i386-gen: use EBX as 4th register

May be enabled/disabled by changing this line:
    #define USE_EBX 1
This commit is contained in:
grischka 2016-10-19 19:22:15 +02:00
parent 02642bc94c
commit 3054a76249

View File

@ -21,7 +21,7 @@
#ifdef TARGET_DEFS_ONLY
/* number of available registers */
#define NB_REGS 4
#define NB_REGS 5
#define NB_ASM_REGS 8
/* a register can belong to several classes. The classes must be
@ -33,6 +33,8 @@
#define RC_ST0 0x0008
#define RC_ECX 0x0010
#define RC_EDX 0x0020
#define RC_EBX 0x0040
#define RC_IRET RC_EAX /* function return: integer register */
#define RC_LRET RC_EDX /* function return: second integer register */
#define RC_FRET RC_ST0 /* function return: float register */
@ -42,6 +44,7 @@ enum {
TREG_EAX = 0,
TREG_ECX,
TREG_EDX,
TREG_EBX,
TREG_ST0,
TREG_ESP = 4
};
@ -89,10 +92,14 @@ enum {
/******************************************************/
#include "tcc.h"
/* define to 1/0 to [not] have EBX as 4th register */
#define USE_EBX 1
ST_DATA const int reg_classes[NB_REGS] = {
/* eax */ RC_INT | RC_EAX,
/* ecx */ RC_INT | RC_ECX,
/* edx */ RC_INT | RC_EDX,
/* ebx */ (RC_INT | RC_EBX) * USE_EBX,
/* st0 */ RC_FLOAT | RC_ST0,
};
@ -518,9 +525,9 @@ ST_FUNC void gfunc_call(int nb_args)
}
#ifdef TCC_TARGET_PE
#define FUNC_PROLOG_SIZE 10
#define FUNC_PROLOG_SIZE (10 + USE_EBX)
#else
#define FUNC_PROLOG_SIZE 9
#define FUNC_PROLOG_SIZE (9 + USE_EBX)
#endif
/* generate function prolog of type 't' */
@ -646,6 +653,7 @@ ST_FUNC void gfunc_epilog(void)
o(0x585a); /* restore returned value, if any */
}
#endif
o(0x5b * USE_EBX); /* pop ebx */
o(0xc9); /* leave */
if (func_ret_sub == 0) {
o(0xc3); /* ret */
@ -669,10 +677,11 @@ ST_FUNC void gfunc_epilog(void)
o(0xe58955); /* push %ebp, mov %esp, %ebp */
o(0xec81); /* sub esp, stacksize */
gen_le32(v);
#if FUNC_PROLOG_SIZE == 10
#ifdef TCC_TARGET_PE
o(0x90); /* adjust to FUNC_PROLOG_SIZE */
#endif
}
o(0x53 * USE_EBX); /* push ebx */
ind = saved_ind;
}