Refactor C interface to pass operation as enum

This is hmatrix style, less proliferation of functions as the number of
ops increases

2 files changed, 118 insertions, 6 deletions

diff --git a/cbits/arith.c b/cbits/arith.c
index 002910c..65cdb41 100644
--- a/cbits/arith.c
+++ b/cbits/arith.c
@@ -1,28 +1,42 @@
+#include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
 #include <math.h>
 
+// These are the wrapper macros used in arith_lists.h. Preset them to empty to
+// avoid having to touch macros unrelated to the particular operation set below.
+#define LIST_BINOP(name, id, hsop)
+#define LIST_UNOP(name, id, _)
+#define LIST_REDOP(name, id, _)
+
+
+// Shorter names, due to CPP used both in function names and in C types.
 typedef int32_t i32;
 typedef int64_t i64;
 
+
+/*****************************************************************************
+ *                             Kernel functions                              *
+ *****************************************************************************/
+
 #define COMM_OP(name, op, typ) \
-  void oxarop_ ## name ## _ ## typ ## _sv(i64 n, typ *out, typ x, const typ *y) { \
+  static void oxarop_op_ ## name ## _ ## typ ## _sv(i64 n, typ *out, typ x, const typ *y) { \
     for (i64 i = 0; i < n; i++) out[i] = x op y[i]; \
   } \
-  void oxarop_ ## name ## _ ## typ ## _vv(i64 n, typ *out, const typ *x, const typ *y) { \
+  static void oxarop_op_ ## name ## _ ## typ ## _vv(i64 n, typ *out, const typ *x, const typ *y) { \
     for (i64 i = 0; i < n; i++) out[i] = x[i] op y[i]; \
   }
 
 #define NONCOMM_OP(name, op, typ) \
   COMM_OP(name, op, typ) \
-  void oxarop_ ## name ## _ ## typ ## _vs(i64 n, typ *out, const typ *x, typ y) { \
+  static void oxarop_op_ ## name ## _ ## typ ## _vs(i64 n, typ *out, const typ *x, typ y) { \
     for (i64 i = 0; i < n; i++) out[i] = x[i] op y; \
   }
 
 #define UNARY_OP(name, op, typ) \
-  void oxarop_ ## name ## _ ## typ(i64 n, typ *out, const typ *x) { \
+  static void oxarop_op_ ## name ## _ ## typ(i64 n, typ *out, const typ *x) { \
     for (i64 i = 0; i < n; i++) out[i] = op(x[i]); \
   }
 
@@ -68,7 +82,7 @@ typedef int64_t i64;
 // Reduces along the innermost dimension.
 // 'out' will be filled densely in linearisation order.
 #define REDUCE1_OP(name, op, typ) \
-  void oxarop_ ## name ## _ ## typ(i64 rank, const i64 *shape, const i64 *strides, typ *out, const typ *arr) { \
+  static void oxarop_op_ ## name ## _ ## typ(i64 rank, const i64 *shape, const i64 *strides, typ *out, const typ *arr) { \
     if (strides[rank - 1] == 1) { \
       TARRAY_WALK_NOINNER(again1, rank, shape, strides, { \
         typ accum = arr[arrlinidx]; \
@@ -88,6 +102,91 @@ typedef int64_t i64;
     } \
   }
 
+
+/*****************************************************************************
+ *                           Entry point functions                           *
+ *****************************************************************************/
+
+__attribute__((noreturn, cold))
+static void wrong_op(const char *name, int tag) {
+  fprintf(stderr, "ox-arrays: Invalid operation tag passed to %s C code: %d\n", name, tag);
+  abort();
+}
+
+enum binop_tag_t {
+#undef LIST_BINOP
+#define LIST_BINOP(name, id, hsop) name = id,
+#include "arith_lists.h"
+#undef LIST_BINOP
+#define LIST_BINOP(name, id, hsop)
+};
+
+#define ENTRY_BINARY_OPS(typ) \
+  void oxarop_binary_ ## typ ## _sv(enum binop_tag_t tag, i64 n, typ *out, typ x, const typ *y) { \
+    switch (tag) { \
+      case BO_ADD: oxarop_op_add_ ## typ ## _sv(n, out, x, y); break; \
+      case BO_SUB: oxarop_op_sub_ ## typ ## _sv(n, out, x, y); break; \
+      case BO_MUL: oxarop_op_mul_ ## typ ## _sv(n, out, x, y); break; \
+      default: wrong_op("binary_sv", tag); \
+    } \
+  } \
+  void oxarop_binary_ ## typ ## _vs(enum binop_tag_t tag, i64 n, typ *out, const typ *x, typ y) { \
+    switch (tag) { \
+      case BO_ADD: oxarop_op_add_ ## typ ## _sv(n, out, y, x); break; \
+      case BO_SUB: oxarop_op_sub_ ## typ ## _vs(n, out, x, y); break; \
+      case BO_MUL: oxarop_op_mul_ ## typ ## _sv(n, out, y, x); break; \
+      default: wrong_op("binary_vs", tag); \
+    } \
+  } \
+  void oxarop_binary_ ## typ ## _vv(enum binop_tag_t tag, i64 n, typ *out, const typ *x, const typ *y) { \
+    switch (tag) { \
+      case BO_ADD: oxarop_op_add_ ## typ ## _vv(n, out, x, y); break; \
+      case BO_SUB: oxarop_op_sub_ ## typ ## _vv(n, out, x, y); break; \
+      case BO_MUL: oxarop_op_mul_ ## typ ## _vv(n, out, x, y); break; \
+      default: wrong_op("binary_vv", tag); \
+    } \
+  }
+
+enum unop_tag_t {
+#undef LIST_UNOP
+#define LIST_UNOP(name, id, _) name = id,
+#include "arith_lists.h"
+#undef LIST_UNOP
+#define LIST_UNOP(name, id, _)
+};
+
+#define ENTRY_UNARY_OPS(typ) \
+  void oxarop_unary_ ## typ(enum unop_tag_t tag, i64 n, typ *out, const typ *x) { \
+    switch (tag) { \
+      case UO_NEG: oxarop_op_neg_ ## typ(n, out, x); break; \
+      case UO_ABS: oxarop_op_abs_ ## typ(n, out, x); break; \
+      case UO_SIGNUM: oxarop_op_signum_ ## typ(n, out, x); break; \
+      default: wrong_op("unary", tag); \
+    } \
+  }
+
+enum redop_tag_t {
+#undef LIST_REDOP
+#define LIST_REDOP(name, id, _) name = id,
+#include "arith_lists.h"
+#undef LIST_REDOP
+#define LIST_REDOP(name, id, _)
+};
+
+#define ENTRY_REDUCE_OPS(typ) \
+  void oxarop_reduce_ ## typ(enum redop_tag_t tag, i64 rank, const i64 *shape, const i64 *strides, typ *out, const typ *arr) { \
+    switch (tag) { \
+      case RO_SUM1: oxarop_op_sum1_ ## typ(rank, shape, strides, out, arr); break; \
+      case RO_PRODUCT1: oxarop_op_product1_ ## typ(rank, shape, strides, out, arr); break; \
+      default: wrong_op("reduce", tag); \
+    } \
+  }
+
+
+/*****************************************************************************
+ *                        Generate all the functions                         *
+ *****************************************************************************/
+
 #define NUM_TYPES_LOOP_XLIST \
   X(i32) X(i64) X(double) X(float)
 
@@ -99,6 +198,9 @@ typedef int64_t i64;
   UNARY_OP(abs, GEN_ABS, typ) \
   UNARY_OP(signum, GEN_SIGNUM, typ) \
   REDUCE1_OP(sum1, +, typ) \
-  REDUCE1_OP(product1, *, typ)
+  REDUCE1_OP(product1, *, typ) \
+  ENTRY_BINARY_OPS(typ) \
+  ENTRY_UNARY_OPS(typ) \
+  ENTRY_REDUCE_OPS(typ)
 NUM_TYPES_LOOP_XLIST
 #undef X
diff --git a/cbits/arith_lists.h b/cbits/arith_lists.h
new file mode 100644
index 0000000..c7495e8
--- /dev/null
+++ b/cbits/arith_lists.h
@@ -0,0 +1,10 @@
+LIST_BINOP(BO_ADD, 1, +)
+LIST_BINOP(BO_SUB, 2, -)
+LIST_BINOP(BO_MUL, 3, *)
+
+LIST_UNOP(UO_NEG, 1,)
+LIST_UNOP(UO_ABS, 2,)
+LIST_UNOP(UO_SIGNUM, 3,)
+
+LIST_REDOP(RO_SUM1, 1,)
+LIST_REDOP(RO_PRODUCT1, 2,)