Add more LLVM attributes

• Add more LLVM attributes in the CPU backend.

hercules_cg/src/cpu.rs

@@ -146,7 +146,7 @@ impl<'a> CPUContext<'a> {
                 self.function.name,
             )?;
         }
-        write!(w, ") {{\n")?;
+        write!(w, ") nounwind nosync willreturn norecurse {{\n")?;
 
         let mut blocks: BTreeMap<_, _> = (0..self.function.nodes.len())
             .filter(|idx| self.function.nodes[*idx].is_control())
@@ -346,7 +346,7 @@ impl<'a> CPUContext<'a> {
                     let offset = offsets[&id].0;
                     write!(
                         body,
-                        "  {} = getelementptr i8, ptr %backing, i64 %dc{}\n",
+                        "  {} = getelementptr inbounds i8, ptr %backing, i64 %dc{}\n",
                         self.get_value(id, false),
                         offset.idx()
                     )?;
@@ -473,11 +473,14 @@ impl<'a> CPUContext<'a> {
 
                 let opcode = match (op, op_ty) {
                     (BinaryOperator::Add, OpTy::Float) => "fadd",
-                    (BinaryOperator::Add, _) => "add",
+                    (BinaryOperator::Add, OpTy::Unsigned) => "add nuw",
+                    (BinaryOperator::Add, OpTy::Signed) => "add nsw",
                     (BinaryOperator::Sub, OpTy::Float) => "fsub",
-                    (BinaryOperator::Sub, _) => "sub",
+                    (BinaryOperator::Sub, OpTy::Unsigned) => "sub nuw",
+                    (BinaryOperator::Sub, OpTy::Signed) => "sub nsw",
                     (BinaryOperator::Mul, OpTy::Float) => "fmul",
-                    (BinaryOperator::Mul, _) => "mul",
+                    (BinaryOperator::Mul, OpTy::Unsigned) => "mul nuw",
+                    (BinaryOperator::Mul, OpTy::Signed) => "mul nsw",
                     (BinaryOperator::Div, OpTy::Float) => "fdiv",
                     (BinaryOperator::Div, OpTy::Unsigned) => "udiv",
                     (BinaryOperator::Div, OpTy::Signed) => "sdiv",
@@ -1005,7 +1008,7 @@ impl<'a> CPUContext<'a> {
         let name = format!("%gep.{}", Self::gen_filler_id());
         write!(
             body,
-            "  {} = getelementptr i8, ptr {}, i64 {}\n",
+            "  {} = getelementptr inbounds i8, ptr {}, i64 {}\n",
             name, ptr, size
         )?;
         Ok(name)