Support ^ exponentiation for integers

5 files changed, 19 insertions, 4 deletions

diff --git a/builtins/integers.c b/builtins/integers.c
index 53e38aab..e55d2ab0 100644
--- a/builtins/integers.c
+++ b/builtins/integers.c
@@ -291,6 +291,17 @@ public Int_t Int$abs(Int_t x)
     return Int$from_mpz(result);
 }
 
+public Int_t Int$power(Int_t base, Int_t exponent)
+{
+    int64_t exp = Int$as_i64(exponent);
+    if (__builtin_expect(exp < 0, 0))
+        fail("Cannot take a negative power of an integer!");
+    mpz_t result;
+    mpz_init_set_int(result, base);
+    mpz_pow_ui(result, result, exp);
+    return Int$from_mpz(result);
+}
+
 public Int_t Int$random(Int_t min, Int_t max) {
     int32_t cmp = Int$compare(&min, &max, &$Int);
     if (cmp > 0)
diff --git a/builtins/integers.h b/builtins/integers.h
index 385113b0..8250e0dc 100644
--- a/builtins/integers.h
+++ b/builtins/integers.h
@@ -59,6 +59,7 @@ Int_t Int$random(Int_t min, Int_t max);
 Range_t Int$to(Int_t from, Int_t to);
 Int_t Int$from_text(CORD text);
 Int_t Int$abs(Int_t x);
+Int_t Int$power(Int_t base, Int_t exponent);
 
 #define BIGGEST_SMALL_INT ((1<<29)-1)
 
@@ -72,11 +73,13 @@ Int_t Int$abs(Int_t x);
     }))
 
 #define mpz_init_set_int(mpz, i) do { \
-    if ((i).small & 1) mpz_init_set_si(mpz, (i).small >> 2); \
+    if (__builtin_expect((i).small & 1, 1)) mpz_init_set_si(mpz, (i).small >> 2); \
     else mpz_init_set(mpz, *(i).big); \
 } while (0)
 
-#define Int$as_i64(i) (((i).small & 1) ? (int64_t)((i).small >> 2) : mpz_get_si(*(i).big))
+#define Int$as_i64(i) (__builtin_expect((i).small & 1, 1) ? (int64_t)((i).small >> 2) : \
+                       ({ if (!__builtin_expect(mpz_fits_slong_p(*(i).big), 1)) fail("Integer is too big to fit in a 64-bit integer!"); \
+                        mpz_get_si(*(i).big); }))
 Int_t Int$from_i64(int64_t i);
 Int_t Int$from_num(double n);
 double Int$as_num(Int_t i);
diff --git a/compile.c b/compile.c
index 1053b739..1aaae695 100644
--- a/compile.c
+++ b/compile.c
@@ -1351,7 +1351,7 @@ CORD compile_math_method(env_t *env, binop_e op, ast_t *lhs, ast_t *rhs, type_t
         break;
     }
     case BINOP_POWER: {
-        if (rhs_t->tag == NumType) {
+        if (rhs_t->tag == NumType || rhs_t->tag == IntType) {
             binding_t *b = get_namespace_binding(env, lhs, binop_method_names[op]);
             if (binding_works(b, lhs_t, rhs_t, lhs_t))
                 return CORD_all(b->code, "(", compile(env, lhs), ", ", compile(env, rhs), ")");
diff --git a/environment.c b/environment.c
index 57fbc6fa..c8056cc5 100644
--- a/environment.c
+++ b/environment.c
@@ -107,6 +107,7 @@ env_t *new_compilation_unit(CORD *libname)
             {"negative", "Int$negative", "func(x:Int)->Int"},
             {"negated", "Int$negated", "func(x:Int)->Int"},
             {"abs", "Int$abs", "func(x:Int)->Int"},
+            {"power", "Int$power", "func(base:Int,exponent:Int)->Int"},
         )},
         {"Int64", Type(IntType, .bits=64), "Int64_t", "$Int64", TypedArray(ns_entry_t,
             {"format", "Int64$format", "func(i:Int64, digits=0)->Text"},
diff --git a/typecheck.c b/typecheck.c
index 3e657dfa..1100aedc 100644
--- a/typecheck.c
+++ b/typecheck.c
@@ -899,7 +899,7 @@ type_t *get_type(env_t *env, ast_t *ast)
             break;
         }
         case BINOP_POWER: {
-            if (rhs_t->tag == NumType && binding_works(binop_method_names[binop->op], binop->lhs, lhs_t, rhs_t, lhs_t))
+            if ((rhs_t->tag == NumType || rhs_t->tag == IntType) && binding_works(binop_method_names[binop->op], binop->lhs, lhs_t, rhs_t, lhs_t))
                 return lhs_t;
             break;
         }