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linux-user: Determine the desired FPU mode from MIPS.abiflags

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Floating-point mode is calculated from MIPS.abiflags FP ABI value
(based on kernel implementation). Illegal combinations are rejected.

Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
This commit is contained in:
Stefan Markovic 2018-10-23 11:44:36 +02:00 committed by Aleksandar Markovic
parent c94cb6c946
commit 0c1bbedc10
1 changed files with 75 additions and 0 deletions
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75
linux-user/mips/cpu_loop.c
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@ -740,6 +740,34 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
struct image_info *info = ts->info;
int i;
struct mode_req {
bool single;
bool soft;
bool fr1;
bool frdefault;
bool fre;
};
static const struct mode_req fpu_reqs[] = {
[MIPS_ABI_FP_ANY] = { true, true, true, true, true },
[MIPS_ABI_FP_DOUBLE] = { false, false, false, true, true },
[MIPS_ABI_FP_SINGLE] = { true, false, false, false, false },
[MIPS_ABI_FP_SOFT] = { false, true, false, false, false },
[MIPS_ABI_FP_OLD_64] = { false, false, false, false, false },
[MIPS_ABI_FP_XX] = { false, false, true, true, true },
[MIPS_ABI_FP_64] = { false, false, true, false, false },
[MIPS_ABI_FP_64A] = { false, false, true, false, true }
};
/*
* Mode requirements when .MIPS.abiflags is not present in the ELF.
* Not present means that everything is acceptable except FR1.
*/
static struct mode_req none_req = { true, true, false, true, true };
struct mode_req prog_req;
struct mode_req interp_req;
for(i = 0; i < 32; i++) {
env->active_tc.gpr[i] = regs->regs[i];
}
@ -747,6 +775,53 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
if (regs->cp0_epc & 1) {
env->hflags |= MIPS_HFLAG_M16;
}
#ifdef TARGET_ABI_MIPSO32
# define MAX_FP_ABI MIPS_ABI_FP_64A
#else
# define MAX_FP_ABI MIPS_ABI_FP_SOFT
#endif
if ((info->fp_abi > MAX_FP_ABI && info->fp_abi != MIPS_ABI_FP_UNKNOWN)
|| (info->interp_fp_abi > MAX_FP_ABI &&
info->interp_fp_abi != MIPS_ABI_FP_UNKNOWN)) {
fprintf(stderr, "qemu: Unexpected FPU mode\n");
exit(1);
}
prog_req = (info->fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
: fpu_reqs[info->fp_abi];
interp_req = (info->interp_fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
: fpu_reqs[info->interp_fp_abi];
prog_req.single &= interp_req.single;
prog_req.soft &= interp_req.soft;
prog_req.fr1 &= interp_req.fr1;
prog_req.frdefault &= interp_req.frdefault;
prog_req.fre &= interp_req.fre;
bool cpu_has_mips_r2_r6 = env->insn_flags & ISA_MIPS32R2 ||
env->insn_flags & ISA_MIPS64R2 ||
env->insn_flags & ISA_MIPS32R6 ||
env->insn_flags & ISA_MIPS64R6;
if (prog_req.fre && !prog_req.frdefault && !prog_req.fr1) {
env->CP0_Config5 |= (1 << CP0C5_FRE);
if (env->active_fpu.fcr0 & (1 << FCR0_FREP)) {
env->hflags |= MIPS_HFLAG_FRE;
}
} else if ((prog_req.fr1 && prog_req.frdefault) ||
(prog_req.single && !prog_req.frdefault)) {
if ((env->active_fpu.fcr0 & (1 << FCR0_F64)
&& cpu_has_mips_r2_r6) || prog_req.fr1) {
env->CP0_Status |= (1 << CP0St_FR);
env->hflags |= MIPS_HFLAG_F64;
}
} else if (!prog_req.fre && !prog_req.frdefault &&
!prog_req.fr1 && !prog_req.single && !prog_req.soft) {
fprintf(stderr, "qemu: Can't find a matching FPU mode\n");
exit(1);
}
if (env->insn_flags & ISA_NANOMIPS32) {
return;
}