feat(compiler) Windows ABI needs RSI and RDI to be saved.So save them…

… uncoditionnaly for now
wasmerio · Sep 17, 2021 · 45f56d0 · 45f56d0
1 parent c914b48
commit 45f56d0
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Showing 2 changed files with 35 additions and 2 deletions.
diff --git a/lib/compiler-singlepass/src/codegen_x64.rs b/lib/compiler-singlepass/src/codegen_x64.rs
@@ -6696,7 +6696,7 @@ impl<'a> FuncGen<'a> {
                 if self.control_stack.is_empty() {
                     self.assembler.emit_label(frame.label);
                     self.machine
-                        .finalize_locals(&mut self.assembler, &self.locals);
+                    .finalize_locals(&mut self.assembler, &self.locals, self.config.calling_convention);
                     self.assembler.emit_mov(
                         Size::S64,
                         Location::GPR(GPR::RBP),

diff --git a/lib/compiler-singlepass/src/machine.rs b/lib/compiler-singlepass/src/machine.rs
@@ -369,6 +369,11 @@ impl Machine {
         // Callee-saved R15 for vmctx.
         static_area_size += 8;
 
+        // For Windows ABI, save RDI and RSI
+        if calling_convention == CallingConvention::WindowsFastcall {
+            static_area_size += 8 * 2;
+        }
+
         // Total size of callee saved registers.
         let callee_saved_regs_size = static_area_size;
 
@@ -413,6 +418,29 @@ impl Machine {
             X64Register::GPR(GPR::R15).to_index(),
         ));
 
+        if calling_convention == CallingConvention::WindowsFastcall {
+            // Save RDI
+            self.stack_offset.0 += 8;
+            a.emit_mov(
+                Size::S64,
+                Location::GPR(GPR::RDI),
+                Location::Memory(GPR::RBP, -(self.stack_offset.0 as i32)),
+            );
+            self.state.stack_values.push(MachineValue::PreserveRegister(
+                X64Register::GPR(GPR::RDI).to_index(),
+            ));
+            // Save RSI
+            self.stack_offset.0 += 8;
+            a.emit_mov(
+                Size::S64,
+                Location::GPR(GPR::RSI),
+                Location::Memory(GPR::RBP, -(self.stack_offset.0 as i32)),
+            );
+            self.state.stack_values.push(MachineValue::PreserveRegister(
+                X64Register::GPR(GPR::RSI).to_index(),
+            ));
+        }
+
         // Save the offset of register save area.
         self.save_area_offset = Some(MachineStackOffset(self.stack_offset.0));
 
@@ -501,7 +529,7 @@ impl Machine {
         locations
     }
 
-    pub fn finalize_locals<E: Emitter>(&mut self, a: &mut E, locations: &[Location]) {
+    pub fn finalize_locals<E: Emitter>(&mut self, a: &mut E, locations: &[Location], calling_convention: CallingConvention) {
         // Unwind stack to the "save area".
         a.emit_lea(
             Size::S64,
@@ -512,6 +540,11 @@ impl Machine {
             Location::GPR(GPR::RSP),
         );
 
+        if calling_convention == CallingConvention::WindowsFastcall {
+            // Restore RSI and RDI
+            a.emit_pop(Size::S64, Location::GPR(GPR::RSI));
+            a.emit_pop(Size::S64, Location::GPR(GPR::RDI));
+        }
         // Restore R15 used by vmctx.
         a.emit_pop(Size::S64, Location::GPR(GPR::R15));