Basic native ARM emitter

py/asmarm.c

@@ -0,0 +1,326 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Fabian Vogt
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+
+#include "mpconfig.h"
+#include "misc.h"
+#include "asmarm.h"
+
+// wrapper around everything in this file
+#if MICROPY_EMIT_ARM
+
+#define SIGNED_FIT24(x) (((x) & 0xff800000) == 0) || (((x) & 0xff000000) == 0xff000000)
+
+struct _asm_arm_t {
+    uint pass;
+    uint code_offset;
+    uint code_size;
+    byte *code_base;
+    byte dummy_data[4];
+
+    uint max_num_labels;
+    int *label_offsets;
+    int num_locals;
+    uint push_reglist;
+    uint stack_adjust;
+};
+
+asm_arm_t *asm_arm_new(uint max_num_labels) {
+    asm_arm_t *as;
+
+    as = m_new0(asm_arm_t, 1);
+    as->max_num_labels = max_num_labels;
+    as->label_offsets = m_new(int, max_num_labels);
+
+    return as;
+}
+
+void asm_arm_free(asm_arm_t *as, bool free_code) {
+    if (free_code) {
+        m_del(byte, as->code_base, as->code_size);
+    }
+
+    m_del_obj(asm_arm_t, as);
+}
+
+void asm_arm_start_pass(asm_arm_t *as, uint pass) {
+    as->pass = pass;
+    as->code_offset = 0;
+    if (pass == ASM_ARM_PASS_COMPUTE) {
+        memset(as->label_offsets, -1, as->max_num_labels * sizeof(int));
+    }
+}
+
+void asm_arm_end_pass(asm_arm_t *as) {
+    if (as->pass == ASM_ARM_PASS_COMPUTE) {
+        // calculate size of code in bytes
+        as->code_size = as->code_offset;
+        as->code_base = m_new(byte, as->code_size);
+    }
+}
+
+// all functions must go through this one to emit bytes
+// if as->pass < ASM_ARM_PASS_EMIT, then this function only returns a buffer of 4 bytes length
+STATIC byte *asm_arm_get_cur_to_write_bytes(asm_arm_t *as, int num_bytes_to_write) {
+    if (as->pass < ASM_ARM_PASS_EMIT) {
+        as->code_offset += num_bytes_to_write;
+        return as->dummy_data;
+    } else {
+        assert(as->code_offset + num_bytes_to_write <= as->code_size);
+        byte *c = as->code_base + as->code_offset;
+        as->code_offset += num_bytes_to_write;
+        return c;
+    }
+}
+
+uint asm_arm_get_code_size(asm_arm_t *as) {
+    return as->code_size;
+}
+
+void *asm_arm_get_code(asm_arm_t *as) {
+    return as->code_base;
+}
+
+// Insert word into instruction flow
+STATIC void emit(asm_arm_t *as, uint op) {
+    *(uint*)asm_arm_get_cur_to_write_bytes(as, 4) = op;
+}
+
+// Insert word into instruction flow, add "ALWAYS" condition code
+STATIC void emit_al(asm_arm_t *as, uint op) {
+    emit(as, op | ARM_CC_AL);
+}
+
+// Basic instructions without condition code
+STATIC uint asm_arm_op_push(uint reglist) {
+    // stmfd sp!, {reglist}
+    return 0x92d0000 | (reglist & 0xFFFF);
+}
+
+STATIC uint asm_arm_op_pop(uint reglist) {
+    // ldmfd sp!, {reglist}
+    return 0x8bd0000 | (reglist & 0xFFFF);
+}
+
+STATIC uint asm_arm_op_mov_reg(uint rd, uint rn) {
+    // mov rd, rn
+    return 0x1a00000 | (rd << 12) | rn;
+}
+
+STATIC uint asm_arm_op_mov_imm(uint rd, uint imm) {
+    // mov rd, #imm
+    return 0x3a00000 | (rd << 12) | imm;
+}
+
+STATIC uint asm_arm_op_mvn_imm(uint rd, uint imm) {
+    // mvn rd, #imm
+    return 0x3e00000 | (rd << 12) | imm;
+}
+
+STATIC uint asm_arm_op_add_imm(uint rd, uint rn, uint imm) {
+    // add rd, rn, #imm
+    return 0x2800000 | (rn << 16) | (rd << 12) | (imm & 0xFF);
+}
+
+STATIC uint asm_arm_op_add_reg(uint rd, uint rn, uint rm) {
+    // add rd, rn, rm
+    return 0x0800000 | (rn << 16) | (rd << 12) | rm;
+}
+
+STATIC uint asm_arm_op_sub_imm(uint rd, uint rn, uint imm) {
+    // sub rd, rn, #imm
+    return 0x2400000 | (rn << 16) | (rd << 12) | (imm & 0xFF);
+}
+
+void asm_arm_bkpt(asm_arm_t *as) {
+    // bkpt #0
+    emit_al(as, 0x1200070); 
+}
+
+// locals:
+//  - stored on the stack in ascending order
+//  - numbered 0 through as->num_locals-1
+//  - SP points to first local
+//
+//  | SP
+//  v
+//  l0  l1  l2  ...  l(n-1)
+//  ^                ^
+//  | low address    | high address in RAM
+
+void asm_arm_entry(asm_arm_t *as, int num_locals) {
+
+    if (num_locals < 0) {
+        num_locals = 0;
+    }
+
+    as->stack_adjust = 0;
+    as->num_locals = num_locals;
+    as->push_reglist = 1 << REG_R1 | 1 << REG_R2 | 1 << REG_R3 | 1 << REG_R4
+            | 1 << REG_R5 | 1 << REG_R6 | 1 << REG_R7 | 1 << REG_R8;
+
+    // Only adjust the stack if there are more locals than usable registers
+    if(num_locals > 3) {
+        as->stack_adjust = num_locals * 4;
+        // Align stack to 8 bytes
+        if(as->num_locals & 1)
+            as->stack_adjust += 4;
+    }
+
+    emit_al(as, asm_arm_op_push(as->push_reglist | 1 << REG_LR));
+    if (as->stack_adjust > 0) {
+        emit_al(as, asm_arm_op_sub_imm(REG_SP, REG_SP, as->stack_adjust));
+    }
+}
+
+void asm_arm_exit(asm_arm_t *as) {
+    if (as->stack_adjust > 0) {
+        emit_al(as, asm_arm_op_add_imm(REG_SP, REG_SP, as->stack_adjust));
+    }
+
+    emit_al(as, asm_arm_op_pop(as->push_reglist | (1 << REG_PC)));
+}
+
+void asm_arm_label_assign(asm_arm_t *as, uint label) {
+    assert(label < as->max_num_labels);
+    if (as->pass < ASM_ARM_PASS_EMIT) {
+        // assign label offset
+        assert(as->label_offsets[label] == -1);
+        as->label_offsets[label] = as->code_offset;
+    } else {
+        // ensure label offset has not changed from PASS_COMPUTE to PASS_EMIT
+        assert(as->label_offsets[label] == as->code_offset);
+    }
+}
+
+void asm_arm_align(asm_arm_t* as, uint align) {
+    // TODO fill unused data with NOPs?
+    as->code_offset = (as->code_offset + align - 1) & (~(align - 1));
+}
+
+void asm_arm_data(asm_arm_t* as, uint bytesize, uint val) {
+    byte *c = asm_arm_get_cur_to_write_bytes(as, bytesize);
+    // only write to the buffer in the emit pass (otherwise we overflow dummy_data)
+    if (as->pass == ASM_ARM_PASS_EMIT) {
+        // little endian
+        for (uint i = 0; i < bytesize; i++) {
+            *c++ = val;
+            val >>= 8;
+        }
+    }
+}
+
+void asm_arm_mov_reg_reg(asm_arm_t *as, uint reg_dest, uint reg_src) {
+    emit_al(as, asm_arm_op_mov_reg(reg_dest, reg_src));
+}
+
+void asm_arm_mov_reg_i32(asm_arm_t *as, uint rd, int imm) {
+    // TODO: There are more variants of immediate values
+    if ((imm & 0xFF) == imm) {
+        emit_al(as, asm_arm_op_mov_imm(rd, imm));
+    } else if (imm < 0 && ((-imm) & 0xFF) == -imm) {
+        emit_al(as, asm_arm_op_mvn_imm(rd, -imm));
+    } else {
+        //Insert immediate into code and jump over it
+        emit_al(as, 0x59f0000 | (rd << 12)); // ldr rd, [pc]
+        emit_al(as, 0xa000000); // b pc
+        emit(as, imm);
+    }
+}
+
+void asm_arm_mov_local_reg(asm_arm_t *as, int local_num, uint rd) {
+    // str rd, [sp, #local_num*4]
+    emit_al(as, 0x58d0000 | (rd << 12) | (local_num << 2));
+}
+
+void asm_arm_mov_reg_local(asm_arm_t *as, uint rd, int local_num) {
+    // ldr rd, [sp, #local_num*4]
+    emit_al(as, 0x59d0000 | (rd << 12) | (local_num << 2));
+}
+
+void asm_arm_cmp_reg_i8(asm_arm_t *as, uint rd, int imm) {
+    // cmp rd, #imm
+    emit_al(as, 0x3500000 | (rd << 16) | (imm & 0xFF));
+}
+
+void asm_arm_cmp_reg_reg(asm_arm_t *as, uint rd, uint rn) {
+    // cmp rd, rn
+    emit_al(as, 0x1500000 | (rd << 16) | rn);
+}
+
+void asm_arm_less_op(asm_arm_t *as, uint rd, uint rn) {
+    asm_arm_cmp_reg_reg(as, rd, rn); // cmp rd, rn
+    emit(as, asm_arm_op_mov_imm(REG_RET, 1) | ARM_CC_LT); // movlt REG_RET, #1
+    emit(as, asm_arm_op_mov_imm(REG_RET, 0) | ARM_CC_GE); // movge REG_RET, #0
+}
+
+void asm_arm_add_reg(asm_arm_t *as, uint rd, uint rn, uint rm) {
+    // add rd, rn, rm
+    emit_al(as, asm_arm_op_add_reg(rd, rn, rm));
+}
+
+void asm_arm_mov_reg_local_addr(asm_arm_t *as, uint rd, int local_num) {
+    // add rd, sp, #local_num*4
+    emit_al(as, asm_arm_op_add_imm(rd, REG_SP, local_num << 2));
+}
+
+void asm_arm_bcc_label(asm_arm_t *as, int cond, uint label) {
+    assert(label < as->max_num_labels);
+    int dest = as->label_offsets[label];
+    int rel = dest - as->code_offset;
+    rel -= 8; // account for instruction prefetch, PC is 8 bytes ahead of this instruction
+    rel >>= 2; // in ARM mode the branch target is 32-bit aligned, so the 2 LSB are omitted
+
+    if (SIGNED_FIT24(rel)) {
+        emit(as, cond | 0xa000000 | (rel & 0xffffff));
+    } else {
+        printf("asm_arm_bcc: branch does not fit in 24 bits\n");
+    }
+}
+
+void asm_arm_b_label(asm_arm_t *as, uint label) {
+    asm_arm_bcc_label(as, ARM_CC_AL, label);
+}
+
+void asm_arm_bl_ind(asm_arm_t *as, void *fun_ptr, uint fun_id, uint reg_temp) {
+    // If the table offset fits into the ldr instruction
+    if(fun_id < (0x1000 / 4)) {
+        emit_al(as, asm_arm_op_mov_reg(REG_LR, REG_PC)); // mov lr, pc
+        emit_al(as, 0x597f000 | (fun_id << 2)); // ldr pc, [r7, #fun_id*4]
+        return;
+    }
+    
+    emit_al(as, 0x59f0004 | (reg_temp << 12)); // ldr rd, [pc, #4]
+    // Set lr after fun_ptr
+    emit_al(as, asm_arm_op_add_imm(REG_LR, REG_PC, 4)); // add lr, pc, #4
+    emit_al(as, asm_arm_op_mov_reg(REG_PC, reg_temp)); // mov pc, reg_temp
+    emit(as, (uint) fun_ptr);
+}
+
+#endif // MICROPY_EMIT_ARM

py/asmarm.h

@@ -0,0 +1,103 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014 Fabian Vogt
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#define ASM_ARM_PASS_COMPUTE (1)
+#define ASM_ARM_PASS_EMIT    (2)
+
+#define REG_R0  (0)
+#define REG_R1  (1)
+#define REG_R2  (2)
+#define REG_R3  (3)
+#define REG_R4  (4)
+#define REG_R5  (5)
+#define REG_R6  (6)
+#define REG_R7  (7)
+#define REG_R8  (8)
+#define REG_R9  (9)
+#define REG_R10 (10)
+#define REG_R11 (11)
+#define REG_R12 (12)
+#define REG_R13 (13)
+#define REG_R14 (14)
+#define REG_R15 (15)
+#define REG_SP  (REG_R13)
+#define REG_LR  (REG_R14)
+#define REG_PC  (REG_R15)
+
+#define REG_RET REG_R0
+#define REG_ARG_1 REG_R0
+#define REG_ARG_2 REG_R1
+#define REG_ARG_3 REG_R2
+#define REG_ARG_4 REG_R3
+
+#define ARM_CC_EQ (0x0 << 28)
+#define ARM_CC_NE (0x1 << 28)
+#define ARM_CC_CS (0x2 << 28)
+#define ARM_CC_CC (0x3 << 28)
+#define ARM_CC_MI (0x4 << 28)
+#define ARM_CC_PL (0x5 << 28)
+#define ARM_CC_VS (0x6 << 28)
+#define ARM_CC_VC (0x7 << 28)
+#define ARM_CC_HI (0x8 << 28)
+#define ARM_CC_LS (0x9 << 28)
+#define ARM_CC_GE (0xa << 28)
+#define ARM_CC_LT (0xb << 28)
+#define ARM_CC_GT (0xc << 28)
+#define ARM_CC_LE (0xd << 28)
+#define ARM_CC_AL (0xe << 28)
+
+typedef struct _asm_arm_t asm_arm_t;
+
+asm_arm_t *asm_arm_new(uint max_num_labels);
+void asm_arm_free(asm_arm_t *as, bool free_code);
+void asm_arm_start_pass(asm_arm_t *as, uint pass);
+void asm_arm_end_pass(asm_arm_t *as);
+uint asm_arm_get_code_size(asm_arm_t *as);
+void *asm_arm_get_code(asm_arm_t *as);
+
+void asm_arm_entry(asm_arm_t *as, int num_locals);
+void asm_arm_exit(asm_arm_t *as);
+void asm_arm_label_assign(asm_arm_t *as, uint label);
+
+void asm_arm_align(asm_arm_t* as, uint align);
+void asm_arm_data(asm_arm_t* as, uint bytesize, uint val);
+
+void asm_arm_bkpt(asm_arm_t *as);
+void asm_arm_mov_reg_reg(asm_arm_t *as, uint reg_dest, uint reg_src);
+void asm_arm_mov_reg_i32(asm_arm_t *as, uint rd, int imm);
+void asm_arm_mov_local_reg(asm_arm_t *as, int local_num, uint rd);
+void asm_arm_mov_reg_local(asm_arm_t *as, uint rd, int local_num);
+
+void asm_arm_cmp_reg_i8(asm_arm_t *as, uint rd, int imm);
+void asm_arm_cmp_reg_reg(asm_arm_t *as, uint rd, uint rn);
+void asm_arm_less_op(asm_arm_t *as, uint rd, uint rn);
+void asm_arm_add_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
+void asm_arm_mov_reg_local_addr(asm_arm_t *as, uint rd, int local_num);
+
+void asm_arm_bcc_label(asm_arm_t *as, int cond, uint label);
+void asm_arm_b_label(asm_arm_t *as, uint label);
+void asm_arm_bl_ind(asm_arm_t *as, void *fun_ptr, uint fun_id, uint reg_temp);
+

py/compile.c

@@ -3626,6 +3626,11 @@ mp_obj_t mp_compile(mp_parse_node_t pn, qstr source_file, uint emit_opt, bool is
                         emit_native = emit_native_thumb_new(max_num_labels);
                     }
                     comp->emit_method_table = &emit_native_thumb_method_table;
+#elif MICROPY_EMIT_ARM
+                    if (emit_native == NULL) {
+                        emit_native = emit_native_arm_new(max_num_labels);
+                    }
+                    comp->emit_method_table = &emit_native_arm_method_table;
 #endif
                     comp->emit = emit_native;
                     EMIT_ARG(set_native_type, MP_EMIT_NATIVE_TYPE_ENABLE, s->emit_options == MP_EMIT_OPT_VIPER, 0);
@@ -3669,6 +3674,8 @@ mp_obj_t mp_compile(mp_parse_node_t pn, qstr source_file, uint emit_opt, bool is
         emit_native_x64_free(emit_native);
 #elif MICROPY_EMIT_THUMB
         emit_native_thumb_free(emit_native);
+#elif MICROPY_EMIT_ARM
+	emit_native_arm_free(emit_native);
 #endif
     }
 #endif

py/emit.h

@@ -161,17 +161,20 @@ extern const emit_method_table_t emit_cpython_method_table;
 extern const emit_method_table_t emit_bc_method_table;
 extern const emit_method_table_t emit_native_x64_method_table;
 extern const emit_method_table_t emit_native_thumb_method_table;
+extern const emit_method_table_t emit_native_arm_method_table;
 
 emit_t *emit_pass1_new(void);
 emit_t *emit_cpython_new(uint max_num_labels);
 emit_t *emit_bc_new(uint max_num_labels);
 emit_t *emit_native_x64_new(uint max_num_labels);
 emit_t *emit_native_thumb_new(uint max_num_labels);
+emit_t *emit_native_arm_new(uint max_num_labels);
 
 void emit_pass1_free(emit_t *emit);
 void emit_bc_free(emit_t *emit);
 void emit_native_x64_free(emit_t *emit);
 void emit_native_thumb_free(emit_t *emit);
+void emit_native_arm_free(emit_t *emit);
 
 typedef struct _emit_inline_asm_t emit_inline_asm_t;
 

py/emitnative.c

@@ -69,7 +69,7 @@
 #endif
 
 // wrapper around everything in this file
-#if (MICROPY_EMIT_X64 && N_X64) || (MICROPY_EMIT_THUMB && N_THUMB)
+#if (MICROPY_EMIT_X64 && N_X64) || (MICROPY_EMIT_THUMB && N_THUMB) || (MICROPY_EMIT_ARM && N_ARM)
 
 #if N_X64
 
@@ -117,6 +117,30 @@
 #define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_thumb_mov_reg_reg(emit->as, (reg_dest), (reg_src))
 #define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_thumb_mov_reg_local_addr(emit->as, (reg), (local_num))
 
+#elif N_ARM
+
+// ARM specific stuff
+
+#include "asmarm.h"
+
+#define REG_LOCAL_1 (REG_R4)
+#define REG_LOCAL_2 (REG_R5)
+#define REG_LOCAL_3 (REG_R6)
+#define REG_LOCAL_NUM (3)
+
+#define EXPORT_FUN(name) emit_native_arm_##name
+
+#define REG_TEMP0 (REG_R0)
+#define REG_TEMP1 (REG_R1)
+#define REG_TEMP2 (REG_R2)
+#define ASM_MOV_REG_TO_LOCAL(reg, local_num) asm_arm_mov_local_reg(emit->as, (local_num), (reg))
+#define ASM_MOV_IMM_TO_REG(imm, reg) asm_arm_mov_reg_i32(emit->as, (reg), (imm))
+#define ASM_MOV_ALIGNED_IMM_TO_REG(imm, reg) asm_arm_mov_reg_i32(emit->as, (reg), (imm))
+#define ASM_MOV_IMM_TO_LOCAL_USING(imm, local_num, reg_temp) do { asm_arm_mov_reg_i32(emit->as, (reg_temp), (imm)); asm_arm_mov_local_reg(emit->as, (local_num), (reg_temp)); } while (false)
+#define ASM_MOV_LOCAL_TO_REG(local_num, reg) asm_arm_mov_reg_local(emit->as, (reg), (local_num))
+#define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_arm_mov_reg_reg(emit->as, (reg_dest), (reg_src))
+#define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_arm_mov_reg_local_addr(emit->as, (reg), (local_num))
+
 #endif
 
 typedef enum {
@@ -169,6 +193,8 @@ struct _emit_t {
     asm_x64_t *as;
 #elif N_THUMB
     asm_thumb_t *as;
+#elif N_ARM
+    asm_arm_t *as;
 #endif
 };
 
@@ -178,6 +204,8 @@ emit_t *EXPORT_FUN(new)(uint max_num_labels) {
     emit->as = asm_x64_new(max_num_labels);
 #elif N_THUMB
     emit->as = asm_thumb_new(max_num_labels);
+#elif N_ARM
+    emit->as = asm_arm_new(max_num_labels);
 #endif
     return emit;
 }
@@ -187,6 +215,8 @@ void EXPORT_FUN(free)(emit_t *emit) {
     asm_x64_free(emit->as, false);
 #elif N_THUMB
     asm_thumb_free(emit->as, false);
+#elif N_ARM
+    asm_arm_free(emit->as, false);
 #endif
     m_del(vtype_kind_t, emit->local_vtype, emit->local_vtype_alloc);
     m_del(stack_info_t, emit->stack_info, emit->stack_info_alloc);
@@ -260,6 +290,8 @@ STATIC void emit_native_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scop
     asm_x64_start_pass(emit->as, pass == MP_PASS_EMIT ? ASM_X64_PASS_EMIT : ASM_X64_PASS_COMPUTE);
 #elif N_THUMB
     asm_thumb_start_pass(emit->as, pass == MP_PASS_EMIT ? ASM_THUMB_PASS_EMIT : ASM_THUMB_PASS_COMPUTE);
+#elif N_ARM
+    asm_arm_start_pass(emit->as, pass == MP_PASS_EMIT ? ASM_ARM_PASS_EMIT : ASM_ARM_PASS_COMPUTE);
 #endif
 
     // entry to function
@@ -276,6 +308,8 @@ STATIC void emit_native_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scop
     asm_x64_entry(emit->as, num_locals);
 #elif N_THUMB
     asm_thumb_entry(emit->as, num_locals);
+#elif N_ARM
+    asm_arm_entry(emit->as, num_locals);
 #endif
 
     // initialise locals from parameters
@@ -309,6 +343,23 @@ STATIC void emit_native_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scop
     }
 
     asm_thumb_mov_reg_i32(emit->as, REG_R7, (mp_uint_t)mp_fun_table);
+#elif N_ARM
+    for (int i = 0; i < scope->num_pos_args; i++) {
+        if (i == 0) {
+            asm_arm_mov_reg_reg(emit->as, REG_LOCAL_1, REG_ARG_1);
+        } else if (i == 1) {
+            asm_arm_mov_reg_reg(emit->as, REG_LOCAL_2, REG_ARG_2);
+        } else if (i == 2) {
+            asm_arm_mov_reg_reg(emit->as, REG_LOCAL_3, REG_ARG_3);
+        } else if (i == 3) {
+            asm_arm_mov_local_reg(emit->as, i - REG_LOCAL_NUM, REG_ARG_4);
+        } else {
+            // TODO not implemented
+            assert(0);
+        }
+    }
+
+    asm_arm_mov_reg_i32(emit->as, REG_R7, (mp_uint_t)mp_fun_table);
 #endif
 }
 
@@ -323,6 +374,11 @@ STATIC void emit_native_end_pass(emit_t *emit) {
         asm_thumb_exit(emit->as);
     }
     asm_thumb_end_pass(emit->as);
+#elif N_ARM
+    if (!emit->last_emit_was_return_value) {
+        asm_arm_exit(emit->as);
+    }
+    asm_arm_end_pass(emit->as);    
 #endif
 
     // check stack is back to zero size
@@ -337,6 +393,9 @@ STATIC void emit_native_end_pass(emit_t *emit) {
 #elif N_THUMB
         void *f = asm_thumb_get_code(emit->as);
         mp_uint_t f_len = asm_thumb_get_code_size(emit->as);
+#elif N_ARM
+	void *f = asm_arm_get_code(emit->as);
+        mp_uint_t f_len = asm_arm_get_code_size(emit->as);
 #endif
 
         // compute type signature
@@ -536,6 +595,8 @@ STATIC void emit_call(emit_t *emit, mp_fun_kind_t fun_kind) {
     asm_x64_call_ind(emit->as, mp_fun_table[fun_kind], REG_RAX);
 #elif N_THUMB
     asm_thumb_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
+#elif N_ARM
+    asm_arm_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
 #endif
 }
 
@@ -546,6 +607,8 @@ STATIC void emit_call_with_imm_arg(emit_t *emit, mp_fun_kind_t fun_kind, mp_int_
     asm_x64_call_ind(emit->as, mp_fun_table[fun_kind], REG_RAX);
 #elif N_THUMB
     asm_thumb_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
+#elif N_ARM
+    asm_arm_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
 #endif
 }
 
@@ -557,6 +620,8 @@ STATIC void emit_call_with_imm_arg_aligned(emit_t *emit, mp_fun_kind_t fun_kind,
     asm_x64_call_ind(emit->as, mp_fun_table[fun_kind], REG_RAX);
 #elif N_THUMB
     asm_thumb_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
+#elif N_ARM
+    asm_arm_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
 #endif
 }
 
@@ -568,6 +633,8 @@ STATIC void emit_call_with_2_imm_args(emit_t *emit, mp_fun_kind_t fun_kind, mp_i
     asm_x64_call_ind(emit->as, mp_fun_table[fun_kind], REG_RAX);
 #elif N_THUMB
     asm_thumb_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
+#elif N_ARM
+    asm_arm_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
 #endif
 }
 
@@ -581,6 +648,8 @@ STATIC void emit_call_with_3_imm_args_and_first_aligned(emit_t *emit, mp_fun_kin
     asm_x64_call_ind(emit->as, mp_fun_table[fun_kind], REG_RAX);
 #elif N_THUMB
     asm_thumb_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
+#elif N_ARM
+    asm_arm_bl_ind(emit->as, mp_fun_table[fun_kind], fun_kind, REG_R3);
 #endif
 }
 
@@ -673,6 +742,8 @@ STATIC void emit_native_label_assign(emit_t *emit, uint l) {
     asm_x64_label_assign(emit->as, l);
 #elif N_THUMB
     asm_thumb_label_assign(emit->as, l);
+#elif N_ARM
+    asm_arm_label_assign(emit->as, l);
 #endif
     emit_post(emit);
 }
@@ -804,6 +875,18 @@ STATIC void emit_native_load_fast(emit_t *emit, qstr qstr, uint id_flags, int lo
         asm_thumb_mov_reg_local(emit->as, REG_R0, local_num - REG_LOCAL_NUM);
         emit_post_push_reg(emit, vtype, REG_R0);
     }
+#elif N_ARM
+    if (local_num == 0) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_1);
+    } else if (local_num == 1) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_2);
+    } else if (local_num == 2) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_3);
+    } else {
+        need_reg_single(emit, REG_R0, 0);
+        asm_arm_mov_reg_local(emit->as, REG_R0, local_num - REG_LOCAL_NUM);
+        emit_post_push_reg(emit, vtype, REG_R0);
+    }
 #endif
 }
 
@@ -882,6 +965,17 @@ STATIC void emit_native_store_fast(emit_t *emit, qstr qstr, int local_num) {
         emit_pre_pop_reg(emit, &vtype, REG_R0);
         asm_thumb_mov_local_reg(emit->as, local_num - REG_LOCAL_NUM, REG_R0);
     }
+#elif N_ARM
+    if (local_num == 0) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_1);
+    } else if (local_num == 1) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_2);
+    } else if (local_num == 2) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_3);
+    } else {
+        emit_pre_pop_reg(emit, &vtype, REG_R0);
+        asm_arm_mov_local_reg(emit->as, local_num - REG_LOCAL_NUM, REG_R0);
+    }
 #endif
 
     emit_post(emit);
@@ -1022,6 +1116,8 @@ STATIC void emit_native_jump(emit_t *emit, uint label) {
     asm_x64_jmp_label(emit->as, label);
 #elif N_THUMB
     asm_thumb_b_label(emit->as, label);
+#elif N_ARM
+    asm_arm_b_label(emit->as, label);
 #endif
     emit_post(emit);
 }
@@ -1055,6 +1151,9 @@ STATIC void emit_native_pop_jump_if_true(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_i8(emit->as, REG_RET, 0);
     asm_thumb_bcc_label(emit->as, THUMB_CC_NE, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_NE, label);
 #endif
     emit_post(emit);
 }
@@ -1067,6 +1166,9 @@ STATIC void emit_native_pop_jump_if_false(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_i8(emit->as, REG_RET, 0);
     asm_thumb_bcc_label(emit->as, THUMB_CC_EQ, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_EQ, label);
 #endif
     emit_post(emit);
 }
@@ -1079,6 +1181,9 @@ STATIC void emit_native_jump_if_true_or_pop(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_i8(emit->as, REG_RET, 0);
     asm_thumb_bcc_label(emit->as, THUMB_CC_NE, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_NE, label);
 #endif
     adjust_stack(emit, -1);
     emit_post(emit);
@@ -1092,6 +1197,9 @@ STATIC void emit_native_jump_if_false_or_pop(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_i8(emit->as, REG_RET, 0);
     asm_thumb_bcc_label(emit->as, THUMB_CC_EQ, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_EQ, label);
 #endif
     adjust_stack(emit, -1);
     emit_post(emit);
@@ -1126,6 +1234,9 @@ STATIC void emit_native_setup_except(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_i8(emit->as, REG_RET, 0);
     asm_thumb_bcc_label(emit->as, THUMB_CC_NE, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_NE, label);
 #endif
     emit_post(emit);
 }
@@ -1162,6 +1273,9 @@ STATIC void emit_native_for_iter(emit_t *emit, uint label) {
 #elif N_THUMB
     asm_thumb_cmp_rlo_rlo(emit->as, REG_RET, REG_TEMP1);
     asm_thumb_bcc_label(emit->as, THUMB_CC_EQ, label);
+#elif N_ARM
+    asm_arm_cmp_reg_i8(emit->as, REG_RET, 0);
+    asm_arm_bcc_label(emit->as, ARM_CC_EQ, label);
 #endif
     emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
 }
@@ -1211,6 +1325,8 @@ STATIC void emit_native_binary_op(emit_t *emit, mp_binary_op_t op) {
             asm_x64_add_r64_to_r64(emit->as, REG_ARG_3, REG_ARG_2);
 #elif N_THUMB
             asm_thumb_add_rlo_rlo_rlo(emit->as, REG_ARG_2, REG_ARG_2, REG_ARG_3);
+#elif N_ARM
+            asm_arm_add_reg(emit->as, REG_ARG_2, REG_ARG_2, REG_ARG_3);
 #endif
             emit_post_push_reg(emit, VTYPE_INT, REG_ARG_2);
         } else if (op == MP_BINARY_OP_LESS) {
@@ -1223,6 +1339,8 @@ STATIC void emit_native_binary_op(emit_t *emit, mp_binary_op_t op) {
             asm_thumb_ite_ge(emit->as);
             asm_thumb_mov_rlo_i8(emit->as, REG_RET, 0); // if r0 >= r1
             asm_thumb_mov_rlo_i8(emit->as, REG_RET, 1); // if r0 < r1
+#elif N_ARM
+            asm_arm_less_op(emit->as, REG_ARG_2, REG_ARG_3);
 #endif
             emit_post_push_reg(emit, VTYPE_BOOL, REG_RET);
         } else {
@@ -1456,6 +1574,9 @@ STATIC void emit_native_return_value(emit_t *emit) {
 #elif N_THUMB
     //asm_thumb_call_ind(emit->as, 0, REG_R0); to seg fault for debugging with gdb
     asm_thumb_exit(emit->as);
+#elif N_ARM
+    //asm_arm_bkpt(emit->as); to insert a bkpt and not segfault for debugging
+    asm_arm_exit(emit->as);
 #endif
 }
 
@@ -1584,4 +1705,4 @@ const emit_method_table_t EXPORT_FUN(method_table) = {
     emit_native_end_except_handler,
 };
 
-#endif // (MICROPY_EMIT_X64 && N_X64) || (MICROPY_EMIT_THUMB && N_THUMB)
+#endif // (MICROPY_EMIT_X64 && N_X64) || (MICROPY_EMIT_THUMB && N_THUMB) || (MICROPY_EMIT_ARM && N_ARM)

py/mpconfig.h

@@ -111,8 +111,13 @@
 #define MICROPY_EMIT_INLINE_THUMB (0)
 #endif
 
+// Whether to emit ARM native code
+#ifndef MICROPY_EMIT_ARM
+#define MICROPY_EMIT_ARM (0)
+#endif
+
 // Convenience definition for whether any native emitter is enabled
-#define MICROPY_EMIT_NATIVE (MICROPY_EMIT_X64 || MICROPY_EMIT_THUMB)
+#define MICROPY_EMIT_NATIVE (MICROPY_EMIT_X64 || MICROPY_EMIT_THUMB || MICROPY_EMIT_ARM)
 
 /*****************************************************************************/
 /* Compiler configuration                                                    */

py/py.mk

@@ -38,6 +38,8 @@ PY_O_BASENAME = \
 	asmthumb.o \
 	emitnthumb.o \
 	emitinlinethumb.o \
+	asmarm.o \
+	emitnarm.o \
 	formatfloat.o \
 	parsenumbase.o \
 	parsenum.o \
@@ -145,6 +147,10 @@ $(PY_BUILD)/emitnthumb.o: CFLAGS += -DN_THUMB
 $(PY_BUILD)/emitnthumb.o: py/emitnative.c
 	$(call compile_c)
 
+$(PY_BUILD)/emitnarm.o: CFLAGS += -DN_ARM
+$(PY_BUILD)/emitnarm.o: py/emitnative.c
+	$(call compile_c)
+
 # optimising gc for speed; 5ms down to 4ms on pybv2
 $(PY_BUILD)/gc.o: CFLAGS += $(CSUPEROPT)
 

py/qstrdefs.h

@@ -73,7 +73,7 @@ Q(micropython)
 Q(bytecode)
 Q(const)
 
-#if MICROPY_EMIT_X64 || MICROPY_EMIT_THUMB
+#if MICROPY_EMIT_X64 || MICROPY_EMIT_THUMB || MICROPY_EMIT_ARM
 Q(native)
 Q(viper)
 Q(uint)