target/m68k: implement rtd

Add "Return and Deallocate" (rtd) instruction.

RTD #d

(SP) -> PC
SP + 4 + d -> SP

Backports commit 18059c9e1648bf4fc5c7c1bae6f54690742b05ba from qemu
This commit is contained in:
Laurent Vivier 2018-03-03 14:26:29 -05:00 committed by Lioncash
parent 2c49a6b2f6
commit ce25609ed3
No known key found for this signature in database
GPG Key ID: 4E3C3CC1031BA9C7
3 changed files with 15 additions and 0 deletions

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@ -120,6 +120,7 @@ static void m68020_cpu_initfn(struct uc_struct *uc, Object *obj, void *opaque)
m68k_set_feature(env, M68K_FEATURE_FPU);
m68k_set_feature(env, M68K_FEATURE_CAS);
m68k_set_feature(env, M68K_FEATURE_BKPT);
m68k_set_feature(env, M68K_FEATURE_RTD);
}
#define m68030_cpu_initfn m68020_cpu_initfn
#define m68040_cpu_initfn m68020_cpu_initfn
@ -141,6 +142,7 @@ static void m68060_cpu_initfn(struct uc_struct *uc, Object *obj, void *opaque)
m68k_set_feature(env, M68K_FEATURE_FPU);
m68k_set_feature(env, M68K_FEATURE_CAS);
m68k_set_feature(env, M68K_FEATURE_BKPT);
m68k_set_feature(env, M68K_FEATURE_RTD);
}
static void m5208_cpu_initfn(struct uc_struct *uc, Object *obj, void *opaque)

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@ -248,6 +248,7 @@ enum m68k_features {
M68K_FEATURE_FPU,
M68K_FEATURE_CAS,
M68K_FEATURE_BKPT,
M68K_FEATURE_RTD,
};
static inline int m68k_feature(CPUM68KState *env, int feature)

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@ -2550,6 +2550,17 @@ DISAS_INSN(nop)
{
}
DISAS_INSN(rtd)
{
TCGContext *tcg_ctx = s->uc->tcg_ctx;
TCGv tmp;
int16_t offset = read_im16(env, s);
tmp = gen_load(s, OS_LONG, QREG_SP, 0);
tcg_gen_addi_i32(tcg_ctx,QREG_SP, QREG_SP, offset + 4);
gen_jmp(s, tmp);
}
DISAS_INSN(rts)
{
TCGContext *tcg_ctx = s->uc->tcg_ctx;
@ -5076,6 +5087,7 @@ void register_m68k_insns (CPUM68KState *env)
BASE(nop, 4e71, ffff);
BASE(stop, 4e72, ffff);
BASE(rte, 4e73, ffff);
INSN(rtd, 4e74, ffff, RTD);
BASE(rts, 4e75, ffff);
INSN(movec, 4e7b, ffff, CF_ISA_A);
BASE(jump, 4e80, ffc0);