arm bits

arm-asm.c: add forward branches & some ops
lib/armeabi.c: faster i/udivmod (asm)
arm-gen.c: use movw/movt to load constants for CPUVER >= 70
configure: use dwarf-4 debug sections on android, detect idiv
lib/Makefile: always add -I$(TOP) for access to config.h
tcdbg.c: add a "code mapping symbol" to help out llvm-objdump
tccelf.c: don't load SHT_ARM_EXIDX, modify ARM.attributes
tccpp.c: accept '@' for arm asm comments

Author: grischka

arm-asm.c

@@ -971,13 +971,22 @@ static void asm_multiplication_opcode(TCCState *s1, int token)
         opcode |= 1 << 20; // Status
         /* fallthrough */
     case TOK_ASM_mlaeq:
+    case_TOK_ASM_mlaeq:
         if (nb_ops != 4)
             expect("four operands");
         else {
             opcode |= 1 << 21; // Accumulate
             asm_emit_opcode(token, opcode);
         }
         break;
+    case TOK_ASM_mlseq:
+        opcode |= 0x00400000;
+        goto case_TOK_ASM_mlaeq;
+    case TOK_ASM_udiveq:
+        opcode |= 0x00200000;
+    case TOK_ASM_sdiveq:
+        asm_emit_opcode(token, (opcode & ~0x80) | 0x0710f010);
+        break;
     default:
         expect("known multiplication instruction");
     }
@@ -1084,6 +1093,7 @@ static void asm_single_data_transfer_opcode(TCCState *s1, int token)
     next(); // skip ','
 
     switch (ARM_INSTRUCTION_GROUP(token)) {
+    case TOK_ASM_strexheq:
     case TOK_ASM_strexbeq:
     case TOK_ASM_strexeq:
         parse_operand(s1, &strex_operand);
@@ -1200,6 +1210,8 @@ static void asm_single_data_transfer_opcode(TCCState *s1, int token)
             opcode |= asm_encode_shift(&shift);
         asm_emit_opcode(token, opcode);
         break;
+    case TOK_ASM_strexheq:
+        opcode |= 1 << 21;
     case TOK_ASM_strexbeq:
         opcode |= 1 << 22; // B
         /* fallthrough */
@@ -1217,6 +1229,8 @@ static void asm_single_data_transfer_opcode(TCCState *s1, int token)
         opcode |= strex_operand.reg;
         asm_emit_opcode(token, opcode);
         break;
+    case TOK_ASM_ldrexheq:
+        opcode |= 1 << 21;
     case TOK_ASM_ldrexbeq:
         opcode |= 1 << 22; // B
         /* fallthrough */
@@ -2305,11 +2319,16 @@ static void asm_branch_opcode(TCCState *s1, int token)
     case TOK_ASM_beq:
     case TOK_ASM_bleq:
         asm_expr(s1, &e);
-        esym = elfsym(e.sym);
-        if (!esym || esym->st_shndx != cur_text_section->sh_num) {
-            tcc_error("invalid branch target");
+        if (e.sym) {
+            esym = elfsym(e.sym);
+            if (esym && esym->st_shndx == cur_text_section->sh_num) {
+                jmp_disp = esym->st_value;
+            } else {
+                greloca(cur_text_section, e.sym, ind, R_ARM_PC24, 0);
+                jmp_disp = ind;
+            }
         }
-        jmp_disp = encbranchoffset(ind, e.v + esym->st_value, 1);
+        jmp_disp = encbranchoffset(ind, e.v + jmp_disp, 1);
         break;
     default:
         parse_operand(s1, &op);
@@ -2409,8 +2428,10 @@ ST_FUNC void asm_opcode(TCCState *s1, int token)
     case TOK_ASM_strbeq:
     case TOK_ASM_ldrexeq:
     case TOK_ASM_ldrexbeq:
+    case TOK_ASM_ldrexheq:
     case TOK_ASM_strexeq:
     case TOK_ASM_strexbeq:
+    case TOK_ASM_strexheq:
         asm_single_data_transfer_opcode(s1, token);
         return;
 
@@ -2473,6 +2494,9 @@ ST_FUNC void asm_opcode(TCCState *s1, int token)
     case TOK_ASM_mulseq:
     case TOK_ASM_mlaeq:
     case TOK_ASM_mlaseq:
+    case TOK_ASM_mlseq:
+    case TOK_ASM_udiveq:
+    case TOK_ASM_sdiveq:
         asm_multiplication_opcode(s1, token);
         return;
 

arm-gen.c

@@ -541,6 +541,15 @@ static int negcc(int cc)
    Use relative/got addressing to avoid setting DT_TEXTREL */
 static void load_value(SValue *sv, int r)
 {
+#if CONFIG_TCC_CPUVER >= 7
+    if (!(sv->r & VT_SYM)) {
+        unsigned x=sv->c.i;
+        o(0xE3000000|intr(r)<<12|(x&0xFFF)|(x<<4&0xF0000)); /* movw rx,#x(lo) */
+        if (x&0xFFFF0000)
+          o(0xE3400000|intr(r)<<12|(x>>16&0xFFF)|(x>>12&0xF0000)); /* movt rx,#x(hi) */
+        return;
+    }
+#endif
     o(0xE59F0000|(intr(r)<<12)); /* ldr r, [pc] */
     o(0xEA000000); /* b $+4 */
 #ifndef CONFIG_TCC_PIC

arm-tok.h

@@ -238,6 +238,9 @@
  DEF_ASM_CONDED(smlals)
  DEF_ASM_CONDED(umlal)
  DEF_ASM_CONDED(umlals)
+ DEF_ASM_CONDED(mls)
+ DEF_ASM_CONDED(udiv)
+ DEF_ASM_CONDED(sdiv)
 
  /* load/store */
 
@@ -247,8 +250,10 @@
  DEF_ASM_CONDED(strb)
  DEF_ASM_CONDED(ldrex)
  DEF_ASM_CONDED(ldrexb)
+ DEF_ASM_CONDED(ldrexh)
  DEF_ASM_CONDED(strex)
  DEF_ASM_CONDED(strexb)
+ DEF_ASM_CONDED(strexh)
  DEF_ASM_CONDED(ldrh)
  DEF_ASM_CONDED(ldrsh)
  DEF_ASM_CONDED(ldrsb)

configure

@@ -381,7 +381,7 @@ case $targetos in
       default sysroot "/usr"
     fi
     default prefix "${sysroot}"
-    confvars_set Android new_dtags rpath=no
+    confvars_set Android new_dtags rpath=no dwarf=4
     test "${cpu}" != "i386" && confvars_set pie
     default_conf "static=no"
     case "$cpu" in
@@ -510,6 +510,11 @@ if test "$cpu" = "arm"; then
       confvars_set arm_vfp
     fi
   fi
+  if test -z "$build_cross"; then
+    if grep -s -q "^Features.* \(idiv\)" /proc/cpuinfo ; then
+      confvars_set arm_idiv
+    fi
+  fi
 fi
 
 # a final configuration tuning
@@ -648,6 +653,7 @@ for v in $cpu $confvars ; do
                             print_num TCC_ARM_HARDFLOAT 1 ;;
     CONFIG_arm_eabi=yes)    print_num TCC_ARM_EABI 1 ;;
     CONFIG_arm_vfp=yes)     print_num TCC_ARM_VFP 1 ;;
+    CONFIG_arm_idiv=yes)    print_num __ARM_FEATURE_IDIV 1 ;;
     # OS
     CONFIG_WIN32=yes)       print_num TCC_TARGET_PE 1 ;;
     CONFIG_OSX=yes)         print_num TCC_TARGET_MACHO 1 ;;

lib/Makefile

@@ -33,6 +33,8 @@ ifeq "$($(T)-libtcc1-usegcc)" "yes"
  BFLAGS = $(if $(CONFIG_dwarf),-gdwarf,-gstabs)
 endif
 
+XFLAGS += -I$(TOP)
+
 I386_O = libtcc1.o alloca.o alloca-bt.o $(COMMON_O)
 X86_64_O = libtcc1.o alloca.o alloca-bt.o $(COMMON_O)
 ARM_O = libtcc1.o armeabi.o alloca.o armflush.o $(COMMON_O)
@@ -91,9 +93,7 @@ $(X)%.o : %.S $(TCC)
 $(TOP)/%.o : %.c $(TCC)
 	$S$(XCC) -c $< -o $@ $(XFLAGS)
 
-$(TOP)/bcheck.o : XFLAGS += $(BFLAGS) -I$(TOP)
-# includes tccrun.c, $(TOP) for config.h  (tccrun.c prerequisite via $(TCC))
-$(TOP)/bt-exe.o : XFLAGS += -I$(TOP)
+$(TOP)/bcheck.o : XFLAGS += $(BFLAGS)
 
 $(X)crt1w.o : crt1.c
 $(X)wincrt1w.o : wincrt1.c

lib/armeabi.c

@@ -47,7 +47,7 @@ typedef struct unsigned_int_struct {
 } unsigned_int_struct;
 
 #define REGS_RETURN(name, type) \
-    void name ## _return(type ret) {}
+    static void name ## _return(type ret) {}
 
 
 /* Float helper functions */
@@ -339,7 +339,7 @@ __AEABI_XL2D(ul2d, 0)
 /* long long to double conversion */
 __AEABI_XL2D(l2d, 1)
 
-
+#if 1
 /* Long long helper functions */
 
 /* TODO: add error in case of den == 0 (see §4.3.1 and §4.3.2) */
@@ -474,6 +474,7 @@ void __aeabi_lasr(unsigned_int_struct val, int shift)
 
 /* Integer division functions */
 
+#if 0 /* very slow */
 AEABI_UXDIVMOD(uidivmod, unsigned, uidiv_t, UINT)
 
 int __aeabi_idiv(int numerator, int denominator)
@@ -506,6 +507,9 @@ void __aeabi_uidivmod(unsigned num, unsigned den)
 {
     uidiv_t_return(aeabi_uidivmod(num, den));
 }
+#else
+# define UIDIVMOD_ASM 1
+#endif
 
 /* Some targets do not have all eabi calls (OpenBSD) */
 typedef __SIZE_TYPE__ size_t;
@@ -542,3 +546,97 @@ __aeabi_memset (void *s, size_t n, int c)
 {
     return memset (s, c, n);
 }
+
+/* ***************************************************************** */
+#if UIDIVMOD_ASM
+#include <config.h>
+__asm__(
+   "\n  .global __aeabi_idiv, __aeabi_idivmod"
+   "\n  .global __aeabi_uidiv, __aeabi_uidivmod"
+#if __ARM_FEATURE_IDIV
+   "\n__aeabi_idiv:"
+   "\n__aeabi_idivmod:"
+   "\n  mov     r2, r0"
+   "\n  sdiv    r0, r0, r1"
+   "\n  mls     r1, r1, r0, r2"
+   "\n  bx      lr"
+
+   "\n__aeabi_uidiv:"
+   "\n__aeabi_uidivmod:"
+   "\n  mov     r2, r0"
+   "\n  udiv    r0, r0, r1"
+   "\n  mls     r1, r1, r0, r2"
+   "\n  bx      lr"
+#else
+/* Runtime ABI for the ARM Cortex-M0
+ * idivmod.S: signed 32 bit division (quotient and remainder)
+ *
+ * Copyright (c) 2012 Jörg Mische <[email protected]>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+   "\n__aeabi_idiv:"
+   "\n__aeabi_idivmod:"
+   "\n  cmp     r0, #0"
+   "\n  bge     .Lnumerator_pos"
+   "\n  rsb     r0, r0, #0" // num = -num
+   "\n  cmp     r1, #0"
+   "\n  bge     .Lboth_neg"
+   "\n  rsb     r1, r1, #0" // den = -den
+   "\n  push    {lr}"
+   "\n  bl      __aeabi_uidivmod"
+   "\n  rsb     r1, r1, #0" // rem = -rem
+   "\n  pop     {pc}"
+   "\n.Lboth_neg:"
+   "\n  push    {lr}"
+   "\n  bl      __aeabi_uidivmod"
+   "\n  rsb     r0, r0, #0" // quot = -quot
+   "\n  rsb     r1, r1, #0" // rem = -rem
+   "\n  pop     {pc}"
+   "\n.Ldenom_neg:"
+   "\n  rsb     r1, r1, #0" // den = -den
+   "\n  push    {lr}"
+   "\n  bl      __aeabi_uidivmod"
+   "\n  rsb     r0, r0, #0" // quot = -quot
+   "\n  pop     {pc}"
+   "\n.Lnumerator_pos:"
+   "\n  cmp     r1, #0"
+   "\n  blt     .Ldenom_neg"
+
+   // Divide r0 by r1 and return the quotient in r0 and the remainder in r1
+   "\n__aeabi_uidiv:"
+   "\n__aeabi_uidivmod:"
+   // Shift left the denominator until it is greater than the numerator
+   "\n  mov     r2, #1"	    // counter
+   "\n  mov     r3, #0"	    // result
+   "\n  cmp     r0, r1"
+   "\n  bls     .Lsub_loop"
+   "\n  adds    r1, #0"	    // dont shift if denominator would overflow
+   "\n  bmi     .Lsub_loop"
+   "\n  beq     .Luidiv0"
+   "\n.Ldenom_shift_loop:"
+   "\n  lsl     r2, #1"
+   "\n  lsls    r1, #1"
+   "\n  bmi     .Lsub_loop"
+   "\n  cmp     r0, r1"
+   "\n  bhi     .Ldenom_shift_loop"
+   "\n.Lsub_loop:"
+   "\n  cmp     r0, r1"     // if (num >= den)...
+   "\n  subcs   r0, r1"     // numerator -= denom
+   "\n  orrcs   r3, r2"     // result(r3) |= bitmask(r2)
+   "\n  lsr     r1, #1"	    // denom(r1) >>= 1
+   "\n  lsrs    r2, #1"	    // bitmask(r2) >>= 1
+   "\n  bne     .Lsub_loop"
+   "\n  mov     r1, r0"	    // remainder(r1) = numerator(r0)
+   "\n  mov     r0, r3"	    // quotient(r0) = result(r3)
+   "\n  bx      lr"
+   "\n.Luidiv0:"            // XXX: division by zero
+   "\n  mov     r0, #0"
+   "\n  bx      lr"
+#endif
+);
+#endif /* UIDIVMOD_ASM */
+/* ***************************************************************** */
+#endif

tccdbg.c

@@ -1023,6 +1023,11 @@ ST_FUNC void tcc_debug_start(TCCState *s1)
                 SHN_ABS, filename);
 
     if (s1->do_debug) {
+        /* put a "mapping symbol" '$a' for llvm-objdump etc. tools needed
+           to make them disassemble again when crt1.o had a '$d' before */
+        put_elf_sym(symtab_section, text_section->data_offset, 0,
+            ELFW(ST_INFO)(STB_LOCAL, STT_NOTYPE), 0,
+            text_section->sh_num, "$a");
 
         new_file = last_line_num = 0;
         debug_next_type = N_DEFAULT_DEBUG;

tccelf.c

@@ -2115,15 +2115,6 @@ static int set_sec_sizes(TCCState *s1)
                    || s1->do_debug) {
             s->sh_size = s->data_offset;
         }
-
-#ifdef TCC_TARGET_ARM
-        /* XXX: Suppress stack unwinding section. */
-        if (s->sh_type == SHT_ARM_EXIDX) {
-            s->sh_flags = 0;
-            s->sh_size = 0;
-        }
-#endif
-
     }
     return textrel;
 }
@@ -2762,7 +2753,11 @@ static void create_arm_attribute_section(TCCState *s1)
         'a', 'e', 'a', 'b', 'i', 0x00,   // "aeabi"
         0x01, 0x22, 0x00, 0x00, 0x00,    // 'File Attributes', size 0x22
         0x05, 0x36, 0x00,                // 'CPU_name', "6"
+#if CONFIG_TCC_CPUVER >= 7
+        0x06, 0x0a,                      // 'CPU_arch', 'v7'
+#else
         0x06, 0x06,                      // 'CPU_arch', 'v6'
+#endif
         0x08, 0x01,                      // 'ARM_ISA_use', 'Yes'
         0x09, 0x01,                      // 'THUMB_ISA_use', 'Thumb-1'
         0x0a, 0x02,                      // 'FP_arch', 'VFPv2'
@@ -3184,8 +3179,13 @@ ST_FUNC int tcc_load_object_file(TCCState *s1,
             sh->sh_type != SHT_INIT_ARRAY &&
             sh->sh_type != SHT_FINI_ARRAY
 #ifdef TCC_ARM_EABI
-            && sh->sh_type != SHT_ARM_EXIDX
+            /* Added in commit f99d3de221db23e322c6c18c8249282e27726c25
+               but suppressed in 3cfaaaf1eb97d858e583412616f68f75fdad5da5
+               So don't load it in order to avoid dangling references from
+               (STT_SECTION) symbols. */
+            // && sh->sh_type != SHT_ARM_EXIDX
 #endif
+
 #if TARGETOS_OpenBSD || TARGETOS_FreeBSD || TARGETOS_NetBSD
             && sh->sh_type != SHT_X86_64_UNWIND
 #endif

tccpp.c

@@ -2933,6 +2933,13 @@ static void next_nomacro(void)
         break;
 
         /* simple tokens */
+    case '@': /* only used in assembler */
+#ifdef TCC_TARGET_ARM /* comment on arm asm */
+        if (parse_flags & PARSE_FLAG_ASM_FILE) {
+            p = parse_line_comment(p);
+            goto redo_no_start;
+        }
+#endif
     case '(':
     case ')':
     case '[':
@@ -2944,7 +2951,6 @@ static void next_nomacro(void)
     case ':':
     case '?':
     case '~':
-    case '@': /* only used in assembler */
     parse_simple:
         tok = c;
         p++;