From 51e085a7bad41dc6e279d986f1d0da22e1655944 Mon Sep 17 00:00:00 2001
From: losfair <zhy20000919@hotmail.com>
Date: Tue, 12 May 2020 02:11:43 +0800
Subject: [PATCH] Garbage in upper 32 bits shouldn't propagate to
 I64ExtendI32U's result.

---
 lib/singlepass-backend/src/codegen_x64.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/singlepass-backend/src/codegen_x64.rs b/lib/singlepass-backend/src/codegen_x64.rs
index 9dfc648cc..de7248db3 100644
--- a/lib/singlepass-backend/src/codegen_x64.rs
+++ b/lib/singlepass-backend/src/codegen_x64.rs
@@ -4043,6 +4043,7 @@ impl FunctionCodeGenerator<CodegenError> for X64FunctionCode {
                     false,
                 )[0];
                 self.value_stack.push(ret);
+
                 Self::emit_relaxed_binop(
                     a,
                     &mut self.machine,
@@ -4051,6 +4052,16 @@ impl FunctionCodeGenerator<CodegenError> for X64FunctionCode {
                     loc,
                     ret,
                 );
+                if let Location::Memory(base, off) = ret {
+                    Self::emit_relaxed_binop(
+                        a,
+                        &mut self.machine,
+                        Assembler::emit_mov,
+                        Size::S32,
+                        Location::Imm32(0),
+                        Location::Memory(base, off + 4),
+                    );
+                }
             }
             Operator::I64ExtendI32S => {
                 let loc =