ucc编译器（汇编生成）-锐单电子商城

有了中间代码，很容易在后面生成汇编。需要支持什么？cpu，将中间代码生成相应的汇编代码。这部分工作不复杂，但琐碎。

1、函数入口

void EmitTranslationUnit(AstTranslationUnit transUnit)

2.涉及的文件

emit.c，主要是告诉我们如何生成一个gcc了解汇编文件

https://github.com/sheisc/ucc162.3/blob/a92719fff0ab7eb5b0c45768acedabb3cd70ca05/ucc/ucl/emit.c

x86.c，真正用来生成汇编指令

https://github.com/sheisc/ucc162.3/blob/a92719fff0ab7eb5b0c45768acedabb3cd70ca05/ucc/ucl/x86.c

3、emit.c分析

3.1 EmitTranslationUnit将调用每个接口创建合适的s文件

/**  * Emit  assembly code for the translation unit  */ void EmitTranslationUnit(AstTranslationUnit transUnit) {  if(ASMFileName){   ASMFile = fopen(ASMFileName, "w");   ASMFileName = NULL;  }else{   ASMFile = CreateOutput(Input.filename, ExtName);  }  SwitchTableNum = 1;  // "# Code auto-generated by UCC\n\n"  BeginProgram();  // ".data\n\n"  Segment(DATA);  /**   .str0: .string "%d \012"   .str1: .string "a   b   c   d = %d.\012"   */  EmitStrings();   EmitFloatConstants();   EmitGlobals();  // ".text\n\n"  Segment(CODE);   ImportFunctions();  /**   The key function is     void EmitFunction(FunctionSymbol fsym)   in x86.c   */  EmitFunctions(transUnit);   EndProgram();   fclose(ASMFile); }

在这个函数中，Segement、Strings、FloatConstants、Globals、ImportFuncions这些都是为了创建汇编文件的格式基础和后续文件EmitFunctions做铺垫。在这些函数中调用的子函数需要具体的内容cpu例如Segment这种函数。

3.2 emit.c和x86.c最重要的连接EmitFunction

/**  * Emit all the functions  */ static void EmitFunctions(AstTranslationUnit transUnit) {  AstNode p;  FunctionSymbol fsym;   p = transUnit->extDecls;  while (p != NULL)  {   if (p->kind == NK_Function)   {    fsym = ((AstFunction)p)->fsym;    if (fsym->sclass != TK_STATIC || fsym->ref > 0)    {     EmitFunction(fsym);    }   }   p = p->next;  } }

4、x86.c分析

4.1EmitFunction->EmitBBlock->EmitIRInst，这是最重要的翻译过程

static void EmitIRInst(IRInst inst) {  struct irinst instc = *inst;   (* Emitter[inst->opcode])(&instc);  return; }

4.2 opcode.h一对一翻译

/**  OPCODE(IJMP,    "ijmp",                 IndirectJump)  OPCODE(INC,     "  ",                   Inc)  OPCODE(DEC,     "--",                   Dec)  OPCODE(ADDR,    "&",                    Address)  OPCODE(DEREF,   "*",                    Deref)  OPCODE(EXTI1,   "(int)(char)",          Cast)  OPCODE(EXTU1,   "(int)(unsigned char)", Cast)  */ static void (* Emitter[])(IRInst inst) =  { #define OPCODE(code, name, func) Emit##func,  #include "opcode.h" #undef OPCODE };

4.3 最简单的翻译，Jump跳转

/**  (1) the target of Jump is a BBlock, not Variable.   So no DST->ref -- here.  (2)  X87 top is saved in EmitBlock(),   because Jump must be the last IL in a basic    block.  */ static void EmitJump(IRInst inst) {  BBlock p = (BBlock)DST;   DST = p->sym;  assert(DST->kind == SK_Label);  ClearRegs();  PutASMCode(X86_JMP, inst->opds);  }

4.4 另一个最简单的翻译，获取地址

static void EmitAddress(IRInst inst) {  assert(DST->kind == SK_Temp && SRC1->kind != SK_Temp);  AllocateReg(inst, 0);  PutASMCode(X86_ADDR, inst->opds);  ModifyVar(DST); }

4.5 中间语言和汇编语言之间的映射

enum ASMCode { #define TEMPLATE(code, str) code, #include "x86win32.tpl" #undef TEMPLATE };  static const char * asmCodeName[] = { #define TEMPLATE(code, str) #code, #include "x86win32.tpl" #undef TEMPLATE };

4.6 tpl内容，比如x86linux.tpl

#ifndef TEMPLATE #error "You must define TEMPLATE macro before include this file" #endif    TEMPLATE(X86_BORI4,     "orl %2, %0") TEMPLATE(X86_BORU4,     "orl %2, %0") TEMPLATE(X86_BORF4,     NULL) TEMPLATE(X86_BORF8,     NULL)  TEMPLATE(X86_BXORI4,    "xorl %2, %0") TEMPLATE(X86_BXORU4,    "xorl %2, %0") TEMPLATE(X86_BXORF4,    NULL) TEMPLATE(X86_BXORF8,    NULL)  TEMPLATE(X86_BANDI4,    "andl %2, %0") TEMPLATE(X86_BANDU4,    "andl %2, %0") TEMPLATE(X86_BANDF4,    NULL) TEMPLATE(X86_BANDF8,    NULL)  TEMPLATE(X86_LSHI4,    "shll %2, %0") TEMPLATE(X86_LSHU4,    "shll %2, %0") TEMPLATE(X86_LSHF4,    NULL) TEMPLATE(X86_LSHF8,    NULL)  TEMPLATE(X86_RSHI4,    "sarl %2, %0") TEMPLATE(X86_RSHU4,    "shrl %2, %0") TEMPLATE(X86_RSHF4,    NULL) TEMPLATE(X86_RSHF8,    NULL)  TEMPLATE(X86_ADDI4,    "addl %2, %0") TEMPLATE(X86_ADDU4,    "addl %2, %0") TEMPLATE(X86_ADDF4,    "fadds %2") TEMPLATE(X86_ADDF8,    "faddl %2")  TEMPLATE(X86_SUBI4,    "subl %2, %0") TEMPLATE(X86_SUBU4,    "subl %2,%0")
TEMPLATE(X86_SUBF4,    "fsubs %2")
TEMPLATE(X86_SUBF8,    "fsubl %2")

TEMPLATE(X86_MULI4,    "imull %2, %0")
TEMPLATE(X86_MULU4,    "mull %2")
TEMPLATE(X86_MULF4,    "fmuls %2")
TEMPLATE(X86_MULF8,    "fmull %2")

TEMPLATE(X86_DIVI4,    "cdq;idivl %2")
TEMPLATE(X86_DIVU4,    "movl $0, %%edx;divl %2")
TEMPLATE(X86_DIVF4,    "fdivs %2")
TEMPLATE(X86_DIVF8,    "fdivl %2")

TEMPLATE(X86_MODI4,    "cdq;idivl %2")
TEMPLATE(X86_MODU4,    "movl $0, %%edx; divl %2")
TEMPLATE(X86_MODF4,    NULL)
TEMPLATE(X86_MODF8,    NULL)

TEMPLATE(X86_NEGI4,    "negl %0")
TEMPLATE(X86_NEGU4,    "negl %0")
TEMPLATE(X86_NEGF4,    "fchs")
TEMPLATE(X86_NEGF8,    "fchs")

TEMPLATE(X86_COMPI4,   "notl %0")
TEMPLATE(X86_COMPU4,   "notl %0")
TEMPLATE(X86_COMPF4,   NULL)
TEMPLATE(X86_COMPF8,   NULL)

TEMPLATE(X86_JZI4,     "cmpl $0, %1;je %0")
TEMPLATE(X86_JZU4,     "cmpl $0, %1;je %0")
TEMPLATE(X86_JZF4,     "fldz;fucompp;fnstsw %%ax;test $0x44, %%ah;jnp %0")
TEMPLATE(X86_JZF8,     "fldz;fucompp;fnstsw %%ax;test $0x44, %%ah;jnp %0")

TEMPLATE(X86_JNZI4,    "cmpl $0, %1;jne %0")
TEMPLATE(X86_JNZU4,    "cmpl $0, %1;jne %0")
TEMPLATE(X86_JNZF4,    "fldz;fucompp;fnstsw %%ax;test $0x44, %%ah;jp %0")
TEMPLATE(X86_JNZF8,    "fldz;fucompp;fnstsw %%ax;test $0x44, %%ah;jp %0")

TEMPLATE(X86_JEI4,     "cmpl %2, %1;je %0")
TEMPLATE(X86_JEU4,     "cmpl %2, %1;je %0")
TEMPLATE(X86_JEF4,     "flds %2;fucompp;fnstsw %%ax;test $0x44, %%ah;jnp %0")
TEMPLATE(X86_JEF8,     "fldl %2;fucompp;fnstsw %%ax;test $0x44, %%ah;jnp %0")

TEMPLATE(X86_JNEI4,    "cmpl %2, %1;jne %0")
TEMPLATE(X86_JNEU4,    "cmpl %2, %1;jne %0")
TEMPLATE(X86_JNEF4,    "flds %2;fucompp;fnstsw %%ax;test $0x44, %%ah;jp %0")
TEMPLATE(X86_JNEF8,    "fldl %2;fucompp;fnstsw %%ax;test $0x44, %%ah;jp %0")



TEMPLATE(X86_JGI4,     "cmpl %2, %1;jg %0")
TEMPLATE(X86_JGU4,     "cmpl %2, %1;ja %0")
TEMPLATE(X86_JGF4,     "flds %2;fucompp;fnstsw %%ax;test $0x1, %%ah;jne %0")
TEMPLATE(X86_JGF8,     "fldl %2;fucompp;fnstsw %%ax;test $0x1, %%ah;jne %0")

TEMPLATE(X86_JLI4,     "cmpl %2, %1;jl %0")
TEMPLATE(X86_JLU4,     "cmpl %2, %1;jb %0")
TEMPLATE(X86_JLF4,     "flds %2;fucompp;fnstsw %%ax;test $0x41, %%ah;jp %0")
TEMPLATE(X86_JLF8,     "fldl %2;fucompp;fnstsw %%ax;test $0x41, %%ah;jp %0")

TEMPLATE(X86_JGEI4,    "cmpl %2, %1;jge %0")
TEMPLATE(X86_JGEU4,    "cmpl %2, %1;jae %0")
TEMPLATE(X86_JGEF4,    "flds %2;fucompp;fnstsw %%ax;test $0x41, %%ah;jne %0")
TEMPLATE(X86_JGEF8,    "fldl %2;fucompp;fnstsw %%ax;test $0x41, %%ah;jne %0")

TEMPLATE(X86_JLEI4,    "cmpl %2, %1;jle %0")
TEMPLATE(X86_JLEU4,    "cmpl %2, %1;jbe %0")
TEMPLATE(X86_JLEF4,    "flds %2;fucompp;fnstsw %%ax;test $0x5, %%ah;jp %0")
TEMPLATE(X86_JLEF8,    "fldl %2;fucompp;fnstsw %%ax;test $0x5, %%ah;jp %0")



TEMPLATE(X86_EXTI1,    "movsbl %1, %0")
TEMPLATE(X86_EXTU1,    "movzbl %1, %0")
TEMPLATE(X86_EXTI2,    "movswl %1, %0")
TEMPLATE(X86_EXTU2,    "movzwl %1, %0")
TEMPLATE(X86_TRUI1,    "movb %%al, %0")
TEMPLATE(X86_TRUI2,    "movb %%al, %0")

 
TEMPLATE(X86_CVTI4F4,  "pushl %1;fildl (%%esp);fstps %0;addl $4, %%esp")
TEMPLATE(X86_CVTI4F8,  "pushl %1;fildl (%%esp);fstpl %0;addl $4, %%esp")
TEMPLATE(X86_CVTU4F4,  "pushl $0;pushl %1;fildq (%%esp);fstps %0;addl $8, %%esp")
TEMPLATE(X86_CVTU4F8,  "pushl $0;pushl %1;fildq (%%esp);fstpl %0;addl $8, %%esp")

TEMPLATE(X86_CVTF4,    "flds %1;fstpl %0") 

 
TEMPLATE(X86_CVTF4I4,  "flds %1;subl $16, %%esp;fnstcw (%%esp);movzwl (%%esp), %%eax;"
                       "orl $0x0c00, %%eax;movl %%eax, 4(%%esp);fldcw 4(%%esp);fistpl 8(%%esp);"
                       "fldcw (%%esp);movl 8(%%esp), %%eax;addl $16, %%esp")
 
TEMPLATE(X86_CVTF4U4,  "flds %1;subl $16, %%esp;fnstcw (%%esp);movzwl (%%esp), %%eax;"
                       "orl $0x0c00, %%eax;movl %%eax, 4(%%esp);fldcw 4(%%esp);fistpll 8(%%esp);"
                       "fldcw (%%esp);movl 8(%%esp), %%eax;addl $16, %%esp")
TEMPLATE(X86_CVTF8,    "fldl %1;fstps %0")

TEMPLATE(X86_CVTF8I4,  "fldl %1;subl $16, %%esp;fnstcw (%%esp);movzwl (%%esp), %%eax;"
                       "orl $0x0c00, %%eax;movl %%eax, 4(%%esp);fldcw 4(%%esp);fistpl 8(%%esp);"
                       "fldcw (%%esp);movl 8(%%esp), %%eax; addl $16, %%esp")
 
TEMPLATE(X86_CVTF8U4,  "fldl %1;subl $16, %%esp;fnstcw (%%esp);movzwl (%%esp), %%eax;"
                       "orl $0x0c00, %%eax;movl %%eax, 4(%%esp);fldcw 4(%%esp);fistpll 8(%%esp);"
                       "fldcw (%%esp);movl 8(%%esp), %%eax;addl $16, %%esp")
					
		
TEMPLATE(X86_INCI1,    "incb %0")
TEMPLATE(X86_INCU1,    "incb %0")
TEMPLATE(X86_INCI2,    "incw %0")
TEMPLATE(X86_INCU2,    "incw %0")				
TEMPLATE(X86_INCI4,    "incl %0")
TEMPLATE(X86_INCU4,    "incl %0")
TEMPLATE(X86_INCF4,    "fld1;fadds %0;fstps %0")

 
TEMPLATE(X86_INCF8,    "fld1;faddl %0;fstpl %0")

TEMPLATE(X86_DECI1,    "decb %0")
TEMPLATE(X86_DECU1,    "decb %0")
TEMPLATE(X86_DECI2,    "decw %0")
TEMPLATE(X86_DECU2,    "decw %0")
TEMPLATE(X86_DECI4,    "decl %0")
TEMPLATE(X86_DECU4,    "decl %0")

TEMPLATE(X86_DECF4,    "fld1;fsubs %0;fchs;fstps %0")
TEMPLATE(X86_DECF8,    "fld1;fsubl %0;fchs;fstpl %0")

TEMPLATE(X86_ADDR,     "leal %1, %0")

TEMPLATE(X86_MOVI1,    "movb %1, %0")
TEMPLATE(X86_MOVI2,    "movw %1, %0")
TEMPLATE(X86_MOVI4,    "movl %1, %0")
TEMPLATE(X86_MOVB,     "leal %0, %%edi;leal %1, %%esi;movl %2, %%ecx;rep movsb")


TEMPLATE(X86_JMP,      "jmp %0")
TEMPLATE(X86_IJMP,     "jmp *%0(,%1,4)")

TEMPLATE(X86_PROLOGUE, "pushl %%ebp;pushl %%ebx;pushl %%esi;pushl %%edi;movl %%esp, %%ebp")
TEMPLATE(X86_PUSH,     "pushl %0")
TEMPLATE(X86_PUSHF4,   "pushl %%ecx;flds %0;fstps (%%esp)")
TEMPLATE(X86_PUSHF8,   "subl $8, %%esp;fldl %0;fstpl (%%esp)")
TEMPLATE(X86_PUSHB,    "leal %0, %%esi;subl %2, %%esp;movl %%esp, %%edi;movl %1, %%ecx;rep movsb")
TEMPLATE(X86_EXPANDF,  "subl %0, %%esp")
TEMPLATE(X86_CALL,     "call %1")
TEMPLATE(X86_ICALL,    "call *%1")
TEMPLATE(X86_REDUCEF,  "addl %0, %%esp")
TEMPLATE(X86_EPILOGUE, "movl %%ebp, %%esp;popl %%edi;popl %%esi;popl %%ebx;popl %%ebp;ret")


TEMPLATE(X86_CLEAR,    "pushl %1;pushl $0;leal %0, %%eax;pushl %%eax;call memset;addl $12, %%esp")

TEMPLATE(X86_LDF4,     "flds %0")
TEMPLATE(X86_LDF8,     "fldl %0")
TEMPLATE(X86_STF4,     "fstps %0")
TEMPLATE(X86_STF8,     "fstpl %0")


TEMPLATE(X86_STF4_NO_POP,     "fsts %0")
TEMPLATE(X86_STF8_NO_POP,     "fstl %0")

TEMPLATE(X86_X87_POP,     "fstp %%st(0)")

4.7 汇编语言的打印

目前主要是PutASMCode实现，

这个函数在x86linux.c & x86win32.c都进行了实现

这就看自己需要实现哪一种os下的汇编代码了

4.8 函数翻译过程中涉及到其他问题

Export，函数输出

LayoutFrame & EmitPrologue，堆栈处理

EmitEpilogue，堆栈复原

4.9 寄存器的处理

reg.c

https://github.com/sheisc/ucc162.3/blob/a92719fff0ab7eb5b0c45768acedabb3cd70ca05/ucc/ucl/reg.c

4.10 总结

相对而言，后端移植涉及到很多文件，比如emit.c、x86.c、reg.c、x86win32.c、x86linux.c，还涉及到opinfo.h、x86linux.tpl、x86win32.tpl，作为阅读代码同学，要了解每一个文件的作用，至少需要知道里面的处理流程。评价自己是否真正理解了这个理解，就看自己是不是可以把ucc移植到另外一个cpu架构上了，这是最好的判别方法。

资讯详情

ucc编译器（汇编生成）

动力学技术KTU1121 USB Type-C 端口保护器的介绍、特性、及应用

ucc编译器（汇编生成）

动力学技术KTU1121 USB Type-C 端口保护器的介绍、特性、及应用

最近热搜

历史搜索 清除历史记录

历史搜索清除历史记录