RAX);
-                        this.assembler.emit_label(after);
-                        this.assembler.emit_call_label(label);
+                        this.assembler.emit_call_register(GPR::RAX);
                     },
                     // [vmctx, val, memory_index]
                     iter::once(param_pages)

diff --git a/lib/compiler-singlepass/src/emitter_x64.rs b/lib/compiler-singlepass/src/emitter_x64.rs
@@ -205,6 +205,8 @@ pub trait Emitter {
     fn emit_call_label(&mut self, label: Self::Label);
     fn emit_call_location(&mut self, loc: Location);
 
+    fn emit_call_register(&mut self, reg: GPR);
+
     fn emit_bkpt(&mut self);
 
     fn emit_host_redirection(&mut self, target: GPR);
@@ -1389,6 +1391,10 @@ impl Emitter for Assembler {
         }
     }
 
+    fn emit_call_register(&mut self, reg: GPR) {
+        dynasm!(self ; call Rq(reg as u8));
+    }
+
     fn emit_bkpt(&mut self) {
         dynasm!(self ; int 0x3);
     }