refactor AArch64 and subtractor

Author: WalterBright

compiler/src/dmd/backend/dwarfdbginf.d

@@ -296,7 +296,7 @@ static if (1)
             }
             return reg;
         }
-        else if (config.target_cpu == TARGET_AArch64)
+        else if (AArch64)
         {   // https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#dwarf-register-names
             return (reg < 32) ? reg : reg - 32 + 64;
         }
@@ -652,7 +652,7 @@ static if (1)
          * EH code: "zPLR"
          */
 
-        const bool AArch64 = config.target_cpu == TARGET_AArch64;
+        const bool AArch64 = AArch64();
         const uint startsize = cast(uint)buf.length();
 
         // Length of CIE, not including padding
@@ -925,7 +925,7 @@ static if (1)
                 err_nomem();
             memcpy(name, getSymName(sfunc), len);
             memcpy(name + len, ".eh".ptr, 3 + 1);
-            SC sclass = (config.target_cpu == TARGET_AArch64) ? SC.locstat : SC.global;
+            SC sclass = AArch64 ? SC.locstat : SC.global;
             fdesym = symbol_name(name[0 .. len + 3], sclass, tspvoid);
             Obj.pubdef(dfseg, fdesym, startsize);
             symbol_keep(fdesym);
@@ -937,7 +937,7 @@ static if (1)
             /* Do not have info on naked functions. Assume they set up standard stack frame.
              */
             int cfa_offset;
-            dwarf_emit_eh_frame(config.target_cpu == TARGET_AArch64, 0, cfa_offset);
+            dwarf_emit_eh_frame(AArch64, 0, cfa_offset);
         }
 
         // Length of FDE, not including padding
@@ -965,7 +965,7 @@ static if (1)
         if (config.objfmt == OBJ_ELF)
         {
             fixup = I64 ? R_X86_64_PC32 : R_386_PC32;
-            if (config.target_cpu == TARGET_AArch64)
+            if (AArch64)
                 fixup = R_AARCH64_PREL32;
             buf.write32(cast(uint)(I64 ? 0 : sfunc.Soffset));             // address of function
             Obj.addrel(dfseg, startsize + 8, fixup, cast(int)MAP_SEG2SYMIDX(sfunc.Sseg), sfunc.Soffset);
@@ -1742,7 +1742,7 @@ static if (1)
         //printf("dwarf_func_start(%s)\n", sfunc.Sident.ptr);
         CFA_state* cfa_state = &CFA_state_current;
         memset(cfa_state,0,CFA_state.sizeof);
-        if (config.target_cpu == TARGET_AArch64)
+        if (AArch64)
         {
             cfa_state.reg      = INSTR.SP;
             cfa_state.offset   = OFFSET_FAC;
@@ -3324,3 +3324,6 @@ private char* filespecname(const(char)* filespec) nothrow
     { }
     return cast(char*)p;
 }
+
+private nothrow
+bool AArch64() { return config.target_cpu == TARGET_AArch64; }

compiler/src/dmd/backend/machobj.d

@@ -1,5 +1,7 @@
 /**
- * Generate Mach-O object files
+ * Generate Mach-O object files.
+ * Does 64 bit X86_64 and 64 bit AArch64.
+ * 32 bit X86_64 is more or less abandoned.
  *
  * Compiler implementation of the
  * $(LINK2 https://www.dlang.org, D programming language).
@@ -252,7 +254,7 @@ struct Relocation
     uint targseg;       // if !=0, then location is to be fixed up
                         // to address of start of this segment
     REL rtype;          // REL.address or REL.rel or REL.add
-    ubyte flag;         // 1: emit SUBTRACTOR/UNSIGNED pair
+    bool subtractor;    // true: emit SUBTRACTOR/UNSIGNED pair
     short val;          // 0, -1, -2, -4
 }
 
@@ -911,13 +913,13 @@ void MachObj_term(const(char)[] objfilename)
                         bool isPersonality = strcmp(s.Sident.ptr,  "_D6object8TypeInfo8opEqualsMxFNbNfxCQBbZb") == 0;
                         if (isPersonality)
                         {   symbol_print(*s);
-                            printf("%d:x%04llx isCode %x : targseg %d targsym %s REL%s flag %d\n", seg, r.offset, pseg.isCode(), r.targseg, s ? s.Sident.ptr : "0", rs, r.flag);
+                            printf("%d:x%04llx isCode %x : targseg %d targsym %s REL%s flag %d\n", seg, r.offset, pseg.isCode(), r.targseg, s ? s.Sident.ptr : "0", rs, r.subtractor);
                         }
                         if (0)//s.Sclass == SC.locstat)
                         {   symbol_print(*s);
-                            printf("%d:x%04llx isCode %x : targseg %d targsym %s REL%s flag %d\n", seg, r.offset, pseg.isCode(), r.targseg, s ? s.Sident.ptr : "0", rs, r.flag);
+                            printf("%d:x%04llx isCode %x : targseg %d targsym %s REL%s flag %d\n", seg, r.offset, pseg.isCode(), r.targseg, s ? s.Sident.ptr : "0", rs, r.subtractor);
                         }
-                        if (r.flag == 1)  // emit SUBTRACTOR/UNSIGNED pair
+                        if (r.subtractor)  // emit SUBTRACTOR/UNSIGNED pair
                         {
                             //printf("rel1\n");
                             rel.r_type = ARM64_RELOC_SUBTRACTOR;
@@ -1188,7 +1190,7 @@ void MachObj_term(const(char)[] objfilename)
                     {
                         //printf("Relocation\n");
                         //symbol_print(*s);
-                        if (r.flag == 1)  // emit SUBTRACTOR/UNSIGNED pair
+                        if (r.subtractor)  // emit SUBTRACTOR/UNSIGNED pair
                         {
                             if (I64)
                             {
@@ -2727,7 +2729,7 @@ void MachObj_addrel(int seg, targ_size_t offset, Symbol* targsym,
     rel.targsym = targsym;
     rel.targseg = targseg;
     rel.rtype = rtype;
-    rel.flag = 0;
+    rel.subtractor = false;
     rel.funcsym = funcsym_p;
     rel.val = cast(short)val;
     seg_data* pseg = SegData[seg];
@@ -2963,7 +2965,7 @@ int MachObj_reftoident(int seg, targ_size_t offset, Symbol* s, targ_size_t val,
                     rel.targsym = null;
                     rel.targseg = machobj.pointersSeg;
                     rel.rtype = REL.address;
-                    rel.flag = 0;
+                    rel.subtractor = false;
                     rel.funcsym = null;
                     rel.val = 0;
                     seg_data* pseg2 = SegData[seg];
@@ -3248,7 +3250,7 @@ int dwarf_eh_frame_fixup(int dfseg, targ_size_t offset, Symbol* s, targ_size_t v
     rel.targsym = s;
     rel.targseg = 0;
     rel.rtype = REL.address;
-    rel.flag = 1;
+    rel.subtractor = true;
     rel.funcsym = fdesym;
     rel.val = 0;
     seg_data* pseg = SegData[dfseg];