MIR Optimise - basic size_of replacemnt

3 files changed, 166 insertions, 14 deletions

diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp
index 5062fcf7..173b5d7e 100644
--- a/src/mir/optimise.cpp
+++ b/src/mir/optimise.cpp
@@ -15,6 +15,7 @@
 #include <mir/visit_crate_mir.hpp>
 #include <algorithm>
 #include <iomanip>
+#include <trans/target.hpp>
 
 namespace {
     ::MIR::BasicBlockId get_new_target(const ::MIR::TypeResolve& state, ::MIR::BasicBlockId bb)
@@ -1738,23 +1739,25 @@ bool MIR_Optimise_ConstPropagte(::MIR::TypeResolve& state, ::MIR::Function& fcn)
         const auto& tef = te.fcn.as_Intrinsic();
         if( tef.name == "size_of" )
         {
-            //size_t size_val = 0;
-            //if( Target_GetSizeOf(tef.params.m_types.at(0), size_val) )
-            //{
-            //    bb.statements.push_back(::MIR::Statement::make_Assign({ mv$(te.ret_val), ::MIR::Constant::make_Uint(size_val) }));
-            //    bb.terminator = ::MIR::Terminator::make_Goto(te.ret_block);
-            //    changed = true;
-            //}
+            size_t size_val = 0;
+            if( Target_GetSizeOf(state.sp, tef.params.m_types.at(0), size_val) )
+            {
+                auto val = ::MIR::Constant::make_Uint({ size_val, ::HIR::CoreType::Usize });
+                bb.statements.push_back(::MIR::Statement::make_Assign({ mv$(te.ret_val), mv$(val) }));
+                bb.terminator = ::MIR::Terminator::make_Goto(te.ret_block);
+                changed = true;
+            }
         }
         else if( tef.name == "align_of" )
         {
-            //size_t size_val = 0;
-            //if( Target_GetAlignOf(tef.params.m_types.at(0), size_val) )
-            //{
-            //    bb.statements.push_back(::MIR::Statement::make_Assign({ mv$(te.ret_val), ::MIR::Constant::make_Uint(size_val) }));
-            //    bb.terminator = ::MIR::Terminator::make_Goto(te.ret_block);
-            //    changed = true;
-            //}
+            size_t align_val = 0;
+            if( Target_GetAlignOf(state.sp, tef.params.m_types.at(0), align_val) )
+            {
+                auto val = ::MIR::Constant::make_Uint({ align_val, ::HIR::CoreType::Usize });
+                bb.statements.push_back(::MIR::Statement::make_Assign({ mv$(te.ret_val), mv$(val) }));
+                bb.terminator = ::MIR::Terminator::make_Goto(te.ret_block);
+                changed = true;
+            }
         }
         // NOTE: Quick special-case for bswap<u8> (a no-op)
         else if( tef.name == "bswap" && tef.params.m_types.at(0) == ::HIR::CoreType::U8 )
diff --git a/src/trans/target.cpp b/src/trans/target.cpp
new file mode 100644
index 00000000..21555101
--- /dev/null
+++ b/src/trans/target.cpp
@@ -0,0 +1,134 @@
+/*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/target.cpp
+ * - Target-specific information
+ */
+#include "target.hpp"
+
+// TODO: Replace with target selection
+#define POINTER_SIZE_BYTES  8
+
+bool Target_GetSizeAndAlignOf(const Span& sp, const ::HIR::TypeRef& ty, size_t& out_size, size_t& out_align)
+{
+    TU_MATCHA( (ty.m_data), (te),
+    (Infer,
+        BUG(sp, "sizeof on _ type");
+        ),
+    (Diverge,
+        out_size = 0;
+        out_align = 0;
+        return true;
+        ),
+    (Primitive,
+        switch(te)
+        {
+        case ::HIR::CoreType::Bool:
+        case ::HIR::CoreType::U8:
+        case ::HIR::CoreType::I8:
+            out_size = 1;
+            out_align = 1;
+            return true;
+        case ::HIR::CoreType::U16:
+        case ::HIR::CoreType::I16:
+            out_size = 2;
+            out_align = 2;
+            return true;
+        case ::HIR::CoreType::U32:
+        case ::HIR::CoreType::I32:
+        case ::HIR::CoreType::Char:
+            out_size = 4;
+            out_align = 4;
+            return true;
+        case ::HIR::CoreType::U64:
+        case ::HIR::CoreType::I64:
+            out_size = 8;
+            out_align = 8;
+            return true;
+        case ::HIR::CoreType::U128:
+        case ::HIR::CoreType::I128:
+            out_size = 16;
+            // TODO: If i128 is emulated, this can be 8
+            out_align = 16;
+            return true;
+        case ::HIR::CoreType::Usize:
+        case ::HIR::CoreType::Isize:
+            out_size = POINTER_SIZE_BYTES;
+            out_align = POINTER_SIZE_BYTES;
+            return true;
+        case ::HIR::CoreType::F32:
+            out_size = 4;
+            out_align = 4;
+            return true;
+        case ::HIR::CoreType::F64:
+            out_size = 8;
+            out_align = 8;
+            return true;
+        case ::HIR::CoreType::Str:
+            BUG(sp, "sizeof on a `str` - unsized");
+        }
+        ),
+    (Path,
+        // TODO:
+        return false;
+        ),
+    (Generic,
+        // Unknown - return false
+        return false;
+        ),
+    (TraitObject,
+        BUG(sp, "sizeof on a trait object - unsized");
+        ),
+    (ErasedType,
+        BUG(sp, "sizeof on an erased type - shouldn't exist");
+        ),
+    (Array,
+        // TODO: 
+        size_t  size;
+        if( !Target_GetSizeAndAlignOf(sp, *te.inner, size,out_align) )
+            return false;
+        size *= te.size_val;
+        ),
+    (Slice,
+        BUG(sp, "sizeof on a slice - unsized");
+        ),
+    (Tuple,
+        out_size = 0;
+        out_align = 0;
+
+        // TODO: Struct reordering
+        for(const auto& t : te)
+        {
+            size_t  size, align;
+            if( !Target_GetSizeAndAlignOf(sp, t, size,align) )
+                return false;
+            out_size += size;
+            out_align = ::std::max(out_align, align);
+        }
+        ),
+    (Borrow,
+        // TODO
+        ),
+    (Pointer,
+        // TODO
+        ),
+    (Function,
+        // Pointer size
+        ),
+    (Closure,
+        // TODO.
+        )
+    )
+    return false;
+}
+bool Target_GetSizeOf(const Span& sp, const ::HIR::TypeRef& ty, size_t& out_size)
+{
+    size_t  ignore_align;
+    return Target_GetSizeAndAlignOf(sp, ty, out_size, ignore_align);
+}
+bool Target_GetAlignOf(const Span& sp, const ::HIR::TypeRef& ty, size_t& out_align)
+{
+    size_t  ignore_size;
+    return Target_GetSizeAndAlignOf(sp, ty, ignore_size, out_align);
+}
diff --git a/src/trans/target.hpp b/src/trans/target.hpp
new file mode 100644
index 00000000..1c081b54
--- /dev/null
+++ b/src/trans/target.hpp
@@ -0,0 +1,15 @@
+/*
+ * MRustC - Rust Compiler
+ * - By John Hodge (Mutabah/thePowersGang)
+ *
+ * trans/target.hpp
+ * - Target-specific information
+ */
+#pragma once
+
+#include <cstddef>
+#include <hir/type.hpp>
+
+extern bool Target_GetSizeOf(const Span& sp, const ::HIR::TypeRef& ty, size_t& out_size);
+extern bool Target_GetAlignOf(const Span& sp, const ::HIR::TypeRef& ty, size_t& out_align);
+