diff --git a/chibicc.h b/chibicc.h
index 31c5479..b850385 100644
--- a/chibicc.h
+++ b/chibicc.h
@@ -291,6 +291,7 @@ extern Type *ty_double;
 
 bool is_integer(Type *ty);
 bool is_flonum(Type *ty);
+bool is_numeric(Type *ty);
 Type *copy_type(Type *ty);
 Type *pointer_to(Type *base);
 Type *func_type(Type *return_ty);
diff --git a/codegen.c b/codegen.c
index a775136..70b9f63 100644
--- a/codegen.c
+++ b/codegen.c
@@ -279,6 +279,22 @@ static void gen_expr(Node *node) {
   }
   case ND_NEG:
     gen_expr(node->lhs);
+
+    switch (node->ty->kind) {
+    case TY_FLOAT:
+      println("  mov $1, %%rax");
+      println("  shl $31, %%rax");
+      println("  movq %%rax, %%xmm1");
+      println("  xorps %%xmm1, %%xmm0");
+      return;
+    case TY_DOUBLE:
+      println("  mov $1, %%rax");
+      println("  shl $63, %%rax");
+      println("  movq %%rax, %%xmm1");
+      println("  xorpd %%xmm1, %%xmm0");
+      return;
+    }
+
     println("  neg %%rax");
     return;
   case ND_VAR:
@@ -424,6 +440,18 @@ static void gen_expr(Node *node) {
     char *sz = (node->lhs->ty->kind == TY_FLOAT) ? "ss" : "sd";
 
     switch (node->kind) {
+    case ND_ADD:
+      println("  add%s %%xmm1, %%xmm0", sz);
+      return;
+    case ND_SUB:
+      println("  sub%s %%xmm1, %%xmm0", sz);
+      return;
+    case ND_MUL:
+      println("  mul%s %%xmm1, %%xmm0", sz);
+      return;
+    case ND_DIV:
+      println("  div%s %%xmm1, %%xmm0", sz);
+      return;
     case ND_EQ:
     case ND_NE:
     case ND_LT:
@@ -496,13 +524,13 @@ static void gen_expr(Node *node) {
       println("  mov %%rdx, %%rax");
     return;
   case ND_BITAND:
-    println("  and %%rdi, %%rax");
+    println("  and %s, %s", di, ax);
     return;
   case ND_BITOR:
-    println("  or %%rdi, %%rax");
+    println("  or %s, %s", di, ax);
     return;
   case ND_BITXOR:
-    println("  xor %%rdi, %%rax");
+    println("  xor %s, %s", di, ax);
     return;
   case ND_EQ:
   case ND_NE:
diff --git a/parse.c b/parse.c
index ac1a792..fef1192 100644
--- a/parse.c
+++ b/parse.c
@@ -1759,7 +1759,7 @@ static Node *new_add(Node *lhs, Node *rhs, Token *tok) {
   add_type(rhs);
 
   // num + num
-  if (is_integer(lhs->ty) && is_integer(rhs->ty))
+  if (is_numeric(lhs->ty) && is_numeric(rhs->ty))
     return new_binary(ND_ADD, lhs, rhs, tok);
 
   if (lhs->ty->base && rhs->ty->base)
@@ -1783,7 +1783,7 @@ static Node *new_sub(Node *lhs, Node *rhs, Token *tok) {
   add_type(rhs);
 
   // num - num
-  if (is_integer(lhs->ty) && is_integer(rhs->ty))
+  if (is_numeric(lhs->ty) && is_numeric(rhs->ty))
     return new_binary(ND_SUB, lhs, rhs, tok);
 
   // ptr - num
diff --git a/test/float.c b/test/float.c
index 082a9fa..2ad0853 100644
--- a/test/float.c
+++ b/test/float.c
@@ -59,6 +59,27 @@ int main() {
   ASSERT(1, 5.0f<=5);
   ASSERT(1, 4.9f<=5);
 
+  ASSERT(6, 2.3+3.8);
+  ASSERT(-1, 2.3-3.8);
+  ASSERT(-3, -3.8);
+  ASSERT(13, 3.3*4);
+  ASSERT(2, 5.0/2);
+
+  ASSERT(6, 2.3f+3.8f);
+  ASSERT(6, 2.3f+3.8);
+  ASSERT(-1, 2.3f-3.8);
+  ASSERT(-3, -3.8f);
+  ASSERT(13, 3.3f*4);
+  ASSERT(2, 5.0f/2);
+
+  ASSERT(0, 0.0/0.0 == 0.0/0.0);
+  ASSERT(1, 0.0/0.0 != 0.0/0.0);
+
+  ASSERT(0, 0.0/0.0 < 0);
+  ASSERT(0, 0.0/0.0 <= 0);
+  ASSERT(0, 0.0/0.0 > 0);
+  ASSERT(0, 0.0/0.0 >= 0);
+
   printf("OK\n");
   return 0;
 }
diff --git a/test/sizeof.c b/test/sizeof.c
index c550c8c..1ec50f4 100644
--- a/test/sizeof.c
+++ b/test/sizeof.c
@@ -87,6 +87,15 @@ int main() {
   ASSERT(4, sizeof(float));
   ASSERT(8, sizeof(double));
 
+  ASSERT(4, sizeof(1f+2));
+  ASSERT(8, sizeof(1.0+2));
+  ASSERT(4, sizeof(1f-2));
+  ASSERT(8, sizeof(1.0-2));
+  ASSERT(4, sizeof(1f*2));
+  ASSERT(8, sizeof(1.0*2));
+  ASSERT(4, sizeof(1f/2));
+  ASSERT(8, sizeof(1.0/2));
+
   printf("OK\n");
   return 0;
 }
diff --git a/type.c b/type.c
index 358919f..6c3a14d 100644
--- a/type.c
+++ b/type.c
@@ -34,6 +34,10 @@ bool is_flonum(Type *ty) {
   return ty->kind == TY_FLOAT || ty->kind == TY_DOUBLE;
 }
 
+bool is_numeric(Type *ty) {
+  return is_integer(ty) || is_flonum(ty);
+}
+
 Type *copy_type(Type *ty) {
   Type *ret = calloc(1, sizeof(Type));
   *ret = *ty;