Add an offset to cranelift-wasm's GlobalVariable.

lib/wasm/Cargo.toml

@@ -18,6 +18,7 @@ hashmap_core = { version = "0.1.9", optional = true }
 failure = { version = "0.1.1", default-features = false, features = ["derive"] }
 failure_derive = { version = "0.1.1", default-features = false }
 log = { version = "0.4.4", default-features = false }
+cast = { version = "0.2.2" }
 
 [dev-dependencies]
 wabt = "0.7.0"

lib/wasm/src/code_translator.rs

@@ -75,12 +75,12 @@ pub fn translate_operator<FE: FuncEnvironment + ?Sized>(
         Operator::GetGlobal { global_index } => {
             let val = match state.get_global(builder.func, global_index, environ) {
                 GlobalVariable::Const(val) => val,
-                GlobalVariable::Memory { gv, ty } => {
+                GlobalVariable::Memory { gv, offset, ty } => {
                     let addr = builder.ins().global_value(environ.pointer_type(), gv);
                     let mut flags = ir::MemFlags::new();
                     flags.set_notrap();
                     flags.set_aligned();
-                    builder.ins().load(ty, flags, addr, 0)
+                    builder.ins().load(ty, flags, addr, offset)
                 }
             };
             state.push1(val);
@@ -88,13 +88,14 @@ pub fn translate_operator<FE: FuncEnvironment + ?Sized>(
         Operator::SetGlobal { global_index } => {
             match state.get_global(builder.func, global_index, environ) {
                 GlobalVariable::Const(_) => panic!("global #{} is a constant", global_index),
-                GlobalVariable::Memory { gv, .. } => {
+                GlobalVariable::Memory { gv, offset, ty } => {
                     let addr = builder.ins().global_value(environ.pointer_type(), gv);
                     let mut flags = ir::MemFlags::new();
                     flags.set_notrap();
                     flags.set_aligned();
                     let val = state.pop1();
-                    builder.ins().store(flags, val, addr, 0);
+                    debug_assert_eq!(ty, builder.func.dfg.value_type(val));
+                    builder.ins().store(flags, val, addr, offset);
                 }
             }
         }

lib/wasm/src/environ/dummy.rs

@@ -1,6 +1,7 @@
 //! "Dummy" implementations of `ModuleEnvironment` and `FuncEnvironment` for testing
 //! wasm translation.
 
+use cast;
 use cranelift_codegen::cursor::FuncCursor;
 use cranelift_codegen::ir::immediates::{Offset32, Uimm64};
 use cranelift_codegen::ir::types::*;
@@ -169,15 +170,11 @@ impl<'dummy_environment> FuncEnvironment for DummyFuncEnvironment<'dummy_environ
 
     fn make_global(&mut self, func: &mut ir::Function, index: GlobalIndex) -> GlobalVariable {
         // Just create a dummy `vmctx` global.
-        let offset = ((index.index() * 8) as i64 + 8).into();
+        let offset = cast::i32((index.index() * 8) + 8).unwrap().into();
         let vmctx = func.create_global_value(ir::GlobalValueData::VMContext {});
-        let iadd = func.create_global_value(ir::GlobalValueData::IAddImm {
-            base: vmctx,
-            offset,
-            global_type: self.pointer_type(),
-        });
         GlobalVariable::Memory {
-            gv: iadd,
+            gv: vmctx,
+            offset: offset,
             ty: self.mod_info.globals[index].entity.ty,
         }
     }

lib/wasm/src/environ/spec.rs

@@ -1,6 +1,7 @@
 //! All the runtime support necessary for the wasm to cranelift translation is formalized by the
 //! traits `FunctionEnvironment` and `ModuleEnvironment`.
 use cranelift_codegen::cursor::FuncCursor;
+use cranelift_codegen::ir::immediates::Offset32;
 use cranelift_codegen::ir::{self, InstBuilder};
 use cranelift_codegen::isa::TargetFrontendConfig;
 use std::convert::From;
@@ -20,6 +21,8 @@ pub enum GlobalVariable {
     Memory {
         /// The address of the global variable storage.
         gv: ir::GlobalValue,
+        /// An offset to add to the address.
+        offset: Offset32,
         /// The global variable's type.
         ty: ir::Type,
     },

lib/wasm/src/lib.rs

@@ -36,6 +36,7 @@
 extern crate cranelift_codegen;
 #[macro_use]
 extern crate cranelift_entity;
+extern crate cast;
 extern crate cranelift_frontend;
 #[cfg(test)]
 extern crate target_lexicon;