Add endbr32 for i386

Author: hermantb

i386-asm.c

@@ -1002,21 +1002,24 @@ ST_FUNC void asm_opcode(TCCState *s1, int opcode)
     modrm_index = -1;
     modreg_index = -1;
     if (pa->instr_type & OPC_MODRM) {
-#ifdef TCC_TARGET_X86_64
 	if (!nb_ops) {
 	    /* A modrm opcode without operands is a special case (e.g. mfence).
 	       It has a group and acts as if there's an register operand 0 */
 	    i = 0;
 	    ops[i].type = OP_REG;
+#ifdef TCC_TARGET_X86_64
 	    if (pa->sym == TOK_ASM_endbr64)
 	      ops[i].reg = 2; // dx
 	    else if (pa->sym >= TOK_ASM_lfence && pa->sym <= TOK_ASM_sfence)
   	      ops[i].reg = 0; // ax
+#else
+	    if (pa->sym == TOK_ASM_endbr32)
+	      ops[i].reg = 3; // bx
+#endif
 	    else
 	      tcc_error("bad MODR/M opcode without operands");
 	    goto modrm_found;
 	}
-#endif
         /* first look for an ea operand */
         for(i = 0;i < nb_ops; i++) {
             if (op_type[i] & OP_EA)

i386-asm.h

@@ -37,7 +37,10 @@
      DEF_ASM_OP0(pause, 0xf390)
      DEF_ASM_OP0(xlat, 0xd7)
 
-     /* strings */
+    /* Control-Flow Enforcement */
+    DEF_ASM_OP0L(endbr32, 0xf30f1e, 7, OPC_MODRM)
+
+    /* strings */
 ALT(DEF_ASM_OP0L(cmpsb, 0xa6, 0, OPC_BWLX))
 ALT(DEF_ASM_OP0L(scmpb, 0xa6, 0, OPC_BWLX))