motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 08:13:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

target/m68k: Don't pass NULL float_status to floatx80_default_nan()

Browse source 
Currently m68k_cpu_reset_hold() calls floatx80_default_nan(NULL)
to get the NaN bit pattern to reset the FPU registers. This
works because it happens that our implementation of
floatx80_default_nan() doesn't actually look at the float_status
pointer except for TARGET_MIPS. However, this isn't guaranteed,
and to be able to remove the ifdef in floatx80_default_nan()
we're going to need a real float_status here.

Rearrange m68k_cpu_reset_hold() so that we initialize env->fp_status
earlier, and thus can pass it to floatx80_default_nan().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241202131347.498124-28-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2024-12-11 15:30:59 +00:00
parent dc416d6ca7
commit 04b6a3e471
1 changed files with 7 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

12
target/m68k/cpu.c
View file

@ -76,7 +76,7 @@ static void m68k_cpu_reset_hold(Object *obj, ResetType type)
CPUState *cs = CPU(obj);
M68kCPUClass *mcc = M68K_CPU_GET_CLASS(obj);
CPUM68KState *env = cpu_env(cs);
floatx80 nan = floatx80_default_nan(NULL);
floatx80 nan;
int i;
if (mcc->parent_phases.hold) {
@ -89,10 +89,6 @@ static void m68k_cpu_reset_hold(Object *obj, ResetType type)
#else
cpu_m68k_set_sr(env, SR_S | SR_I);
#endif
for (i = 0; i < 8; i++) {
env->fregs[i].d = nan;
}
cpu_m68k_set_fpcr(env, 0);
/*
* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL
* 3.4 FLOATING-POINT INSTRUCTION DETAILS
@ -109,6 +105,12 @@ static void m68k_cpu_reset_hold(Object *obj, ResetType type)
* preceding paragraph for nonsignaling NaNs.
*/
set_float_2nan_prop_rule(float_2nan_prop_ab, &env->fp_status);
nan = floatx80_default_nan(&env->fp_status);
for (i = 0; i < 8; i++) {
env->fregs[i].d = nan;
}
cpu_m68k_set_fpcr(env, 0);
env->fpsr = 0;
/* TODO: We should set PC from the interrupt vector. */