[PATCH v11 10/26] target/loongarch: Add floating point arithmetic instruction translation

Song Gao posted 26 patches 1 year, 2 months ago
Maintainers: Song Gao <gaosong@loongson.cn>, Laurent Vivier <laurent@vivier.eu>
There is a newer version of this series
[PATCH v11 10/26] target/loongarch: Add floating point arithmetic instruction translation
Posted by Song Gao 1 year, 2 months ago
This includes:
- F{ADD/SUB/MUL/DIV}.{S/D}
- F{MADD/MSUB/NMADD/NMSUB}.{S/D}
- F{MAX/MIN}.{S/D}
- F{MAXA/MINA}.{S/D}
- F{ABS/NEG}.{S/D}
- F{SQRT/RECIP/RSQRT}.{S/D}
- F{SCALEB/LOGB/COPYSIGN}.{S/D}
- FCLASS.{S/D}

Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/loongarch/cpu.c                         |   1 +
 target/loongarch/fpu_helper.c                  | 405 +++++++++++++++++++++++++
 target/loongarch/helper.h                      |  37 +++
 target/loongarch/insn_trans/trans_farith.c.inc | 105 +++++++
 target/loongarch/insns.decode                  |  52 ++++
 target/loongarch/internals.h                   |   2 +
 target/loongarch/translate.c                   |  11 +
 7 files changed, 613 insertions(+)
 create mode 100644 target/loongarch/fpu_helper.c
 create mode 100644 target/loongarch/insn_trans/trans_farith.c.inc

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index b3f4444..ad11b98 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -185,6 +185,7 @@ static void loongarch_cpu_reset(DeviceState *dev)
     env->fcsr0_mask = 0x1f1f031f;
     env->fcsr0 = 0x0;
 
+    restore_fp_status(env);
     cs->exception_index = EXCP_NONE;
 }
 
diff --git a/target/loongarch/fpu_helper.c b/target/loongarch/fpu_helper.c
new file mode 100644
index 0000000..d0ef675
--- /dev/null
+++ b/target/loongarch/fpu_helper.c
@@ -0,0 +1,405 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * LoongArch float point emulation helpers for QEMU
+ *
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+#include "exec/exec-all.h"
+#include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
+#include "internals.h"
+
+#define FLOAT_TO_INT32_OVERFLOW 0x7fffffff
+#define FLOAT_TO_INT64_OVERFLOW 0x7fffffffffffffffULL
+
+static inline uint64_t nanbox_s(float32 fp)
+{
+    return fp | MAKE_64BIT_MASK(32, 32);
+}
+
+/* Convert loongarch rounding mode in fcsr0 to IEEE library */
+static const FloatRoundMode ieee_rm[4] = {
+    float_round_nearest_even,
+    float_round_to_zero,
+    float_round_up,
+    float_round_down
+};
+
+void restore_fp_status(CPULoongArchState *env)
+{
+    set_float_rounding_mode(ieee_rm[(env->fcsr0 >> FCSR0_RM) & 0x3],
+                            &env->fp_status);
+    set_flush_to_zero(0, &env->fp_status);
+}
+
+static int ieee_ex_to_loongarch(int xcpt)
+{
+    int ret = 0;
+    if (xcpt & float_flag_invalid) {
+        ret |= FP_INVALID;
+    }
+    if (xcpt & float_flag_overflow) {
+        ret |= FP_OVERFLOW;
+    }
+    if (xcpt & float_flag_underflow) {
+        ret |= FP_UNDERFLOW;
+    }
+    if (xcpt & float_flag_divbyzero) {
+        ret |= FP_DIV0;
+    }
+    if (xcpt & float_flag_inexact) {
+        ret |= FP_INEXACT;
+    }
+    return ret;
+}
+
+static void update_fcsr0_mask(CPULoongArchState *env, uintptr_t pc, int mask)
+{
+    int flags = get_float_exception_flags(&env->fp_status);
+
+    set_float_exception_flags(0, &env->fp_status);
+
+    if (~mask) {
+        flags = flags & (~mask);
+    }
+
+    if (!flags) {
+        SET_FP_CAUSE(env->fcsr0, flags);
+        return;
+    }
+
+    flags = ieee_ex_to_loongarch(flags);
+    SET_FP_CAUSE(env->fcsr0, flags);
+
+    if (GET_FP_ENABLES(env->fcsr0) & flags) {
+        do_raise_exception(env, EXCP_FPE, pc);
+    } else {
+        UPDATE_FP_FLAGS(env->fcsr0, flags);
+    }
+}
+
+static void update_fcsr0(CPULoongArchState *env, uintptr_t pc)
+{
+    update_fcsr0_mask(env, pc, 0);
+}
+
+uint64_t helper_fadd_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_add((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fadd_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_add(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fsub_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_sub((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fsub_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_sub(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmul_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_mul((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmul_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_mul(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fdiv_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_div((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fdiv_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_div(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmax_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_maxnum((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmax_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_maxnum(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmin_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_minnum((uint32_t)fj, (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmin_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_minnum(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmaxa_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_maxnummag((uint32_t)fj,
+                                    (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmaxa_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_maxnummag(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmina_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_minnummag((uint32_t)fj,
+                                    (uint32_t)fk, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmina_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+
+    fd = float64_minnummag(fj, fk, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fscaleb_s(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+    int32_t n = (int32_t)fk;
+
+    fd = nanbox_s(float32_scalbn((uint32_t)fj,
+                                 n >  0x200 ?  0x200 :
+                                 n < -0x200 ? -0x200 : n,
+                                 &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fscaleb_d(CPULoongArchState *env, uint64_t fj, uint64_t fk)
+{
+    uint64_t fd;
+    int64_t n = (int64_t)fk;
+
+    fd = float64_scalbn(fj,
+                        n >  0x1000 ?  0x1000 :
+                        n < -0x1000 ? -0x1000 : n,
+                        &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fsqrt_s(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_sqrt((uint32_t)fj, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fsqrt_d(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+
+    fd = float64_sqrt(fj, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_frecip_s(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_div(float32_one, (uint32_t)fj, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_frecip_d(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+
+    fd = float64_div(float64_one, fj, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_frsqrt_s(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+    uint32_t fp;
+
+    fp = float32_sqrt((uint32_t)fj, &env->fp_status);
+    fd = nanbox_s(float32_div(float32_one, fp, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_frsqrt_d(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fp, fd;
+
+    fp = float64_sqrt(fj, &env->fp_status);
+    fd = float64_div(float64_one, fp, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_flogb_s(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+    uint32_t fp;
+    float_status *status = &env->fp_status;
+    FloatRoundMode old_mode = get_float_rounding_mode(status);
+
+    set_float_rounding_mode(float_round_down, status);
+    fp = float32_log2((uint32_t)fj, status);
+    fd = nanbox_s(float32_round_to_int(fp, status));
+    set_float_rounding_mode(old_mode, status);
+    update_fcsr0_mask(env, GETPC(), float_flag_inexact);
+    return fd;
+}
+
+uint64_t helper_flogb_d(CPULoongArchState *env, uint64_t fj)
+{
+    uint64_t fd;
+    float_status *status = &env->fp_status;
+    FloatRoundMode old_mode = get_float_rounding_mode(status);
+
+    set_float_rounding_mode(float_round_down, status);
+    fd = float64_log2(fj, status);
+    fd = float64_round_to_int(fd, status);
+    set_float_rounding_mode(old_mode, status);
+    update_fcsr0_mask(env, GETPC(), float_flag_inexact);
+    return fd;
+}
+
+uint64_t helper_fclass_s(CPULoongArchState *env, uint64_t fj)
+{
+    float32 f = fj;
+    bool sign = float32_is_neg(f);
+
+    if (float32_is_infinity(f)) {
+        return sign ? 1 << 0 : 1 << 7;
+    } else if (float32_is_zero(f)) {
+        return sign ? 1 << 3 : 1 << 4;
+    } else if (float32_is_zero_or_denormal(f)) {
+        return sign ? 1 << 2 : 1 << 5;
+    } else if (float32_is_any_nan(f)) {
+        float_status s = { }; /* for snan_bit_is_one */
+        return float32_is_quiet_nan(f, &s) ? 1 << 9 : 1 << 8;
+    } else {
+        return sign ? 1 << 1 : 1 << 6;
+    }
+}
+
+uint64_t helper_fclass_d(CPULoongArchState *env, uint64_t fj)
+{
+    float64 f = fj;
+    bool sign = float64_is_neg(f);
+
+    if (float64_is_infinity(f)) {
+        return sign ? 1 << 0 : 1 << 7;
+    } else if (float64_is_zero(f)) {
+        return sign ? 1 << 3 : 1 << 4;
+    } else if (float64_is_zero_or_denormal(f)) {
+        return sign ? 1 << 2 : 1 << 5;
+    } else if (float64_is_any_nan(f)) {
+        float_status s = { }; /* for snan_bit_is_one */
+        return float64_is_quiet_nan(f, &s) ? 1 << 9 : 1 << 8;
+    } else {
+        return sign ? 1 << 1 : 1 << 6;
+    }
+}
+
+uint64_t helper_fmuladd_s(CPULoongArchState *env, uint64_t fj,
+                          uint64_t fk, uint64_t fa, uint32_t flag)
+{
+    uint64_t fd;
+
+    fd = nanbox_s(float32_muladd((uint32_t)fj, (uint32_t)fk,
+                                 (uint32_t)fa, flag, &env->fp_status));
+    update_fcsr0(env, GETPC());
+    return fd;
+}
+
+uint64_t helper_fmuladd_d(CPULoongArchState *env, uint64_t fj,
+                          uint64_t fk, uint64_t fa, uint32_t flag)
+{
+    uint64_t fd;
+
+    fd = float64_muladd(fj, fk, fa, flag, &env->fp_status);
+    update_fcsr0(env, GETPC());
+    return fd;
+}
diff --git a/target/loongarch/helper.h b/target/loongarch/helper.h
index ec6760d..d6bb412 100644
--- a/target/loongarch/helper.h
+++ b/target/loongarch/helper.h
@@ -15,3 +15,40 @@ DEF_HELPER_3(asrtgt_d, void, env, tl, tl)
 DEF_HELPER_3(crc32, tl, tl, tl, tl)
 DEF_HELPER_3(crc32c, tl, tl, tl, tl)
 DEF_HELPER_2(cpucfg, tl, env, tl)
+
+/* Floating-point helper */
+DEF_HELPER_3(fadd_s, i64, env, i64, i64)
+DEF_HELPER_3(fadd_d, i64, env, i64, i64)
+DEF_HELPER_3(fsub_s, i64, env, i64, i64)
+DEF_HELPER_3(fsub_d, i64, env, i64, i64)
+DEF_HELPER_3(fmul_s, i64, env, i64, i64)
+DEF_HELPER_3(fmul_d, i64, env, i64, i64)
+DEF_HELPER_3(fdiv_s, i64, env, i64, i64)
+DEF_HELPER_3(fdiv_d, i64, env, i64, i64)
+DEF_HELPER_3(fmax_s, i64, env, i64, i64)
+DEF_HELPER_3(fmax_d, i64, env, i64, i64)
+DEF_HELPER_3(fmin_s, i64, env, i64, i64)
+DEF_HELPER_3(fmin_d, i64, env, i64, i64)
+DEF_HELPER_3(fmaxa_s, i64, env, i64, i64)
+DEF_HELPER_3(fmaxa_d, i64, env, i64, i64)
+DEF_HELPER_3(fmina_s, i64, env, i64, i64)
+DEF_HELPER_3(fmina_d, i64, env, i64, i64)
+
+DEF_HELPER_5(fmuladd_s, i64, env, i64, i64, i64, i32)
+DEF_HELPER_5(fmuladd_d, i64, env, i64, i64, i64, i32)
+
+DEF_HELPER_3(fscaleb_s, i64, env, i64, i64)
+DEF_HELPER_3(fscaleb_d, i64, env, i64, i64)
+
+DEF_HELPER_2(flogb_s, i64, env, i64)
+DEF_HELPER_2(flogb_d, i64, env, i64)
+
+DEF_HELPER_2(fsqrt_s, i64, env, i64)
+DEF_HELPER_2(fsqrt_d, i64, env, i64)
+DEF_HELPER_2(frsqrt_s, i64, env, i64)
+DEF_HELPER_2(frsqrt_d, i64, env, i64)
+DEF_HELPER_2(frecip_s, i64, env, i64)
+DEF_HELPER_2(frecip_d, i64, env, i64)
+
+DEF_HELPER_FLAGS_2(fclass_s, TCG_CALL_NO_RWG_SE, i64, env, i64)
+DEF_HELPER_FLAGS_2(fclass_d, TCG_CALL_NO_RWG_SE, i64, env, i64)
diff --git a/target/loongarch/insn_trans/trans_farith.c.inc b/target/loongarch/insn_trans/trans_farith.c.inc
new file mode 100644
index 0000000..a2bdf33
--- /dev/null
+++ b/target/loongarch/insn_trans/trans_farith.c.inc
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ */
+
+static bool gen_fff(DisasContext *ctx, arg_fff *a,
+                    void (*func)(TCGv, TCGv_env, TCGv, TCGv))
+{
+    func(cpu_fpr[a->fd], cpu_env, cpu_fpr[a->fj], cpu_fpr[a->fk]);
+    return true;
+}
+
+static bool gen_ff(DisasContext *ctx, arg_ff *a,
+                   void (*func)(TCGv, TCGv_env, TCGv))
+{
+    func(cpu_fpr[a->fd], cpu_env, cpu_fpr[a->fj]);
+    return true;
+}
+
+static bool gen_muladd(DisasContext *ctx, arg_ffff *a,
+                       void (*func)(TCGv, TCGv_env, TCGv, TCGv, TCGv, TCGv_i32),
+                       int flag)
+{
+    TCGv_i32 tflag = tcg_constant_i32(flag);
+    func(cpu_fpr[a->fd], cpu_env, cpu_fpr[a->fj],
+         cpu_fpr[a->fk], cpu_fpr[a->fa], tflag);
+    return true;
+}
+
+static bool trans_fcopysign_s(DisasContext *ctx, arg_fff *a)
+{
+    tcg_gen_deposit_i64(cpu_fpr[a->fd], cpu_fpr[a->fk], cpu_fpr[a->fj], 0, 31);
+    return true;
+}
+
+static bool trans_fcopysign_d(DisasContext *ctx, arg_fff *a)
+{
+    tcg_gen_deposit_i64(cpu_fpr[a->fd], cpu_fpr[a->fk], cpu_fpr[a->fj], 0, 63);
+    return true;
+}
+
+static bool trans_fabs_s(DisasContext *ctx, arg_ff *a)
+{
+    tcg_gen_andi_i64(cpu_fpr[a->fd], cpu_fpr[a->fj], MAKE_64BIT_MASK(0, 31));
+    gen_nanbox_s(cpu_fpr[a->fd], cpu_fpr[a->fd]);
+    return true;
+}
+
+static bool trans_fabs_d(DisasContext *ctx, arg_ff *a)
+{
+    tcg_gen_andi_i64(cpu_fpr[a->fd], cpu_fpr[a->fj], MAKE_64BIT_MASK(0, 63));
+    return true;
+}
+
+static bool trans_fneg_s(DisasContext *ctx, arg_ff *a)
+{
+    tcg_gen_xori_i64(cpu_fpr[a->fd], cpu_fpr[a->fj], 0x80000000);
+    gen_nanbox_s(cpu_fpr[a->fd], cpu_fpr[a->fd]);
+    return true;
+}
+
+static bool trans_fneg_d(DisasContext *ctx, arg_ff *a)
+{
+    tcg_gen_xori_i64(cpu_fpr[a->fd], cpu_fpr[a->fj], 0x8000000000000000LL);
+    return true;
+}
+
+TRANS(fadd_s, gen_fff, gen_helper_fadd_s)
+TRANS(fadd_d, gen_fff, gen_helper_fadd_d)
+TRANS(fsub_s, gen_fff, gen_helper_fsub_s)
+TRANS(fsub_d, gen_fff, gen_helper_fsub_d)
+TRANS(fmul_s, gen_fff, gen_helper_fmul_s)
+TRANS(fmul_d, gen_fff, gen_helper_fmul_d)
+TRANS(fdiv_s, gen_fff, gen_helper_fdiv_s)
+TRANS(fdiv_d, gen_fff, gen_helper_fdiv_d)
+TRANS(fmax_s, gen_fff, gen_helper_fmax_s)
+TRANS(fmax_d, gen_fff, gen_helper_fmax_d)
+TRANS(fmin_s, gen_fff, gen_helper_fmin_s)
+TRANS(fmin_d, gen_fff, gen_helper_fmin_d)
+TRANS(fmaxa_s, gen_fff, gen_helper_fmaxa_s)
+TRANS(fmaxa_d, gen_fff, gen_helper_fmaxa_d)
+TRANS(fmina_s, gen_fff, gen_helper_fmina_s)
+TRANS(fmina_d, gen_fff, gen_helper_fmina_d)
+TRANS(fscaleb_s, gen_fff, gen_helper_fscaleb_s)
+TRANS(fscaleb_d, gen_fff, gen_helper_fscaleb_d)
+TRANS(fsqrt_s, gen_ff, gen_helper_fsqrt_s)
+TRANS(fsqrt_d, gen_ff, gen_helper_fsqrt_d)
+TRANS(frecip_s, gen_ff, gen_helper_frecip_s)
+TRANS(frecip_d, gen_ff, gen_helper_frecip_d)
+TRANS(frsqrt_s, gen_ff, gen_helper_frsqrt_s)
+TRANS(frsqrt_d, gen_ff, gen_helper_frsqrt_d)
+TRANS(flogb_s, gen_ff, gen_helper_flogb_s)
+TRANS(flogb_d, gen_ff, gen_helper_flogb_d)
+TRANS(fclass_s, gen_ff, gen_helper_fclass_s)
+TRANS(fclass_d, gen_ff, gen_helper_fclass_d)
+TRANS(fmadd_s, gen_muladd, gen_helper_fmuladd_s, 0)
+TRANS(fmadd_d, gen_muladd, gen_helper_fmuladd_d, 0)
+TRANS(fmsub_s, gen_muladd, gen_helper_fmuladd_s, float_muladd_negate_c)
+TRANS(fmsub_d, gen_muladd, gen_helper_fmuladd_d, float_muladd_negate_c)
+TRANS(fnmadd_s, gen_muladd, gen_helper_fmuladd_s,
+      float_muladd_negate_product | float_muladd_negate_c)
+TRANS(fnmadd_d, gen_muladd, gen_helper_fmuladd_d,
+      float_muladd_negate_product | float_muladd_negate_c)
+TRANS(fnmsub_s, gen_muladd, gen_helper_fmuladd_s, float_muladd_negate_product)
+TRANS(fnmsub_d, gen_muladd, gen_helper_fmuladd_d, float_muladd_negate_product)
diff --git a/target/loongarch/insns.decode b/target/loongarch/insns.decode
index 8dca6f2..28a2f5e 100644
--- a/target/loongarch/insns.decode
+++ b/target/loongarch/insns.decode
@@ -23,6 +23,9 @@
 &rrr_sa       rd rj rk sa
 &rr_2bw       rd rj msbw lsbw
 &rr_2bd       rd rj msbd lsbd
+&ff           fd fj
+&fff          fd fj fk
+&ffff         fd fj fk fa
 
 #
 # Formats
@@ -44,6 +47,9 @@
 @rrr_sa3         .... ........ .. sa:3 rk:5 rj:5 rd:5    &rrr_sa
 @rr_2bw        .... ....... msbw:5 . lsbw:5 rj:5 rd:5    &rr_2bw
 @rr_2bd           .... ...... msbd:6 lsbd:6 rj:5 rd:5    &rr_2bd
+@ff               .... ........ ..... ..... fj:5 fd:5    &ff
+@fff               .... ........ ..... fk:5 fj:5 fd:5    &fff
+@ffff               .... ........ fa:5 fk:5 fj:5 fd:5    &ffff
 
 #
 # Fixed point arithmetic operation instruction
@@ -259,3 +265,49 @@ rdtimel_w       0000 00000000 00000 11000 ..... .....    @rr
 rdtimeh_w       0000 00000000 00000 11001 ..... .....    @rr
 rdtime_d        0000 00000000 00000 11010 ..... .....    @rr
 cpucfg          0000 00000000 00000 11011 ..... .....    @rr
+
+#
+# Floating point arithmetic operation instruction
+#
+fadd_s          0000 00010000 00001 ..... ..... .....    @fff
+fadd_d          0000 00010000 00010 ..... ..... .....    @fff
+fsub_s          0000 00010000 00101 ..... ..... .....    @fff
+fsub_d          0000 00010000 00110 ..... ..... .....    @fff
+fmul_s          0000 00010000 01001 ..... ..... .....    @fff
+fmul_d          0000 00010000 01010 ..... ..... .....    @fff
+fdiv_s          0000 00010000 01101 ..... ..... .....    @fff
+fdiv_d          0000 00010000 01110 ..... ..... .....    @fff
+fmadd_s         0000 10000001 ..... ..... ..... .....    @ffff
+fmadd_d         0000 10000010 ..... ..... ..... .....    @ffff
+fmsub_s         0000 10000101 ..... ..... ..... .....    @ffff
+fmsub_d         0000 10000110 ..... ..... ..... .....    @ffff
+fnmadd_s        0000 10001001 ..... ..... ..... .....    @ffff
+fnmadd_d        0000 10001010 ..... ..... ..... .....    @ffff
+fnmsub_s        0000 10001101 ..... ..... ..... .....    @ffff
+fnmsub_d        0000 10001110 ..... ..... ..... .....    @ffff
+fmax_s          0000 00010000 10001 ..... ..... .....    @fff
+fmax_d          0000 00010000 10010 ..... ..... .....    @fff
+fmin_s          0000 00010000 10101 ..... ..... .....    @fff
+fmin_d          0000 00010000 10110 ..... ..... .....    @fff
+fmaxa_s         0000 00010000 11001 ..... ..... .....    @fff
+fmaxa_d         0000 00010000 11010 ..... ..... .....    @fff
+fmina_s         0000 00010000 11101 ..... ..... .....    @fff
+fmina_d         0000 00010000 11110 ..... ..... .....    @fff
+fabs_s          0000 00010001 01000 00001 ..... .....    @ff
+fabs_d          0000 00010001 01000 00010 ..... .....    @ff
+fneg_s          0000 00010001 01000 00101 ..... .....    @ff
+fneg_d          0000 00010001 01000 00110 ..... .....    @ff
+fsqrt_s         0000 00010001 01000 10001 ..... .....    @ff
+fsqrt_d         0000 00010001 01000 10010 ..... .....    @ff
+frecip_s        0000 00010001 01000 10101 ..... .....    @ff
+frecip_d        0000 00010001 01000 10110 ..... .....    @ff
+frsqrt_s        0000 00010001 01000 11001 ..... .....    @ff
+frsqrt_d        0000 00010001 01000 11010 ..... .....    @ff
+fscaleb_s       0000 00010001 00001 ..... ..... .....    @fff
+fscaleb_d       0000 00010001 00010 ..... ..... .....    @fff
+flogb_s         0000 00010001 01000 01001 ..... .....    @ff
+flogb_d         0000 00010001 01000 01010 ..... .....    @ff
+fcopysign_s     0000 00010001 00101 ..... ..... .....    @fff
+fcopysign_d     0000 00010001 00110 ..... ..... .....    @fff
+fclass_s        0000 00010001 01000 01101 ..... .....    @ff
+fclass_d        0000 00010001 01000 01110 ..... .....    @ff
diff --git a/target/loongarch/internals.h b/target/loongarch/internals.h
index 1e69e7d..17219d4 100644
--- a/target/loongarch/internals.h
+++ b/target/loongarch/internals.h
@@ -18,4 +18,6 @@ void QEMU_NORETURN do_raise_exception(CPULoongArchState *env,
 
 const char *loongarch_exception_name(int32_t exception);
 
+void restore_fp_status(CPULoongArchState *env);
+
 #endif
diff --git a/target/loongarch/translate.c b/target/loongarch/translate.c
index ca3ee23..b7ace9e 100644
--- a/target/loongarch/translate.c
+++ b/target/loongarch/translate.c
@@ -15,6 +15,7 @@
 #include "exec/translator.h"
 #include "exec/log.h"
 #include "qemu/qemu-print.h"
+#include "fpu/softfloat.h"
 #include "translate.h"
 #include "internals.h"
 
@@ -31,6 +32,15 @@ static inline int plus_1(DisasContext *ctx, int x)
     return x + 1;
 }
 
+/*
+ * LoongArch the upper 32 bits are undefined ("can be any value").
+ * QEMU chooses to nanbox, because it is most likely to show guest bugs early.
+ */
+static void gen_nanbox_s(TCGv_i64 out, TCGv_i64 in)
+{
+    tcg_gen_ori_i64(out, in, MAKE_64BIT_MASK(32, 32));
+}
+
 void generate_exception(DisasContext *ctx, int excp)
 {
     tcg_gen_movi_tl(cpu_pc, ctx->base.pc_next);
@@ -180,6 +190,7 @@ static void gen_set_gpr(int reg_num, TCGv t, DisasExtend dst_ext)
 #include "insn_trans/trans_memory.c.inc"
 #include "insn_trans/trans_atomic.c.inc"
 #include "insn_trans/trans_extra.c.inc"
+#include "insn_trans/trans_farith.c.inc"
 
 static void loongarch_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
 {
-- 
1.8.3.1


Re: [PATCH v11 10/26] target/loongarch: Add floating point arithmetic instruction translation
Posted by Richard Henderson 1 year, 2 months ago
On 11/19/21 7:13 AM, Song Gao wrote:
> +static void update_fcsr0_mask(CPULoongArchState *env, uintptr_t pc, int mask)
> +{
> +    int flags = get_float_exception_flags(&env->fp_status);
> +
> +    set_float_exception_flags(0, &env->fp_status);
> +
> +    if (~mask) {
> +        flags = flags & (~mask);
> +    }

No need for if -- mask will always be valid.

     flags &= ~mask.

> +    if (!flags) {
> +        SET_FP_CAUSE(env->fcsr0, flags);
> +        return;
> +    }
> +
> +    flags = ieee_ex_to_loongarch(flags);
> +    SET_FP_CAUSE(env->fcsr0, flags);

It looks like this could be hoisted above the !flags check to unify the two statements.


> +/* Floating-point helper */
> +DEF_HELPER_3(fadd_s, i64, env, i64, i64)
> +DEF_HELPER_3(fadd_d, i64, env, i64, i64)
> +DEF_HELPER_3(fsub_s, i64, env, i64, i64)
> +DEF_HELPER_3(fsub_d, i64, env, i64, i64)
> +DEF_HELPER_3(fmul_s, i64, env, i64, i64)
> +DEF_HELPER_3(fmul_d, i64, env, i64, i64)
> +DEF_HELPER_3(fdiv_s, i64, env, i64, i64)
> +DEF_HELPER_3(fdiv_d, i64, env, i64, i64)
> +DEF_HELPER_3(fmax_s, i64, env, i64, i64)
> +DEF_HELPER_3(fmax_d, i64, env, i64, i64)
> +DEF_HELPER_3(fmin_s, i64, env, i64, i64)
> +DEF_HELPER_3(fmin_d, i64, env, i64, i64)
> +DEF_HELPER_3(fmaxa_s, i64, env, i64, i64)
> +DEF_HELPER_3(fmaxa_d, i64, env, i64, i64)
> +DEF_HELPER_3(fmina_s, i64, env, i64, i64)
> +DEF_HELPER_3(fmina_d, i64, env, i64, i64)
> +
> +DEF_HELPER_5(fmuladd_s, i64, env, i64, i64, i64, i32)
> +DEF_HELPER_5(fmuladd_d, i64, env, i64, i64, i64, i32)
> +
> +DEF_HELPER_3(fscaleb_s, i64, env, i64, i64)
> +DEF_HELPER_3(fscaleb_d, i64, env, i64, i64)
> +
> +DEF_HELPER_2(flogb_s, i64, env, i64)
> +DEF_HELPER_2(flogb_d, i64, env, i64)
> +
> +DEF_HELPER_2(fsqrt_s, i64, env, i64)
> +DEF_HELPER_2(fsqrt_d, i64, env, i64)
> +DEF_HELPER_2(frsqrt_s, i64, env, i64)
> +DEF_HELPER_2(frsqrt_d, i64, env, i64)
> +DEF_HELPER_2(frecip_s, i64, env, i64)
> +DEF_HELPER_2(frecip_d, i64, env, i64)

DEF_HELPER_FLAGS_N, TCG_CALL_NO_WG.


r~