From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: laurent@vivier.eu, schwab@linux-m68k.org
Subject: [PATCH v6 03/24] target/m68k: Keep FPSR up-to-date
Date: Sun, 11 May 2025 13:35:25 -0700 [thread overview]
Message-ID: <20250511203546.139788-4-richard.henderson@linaro.org> (raw)
In-Reply-To: <20250511203546.139788-1-richard.henderson@linaro.org>
Proper support for m68k exceptions will require testing the FPCR vs
the FPSR for every instruction. As a step, do not keep FPSR bits in
fp_status, but copy them back to the FPSR in every instruction.
Since most of the FPSR must be updated on every insn, handle this
from the existing helper_ftst and helper_fcmp functions.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/m68k/cpu.h | 2 -
target/m68k/helper.h | 2 -
target/m68k/cpu.c | 10 -----
target/m68k/fpu_helper.c | 94 +++++++++++-----------------------------
target/m68k/helper.c | 4 +-
target/m68k/translate.c | 4 +-
6 files changed, 30 insertions(+), 86 deletions(-)
diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index 035034772b..0630eb26c2 100644
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -201,8 +201,6 @@ void cpu_m68k_set_ccr(CPUM68KState *env, uint32_t);
void cpu_m68k_set_sr(CPUM68KState *env, uint32_t);
void cpu_m68k_restore_fp_status(CPUM68KState *env);
void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val);
-uint32_t cpu_m68k_get_fpsr(CPUM68KState *env);
-void cpu_m68k_set_fpsr(CPUM68KState *env, uint32_t val);
/*
* Instead of computing the condition codes after each m68k instruction,
diff --git a/target/m68k/helper.h b/target/m68k/helper.h
index 95aa5e53bb..2bbe0dc032 100644
--- a/target/m68k/helper.h
+++ b/target/m68k/helper.h
@@ -54,8 +54,6 @@ DEF_HELPER_4(fsdiv, void, env, fp, fp, fp)
DEF_HELPER_4(fddiv, void, env, fp, fp, fp)
DEF_HELPER_4(fsgldiv, void, env, fp, fp, fp)
DEF_HELPER_FLAGS_3(fcmp, TCG_CALL_NO_RWG, void, env, fp, fp)
-DEF_HELPER_2(set_fpsr, void, env, i32)
-DEF_HELPER_1(get_fpsr, i32, env)
DEF_HELPER_FLAGS_2(set_fpcr, TCG_CALL_NO_RWG, void, env, i32)
DEF_HELPER_FLAGS_2(ftst, TCG_CALL_NO_RWG, void, env, fp)
DEF_HELPER_3(fconst, void, env, fp, i32)
diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
index 724138b302..e898156403 100644
--- a/target/m68k/cpu.c
+++ b/target/m68k/cpu.c
@@ -468,20 +468,11 @@ static const VMStateDescription vmstate_freg = {
}
};
-static int fpu_pre_save(void *opaque)
-{
- M68kCPU *s = opaque;
-
- s->env.fpsr = cpu_m68k_get_fpsr(&s->env);
- return 0;
-}
-
static int fpu_post_load(void *opaque, int version)
{
M68kCPU *s = opaque;
cpu_m68k_set_fpcr(&s->env, s->env.fpcr);
- cpu_m68k_set_fpsr(&s->env, s->env.fpsr);
return 0;
}
@@ -490,7 +481,6 @@ const VMStateDescription vmmstate_fpu = {
.version_id = 1,
.minimum_version_id = 1,
.needed = fpu_needed,
- .pre_save = fpu_pre_save,
.post_load = fpu_post_load,
.fields = (const VMStateField[]) {
VMSTATE_UINT32(env.fpcr, M68kCPU),
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index 3e35c20be3..195281f118 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -163,76 +163,34 @@ void HELPER(set_fpcr)(CPUM68KState *env, uint32_t val)
cpu_m68k_set_fpcr(env, val);
}
-/* Convert host exception flags to cpu_m68k form. */
-static int cpu_m68k_exceptbits_from_host(int host_bits)
+static void update_fpsr(CPUM68KState *env, int cc)
{
- int target_bits = 0;
+ uint32_t fpsr = env->fpsr;
+ int flags = get_float_exception_flags(&env->fp_status);
- if (host_bits & float_flag_invalid) {
- target_bits |= FPSR_AEXP_IOP;
- }
- if (host_bits & float_flag_overflow) {
- target_bits |= FPSR_AEXP_OVFL;
- }
- if (host_bits & (float_flag_underflow | float_flag_output_denormal_flushed)) {
- target_bits |= FPSR_AEXP_UNFL;
- }
- if (host_bits & float_flag_divbyzero) {
- target_bits |= FPSR_AEXP_DZ;
- }
- if (host_bits & float_flag_inexact) {
- target_bits |= FPSR_AEXC_INEX;
- }
- return target_bits;
-}
+ fpsr &= ~FPSR_CC_MASK;
+ fpsr |= cc;
-/* Convert cpu_m68k exception flags to target form. */
-static int cpu_m68k_exceptbits_to_host(int target_bits)
-{
- int host_bits = 0;
+ if (flags) {
+ set_float_exception_flags(0, &env->fp_status);
- if (target_bits & FPSR_AEXP_IOP) {
- host_bits |= float_flag_invalid;
+ if (flags & float_flag_invalid) {
+ fpsr |= FPSR_AEXP_IOP;
+ }
+ if (flags & float_flag_overflow) {
+ fpsr |= FPSR_AEXP_OVFL;
+ }
+ if (flags & (float_flag_underflow | float_flag_output_denormal_flushed)) {
+ fpsr |= FPSR_AEXP_UNFL;
+ }
+ if (flags & float_flag_divbyzero) {
+ fpsr |= FPSR_AEXP_DZ;
+ }
+ if (flags & float_flag_inexact) {
+ fpsr |= FPSR_AEXC_INEX;
+ }
}
- if (target_bits & FPSR_AEXP_OVFL) {
- host_bits |= float_flag_overflow;
- }
- if (target_bits & FPSR_AEXP_UNFL) {
- host_bits |= float_flag_underflow;
- }
- if (target_bits & FPSR_AEXP_DZ) {
- host_bits |= float_flag_divbyzero;
- }
- if (target_bits & FPSR_AEXC_INEX) {
- host_bits |= float_flag_inexact;
- }
- return host_bits;
-}
-
-uint32_t cpu_m68k_get_fpsr(CPUM68KState *env)
-{
- int host_flags = get_float_exception_flags(&env->fp_status);
- int target_flags = cpu_m68k_exceptbits_from_host(host_flags);
- int except = (env->fpsr & ~FPSR_AEXC_MASK) | target_flags;
- return except;
-}
-
-uint32_t HELPER(get_fpsr)(CPUM68KState *env)
-{
- return cpu_m68k_get_fpsr(env);
-}
-
-void cpu_m68k_set_fpsr(CPUM68KState *env, uint32_t val)
-{
- env->fpsr = val;
-
- int host_flags = cpu_m68k_exceptbits_to_host((int) env->fpsr);
- set_float_exception_flags(host_flags, &env->fp_status);
-}
-
-void HELPER(set_fpsr)(CPUM68KState *env, uint32_t val)
-{
- cpu_m68k_set_fpsr(env, val);
+ env->fpsr = fpsr;
}
#define PREC_BEGIN(prec) \
@@ -441,12 +399,12 @@ void HELPER(fcmp)(CPUM68KState *env, FPReg *val0, FPReg *val1)
FloatRelation float_compare;
float_compare = floatx80_compare(val1->d, val0->d, &env->fp_status);
- env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | float_comp_to_cc(float_compare);
+ update_fpsr(env, float_comp_to_cc(float_compare));
}
void HELPER(ftst)(CPUM68KState *env, FPReg *val)
{
- uint32_t cc = 0;
+ int cc = 0;
if (floatx80_is_neg(val->d)) {
cc |= FPSR_CC_N;
@@ -459,7 +417,7 @@ void HELPER(ftst)(CPUM68KState *env, FPReg *val)
} else if (floatx80_is_zero(val->d)) {
cc |= FPSR_CC_Z;
}
- env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | cc;
+ update_fpsr(env, cc);
}
void HELPER(fconst)(CPUM68KState *env, FPReg *val, uint32_t offset)
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index 15f110fa7a..b50ef6dec3 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -92,7 +92,7 @@ static int m68k_fpu_gdb_get_reg(CPUState *cs, GByteArray *mem_buf, int n)
case 8: /* fpcontrol */
return gdb_get_reg32(mem_buf, env->fpcr);
case 9: /* fpstatus */
- return gdb_get_reg32(mem_buf, cpu_m68k_get_fpsr(env));
+ return gdb_get_reg32(mem_buf, env->fpsr);
case 10: /* fpiar, not implemented */
return gdb_get_reg32(mem_buf, 0);
}
@@ -114,7 +114,7 @@ static int m68k_fpu_gdb_set_reg(CPUState *cs, uint8_t *mem_buf, int n)
cpu_m68k_set_fpcr(env, ldl_be_p(mem_buf));
return 4;
case 9: /* fpstatus */
- cpu_m68k_set_fpsr(env, ldl_be_p(mem_buf));
+ env->fpsr = ldl_be_p(mem_buf);
return 4;
case 10: /* fpiar, not implemented */
return 4;
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 97afceb129..340d72bc4f 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -4733,7 +4733,7 @@ static void gen_load_fcr(DisasContext *s, TCGv res, int reg)
tcg_gen_movi_i32(res, 0);
break;
case M68K_FPSR:
- gen_helper_get_fpsr(res, tcg_env);
+ tcg_gen_ld_i32(res, tcg_env, offsetof(CPUM68KState, fpsr));
break;
case M68K_FPCR:
tcg_gen_ld_i32(res, tcg_env, offsetof(CPUM68KState, fpcr));
@@ -4747,7 +4747,7 @@ static void gen_store_fcr(DisasContext *s, TCGv val, int reg)
case M68K_FPIAR:
break;
case M68K_FPSR:
- gen_helper_set_fpsr(tcg_env, val);
+ tcg_gen_st_i32(val, tcg_env, offsetof(CPUM68KState, fpsr));
break;
case M68K_FPCR:
gen_helper_set_fpcr(tcg_env, val);
--
2.43.0
next prev parent reply other threads:[~2025-05-11 20:38 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-11 20:35 [PATCH v6 00/24] target/m68k: fpu improvements Richard Henderson
2025-05-11 20:35 ` [PATCH v6 01/24] target/m68k: Add FPSR exception bit defines Richard Henderson
2025-05-11 20:35 ` [PATCH v6 02/24] target/m68k: Restore fp rounding mode on vm load Richard Henderson
2025-05-11 20:35 ` Richard Henderson [this message]
2025-05-11 20:35 ` [PATCH v6 04/24] target/m68k: Update FPSR.EXC Richard Henderson
2025-05-11 20:35 ` [PATCH v6 05/24] target/m68k: Update FPSR for FMOVECR Richard Henderson
2025-05-11 20:35 ` [PATCH v6 06/24] target/m68k: Introduce M68K_FEATURE_FPU_PACKED_DECIMAL Richard Henderson
2025-05-11 20:35 ` [PATCH v6 07/24] target/m68k: Merge gen_ea into SRC_EA and DEST_EA Richard Henderson
2025-05-11 20:35 ` [PATCH v6 08/24] target/m68k: Use g_assert_not_reached in gen_lea_mode and gen_ea_mode Richard Henderson
2025-05-11 20:35 ` [PATCH v6 09/24] target/m68k: Use OS_UNSIZED in LEA, PEA, JMP Richard Henderson
2025-05-12 14:23 ` Philippe Mathieu-Daudé
2025-05-11 20:35 ` [PATCH v6 10/24] target/m68k: Move pre-dec/post-inc to gen_lea_mode Richard Henderson
2025-05-11 20:35 ` [PATCH v6 11/24] target/m68k: Split gen_ea_mode for load/store Richard Henderson
2025-05-11 20:35 ` [PATCH v6 12/24] target/m68k: Remove env argument to gen_lea_indexed Richard Henderson
2025-05-11 20:35 ` [PATCH v6 13/24] target/m68k: Remove env argument to gen_lea_mode Richard Henderson
2025-05-11 20:35 ` [PATCH v6 14/24] target/m68k: Remove env argument to gen_load_mode Richard Henderson
2025-05-11 20:35 ` [PATCH v6 15/24] target/m68k: Remove env argument to gen_store_mode Richard Henderson
2025-05-11 20:35 ` [PATCH v6 16/24] target/m68k: Remove env argument to gen_ea_mode_fp Richard Henderson
2025-05-11 20:35 ` [PATCH v6 17/24] target/m68k: Split gen_ea_mode_fp for load/store Richard Henderson
2025-05-11 20:35 ` [PATCH v6 18/24] target/m68k: Move gen_addr_fault into gen_{load, store}_mode_fp Richard Henderson
2025-05-11 20:35 ` [PATCH v6 19/24] target/m68k: Merge gen_load_fp, gen_load_mode_fp Richard Henderson
2025-05-11 20:35 ` [PATCH v6 20/24] target/m68k: Merge gen_store_fp, gen_store_mode_fp Richard Henderson
2025-05-11 20:35 ` [PATCH v6 21/24] target/m68k: Implement packed decimal real loads and stores Richard Henderson
2025-05-11 20:35 ` [PATCH v6 22/24] tests/tcg/m68k: Add packed decimal tests Richard Henderson
2025-05-11 20:35 ` [PATCH v6 23/24] target/m68k: Make vmstate variables static Richard Henderson
2025-05-11 20:35 ` [PATCH v6 24/24] target/m68k: Implement FPIAR Richard Henderson
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