From 1eb419cddada269bcedc23b989579bc71c3d4d20 Mon Sep 17 00:00:00 2001
From: Jef <jackefransham@gmail.com>
Date: Fri, 15 Mar 2019 11:51:11 +0100
Subject: [PATCH] Implement `memory.size`/`memory.grow`, globals,
 `call_indirect`

---
 README.md                 |  54 +++--
 src/backend.rs            | 427 ++++++++++++++++++++++++++++++++------
 src/function_body.rs      |  46 ++--
 src/microwasm.rs          | 123 ++++++++++-
 src/module.rs             | 150 ++++++++-----
 src/tests.rs              |   2 +
 src/translate_sections.rs |  26 ++-
 7 files changed, 651 insertions(+), 177 deletions(-)

diff --git a/README.md b/README.md
index 611d9986bc..a0c6d6aef2 100644
--- a/README.md
+++ b/README.md
@@ -165,7 +165,7 @@ Now obviously I'm not advocating for replacing FireFox's optimising compiler wit
 
 ## Specification compliance
 
-It's hard to judge, since each test in the spec testsuite covers a wide range of features (to check their interactions), but currently 33 out of 76 of the spec suite tests pass when run in Wasmtime with Lightbeam as a backend. Here's the full test output:
+It's hard to judge, since each test in the spec testsuite covers a wide range of features (to check their interactions), but currently 40 out of 76 of the spec suite tests pass when run in Wasmtime with Lightbeam as a backend. Here's the full test output:
 
 ```
 running 76 tests
@@ -173,22 +173,22 @@ test misc_testsuite::stack_overflow         ... ok
 test spec_testsuite::binary                 ... ok
 test misc_testsuite::misc_traps             ... ok
 test spec_testsuite::align                  ... FAILED
-test spec_testsuite::block                  ... FAILED
-test spec_testsuite::br_if                  ... FAILED
+test spec_testsuite::address                ... FAILED
+test spec_testsuite::block                  ... ok
 test spec_testsuite::break_drop             ... ok
 test spec_testsuite::call                   ... FAILED
+test spec_testsuite::br                     ... ok
 test spec_testsuite::call_indirect          ... FAILED
-test spec_testsuite::address                ... FAILED
 test spec_testsuite::comments               ... ok
 test spec_testsuite::const_                 ... ok
 test spec_testsuite::custom                 ... ok
 test spec_testsuite::custom_section         ... ok
 test spec_testsuite::data                   ... ok
 test spec_testsuite::conversions            ... FAILED
-test spec_testsuite::elem                   ... FAILED
 test spec_testsuite::endianness             ... FAILED
+test spec_testsuite::elem                   ... FAILED
+test spec_testsuite::br_if                  ... ok
 test spec_testsuite::exports                ... ok
-test spec_testsuite::br                     ... ok
 test spec_testsuite::f32_bitwise            ... FAILED
 test spec_testsuite::br_table               ... FAILED
 test spec_testsuite::f64_bitwise            ... FAILED
@@ -196,61 +196,59 @@ test spec_testsuite::f32                    ... FAILED
 test spec_testsuite::f32_cmp                ... FAILED
 test spec_testsuite::fac                    ... ok
 test spec_testsuite::f64                    ... FAILED
-test spec_testsuite::float_memory           ... ok
 test spec_testsuite::f64_cmp                ... FAILED
+test spec_testsuite::float_memory           ... ok
 test spec_testsuite::forward                ... ok
 test spec_testsuite::float_misc             ... FAILED
 test spec_testsuite::func_ptrs              ... FAILED
 test spec_testsuite::get_local              ... FAILED
 test spec_testsuite::float_exprs            ... FAILED
-test spec_testsuite::globals                ... FAILED
 test spec_testsuite::float_literals         ... ok
+test spec_testsuite::globals                ... ok
 test spec_testsuite::if_                    ... FAILED
-test spec_testsuite::imports                ... FAILED
+test spec_testsuite::func                   ... ok
 test spec_testsuite::inline_module          ... ok
-test spec_testsuite::func                   ... FAILED
+test spec_testsuite::imports                ... FAILED
 test spec_testsuite::i32                    ... ok
 test spec_testsuite::i64                    ... ok
-test spec_testsuite::left_to_right          ... FAILED
-test spec_testsuite::linking                ... FAILED
-test spec_testsuite::loop_                  ... FAILED
-test spec_testsuite::labels                 ... ok
 test spec_testsuite::int_literals           ... ok
+test spec_testsuite::labels                 ... ok
+test spec_testsuite::linking                ... FAILED
+test spec_testsuite::left_to_right          ... FAILED
+test spec_testsuite::loop_                  ... FAILED
+test spec_testsuite::memory                 ... FAILED
 test spec_testsuite::memory_grow            ... FAILED
 test spec_testsuite::memory_redundancy      ... ok
-test spec_testsuite::memory                 ... FAILED
 test spec_testsuite::memory_trap            ... FAILED
 test spec_testsuite::resizing               ... FAILED
 test spec_testsuite::nop                    ... FAILED
 test spec_testsuite::return_minimal         ... ok
-test spec_testsuite::select                 ... FAILED
-test spec_testsuite::set_local              ... FAILED
-test spec_testsuite::skip_stack_guard_page  ... FAILED
-test spec_testsuite::stack                  ... FAILED
 test spec_testsuite::int_exprs              ... ok
+test spec_testsuite::set_local              ... FAILED
+test spec_testsuite::select                 ... FAILED
+test spec_testsuite::skip_stack_guard_page  ... FAILED
+test spec_testsuite::stack                  ... ok
 test spec_testsuite::store_retval           ... ok
 test spec_testsuite::start                  ... FAILED
-test spec_testsuite::switch                 ... ok
-test spec_testsuite::token                  ... ok
 test spec_testsuite::tee_local              ... FAILED
+test spec_testsuite::token                  ... ok
+test spec_testsuite::switch                 ... ok
 test spec_testsuite::type_                  ... ok
-test spec_testsuite::traps                  ... FAILED
-test spec_testsuite::typecheck              ... ok
 test spec_testsuite::return_                ... ok
-test spec_testsuite::unreached_invalid      ... ok
+test spec_testsuite::typecheck              ... ok
+test spec_testsuite::traps                  ... FAILED
 test spec_testsuite::unwind                 ... FAILED
+test spec_testsuite::unreached_invalid      ... ok
 test spec_testsuite::utf8_custom_section_id ... ok
 test spec_testsuite::utf8_import_field      ... ok
-test spec_testsuite::utf8_invalid_encoding  ... ok
 test spec_testsuite::utf8_import_module     ... ok
+test spec_testsuite::utf8_invalid_encoding  ... ok
 test spec_testsuite::unreachable            ... ok
 test spec_testsuite::names                  ... FAILED
 
-test result: FAILED. 35 passed; 41 failed; 0 ignored; 0 measured; 0 filtered out
+test result: FAILED. 40 passed; 36 failed; 0 ignored; 0 measured; 0 filtered out
 ```
 
-All the failed tests apart from `address` and `unwind` (whose failure hasn't been investigated yet) are due to features that have yet to be implemented.
-
 ## Getting involved
 
 Our [issue tracker][issue tracker] is pretty barren right now since this is currently more-or-less a one-person project, but if you want to get involved jump into the [CraneStation Gitter room][cranestation-gitter] and someone can direct you to the right place. I wish I could say "the most useful thing you can do is play with it and open issues where you find problems" but until it passes the spec suite that won't be very helpful.
diff --git a/src/backend.rs b/src/backend.rs
index f47ea3169a..59c67dd354 100644
--- a/src/backend.rs
+++ b/src/backend.rs
@@ -6,6 +6,7 @@ use self::registers::*;
 use crate::error::Error;
 use crate::microwasm::Value;
 use crate::module::{ModuleContext, RuntimeFunc};
+use cranelift_codegen::binemit;
 use dynasmrt::x64::Assembler;
 use dynasmrt::{AssemblyOffset, DynamicLabel, DynasmApi, DynasmLabelApi, ExecutableBuffer};
 use std::{
@@ -14,6 +15,35 @@ use std::{
     ops::RangeInclusive,
 };
 
+// TODO: Get rid of this! It's a total hack.
+mod magic {
+    use cranelift_codegen::ir;
+
+    /// Compute an `ir::ExternalName` for the `memory.grow` libcall for
+    /// 32-bit locally-defined memories.
+    pub fn get_memory32_grow_name() -> ir::ExternalName {
+        ir::ExternalName::user(1, 0)
+    }
+
+    /// Compute an `ir::ExternalName` for the `memory.grow` libcall for
+    /// 32-bit imported memories.
+    pub fn get_imported_memory32_grow_name() -> ir::ExternalName {
+        ir::ExternalName::user(1, 1)
+    }
+
+    /// Compute an `ir::ExternalName` for the `memory.size` libcall for
+    /// 32-bit locally-defined memories.
+    pub fn get_memory32_size_name() -> ir::ExternalName {
+        ir::ExternalName::user(1, 2)
+    }
+
+    /// Compute an `ir::ExternalName` for the `memory.size` libcall for
+    /// 32-bit imported memories.
+    pub fn get_imported_memory32_size_name() -> ir::ExternalName {
+        ir::ExternalName::user(1, 3)
+    }
+}
+
 /// Size of a pointer on the target in bytes.
 const WORD_SIZE: u32 = 8;
 
@@ -467,6 +497,7 @@ pub struct FunctionEnd {
 pub struct CodeGenSession<'a, M> {
     assembler: Assembler,
     pub module_context: &'a M,
+    labels: Labels,
     func_starts: Vec<(Option<AssemblyOffset>, DynamicLabel)>,
 }
 
@@ -479,12 +510,17 @@ impl<'a, M> CodeGenSession<'a, M> {
 
         CodeGenSession {
             assembler,
+            labels: Default::default(),
             func_starts,
             module_context,
         }
     }
 
-    pub fn new_context(&mut self, func_idx: u32) -> Context<'_, M> {
+    pub fn new_context<'this>(
+        &'this mut self,
+        func_idx: u32,
+        reloc_sink: &'this mut dyn binemit::RelocSink,
+    ) -> Context<'this, M> {
         {
             let func_start = &mut self.func_starts[func_idx as usize];
 
@@ -496,8 +532,10 @@ impl<'a, M> CodeGenSession<'a, M> {
 
         Context {
             asm: &mut self.assembler,
+            current_function: func_idx,
+            reloc_sink: reloc_sink,
             func_starts: &self.func_starts,
-            labels: Default::default(),
+            labels: &mut self.labels,
             block_state: Default::default(),
             module_context: self.module_context,
         }
@@ -627,22 +665,64 @@ pub enum MemoryAccessMode {
     Unchecked,
 }
 
+struct PendingLabel {
+    label: Label,
+    is_defined: bool,
+}
+
+impl PendingLabel {
+    fn undefined(label: Label) -> Self {
+        PendingLabel {
+            label,
+            is_defined: false,
+        }
+    }
+
+    fn defined(label: Label) -> Self {
+        PendingLabel {
+            label,
+            is_defined: true,
+        }
+    }
+
+    fn as_undefined(&self) -> Option<Label> {
+        if !self.is_defined {
+            Some(self.label)
+        } else {
+            None
+        }
+    }
+}
+
+impl From<Label> for PendingLabel {
+    fn from(label: Label) -> Self {
+        PendingLabel {
+            label,
+            is_defined: false,
+        }
+    }
+}
+
 // TODO: We can share one trap/constant for all functions by reusing this struct
 #[derive(Default)]
 struct Labels {
-    trap: Option<Label>,
-    ret: Option<Label>,
-    neg_const_f32: Option<Label>,
-    neg_const_f64: Option<Label>,
+    trap: Option<PendingLabel>,
+    ret: Option<PendingLabel>,
+    neg_const_f32: Option<PendingLabel>,
+    neg_const_f64: Option<PendingLabel>,
+    abs_const_f32: Option<PendingLabel>,
+    abs_const_f64: Option<PendingLabel>,
 }
 
 pub struct Context<'a, M> {
     asm: &'a mut Assembler,
+    reloc_sink: &'a mut dyn binemit::RelocSink,
     module_context: &'a M,
+    current_function: u32,
     func_starts: &'a Vec<(Option<AssemblyOffset>, DynamicLabel)>,
     /// Each push and pop on the value stack increments or decrements this value by 1 respectively.
     pub block_state: BlockState,
-    labels: Labels,
+    labels: &'a mut Labels,
 }
 
 /// Label in code.
@@ -1487,7 +1567,9 @@ macro_rules! load {
                 dst: GPR,
                 (offset, runtime_offset): (i32, Result<i32, GPR>)
             ) {
-                let vmctx_mem_ptr_offset = ctx.module_context.offset_of_memory_ptr() as i32;
+                let vmctx_mem_ptr_offset = ctx.module_context
+
+                    .vmctx_vmmemory_definition_base(0) as i32;
                 let mem_ptr_reg = ctx.block_state.regs.take(I64);
                 dynasm!(ctx.asm
                     ; mov Rq(mem_ptr_reg.rq().unwrap()), [Rq(VMCTX) + vmctx_mem_ptr_offset]
@@ -1576,7 +1658,9 @@ macro_rules! store {
                 src: GPR,
                 (offset, runtime_offset): (i32, Result<i32, GPR>)
             ) {
-                let vmctx_mem_ptr_offset = ctx.module_context.offset_of_memory_ptr() as i32;
+                let vmctx_mem_ptr_offset = ctx.module_context
+
+                    .vmctx_vmmemory_definition_base(0) as i32;
                 let mem_ptr_reg = ctx.block_state.regs.take(GPRType::Rq);
                 dynasm!(ctx.asm
                     ; mov Rq(mem_ptr_reg.rq().unwrap()), [Rq(VMCTX) + vmctx_mem_ptr_offset]
@@ -2048,6 +2132,41 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         }
     }
 
+    pub fn get_global(&mut self, global_idx: u32) {
+        let offset = self.module_context.vmctx_vmglobal_definition(
+            self.module_context
+                .defined_global_index(global_idx)
+                .expect("TODO: Support imported globals"),
+        );
+
+        let out = self.block_state.regs.take(GPRType::Rq);
+
+        // We always use `Rq` (even for floats) since the globals are not necessarily aligned to 128 bits
+        dynasm!(self.asm
+            ; mov Rq(out.rq().unwrap()), [Rq(VMCTX) + offset as i32]
+        );
+
+        self.push(ValueLocation::Reg(out));
+    }
+
+    pub fn set_global(&mut self, global_idx: u32) {
+        let val = self.pop();
+        let offset = self.module_context.vmctx_vmglobal_definition(
+            self.module_context
+                .defined_global_index(global_idx)
+                .expect("TODO: Support imported globals"),
+        );
+
+        let val = self.into_reg(GPRType::Rq, val);
+
+        // We always use `Rq` (even for floats) since the globals are not necessarily aligned to 128 bits
+        dynasm!(self.asm
+            ; mov [Rq(VMCTX) + offset as i32], Rq(val.rq().unwrap())
+        );
+
+        self.block_state.regs.release(val);
+    }
+
     fn immediate_to_reg(&mut self, reg: GPR, val: Value) {
         if val.as_bytes() == 0 {
             self.zero_reg(reg);
@@ -2397,6 +2516,48 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         self.push(out);
     }
 
+    pub fn f32_abs(&mut self) {
+        let val = self.pop();
+
+        let out = if let Some(i) = val.imm_f32() {
+            ValueLocation::Immediate(
+                wasmparser::Ieee32(f32::from_bits(i.bits()).abs().to_bits()).into(),
+            )
+        } else {
+            let reg = self.into_temp_reg(GPRType::Rx, val);
+            let const_label = self.abs_const_f32_label();
+
+            dynasm!(self.asm
+                ; andps Rx(reg.rx().unwrap()), [=>const_label.0]
+            );
+
+            ValueLocation::Reg(reg)
+        };
+
+        self.push(out);
+    }
+
+    pub fn f64_abs(&mut self) {
+        let val = self.pop();
+
+        let out = if let Some(i) = val.imm_f64() {
+            ValueLocation::Immediate(
+                wasmparser::Ieee64(f64::from_bits(i.bits()).abs().to_bits()).into(),
+            )
+        } else {
+            let reg = self.into_temp_reg(GPRType::Rx, val);
+            let const_label = self.abs_const_f64_label();
+
+            dynasm!(self.asm
+                ; andps Rx(reg.rx().unwrap()), [=>const_label.0]
+            );
+
+            ValueLocation::Reg(reg)
+        };
+
+        self.push(out);
+    }
+
     unop!(i32_clz, lzcnt, Rd, u32, u32::leading_zeros);
     unop!(i64_clz, lzcnt, Rq, u64, |a: u64| a.leading_zeros() as u64);
     unop!(i32_ctz, tzcnt, Rd, u32, u32::trailing_zeros);
@@ -2507,10 +2668,9 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         let mut val = self.pop();
 
         let out_val = match val {
-            ValueLocation::Immediate(imm) =>
-                ValueLocation::Immediate(
-                    wasmparser::Ieee32((imm.as_i32().unwrap() as u32 as f32).to_bits()).into()
-                ),
+            ValueLocation::Immediate(imm) => ValueLocation::Immediate(
+                wasmparser::Ieee32((imm.as_i32().unwrap() as u32 as f32).to_bits()).into(),
+            ),
             _ => {
                 let reg = self.into_reg(I32, val);
                 val = ValueLocation::Reg(reg);
@@ -3040,18 +3200,63 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         self.push(ValueLocation::Immediate(imm));
     }
 
-    pub fn memory_size(&mut self) {
-        let tmp = self.block_state.regs.take(I32);
-
-        // 16 is log2(64KiB as bytes)
-        dynasm!(self.asm
-            ; mov Rd(tmp.rq().unwrap()), [
-                rdi + self.module_context.offset_of_memory_len() as i32
-            ]
-            ; shr Rd(tmp.rq().unwrap()), 16
+    fn relocated_function_call(
+        &mut self,
+        name: &cranelift_codegen::ir::ExternalName,
+        args: impl IntoIterator<Item = SignlessType>,
+        rets: impl IntoIterator<Item = SignlessType>,
+    ) {
+        self.pass_outgoing_args(&arg_locs(args));
+        // 2 bytes for the 64-bit `mov` opcode + register ident, the rest is the immediate
+        self.reloc_sink.reloc_external(
+            (self.asm.offset().0
+                - self.func_starts[self.current_function as usize]
+                    .0
+                    .unwrap()
+                    .0) as u32
+                + 2,
+            binemit::Reloc::Abs8,
+            name,
+            0,
         );
+        let temp = self.block_state.regs.take(I64);
+        dynasm!(self.asm
+            ; mov Rq(temp.rq().unwrap()), QWORD 0xdeadbeefdeadbeefu64 as i64
+            ; call Rq(temp.rq().unwrap())
+        );
+        self.block_state.regs.release(temp);
+        self.push_function_returns(rets);
+    }
 
-        self.push(ValueLocation::Reg(tmp));
+    // TODO: Other memory indices
+    pub fn memory_size(&mut self) {
+        self.push(ValueLocation::Immediate(0u32.into()));
+        self.relocated_function_call(
+            &magic::get_memory32_size_name(),
+            iter::once(I32),
+            iter::once(I32),
+        );
+        // let tmp = self.block_state.regs.take(I32);
+        //
+        // // 16 is log2(64KiB as bytes)
+        // dynasm!(self.asm
+        // ; mov Rd(tmp.rq().unwrap()), [
+        // rdi + self.module_context.vmctx_vmmemory_definition_current_length(0) as i32
+        // ]
+        // ; shr Rd(tmp.rq().unwrap()), 16
+        // );
+        //
+        // self.push(ValueLocation::Reg(tmp));
+    }
+
+    // TODO: Other memory indices
+    pub fn memory_grow(&mut self) {
+        self.push(ValueLocation::Immediate(0u32.into()));
+        self.relocated_function_call(
+            &magic::get_memory32_grow_name(),
+            iter::once(I32).chain(iter::once(I32)),
+            iter::once(I32),
+        );
     }
 
     // TODO: Use `ArrayVec`?
@@ -3172,27 +3377,23 @@ impl<'module, M: ModuleContext> Context<'module, M> {
     }
 
     // TODO: Multiple returns
-    fn push_function_return(&mut self, arity: u32) {
-        if arity == 0 {
-            return;
+    fn push_function_returns(&mut self, returns: impl IntoIterator<Item = SignlessType>) {
+        for loc in ret_locs(returns) {
+            if let CCLoc::Reg(reg) = loc {
+                self.block_state.regs.mark_used(reg);
+            }
+
+            self.push(loc.into());
         }
-        debug_assert_eq!(arity, 1);
-        self.block_state.regs.mark_used(RAX);
-        self.push(ValueLocation::Reg(RAX));
     }
 
     // TODO: Do return types properly
     pub fn call_indirect(
         &mut self,
-        signature_hash: u32,
+        type_id: u32,
         arg_types: impl IntoIterator<Item = SignlessType>,
-        return_arity: u32,
+        return_types: impl IntoIterator<Item = SignlessType>,
     ) {
-        debug_assert!(
-            return_arity == 0 || return_arity == 1,
-            "We don't support multiple return yet"
-        );
-
         let locs = arg_locs(arg_types);
 
         for &loc in &locs {
@@ -3204,6 +3405,7 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         let callee = self.pop();
         let callee = self.into_temp_reg(I32, callee);
         let temp0 = self.block_state.regs.take(I64);
+        let temp1 = self.block_state.regs.take(I64);
 
         for &loc in &locs {
             if let CCLoc::Reg(r) = loc {
@@ -3217,30 +3419,44 @@ impl<'module, M: ModuleContext> Context<'module, M> {
 
         // TODO: Consider generating a single trap function and jumping to that instead.
         dynasm!(self.asm
-            ; cmp Rd(callee.rq().unwrap()), [Rq(VMCTX) + self.module_context.offset_of_funcs_len() as i32]
+            ; cmp Rd(callee.rq().unwrap()), [
+                Rq(VMCTX) +
+                    self.module_context
+                        .vmctx_vmtable_definition_current_elements(0) as i32
+            ]
             ; jae =>fail
-            ; imul Rd(callee.rq().unwrap()), Rd(callee.rq().unwrap()), mem::size_of::<RuntimeFunc>() as i32
-            ; mov Rq(temp0.rq().unwrap()), [Rq(VMCTX) + self.module_context.offset_of_funcs_ptr() as i32]
+            ; imul
+                Rd(callee.rq().unwrap()),
+                Rd(callee.rq().unwrap()),
+                self.module_context.size_of_vmcaller_checked_anyfunc() as i32
+            ; mov Rq(temp0.rq().unwrap()), [
+                Rq(VMCTX) +
+                    self.module_context
+                        .vmctx_vmtable_definition_base(0) as i32
+            ]
+            ; mov Rd(temp1.rq().unwrap()), [
+                Rq(VMCTX) +
+                    self.module_context
+                        .vmctx_vmshared_signature_id(type_id) as i32
+            ]
             ; cmp DWORD [
                 Rq(temp0.rq().unwrap()) +
                     Rq(callee.rq().unwrap()) +
-                    RuntimeFunc::offset_of_sig_hash() as i32
-            ], signature_hash as i32
+                    self.module_context.vmcaller_checked_anyfunc_type_index() as i32
+            ], Rd(temp1.rq().unwrap())
             ; jne =>fail
-        );
-
-        dynasm!(self.asm
             ; call QWORD [
                 Rq(temp0.rq().unwrap()) +
                     Rq(callee.rq().unwrap()) +
-                    RuntimeFunc::offset_of_func_start() as i32
+                    self.module_context.vmcaller_checked_anyfunc_func_ptr() as i32
             ]
         );
 
         self.block_state.regs.release(temp0);
+        self.block_state.regs.release(temp1);
         self.block_state.regs.release(callee);
 
-        self.push_function_return(return_arity);
+        self.push_function_returns(return_types);
     }
 
     pub fn swap(&mut self, depth: u32) {
@@ -3253,13 +3469,8 @@ impl<'module, M: ModuleContext> Context<'module, M> {
         &mut self,
         index: u32,
         arg_types: impl IntoIterator<Item = SignlessType>,
-        return_arity: u32,
+        return_types: impl IntoIterator<Item = SignlessType>,
     ) {
-        debug_assert!(
-            return_arity == 0 || return_arity == 1,
-            "We don't support multiple return yet"
-        );
-
         self.pass_outgoing_args(&arg_locs(arg_types));
 
         let label = &self.func_starts[index as usize].1;
@@ -3267,7 +3478,7 @@ impl<'module, M: ModuleContext> Context<'module, M> {
             ; call =>*label
         );
 
-        self.push_function_return(return_arity);
+        self.push_function_returns(return_types);
     }
 
     // TODO: Reserve space to store RBX, RBP, and R12..R15 so we can use them
@@ -3295,21 +3506,38 @@ impl<'module, M: ModuleContext> Context<'module, M> {
     /// conditional traps in `call_indirect` use)
     pub fn epilogue(&mut self) {
         // TODO: We don't want to redefine this label if we're sharing it between functions
-        if let Some(l) = self.labels.trap {
+        if let Some(l) = self
+            .labels
+            .trap
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
             self.define_label(l);
             dynasm!(self.asm
                 ; ud2
             );
+            self.labels.trap = Some(PendingLabel::defined(l));
         }
 
-        if let Some(l) = self.labels.ret {
+        if let Some(l) = self
+            .labels
+            .ret
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
             self.define_label(l);
             dynasm!(self.asm
                 ; ret
             );
+            self.labels.ret = Some(PendingLabel::defined(l));
         }
 
-        if let Some(l) = self.labels.neg_const_f32 {
+        if let Some(l) = self
+            .labels
+            .neg_const_f32
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
             self.align(16);
             self.define_label(l);
             dynasm!(self.asm
@@ -3318,9 +3546,15 @@ impl<'module, M: ModuleContext> Context<'module, M> {
                 ; .dword 0
                 ; .dword 0
             );
+            self.labels.neg_const_f32 = Some(PendingLabel::defined(l));
         }
 
-        if let Some(l) = self.labels.neg_const_f64 {
+        if let Some(l) = self
+            .labels
+            .neg_const_f64
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
             self.align(16);
             self.define_label(l);
             dynasm!(self.asm
@@ -3329,6 +3563,39 @@ impl<'module, M: ModuleContext> Context<'module, M> {
                 ; .dword 0
                 ; .dword 0
             );
+            self.labels.neg_const_f64 = Some(PendingLabel::defined(l));
+        }
+
+        if let Some(l) = self
+            .labels
+            .abs_const_f32
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
+            self.align(16);
+            self.define_label(l);
+            dynasm!(self.asm
+                ; .dword 2147483647
+                ; .dword 2147483647
+                ; .dword 2147483647
+                ; .dword 2147483647
+            );
+            self.labels.abs_const_f32 = Some(PendingLabel::defined(l));
+        }
+
+        if let Some(l) = self
+            .labels
+            .abs_const_f64
+            .as_ref()
+            .and_then(PendingLabel::as_undefined)
+        {
+            self.align(16);
+            self.define_label(l);
+            dynasm!(self.asm
+                ; .qword 9223372036854775807
+                ; .qword 9223372036854775807
+            );
+            self.labels.abs_const_f64 = Some(PendingLabel::defined(l));
         }
     }
 
@@ -3347,45 +3614,67 @@ impl<'module, M: ModuleContext> Context<'module, M> {
 
     #[must_use]
     fn trap_label(&mut self) -> Label {
-        if let Some(l) = self.labels.trap {
-            return l;
+        if let Some(l) = &self.labels.trap {
+            return l.label;
         }
 
         let label = self.create_label();
-        self.labels.trap = Some(label);
+        self.labels.trap = Some(label.into());
         label
     }
 
     #[must_use]
     fn ret_label(&mut self) -> Label {
-        if let Some(l) = self.labels.ret {
-            return l;
+        if let Some(l) = &self.labels.ret {
+            return l.label;
         }
 
         let label = self.create_label();
-        self.labels.ret = Some(label);
+        self.labels.ret = Some(label.into());
         label
     }
 
     #[must_use]
     fn neg_const_f32_label(&mut self) -> Label {
-        if let Some(l) = self.labels.neg_const_f32 {
-            return l;
+        if let Some(l) = &self.labels.neg_const_f32 {
+            return l.label;
         }
 
         let label = self.create_label();
-        self.labels.neg_const_f32 = Some(label);
+        self.labels.neg_const_f32 = Some(label.into());
         label
     }
 
     #[must_use]
     fn neg_const_f64_label(&mut self) -> Label {
-        if let Some(l) = self.labels.neg_const_f64 {
-            return l;
+        if let Some(l) = &self.labels.neg_const_f64 {
+            return l.label;
         }
 
         let label = self.create_label();
-        self.labels.neg_const_f64 = Some(label);
+        self.labels.neg_const_f64 = Some(label.into());
+        label
+    }
+
+    #[must_use]
+    fn abs_const_f32_label(&mut self) -> Label {
+        if let Some(l) = &self.labels.abs_const_f32 {
+            return l.label;
+        }
+
+        let label = self.create_label();
+        self.labels.abs_const_f32 = Some(label.into());
+        label
+    }
+
+    #[must_use]
+    fn abs_const_f64_label(&mut self) -> Label {
+        if let Some(l) = &self.labels.abs_const_f64 {
+            return l.label;
+        }
+
+        let label = self.create_label();
+        self.labels.abs_const_f64 = Some(label.into());
         label
     }
 }
diff --git a/src/function_body.rs b/src/function_body.rs
index 2e11e715cd..78088c5692 100644
--- a/src/function_body.rs
+++ b/src/function_body.rs
@@ -2,6 +2,7 @@ use crate::backend::*;
 use crate::error::Error;
 use crate::microwasm::*;
 use crate::module::{quickhash, ModuleContext, SigType, Signature};
+use cranelift_codegen::binemit;
 use either::{Either, Left, Right};
 use multi_mut::HashMapMultiMut;
 use std::{collections::HashMap, convert::TryInto, hash::Hash};
@@ -28,12 +29,14 @@ impl Block {
 
 const DISASSEMBLE: bool = false;
 
-pub fn translate_wasm<M: ModuleContext>(
+pub fn translate_wasm<M>(
     session: &mut CodeGenSession<M>,
+    reloc_sink: &mut dyn binemit::RelocSink,
     func_idx: u32,
     body: &wasmparser::FunctionBody,
 ) -> Result<(), Error>
 where
+    M: ModuleContext,
     for<'any> &'any M::Signature: Into<OpSig>,
 {
     let ty = session.module_context.func_type(func_idx);
@@ -64,17 +67,20 @@ where
 
     translate(
         session,
+        reloc_sink,
         func_idx,
         microwasm_conv.flat_map(|i| i.expect("TODO: Make this not panic")),
     )
 }
 
-pub fn translate<M: ModuleContext, I, L>(
+pub fn translate<M, I, L>(
     session: &mut CodeGenSession<M>,
+    reloc_sink: &mut dyn binemit::RelocSink,
     func_idx: u32,
     body: I,
 ) -> Result<(), Error>
 where
+    M: ModuleContext,
     I: IntoIterator<Item = Operator<L>>,
     L: Hash + Clone + Eq,
     Operator<L>: std::fmt::Display,
@@ -90,7 +96,7 @@ where
     let mut body = body.into_iter().peekable();
 
     let module_context = &*session.module_context;
-    let ctx = &mut session.new_context(func_idx);
+    let ctx = &mut session.new_context(func_idx, reloc_sink);
 
     let params = func_type
         .params()
@@ -367,7 +373,7 @@ where
                     }
 
                     let cc = cc.unwrap_or_else(||
-                        if max_num_callers == Some(1) {
+                        if max_num_callers.map(|callers| callers <= 1).unwrap_or(false) {
                             Right(ctx.virtual_calling_convention())
                         } else {
                             Left(ctx.serialize_args(params))
@@ -452,6 +458,7 @@ where
             Operator::Sub(F32) => ctx.f32_sub(),
             Operator::Div(SF32) => ctx.f32_div(),
             Operator::Neg(Size::_32) => ctx.f32_neg(),
+            Operator::Abs(Size::_32) => ctx.f32_abs(),
             Operator::Gt(SF32) => ctx.f32_gt(),
             Operator::Ge(SF32) => ctx.f32_ge(),
             Operator::Lt(SF32) => ctx.f32_lt(),
@@ -461,6 +468,7 @@ where
             Operator::Sub(F64) => ctx.f64_sub(),
             Operator::Div(SF64) => ctx.f64_div(),
             Operator::Neg(Size::_64) => ctx.f64_neg(),
+            Operator::Abs(Size::_64) => ctx.f64_abs(),
             Operator::Gt(SF64) => ctx.f64_gt(),
             Operator::Ge(SF64) => ctx.f64_ge(),
             Operator::Lt(SF64) => ctx.f64_lt(),
@@ -487,16 +495,12 @@ where
             } => ctx.i32_extend_s(),
             Operator::FConvertFromI {
                 input_ty: sint::I32,
-                output_ty: Size::_32
-            } => {
-                ctx.f32_convert_from_i32_s()
-            },
+                output_ty: Size::_32,
+            } => ctx.f32_convert_from_i32_s(),
             Operator::FConvertFromI {
                 input_ty: sint::U32,
-                output_ty: Size::_32
-            } => {
-                ctx.f32_convert_from_i32_u()
-            },
+                output_ty: Size::_32,
+            } => ctx.f32_convert_from_i32_u(),
             Operator::Load8 {
                 ty: sint::U32,
                 memarg,
@@ -543,19 +547,23 @@ where
             Operator::Load { ty: F64, memarg } => ctx.f64_load(memarg.offset),
             Operator::Store8 { ty: _, memarg } => ctx.store8(memarg.offset),
             Operator::Store16 { ty: _, memarg } => ctx.store16(memarg.offset),
-            Operator::Store32 { memarg } => ctx.store32(memarg.offset),
-            Operator::Store { ty: I32, memarg } | Operator::Store { ty: F32, memarg } => {
-                ctx.store32(memarg.offset)
-            }
+            Operator::Store32 { memarg }
+            | Operator::Store { ty: I32, memarg }
+            | Operator::Store { ty: F32, memarg } => ctx.store32(memarg.offset),
             Operator::Store { ty: I64, memarg } | Operator::Store { ty: F64, memarg } => {
                 ctx.store64(memarg.offset)
             }
+            Operator::GetGlobal(idx) => ctx.get_global(idx),
+            Operator::SetGlobal(idx) => ctx.set_global(idx),
             Operator::Select => {
                 ctx.select();
             }
             Operator::MemorySize { reserved: _ } => {
                 ctx.memory_size();
             }
+            Operator::MemoryGrow { reserved: _ } => {
+                ctx.memory_grow();
+            }
             Operator::Call { function_index } => {
                 let function_index = module_context
                     .defined_func_index(function_index)
@@ -566,7 +574,7 @@ where
                 ctx.call_direct(
                     function_index,
                     callee_ty.params().iter().map(|t| t.to_microwasm_type()),
-                    callee_ty.returns().len() as u32,
+                    callee_ty.returns().iter().map(|t| t.to_microwasm_type()),
                 );
             }
             Operator::CallIndirect {
@@ -580,9 +588,9 @@ where
                 // TODO: this implementation assumes that this function is locally defined.
 
                 ctx.call_indirect(
-                    quickhash(callee_ty) as u32,
+                    type_index,
                     callee_ty.params().iter().map(|t| t.to_microwasm_type()),
-                    callee_ty.returns().len() as u32,
+                    callee_ty.returns().iter().map(|t| t.to_microwasm_type()),
                 );
             }
             op => {
diff --git a/src/microwasm.rs b/src/microwasm.rs
index 1c171eac7b..d572cea4b3 100644
--- a/src/microwasm.rs
+++ b/src/microwasm.rs
@@ -467,12 +467,8 @@ pub enum Operator<Label> {
     // TODO: Is it better to have `Swap`, to have `Pull` (which moves the `nth` element instead of swapping)
     //       or to have both?
     Swap(u32),
-    GetGlobal {
-        index: u32,
-    },
-    SetGlobal {
-        index: u32,
-    },
+    GetGlobal(u32),
+    SetGlobal(u32),
     Load {
         ty: SignlessType,
         memarg: MemoryImmediate,
@@ -799,12 +795,111 @@ where
             Operator::FConvertFromI {
                 input_ty,
                 output_ty,
-            } => write!(f, "{}.convert_from.{}", input_ty, Type::Float::<Int>(*output_ty)),
+            } => write!(
+                f,
+                "{}.convert_from.{}",
+                input_ty,
+                Type::Float::<Int>(*output_ty)
+            ),
             _ => unimplemented!(),
         }
     }
 }
 
+// TODO: If we return a `Vec<<T as MicrowasmReceiver>::Item>` will that convert to (essentially) a no-op
+//       in the case that `Item` is a ZST? That is important for ensuring that we don't do unnecessary
+//       work when we're directly generating asm.
+/// WIP: Trait to abstract over either producing a stream of Microwasm or directly producing assembly
+/// from the Wasm. This should give a significant speedup since we don't need to allocate any vectors
+/// or pay the cost of branches - we can just use iterators and direct function calls.
+pub trait MicrowasmReceiver<Label> {
+    type Item;
+
+    fn unreachable(&mut self) -> Self::Item;
+    fn block(
+        &mut self,
+        label: Label,
+        params: impl Iterator<Item = SignlessType>,
+        has_backwards_callers: bool,
+        num_callers: Option<u32>,
+    ) -> Self::Item;
+    fn label(&mut self, _: Label) -> Self::Item;
+    fn br(&mut self, target: BrTarget<Label>) -> Self::Item;
+    fn br_if(&mut self, then: BrTargetDrop<Label>, else_: BrTargetDrop<Label>) -> Self::Item;
+    fn br_table(&mut self, _: BrTable<Label>) -> Self::Item;
+    fn call(&mut self, function_index: u32) -> Self::Item;
+    fn call_indirect(&mut self, type_index: u32, table_index: u32) -> Self::Item;
+    fn drop(&mut self, _: RangeInclusive<u32>) -> Self::Item;
+    fn select(&mut self) -> Self::Item;
+    fn pick(&mut self, _: u32) -> Self::Item;
+    fn swap(&mut self, _: u32) -> Self::Item;
+    fn get_global(&mut self, index: u32) -> Self::Item;
+    fn set_global(&mut self, index: u32) -> Self::Item;
+    fn load(&mut self, ty: SignlessType, memarg: MemoryImmediate) -> Self::Item;
+    fn load8(&mut self, ty: SignfulInt, memarg: MemoryImmediate) -> Self::Item;
+    fn load16(&mut self, ty: SignfulInt, memarg: MemoryImmediate) -> Self::Item;
+    fn load32(&mut self, sign: Signedness, memarg: MemoryImmediate) -> Self::Item;
+    fn store(&mut self, ty: SignlessType, memarg: MemoryImmediate) -> Self::Item;
+    fn store8(&mut self, ty: Int, memarg: MemoryImmediate) -> Self::Item;
+    fn store16(&mut self, ty: Int, memarg: MemoryImmediate) -> Self::Item;
+    fn store32(&mut self, memarg: MemoryImmediate) -> Self::Item;
+    fn memory_size(&mut self, reserved: u32) -> Self::Item;
+    fn memory_grow(&mut self, reserved: u32) -> Self::Item;
+    fn const_(&mut self, _: Value) -> Self::Item;
+    fn ref_null(&mut self) -> Self::Item;
+    fn ref_is_null(&mut self) -> Self::Item;
+    fn eq(&mut self, _: SignlessType) -> Self::Item;
+    fn ne(&mut self, _: SignlessType) -> Self::Item;
+    fn eqz(&mut self, _: Int) -> Self::Item;
+    fn lt(&mut self, _: SignfulType) -> Self::Item;
+    fn gt(&mut self, _: SignfulType) -> Self::Item;
+    fn le(&mut self, _: SignfulType) -> Self::Item;
+    fn ge(&mut self, _: SignfulType) -> Self::Item;
+    fn add(&mut self, _: SignlessType) -> Self::Item;
+    fn sub(&mut self, _: SignlessType) -> Self::Item;
+    fn mul(&mut self, _: SignlessType) -> Self::Item;
+    fn clz(&mut self, _: Int) -> Self::Item;
+    fn ctz(&mut self, _: Int) -> Self::Item;
+    fn popcnt(&mut self, _: Int) -> Self::Item;
+    fn div(&mut self, _: SignfulType) -> Self::Item;
+    fn rem(&mut self, _: SignfulInt) -> Self::Item;
+    fn and(&mut self, _: Int) -> Self::Item;
+    fn or(&mut self, _: Int) -> Self::Item;
+    fn xor(&mut self, _: Int) -> Self::Item;
+    fn shl(&mut self, _: Int) -> Self::Item;
+    fn shr(&mut self, _: SignfulInt) -> Self::Item;
+    fn rotl(&mut self, _: Int) -> Self::Item;
+    fn rotr(&mut self, _: Int) -> Self::Item;
+    fn abs(&mut self, _: Float) -> Self::Item;
+    fn neg(&mut self, _: Float) -> Self::Item;
+    fn ceil(&mut self, _: Float) -> Self::Item;
+    fn floor(&mut self, _: Float) -> Self::Item;
+    fn trunc(&mut self, _: Float) -> Self::Item;
+    fn nearest(&mut self, _: Float) -> Self::Item;
+    fn sqrt(&mut self, _: Float) -> Self::Item;
+    fn min(&mut self, _: Float) -> Self::Item;
+    fn max(&mut self, _: Float) -> Self::Item;
+    fn copysign(&mut self, _: Float) -> Self::Item;
+    fn i32_wrap_from_i64(&mut self) -> Self::Item;
+    fn i_trunc_from_f(&mut self, input_ty: Float, output_ty: SignfulInt) -> Self::Item;
+    fn f_convert_from_i(&mut self, input_ty: SignfulInt, output_ty: Float) -> Self::Item;
+    fn f32_demote_from_f64(&mut self) -> Self::Item;
+    fn f64_promote_from_f32(&mut self) -> Self::Item;
+    fn i32_reinterpret_from_f32(&mut self) -> Self::Item;
+    fn i64_reinterpret_from_f64(&mut self) -> Self::Item;
+    fn f32_reinterpret_from_i32(&mut self) -> Self::Item;
+    fn f64_reinterpret_from_i64(&mut self) -> Self::Item;
+    fn extend(&mut self, sign: Signedness) -> Self::Item;
+    fn i_sat_trunc_from_f(&mut self, input_ty: Float, output_ty: SignfulInt) -> Self::Item;
+    fn memory_init(&mut self, segment: u32) -> Self::Item;
+    fn data_drop(&mut self, segment: u32) -> Self::Item;
+    fn memory_copy(&mut self) -> Self::Item;
+    fn memory_fill(&mut self) -> Self::Item;
+    fn table_init(&mut self, segment: u32) -> Self::Item;
+    fn elem_drop(&mut self, segment: u32) -> Self::Item;
+    fn table_copy(&mut self) -> Self::Item;
+}
+
 /// Type of a control frame.
 #[derive(Debug, Clone, PartialEq)]
 enum ControlFrameKind {
@@ -1074,11 +1169,11 @@ where
                 sig!((ty) -> (ty))
             }
 
-            WasmOperator::GetGlobal { global_index: _ } => {
-                unimplemented!("Haven't implemented getting type of globals yet")
+            WasmOperator::GetGlobal { global_index } => {
+                sig!(() -> (self.module.global_type(*global_index).to_microwasm_type()))
             }
-            WasmOperator::SetGlobal { global_index: _ } => {
-                unimplemented!("Haven't implemented getting type of globals yet")
+            WasmOperator::SetGlobal { global_index } => {
+                sig!((self.module.global_type(*global_index).to_microwasm_type()) -> ())
             }
 
             WasmOperator::F32Load { .. } => sig!((I32) -> (F32)),
@@ -1712,6 +1807,12 @@ where
                     Operator::Pick(depth - 1),
                 ]
             }
+            WasmOperator::GetGlobal { global_index } => {
+                smallvec![Operator::GetGlobal(global_index)]
+            }
+            WasmOperator::SetGlobal { global_index } => {
+                smallvec![Operator::SetGlobal(global_index)]
+            }
 
             WasmOperator::I32Load { memarg } => smallvec![Operator::Load { ty: I32, memarg }],
             WasmOperator::I64Load { memarg } => smallvec![Operator::Load { ty: I64, memarg }],
diff --git a/src/module.rs b/src/module.rs
index d93e957242..351b045b67 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -102,7 +102,7 @@ impl_function_args!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S);
 #[derive(Default)]
 pub struct TranslatedModule {
     translated_code_section: Option<TranslatedCodeSection>,
-    types: SimpleContext,
+    ctx: SimpleContext,
     // TODO: Should we wrap this in a `Mutex` so that calling functions from multiple
     //       threads doesn't cause data races?
     table: Option<(TableType, Vec<u32>)>,
@@ -122,7 +122,7 @@ impl TranslatedModule {
                 .translated_code_section
                 .as_ref()
                 .expect("We don't currently support a table section without a code section");
-            let types = &self.types;
+            let ctx = &self.ctx;
 
             self.table
                 .as_mut()
@@ -131,11 +131,11 @@ impl TranslatedModule {
                         .iter()
                         .map(|i| {
                             let start = code_section.func_start(*i as _);
-                            let ty = types.func_type(*i);
+                            let ty = ctx.func_type(*i);
 
                             RuntimeFunc {
                                 func_start: start,
-                                sig_hash: quickhash(ty) as u32,
+                                sig_hash: quickhash(ty),
                             }
                         })
                         .collect::<Vec<_>>();
@@ -154,7 +154,17 @@ impl TranslatedModule {
             .into();
 
         let ctx = if mem.len > 0 || table.len > 0 {
-            Some(Box::new(VmCtx { table, mem }))
+            let hashes = self.ctx.types.iter().map(quickhash).collect::<Vec<_>>();
+
+            // Hardcoded maximum number of hashes supported for now - we will eventually port all our
+            // tests over to wasmtime which will make this obsolete so implementing this properly is
+            // unnecessary.
+            let mut out = [0; 64];
+
+            // This will panic if `hashes.len() > 64`
+            out[..hashes.len()].copy_from_slice(&hashes[..]);
+
+            Some(Box::new(GVmCtx { table, mem, hashes: out }) as Box<VmCtx>)
         } else {
             None
         };
@@ -215,11 +225,11 @@ impl ExecutableModule {
     ) -> Result<T, ExecutionError> {
         let module = &self.module;
 
-        if func_idx as usize >= module.types.func_ty_indicies.len() {
+        if func_idx as usize >= module.ctx.func_ty_indicies.len() {
             return Err(ExecutionError::FuncIndexOutOfBounds);
         }
 
-        let type_ = module.types.func_type(func_idx);
+        let type_ = module.ctx.func_type(func_idx);
 
         // TODO: Handle "compatible" types (i.e. f32 and i32)
         if (&type_.params[..], &type_.returns[..]) != (Args::TYPE_LIST, T::TYPE_LIST) {
@@ -237,7 +247,7 @@ impl ExecutableModule {
 type FuncRef = *const u8;
 
 pub struct RuntimeFunc {
-    sig_hash: u32,
+    sig_hash: u64,
     func_start: FuncRef,
 }
 
@@ -279,32 +289,41 @@ impl<T> Drop for BoxSlice<T> {
     }
 }
 
-pub struct VmCtx {
+pub type VmCtx = GVmCtx<[u64]>;
+
+pub struct GVmCtx<T: ?Sized> {
     table: BoxSlice<RuntimeFunc>,
     mem: BoxSlice<u8>,
+    hashes: T,
 }
 
-impl VmCtx {
-    pub fn offset_of_memory_ptr() -> u8 {
-        offset_of!(Self, mem.ptr)
+impl<T: ?Sized> GVmCtx<T> {
+    pub fn offset_of_memory_ptr() -> u32 {
+        offset_of!(GVmCtx<[u64; 0]>, mem.ptr)
             .try_into()
-            .expect("Offset exceeded size of u8")
+            .expect("Offset exceeded size of u32")
     }
 
-    pub fn offset_of_memory_len() -> u8 {
-        offset_of!(Self, mem.len)
+    pub fn offset_of_memory_len() -> u32 {
+        offset_of!(GVmCtx<[u64; 0]>, mem.len)
             .try_into()
-            .expect("Offset exceeded size of u8")
+            .expect("Offset exceeded size of u32")
     }
 
     pub fn offset_of_funcs_ptr() -> u8 {
-        offset_of!(Self, table.ptr)
+        offset_of!(GVmCtx<[u64; 0]>, table.ptr)
             .try_into()
             .expect("Offset exceeded size of u8")
     }
 
     pub fn offset_of_funcs_len() -> u8 {
-        offset_of!(Self, table.len)
+        offset_of!(GVmCtx<[u64; 0]>, table.len)
+            .try_into()
+            .expect("Offset exceeded size of u8")
+    }
+
+    pub fn offset_of_hashes() -> u8 {
+        offset_of!(GVmCtx<[u64; 0]>, hashes)
             .try_into()
             .expect("Offset exceeded size of u8")
     }
@@ -327,21 +346,20 @@ pub trait Signature {
 
 pub trait SigType {
     fn to_microwasm_type(&self) -> microwasm::SignlessType;
-    fn is_float(&self) -> bool;
 }
 
-impl SigType for AbiParam {
+impl SigType for ir::Type {
     fn to_microwasm_type(&self) -> microwasm::SignlessType {
         use crate::microwasm::{Size::*, Type::*};
 
-        if self.value_type.is_int() {
-            match self.value_type.bits() {
+        if self.is_int() {
+            match self.bits() {
                 32 => Int(_32),
                 64 => Int(_64),
                 _ => unimplemented!(),
             }
-        } else if self.value_type.is_float() {
-            match self.value_type.bits() {
+        } else if self.is_float() {
+            match self.bits() {
                 32 => Float(_32),
                 64 => Float(_64),
                 _ => unimplemented!(),
@@ -350,9 +368,11 @@ impl SigType for AbiParam {
             unimplemented!()
         }
     }
+}
 
-    fn is_float(&self) -> bool {
-        self.value_type.is_float()
+impl SigType for AbiParam {
+    fn to_microwasm_type(&self) -> microwasm::SignlessType {
+        self.value_type.to_microwasm_type()
     }
 }
 
@@ -377,13 +397,6 @@ impl SigType for wasmparser::Type {
     fn to_microwasm_type(&self) -> microwasm::SignlessType {
         microwasm::Type::from_wasm(*self).unwrap()
     }
-
-    fn is_float(&self) -> bool {
-        match self {
-            wasmparser::Type::F32 | wasmparser::Type::F64 => true,
-            _ => false,
-        }
-    }
 }
 
 impl Signature for FuncType {
@@ -399,14 +412,24 @@ impl Signature for FuncType {
 }
 
 pub trait ModuleContext {
-    type Signature: Signature + Hash;
+    type Signature: Signature;
+    type GlobalType: SigType;
+
+    fn vmctx_vmglobal_definition(&self, index: u32) -> u32;
+    fn vmctx_vmmemory_definition_base(&self, defined_memory_index: u32) -> u32;
+    fn vmctx_vmmemory_definition_current_length(&self, defined_memory_index: u32) -> u32;
+    fn vmctx_vmtable_definition_base(&self, defined_table_index: u32) -> u32;
+    fn vmctx_vmtable_definition_current_elements(&self, defined_table_index: u32) -> u32;
+    fn vmctx_vmshared_signature_id(&self, signature_idx: u32) -> u32;
+    fn vmcaller_checked_anyfunc_type_index(&self) -> u8;
+    fn vmcaller_checked_anyfunc_func_ptr(&self) -> u8;
+    fn size_of_vmcaller_checked_anyfunc(&self) -> u8;
+
+    fn defined_global_index(&self, global_index: u32) -> Option<u32>;
+    fn global_type(&self, global_index: u32) -> &Self::GlobalType;
 
     fn func_type_index(&self, func_idx: u32) -> u32;
     fn signature(&self, index: u32) -> &Self::Signature;
-    fn offset_of_memory_ptr(&self) -> u32;
-    fn offset_of_memory_len(&self) -> u32;
-    fn offset_of_funcs_ptr(&self) -> u8;
-    fn offset_of_funcs_len(&self) -> u8;
 
     fn func_index(&self, defined_func_index: u32) -> u32;
     fn defined_func_index(&self, func_index: u32) -> Option<u32>;
@@ -424,6 +447,7 @@ pub trait ModuleContext {
 
 impl ModuleContext for SimpleContext {
     type Signature = FuncType;
+    type GlobalType = wasmparser::Type;
 
     // TODO: We don't support external functions yet
     fn func_index(&self, func_idx: u32) -> u32 {
@@ -438,24 +462,52 @@ impl ModuleContext for SimpleContext {
         self.func_ty_indicies[func_idx as usize]
     }
 
+    fn defined_global_index(&self, index: u32) -> Option<u32> {
+        unimplemented!()
+    }
+
+    fn global_type(&self, global_index: u32) -> &Self::GlobalType {
+        unimplemented!()
+    }
+
     fn signature(&self, index: u32) -> &Self::Signature {
         &self.types[index as usize]
     }
 
-    fn offset_of_memory_ptr(&self) -> u32 {
-        VmCtx::offset_of_memory_ptr() as _
+    fn vmctx_vmglobal_definition(&self, index: u32) -> u32 {
+        unimplemented!()
     }
 
-    fn offset_of_memory_len(&self) -> u32 {
-        VmCtx::offset_of_memory_len() as _
+    fn vmctx_vmmemory_definition_base(&self, defined_memory_index: u32) -> u32 {
+        VmCtx::offset_of_memory_ptr()
     }
 
-    fn offset_of_funcs_ptr(&self) -> u8 {
-        VmCtx::offset_of_funcs_ptr()
+    fn vmctx_vmmemory_definition_current_length(&self, defined_memory_index: u32) -> u32 {
+        VmCtx::offset_of_memory_len()
     }
 
-    fn offset_of_funcs_len(&self) -> u8 {
-        VmCtx::offset_of_funcs_len()
+    fn vmctx_vmtable_definition_base(&self, defined_table_index: u32) -> u32 {
+        VmCtx::offset_of_funcs_ptr() as _
+    }
+
+    fn vmctx_vmtable_definition_current_elements(&self, defined_table_index: u32) -> u32 {
+        VmCtx::offset_of_funcs_len() as _
+    }
+
+    fn vmcaller_checked_anyfunc_type_index(&self) -> u8 {
+        RuntimeFunc::offset_of_sig_hash() as _
+    }
+
+    fn vmcaller_checked_anyfunc_func_ptr(&self) -> u8 {
+        RuntimeFunc::offset_of_func_start() as _
+    }
+
+    fn size_of_vmcaller_checked_anyfunc(&self) -> u8 {
+        std::mem::size_of::<RuntimeFunc>() as _
+    }
+
+    fn vmctx_vmshared_signature_id(&self, signature_idx: u32) -> u32 {
+        VmCtx::offset_of_hashes() as u32 + signature_idx * std::mem::size_of::<u64>() as u32
     }
 
     // TODO: type of a global
@@ -479,7 +531,7 @@ pub fn translate_only(data: &[u8]) -> Result<TranslatedModule, Error> {
 
     if let SectionCode::Type = section.code {
         let types_reader = section.get_type_section_reader()?;
-        output.types.types = translate_sections::type_(types_reader)?;
+        output.ctx.types = translate_sections::type_(types_reader)?;
 
         reader.skip_custom_sections()?;
         if reader.eof() {
@@ -501,7 +553,7 @@ pub fn translate_only(data: &[u8]) -> Result<TranslatedModule, Error> {
 
     if let SectionCode::Function = section.code {
         let functions = section.get_function_section_reader()?;
-        output.types.func_ty_indicies = translate_sections::function(functions)?;
+        output.ctx.func_ty_indicies = translate_sections::function(functions)?;
 
         reader.skip_custom_sections()?;
         if reader.eof() {
@@ -598,7 +650,7 @@ pub fn translate_only(data: &[u8]) -> Result<TranslatedModule, Error> {
 
     if let SectionCode::Code = section.code {
         let code = section.get_code_section_reader()?;
-        output.translated_code_section = Some(translate_sections::code(code, &output.types)?);
+        output.translated_code_section = Some(translate_sections::code(code, &output.ctx)?);
 
         reader.skip_custom_sections()?;
         if reader.eof() {
diff --git a/src/tests.rs b/src/tests.rs
index 0a9bd60086..572d4528ac 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -404,6 +404,7 @@ mod opf32 {
     binop_test!(le, |a, b| a <= b, i32);
 
     unop_test!(neg, |a: f32| -a);
+    unop_test!(abs, |a: f32| a.abs());
 }
 
 mod opf64 {
@@ -520,6 +521,7 @@ mod opf64 {
     binop_test!(le, |a, b| a <= b, i32);
 
     unop_test!(neg, |a: f64| -a);
+    unop_test!(abs, |a: f64| a.abs());
 }
 
 quickcheck! {
diff --git a/src/translate_sections.rs b/src/translate_sections.rs
index 007c56433f..712e6a867f 100644
--- a/src/translate_sections.rs
+++ b/src/translate_sections.rs
@@ -3,6 +3,7 @@ use crate::error::Error;
 use crate::function_body;
 use crate::microwasm::{MicrowasmConv, Type as MWType};
 use crate::module::{ModuleContext, SimpleContext};
+use cranelift_codegen::{binemit, ir};
 #[allow(unused_imports)] // for now
 use wasmparser::{
     CodeSectionReader, Data, DataSectionReader, Element, ElementSectionReader, Export,
@@ -105,6 +106,28 @@ pub fn element(elements: ElementSectionReader) -> Result<Vec<u32>, Error> {
     Ok(out)
 }
 
+struct UnimplementedRelocSink;
+
+impl binemit::RelocSink for UnimplementedRelocSink {
+    fn reloc_ebb(&mut self, _: binemit::CodeOffset, _: binemit::Reloc, _: binemit::CodeOffset) {
+        unimplemented!()
+    }
+
+    fn reloc_external(
+        &mut self,
+        _: binemit::CodeOffset,
+        _: binemit::Reloc,
+        _: &ir::ExternalName,
+        _: binemit::Addend,
+    ) {
+        unimplemented!()
+    }
+
+    fn reloc_jt(&mut self, _: binemit::CodeOffset, _: binemit::Reloc, _: ir::JumpTable) {
+        unimplemented!()
+    }
+}
+
 /// Parses the Code section of the wasm module.
 pub fn code(
     code: CodeSectionReader,
@@ -115,8 +138,9 @@ pub fn code(
 
     for (idx, body) in code.into_iter().enumerate() {
         let body = body?;
+        let mut relocs = UnimplementedRelocSink;
 
-        function_body::translate_wasm(&mut session, idx as u32, &body)?;
+        function_body::translate_wasm(&mut session, &mut relocs, idx as u32, &body)?;
     }
 
     Ok(session.into_translated_code_section()?)