Add janet_sysir_scalarize

Makes it easier to add simpler backends without needing to completely
handle vectorization.

Author: bakpakin

examples/sysir/arrays2.janet

@@ -17,3 +17,7 @@
 (def ctx (sysir/context))
 (sysir/asm ctx ir-asm)
 (print (sysir/to-c ctx))
+(printf "%.99M" (sysir/to-ir ctx))
+(print (sysir/scalarize ctx))
+(printf "%.99M" (sysir/to-ir ctx))
+(print (sysir/to-c ctx))

src/core/sysir.c

@@ -103,9 +103,9 @@ const char *janet_sysop_names[] = {
     "type-struct", /* JANET_SYSOP_TYPE_STRUCT */
     "type-bind", /* JANET_SYSOP_TYPE_BIND */
     "arg", /* JANET_SYSOP_ARG */
-    "field-getp", /* JANET_SYSOP_FIELD_GETP */
-    "array-getp", /* JANET_SYSOP_ARRAY_GETP */
-    "array-pgetp", /* JANET_SYSOP_ARRAY_PGETP */
+    "fgetp", /* JANET_SYSOP_FIELD_GETP */
+    "agetp", /* JANET_SYSOP_ARRAY_GETP */
+    "apgetp", /* JANET_SYSOP_ARRAY_PGETP */
     "type-pointer", /* JANET_SYSOP_TYPE_POINTER */
     "type-array", /* JANET_SYSOP_TYPE_ARRAY */
     "type-union", /* JANET_SYSOP_TYPE_UNION */
@@ -198,9 +198,9 @@ static JanetString *table_to_string_array(JanetTable *strings_to_indices, int32_
         return NULL;
     }
     janet_assert(count > 0, "bad count");
-    JanetString *strings = janet_malloc(count * sizeof(JanetString));
+    JanetString *strings = NULL;
     for (int32_t i = 0; i < count; i++) {
-        strings[i] = NULL;
+        janet_v_push(strings, NULL);
     }
     for (int32_t i = 0; i < strings_to_indices->capacity; i++) {
         JanetKV *kv = strings_to_indices->data + i;
@@ -307,24 +307,29 @@ static uint32_t instr_read_type_operand(Janet x, JanetSysIR *ir, ReadOpMode rmod
     return operand;
 }
 
+static uint32_t janet_sys_makeconst(JanetSysIR *sysir, uint32_t type, Janet x) {
+    JanetSysConstant jsc;
+    jsc.type = type;
+    jsc.value = x;
+    for (int32_t i = 0; i < janet_v_count(sysir->constants); i++) {
+        if (sysir->constants[i].type != jsc.type) continue;
+        if (!janet_equals(sysir->constants[i].value, x)) continue;
+        /* Found a constant */
+        return JANET_SYS_CONSTANT_PREFIX + i;
+    }
+    uint32_t index = (uint32_t) janet_v_count(sysir->constants);
+    janet_v_push(sysir->constants, jsc);
+    sysir->constant_count++;
+    return JANET_SYS_CONSTANT_PREFIX + index;
+}
+
 static uint32_t instr_read_operand_or_const(Janet x, JanetSysIR *ir) {
     if (janet_checktype(x, JANET_TUPLE)) {
-        JanetSysConstant jsc;
         const Janet *tup = janet_unwrap_tuple(x);
         if (janet_tuple_length(tup) != 2) janet_panicf("expected constant wrapped in tuple, got %p", x);
         Janet c = tup[1];
-        jsc.type = instr_read_type_operand(tup[0], ir, READ_TYPE_REFERENCE);
-        jsc.value = c;
-        /* TODO - Use a hash table or something better than linear lookup */
-        for (int32_t i = 0; i < janet_v_count(ir->constants); i++) {
-            if (ir->constants[i].type != jsc.type) continue;
-            if (!janet_equals(ir->constants[i].value, c)) continue;
-            /* Found a constant */
-            return JANET_SYS_CONSTANT_PREFIX + i;
-        }
-        uint32_t index = (uint32_t) janet_v_count(ir->constants);
-        janet_v_push(ir->constants, jsc);
-        return JANET_SYS_CONSTANT_PREFIX + index;
+        uint32_t t = instr_read_type_operand(tup[0], ir, READ_TYPE_REFERENCE);
+        return janet_sys_makeconst(ir, t, c);
     }
     return instr_read_operand(x, ir);
 }
@@ -665,7 +670,6 @@ static void janet_sysir_init_instructions(JanetSysIR *out, JanetView instruction
 
     /* Build constants */
     out->constant_count = janet_v_count(out->constants);
-    out->constants = janet_v_flatten(out->constants);
 }
 
 /* Get a type index given an operand */
@@ -724,14 +728,19 @@ static void tcheck_redef(JanetSysIR *ir, uint32_t typeid) {
 static void janet_sysir_init_types(JanetSysIR *ir) {
     JanetSysIRLinkage *linkage = ir->linkage;
     JanetSysTypeField *fields = NULL;
-    JanetSysTypeInfo *type_defs = janet_realloc(linkage->type_defs, sizeof(JanetSysTypeInfo) * (linkage->type_def_count));
+    JanetSysTypeInfo td;
+    memset(&td, 0, sizeof(td));
+    for (uint32_t i = 0; i < linkage->type_def_count; i++) {
+        janet_v_push(linkage->type_defs, td);
+    }
+    JanetSysTypeInfo *type_defs = linkage->type_defs;
     uint32_t field_offset = linkage->field_def_count;
-    uint32_t *types = janet_malloc(sizeof(uint32_t) * ir->register_count);
+    uint32_t *types = NULL;
     linkage->type_defs = type_defs;
-    ir->types = types;
     for (uint32_t i = 0; i < ir->register_count; i++) {
-        ir->types[i] = 0;
+        janet_v_push(types, 0);
     }
+    ir->types = types;
     for (uint32_t i = linkage->old_type_def_count; i < linkage->type_def_count; i++) {
         type_defs[i].prim = JANET_PRIM_UNKNOWN;
     }
@@ -795,7 +804,7 @@ static void janet_sysir_init_types(JanetSysIR *ir) {
     if (janet_v_count(fields)) {
         uint32_t new_field_count = field_offset + janet_v_count(fields);
         linkage->field_defs = janet_realloc(linkage->field_defs, sizeof(JanetSysTypeField) * new_field_count);
-        memcpy(linkage->field_defs + field_offset, fields, janet_v_count(fields) * sizeof(JanetSysTypeField));
+        safe_memcpy(linkage->field_defs + field_offset, fields, janet_v_count(fields) * sizeof(JanetSysTypeField));
         linkage->field_def_count = new_field_count;
         janet_v_free(fields);
     }
@@ -1332,7 +1341,7 @@ static void janet_sys_ir_init(JanetSysIR *out, JanetView instructions, JanetSysI
 
     /* Patch up name mapping arrays */
     /* TODO - make more efficient, don't rebuild from scratch every time */
-    if (linkage->type_names) janet_free((void *) linkage->type_names);
+    if (linkage->type_names) janet_v_free((void *) linkage->type_names);
     linkage->type_names = table_to_string_array(linkage->type_name_lookup, linkage->type_def_count);
     ir.register_names = table_to_string_array(ir.register_name_lookup, ir.register_count);
 
@@ -1346,6 +1355,189 @@ static void janet_sys_ir_init(JanetSysIR *out, JanetView instructions, JanetSysI
     janet_array_push(linkage->ir_ordered, janet_wrap_abstract(out));
 }
 
+/*
+ * Passes
+ */
+
+static JanetSysInstruction makethree(JanetSysInstruction source, JanetSysOp opcode, uint32_t dest, uint32_t lhs, uint32_t rhs) {
+    source.opcode = opcode;
+    source.three.dest = dest;
+    source.three.lhs = lhs;
+    source.three.rhs = rhs;
+    return source;
+}
+
+static JanetSysInstruction maketwo(JanetSysInstruction source, JanetSysOp opcode, uint32_t dest, uint32_t src) {
+    source.opcode = opcode;
+    source.two.dest = dest;
+    source.two.src = src;
+    return source;
+}
+
+static JanetSysInstruction makejmp(JanetSysInstruction source, JanetSysOp opcode, uint32_t to) {
+    source.opcode = opcode;
+    source.jump.to = to;
+    return source;
+}
+
+static JanetSysInstruction makebranch(JanetSysInstruction source, JanetSysOp opcode, uint32_t cond, uint32_t labelid) {
+    source.opcode = opcode;
+    source.branch.cond = cond;
+    source.branch.to = labelid;
+    return source;
+}
+
+static JanetSysInstruction makelabel(JanetSysInstruction source, JanetSysOp opcode, uint32_t id) {
+    source.opcode = opcode;
+    source.label.id = id;
+    return source;
+}
+
+static JanetSysInstruction makebind(JanetSysInstruction source, JanetSysOp opcode, uint32_t reg, uint32_t type) {
+    source.opcode = opcode;
+    source.type_bind.dest = reg;
+    source.type_bind.type = type;
+    return source;
+}
+
+
+static uint32_t janet_sysir_getreg(JanetSysIR *sysir, uint32_t type) {
+    uint32_t ret = sysir->register_count++;
+    janet_v_push(sysir->types, type);
+    return ret;
+}
+
+/* Find primitive types in the current linkage to avoid creating tons
+ * of copies of duplicate types. */
+static uint32_t janet_sysir_findprim(JanetSysIRLinkage *linkage, JanetPrim prim, const char *type_name) {
+    for (uint32_t i = 0; i < linkage->type_def_count; i++) {
+        if (linkage->type_defs[i].prim == prim) {
+            return i;
+        }
+    }
+    /* Add new type */
+    JanetSysTypeInfo td;
+    memset(&td, 0, sizeof(td));
+    td.prim = prim;
+    janet_v_push(linkage->type_defs, td);
+    janet_table_put(linkage->type_name_lookup,
+            janet_csymbolv(type_name),
+            janet_wrap_number(linkage->type_def_count));
+    janet_v_push(linkage->type_names, janet_csymbol(type_name));
+    return linkage->type_def_count++;
+}
+
+/* Get a type that is a pointer to another type */
+static uint32_t janet_sysir_findpointer(JanetSysIRLinkage *linkage, uint32_t to, const char *type_name) {
+    for (uint32_t i = 0; i < linkage->type_def_count; i++) {
+        if (linkage->type_defs[i].prim == JANET_PRIM_POINTER) {
+            if (linkage->type_defs[i].pointer.type == to) {
+                return i;
+            }
+        }
+    }
+    /* Add new type */
+    JanetSysTypeInfo td;
+    memset(&td, 0, sizeof(td));
+    td.prim = JANET_PRIM_POINTER;
+    td.pointer.type = to;
+    janet_v_push(linkage->type_defs, td);
+    janet_table_put(linkage->type_name_lookup,
+            janet_csymbolv(type_name),
+            janet_wrap_number(linkage->type_def_count));
+    janet_v_push(linkage->type_names, janet_csymbol(type_name));
+    return linkage->type_def_count++;
+}
+
+/* Unwrap vectorized binops to scalars in one pass to make certain lowering easier. */
+static void janet_sysir_scalarize(JanetSysIRLinkage *linkage) {
+    uint32_t index_type = janet_sysir_findprim(linkage, JANET_PRIM_U32, "U32Index");
+    uint32_t boolean_type = janet_sysir_findprim(linkage, JANET_PRIM_BOOLEAN, "Boolean");
+    for (int32_t j = 0; j < linkage->ir_ordered->count; j++) {
+        JanetSysIR *sysir = janet_unwrap_abstract(linkage->ir_ordered->data[j]);
+        for (uint32_t i = 0; i < sysir->instruction_count; i++) {
+            JanetSysInstruction instruction = sysir->instructions[i];
+            sysir->error_ctx = janet_cstringv(janet_sysop_names[instruction.opcode]);
+            switch (instruction.opcode) {
+                default:
+                    break;
+                case JANET_SYSOP_ADD:
+                case JANET_SYSOP_SUBTRACT:
+                case JANET_SYSOP_MULTIPLY:
+                case JANET_SYSOP_DIVIDE:
+                case JANET_SYSOP_BAND:
+                case JANET_SYSOP_BOR:
+                case JANET_SYSOP_BXOR:
+                case JANET_SYSOP_GT:
+                case JANET_SYSOP_LT:
+                case JANET_SYSOP_EQ:
+                case JANET_SYSOP_NEQ:
+                case JANET_SYSOP_GTE:
+                case JANET_SYSOP_LTE:
+                case JANET_SYSOP_SHL:
+                case JANET_SYSOP_SHR:
+                    ;
+                    {
+                        uint32_t dest_type = janet_sys_optype(sysir, instruction.three.dest);
+                        uint32_t test_type = dest_type;
+                        if (linkage->type_defs[dest_type].prim == JANET_PRIM_POINTER) {
+                            test_type = linkage->type_defs[dest_type].pointer.type;
+                        }
+                        if (linkage->type_defs[test_type].prim != JANET_PRIM_ARRAY) {
+                            break;
+                        }
+                        uint32_t pel_type = janet_sysir_findpointer(linkage, linkage->type_defs[test_type].array.type, "PointerTo"); // fixme - type name would need to be unique
+                        uint32_t lhs_type = janet_sys_optype(sysir, instruction.three.lhs);
+                        uint32_t rhs_type = janet_sys_optype(sysir, instruction.three.rhs);
+                        uint32_t array_size = linkage->type_defs[dest_type].array.fixed_count;
+                        uint32_t index_reg = janet_sysir_getreg(sysir, index_type);
+                        uint32_t compare_reg = janet_sysir_getreg(sysir, boolean_type);
+                        uint32_t temp_lhs = janet_sysir_getreg(sysir, pel_type);
+                        uint32_t temp_rhs = janet_sysir_getreg(sysir, pel_type);
+                        uint32_t temp_dest = janet_sysir_getreg(sysir, pel_type);
+                        uint32_t loopstart_label = sysir->label_count++;
+                        uint32_t loopend_label = sysir->label_count++;
+                        Janet labelkw_loopstart = janet_wrap_keyword(janet_symbol_gen());
+                        Janet labelkw_loopend = janet_wrap_keyword(janet_symbol_gen());
+                        JanetSysOp lhs_getp = (linkage->type_defs[lhs_type].prim == JANET_PRIM_POINTER) ? JANET_SYSOP_ARRAY_PGETP : JANET_SYSOP_ARRAY_GETP;
+                        JanetSysOp rhs_getp = (linkage->type_defs[rhs_type].prim == JANET_PRIM_POINTER) ? JANET_SYSOP_ARRAY_PGETP : JANET_SYSOP_ARRAY_GETP;
+                        JanetSysOp dest_getp = (linkage->type_defs[dest_type].prim == JANET_PRIM_POINTER) ? JANET_SYSOP_ARRAY_PGETP : JANET_SYSOP_ARRAY_GETP;
+                        JanetSysInstruction patch[] = {
+                            makebind(instruction, JANET_SYSOP_TYPE_BIND, index_reg, index_type),
+                            makebind(instruction, JANET_SYSOP_TYPE_BIND, temp_lhs, pel_type),
+                            makebind(instruction, JANET_SYSOP_TYPE_BIND, temp_rhs, pel_type),
+                            makebind(instruction, JANET_SYSOP_TYPE_BIND, temp_dest, pel_type),
+                            makebind(instruction, JANET_SYSOP_TYPE_BIND, compare_reg, boolean_type),
+                            maketwo(instruction, JANET_SYSOP_LOAD, index_reg, janet_sys_makeconst(sysir, index_type, janet_wrap_number(0))),
+                            makelabel(instruction, JANET_SYSOP_LABEL, loopstart_label),
+                            makethree(instruction, JANET_SYSOP_GTE, compare_reg, index_reg, janet_sys_makeconst(sysir, index_type, janet_wrap_number(array_size))),
+                            makebranch(instruction, JANET_SYSOP_BRANCH, compare_reg, loopend_label),
+                            makethree(instruction, lhs_getp, temp_lhs, instruction.three.lhs, index_reg),
+                            makethree(instruction, rhs_getp, temp_rhs, instruction.three.rhs, index_reg),
+                            makethree(instruction, dest_getp, temp_dest, instruction.three.dest, index_reg),
+                            makethree(instruction, instruction.opcode, temp_dest, temp_lhs, temp_rhs),
+                            makethree(instruction, JANET_SYSOP_ADD, index_reg, index_reg, janet_sys_makeconst(sysir, index_type, janet_wrap_number(1))),
+                            makejmp(instruction, JANET_SYSOP_JUMP, loopstart_label),
+                            makelabel(instruction, JANET_SYSOP_LABEL, loopend_label)
+                        };
+                        size_t patchcount = sizeof(patch) / sizeof(patch[0]);
+                        janet_table_put(sysir->labels, labelkw_loopstart, janet_wrap_number(loopstart_label));
+                        janet_table_put(sysir->labels, labelkw_loopend, janet_wrap_number(loopend_label));
+                        janet_table_put(sysir->labels, janet_wrap_number(loopstart_label), janet_wrap_number(i + 1));
+                        janet_table_put(sysir->labels, janet_wrap_number(loopend_label), janet_wrap_number(i + patchcount - 1));
+                        size_t remaining = (sysir->instruction_count - i - 1) * sizeof(JanetSysInstruction);
+                        sysir->instructions = janet_realloc(sysir->instructions, (sysir->instruction_count + patchcount - 1) * sizeof(JanetSysInstruction));
+                        if (remaining) memmove(sysir->instructions + i + patchcount, sysir->instructions + i + 1, remaining);
+                        safe_memcpy(sysir->instructions + i, patch, sizeof(patch));
+                        i += patchcount - 2;
+                        sysir->instruction_count += patchcount - 1;
+                        break;
+                    }
+            }
+        }
+    }
+}
+
 /* Lowering to C */
 
 static const char *c_prim_names[] = {
@@ -1917,10 +2109,10 @@ void janet_sys_ir_lower_to_ir(JanetSysIRLinkage *linkage, JanetArray *into) {
 static int sysir_gc(void *p, size_t s) {
     JanetSysIR *ir = (JanetSysIR *)p;
     (void) s;
-    janet_free(ir->constants);
-    janet_free(ir->types);
+    janet_v_free(ir->constants);
+    janet_v_free(ir->types);
+    janet_v_free(ir->register_names);
     janet_free(ir->instructions);
-    janet_free((void *) ir->register_names);
     return 0;
 }
 
@@ -1949,8 +2141,8 @@ static int sysir_context_gc(void *p, size_t s) {
     JanetSysIRLinkage *linkage = (JanetSysIRLinkage *)p;
     (void) s;
     janet_free(linkage->field_defs);
-    janet_free(linkage->type_defs);
-    janet_free((void *) linkage->type_names);
+    janet_v_free(linkage->type_defs);
+    janet_v_free((void *) linkage->type_names);
     return 0;
 }
 
@@ -2024,6 +2216,15 @@ JANET_CORE_FN(cfun_sysir_toir,
     return janet_wrap_array(array);
 }
 
+JANET_CORE_FN(cfun_sysir_scalarize,
+              "(sysir/scalarize context)",
+              "Lower all vectorized instrinsics to loops of scalar operations.") {
+    janet_fixarity(argc, 1);
+    JanetSysIRLinkage *ir = janet_getabstract(argv, 0, &janet_sysir_context_type);
+    janet_sysir_scalarize(ir);
+    return argv[0];
+}
+
 JANET_CORE_FN(cfun_sysir_tox64,
               "(sysir/to-x64 context &opt buffer target)",
               "Lower IR to x64 machine code.") {
@@ -2052,6 +2253,7 @@ void janet_lib_sysir(JanetTable *env) {
     JanetRegExt cfuns[] = {
         JANET_CORE_REG("sysir/context", cfun_sysir_context),
         JANET_CORE_REG("sysir/asm", cfun_sysir_asm),
+        JANET_CORE_REG("sysir/scalarize", cfun_sysir_scalarize),
         JANET_CORE_REG("sysir/to-c", cfun_sysir_toc),
         JANET_CORE_REG("sysir/to-ir", cfun_sysir_toir),
         JANET_CORE_REG("sysir/to-x64", cfun_sysir_tox64),