2 files changed, 205 insertions, 0 deletions
diff --git a/src/comp/back/abi.rs b/src/comp/back/abi.rs
new file mode 100644
index 00000000..157bf876
--- /dev/null
+++ b/src/comp/back/abi.rs
@@ -0,0 +1,46 @@
+
+const int rc_base_field_refcnt = 0;
+
+const int task_field_refcnt = 0;
+const int task_field_stk = 2;
+const int task_field_runtime_sp = 3;
+const int task_field_rust_sp = 4;
+const int task_field_gc_alloc_chain = 5;
+const int task_field_dom = 6;
+const int n_visible_task_fields = 7;
+
+const int dom_field_interrupt_flag = 1;
+
+const int frame_glue_fns_field_mark = 0;
+const int frame_glue_fns_field_drop = 1;
+const int frame_glue_fns_field_reloc = 2;
+
+const int box_rc_field_refcnt = 0;
+const int box_rc_field_body = 1;
+
+const int general_code_alignment = 16;
+
+const int vec_elt_rc = 0;
+const int vec_elt_alloc = 1;
+const int vec_elt_fill = 2;
+const int vec_elt_data = 3;
+
+const int calltup_elt_out_ptr = 0;
+const int calltup_elt_task_ptr = 1;
+const int calltup_elt_indirect_args = 2;
+const int calltup_elt_ty_params = 3;
+const int calltup_elt_args = 4;
+const int calltup_elt_iterator_args = 5;
+
+const int worst_case_glue_call_args = 7;
+
+//
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End:
+//
diff --git a/src/comp/back/x86.rs b/src/comp/back/x86.rs
new file mode 100644
index 00000000..fcf65cc0
--- /dev/null
+++ b/src/comp/back/x86.rs
@@ -0,0 +1,159 @@
+import lib.llvm.llvm;
+import lib.llvm.llvm.ModuleRef;
+import std._str;
+import std._int;
+import std._vec;
+
+const int wordsz = 4;
+
+fn istr(int i) -> str {
+    ret _int.to_str(i, 10u);
+}
+
+fn wstr(int i) -> str {
+    ret istr(i * wordsz);
+}
+
+fn save_callee_saves() -> vec[str] {
+    ret vec("pushl %ebp",
+            "pushl %edi",
+            "pushl %esi",
+            "pushl %ebx");
+}
+
+fn restore_callee_saves() -> vec[str] {
+    ret vec("popl  %ebx",
+            "popl  %esi",
+            "popl  %edi",
+            "popl  %ebp");
+}
+
+fn load_esp_from_rust_sp() -> vec[str] {
+    ret vec("movl  " + wstr(abi.task_field_rust_sp) + "(%edx), %esp");
+}
+
+fn load_esp_from_runtime_sp() -> vec[str] {
+    ret vec("movl  " + wstr(abi.task_field_runtime_sp) + "(%edx), %esp");
+}
+
+fn store_esp_to_rust_sp() -> vec[str] {
+    ret vec("movl  %esp, " + wstr(abi.task_field_rust_sp) + "(%edx)");
+}
+
+fn store_esp_to_runtime_sp() -> vec[str] {
+    ret vec("movl  %esp, " + wstr(abi.task_field_runtime_sp) + "(%edx)");
+}
+
+fn rust_activate_glue() -> vec[str] {
+    ret vec("movl  4(%esp), %edx    # edx = rust_task")
+        + save_callee_saves()
+        + store_esp_to_runtime_sp()
+        + load_esp_from_rust_sp()
+
+        // This 'add' instruction is a bit surprising.
+        // See lengthy comment in boot/be/x86.ml activate_glue.
+        + vec("addl  $20, " + wstr(abi.task_field_rust_sp) + "(%edx)")
+
+        + restore_callee_saves()
+        + vec("ret");
+}
+
+fn rust_yield_glue() -> vec[str] {
+    ret vec("movl  0(%esp), %edx    # edx = rust_task")
+        + load_esp_from_rust_sp()
+        + save_callee_saves()
+        + store_esp_to_rust_sp()
+        + load_esp_from_runtime_sp()
+        + restore_callee_saves()
+        + vec("ret");
+}
+
+fn upcall_glue(int n_args) -> vec[str] {
+
+    /*
+     * 0, 4, 8, 12 are callee-saves
+     * 16 is retpc
+     * 20 is taskptr
+     * 24 is callee
+     * 28 .. (7+i) * 4 are args
+     */
+
+    fn copy_arg(uint i) -> str {
+        auto off = wstr(7 + (i as int));
+        auto m = vec("movl  " + off + "(%ebp),%edx",
+                     "movl  %edx," + off + "(%esp)");
+        ret _str.connect(m, "\n\t");
+    }
+
+    auto carg = copy_arg;
+
+    ret
+        save_callee_saves()
+
+        + vec("movl  %esp, %ebp     # ebp = rust_sp",
+              "movl  20(%esp), %edx # edx = rust_task")
+
+        + store_esp_to_rust_sp()
+        + load_esp_from_runtime_sp()
+
+        + vec("subl  $" + wstr(n_args + 1) + ", %esp   # esp -= args",
+              "andl  $~0xf, %esp    # align esp down",
+              "movl  %edx, (%esp)   # arg[0] = rust_task ")
+
+        + _vec.init_fn[str](carg, n_args as uint)
+
+        +  vec("movl  24(%ebp), %edx # edx = callee",
+               "call  *%edx          # call *%edx",
+               "movl  20(%ebp), %edx # edx = rust_task")
+
+        + load_esp_from_rust_sp()
+        + restore_callee_saves()
+        + vec("ret");
+
+}
+
+
+fn decl_glue(int align, str prefix, str name, vec[str] insns) -> str {
+    auto sym = prefix + name;
+    ret "\t.globl " + sym + "\n" +
+        "\t.balign " + istr(align) + "\n" +
+        sym + ":\n" +
+        "\t" + _str.connect(insns, "\n\t");
+}
+
+
+fn get_module_asm() -> str {
+    auto align = 4;
+    auto prefix = "";
+
+    auto glues =
+        vec(decl_glue(align, prefix,
+                      "rust_activate_glue",
+                      rust_activate_glue()),
+
+            decl_glue(align, prefix,
+                      "rust_yield_glue",
+                      rust_yield_glue()));
+
+    let int i = 0;
+    let int n_upcall_glues = 7;
+    while (i < n_upcall_glues) {
+        glues += decl_glue(align, prefix,
+                           "rust_upcall_" + istr(i),
+                           upcall_glue(i));
+        i += 1;
+    }
+
+    ret _str.connect(glues, "\n\n");
+}
+
+//
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End:
+//