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authorAlexander Graf <agraf@suse.de>2013-12-03 11:21:08 +0000
committerPeter Maydell <peter.maydell@linaro.org>2013-12-31 13:04:14 +0000
commit9c1d83337479c770deea547643f9a7f1a8470fb9 (patch)
tree9866bffb399a6b43ae02f30822ad299187f8aa7e
parent6705ebcffbea3ea324e979905e55bae12457a70f (diff)
downloadqemu-arm-9c1d83337479c770deea547643f9a7f1a8470fb9.tar.gz
target-arm: A64: Add "Floating-point<->fixed-point" instructions
This patch adds emulation for the instruction group labeled "Floating-point <-> fixed-point conversions" in the ARM ARM. Namely this includes the instructions SCVTF, UCVTF, FCVTZS, FCVTZU (scalar, fixed-point). Signed-off-by: Alexander Graf <agraf@suse.de> [WN: Commit message tweak, rebased, updated to new infrastructure. Applied bug fixes from Michael Matz and Janne Grunau.] Signed-off-by: Will Newton <will.newton@linaro.org> [PMM: significant cleanup] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target-arm/helper.c13
-rw-r--r--target-arm/helper.h2
-rw-r--r--target-arm/translate-a64.c186
3 files changed, 200 insertions, 1 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 7736d4bdee..5b5f24e790 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -4043,6 +4043,19 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64)
#undef VFP_CONV_FIX_FLOAT
#undef VFP_CONV_FLOAT_FIX_ROUND
+/* Set the current fp rounding mode and return the old one.
+ * The argument is a softfloat float_round_ value.
+ */
+uint32_t HELPER(set_rmode)(uint32_t rmode, CPUARMState *env)
+{
+ float_status *fp_status = &env->vfp.fp_status;
+
+ uint32_t prev_rmode = get_float_rounding_mode(fp_status);
+ set_float_rounding_mode(rmode, fp_status);
+
+ return prev_rmode;
+}
+
/* Half precision conversions. */
static float32 do_fcvt_f16_to_f32(uint32_t a, CPUARMState *env, float_status *s)
{
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 2e1af4671c..25b6b4f493 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -148,6 +148,8 @@ DEF_HELPER_3(vfp_uhtod, f64, i64, i32, ptr)
DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr)
DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr)
+DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, env)
+
DEF_HELPER_2(vfp_fcvt_f16_to_f32, f32, i32, env)
DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env)
DEF_HELPER_2(neon_fcvt_f16_to_f32, f32, i32, env)
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index c9fbf0f0f7..ec8abc708a 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -3186,6 +3186,34 @@ static void disas_data_proc_reg(DisasContext *s, uint32_t insn)
}
}
+/* Convert ARM rounding mode to softfloat */
+static inline int arm_rmode_to_sf(int rmode)
+{
+ switch (rmode) {
+ case FPROUNDING_TIEAWAY:
+ rmode = float_round_ties_away;
+ break;
+ case FPROUNDING_ODD:
+ /* FIXME: add support for TIEAWAY and ODD */
+ qemu_log_mask(LOG_UNIMP, "arm: unimplemented rounding mode: %d\n",
+ rmode);
+ case FPROUNDING_TIEEVEN:
+ default:
+ rmode = float_round_nearest_even;
+ break;
+ case FPROUNDING_POSINF:
+ rmode = float_round_up;
+ break;
+ case FPROUNDING_NEGINF:
+ rmode = float_round_down;
+ break;
+ case FPROUNDING_ZERO:
+ rmode = float_round_to_zero;
+ break;
+ }
+ return rmode;
+}
+
static void handle_fp_compare(DisasContext *s, bool is_double,
unsigned int rn, unsigned int rm,
bool cmp_with_zero, bool signal_all_nans)
@@ -3651,6 +3679,132 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
tcg_temp_free_i64(tcg_res);
}
+/* Handle floating point <=> fixed point conversions. Note that we can
+ * also deal with fp <=> integer conversions as a special case (scale == 64)
+ * OPTME: consider handling that special case specially or at least skipping
+ * the call to scalbn in the helpers for zero shifts.
+ */
+static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
+ bool itof, int rmode, int scale, int sf, int type)
+{
+ bool is_signed = !(opcode & 1);
+ bool is_double = type;
+ TCGv_ptr tcg_fpstatus;
+ TCGv_i32 tcg_shift;
+
+ tcg_fpstatus = get_fpstatus_ptr();
+
+ tcg_shift = tcg_const_i32(64 - scale);
+
+ if (itof) {
+ TCGv_i64 tcg_int = cpu_reg(s, rn);
+ if (!sf) {
+ TCGv_i64 tcg_extend = new_tmp_a64(s);
+
+ if (is_signed) {
+ tcg_gen_ext32s_i64(tcg_extend, tcg_int);
+ } else {
+ tcg_gen_ext32u_i64(tcg_extend, tcg_int);
+ }
+
+ tcg_int = tcg_extend;
+ }
+
+ if (is_double) {
+ TCGv_i64 tcg_double = tcg_temp_new_i64();
+ if (is_signed) {
+ gen_helper_vfp_sqtod(tcg_double, tcg_int,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_uqtod(tcg_double, tcg_int,
+ tcg_shift, tcg_fpstatus);
+ }
+ write_fp_dreg(s, rd, tcg_double);
+ tcg_temp_free_i64(tcg_double);
+ } else {
+ TCGv_i32 tcg_single = tcg_temp_new_i32();
+ if (is_signed) {
+ gen_helper_vfp_sqtos(tcg_single, tcg_int,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_uqtos(tcg_single, tcg_int,
+ tcg_shift, tcg_fpstatus);
+ }
+ write_fp_sreg(s, rd, tcg_single);
+ tcg_temp_free_i32(tcg_single);
+ }
+ } else {
+ TCGv_i64 tcg_int = cpu_reg(s, rd);
+ TCGv_i32 tcg_rmode;
+
+ if (extract32(opcode, 2, 1)) {
+ /* There are too many rounding modes to all fit into rmode,
+ * so FCVTA[US] is a special case.
+ */
+ rmode = FPROUNDING_TIEAWAY;
+ }
+
+ tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rmode));
+
+ gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env);
+
+ if (is_double) {
+ TCGv_i64 tcg_double = read_fp_dreg(s, rn);
+ if (is_signed) {
+ if (!sf) {
+ gen_helper_vfp_tosld(tcg_int, tcg_double,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_tosqd(tcg_int, tcg_double,
+ tcg_shift, tcg_fpstatus);
+ }
+ } else {
+ if (!sf) {
+ gen_helper_vfp_tould(tcg_int, tcg_double,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_touqd(tcg_int, tcg_double,
+ tcg_shift, tcg_fpstatus);
+ }
+ }
+ tcg_temp_free_i64(tcg_double);
+ } else {
+ TCGv_i32 tcg_single = read_fp_sreg(s, rn);
+ if (sf) {
+ if (is_signed) {
+ gen_helper_vfp_tosqs(tcg_int, tcg_single,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_touqs(tcg_int, tcg_single,
+ tcg_shift, tcg_fpstatus);
+ }
+ } else {
+ TCGv_i32 tcg_dest = tcg_temp_new_i32();
+ if (is_signed) {
+ gen_helper_vfp_tosls(tcg_dest, tcg_single,
+ tcg_shift, tcg_fpstatus);
+ } else {
+ gen_helper_vfp_touls(tcg_dest, tcg_single,
+ tcg_shift, tcg_fpstatus);
+ }
+ tcg_gen_extu_i32_i64(tcg_int, tcg_dest);
+ tcg_temp_free_i32(tcg_dest);
+ }
+ tcg_temp_free_i32(tcg_single);
+ }
+
+ gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env);
+ tcg_temp_free_i32(tcg_rmode);
+
+ if (!sf) {
+ tcg_gen_ext32u_i64(tcg_int, tcg_int);
+ }
+ }
+
+ tcg_temp_free_ptr(tcg_fpstatus);
+ tcg_temp_free_i32(tcg_shift);
+}
+
/* C3.6.29 Floating point <-> fixed point conversions
* 31 30 29 28 24 23 22 21 20 19 18 16 15 10 9 5 4 0
* +----+---+---+-----------+------+---+-------+--------+-------+------+------+
@@ -3659,7 +3813,37 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
*/
static void disas_fp_fixed_conv(DisasContext *s, uint32_t insn)
{
- unsupported_encoding(s, insn);
+ int rd = extract32(insn, 0, 5);
+ int rn = extract32(insn, 5, 5);
+ int scale = extract32(insn, 10, 6);
+ int opcode = extract32(insn, 16, 3);
+ int rmode = extract32(insn, 19, 2);
+ int type = extract32(insn, 22, 2);
+ bool sbit = extract32(insn, 29, 1);
+ bool sf = extract32(insn, 31, 1);
+ bool itof;
+
+ if (sbit || (type > 1)
+ || (!sf && scale < 32)) {
+ unallocated_encoding(s);
+ return;
+ }
+
+ switch ((rmode << 3) | opcode) {
+ case 0x2: /* SCVTF */
+ case 0x3: /* UCVTF */
+ itof = true;
+ break;
+ case 0x18: /* FCVTZS */
+ case 0x19: /* FCVTZU */
+ itof = false;
+ break;
+ default:
+ unallocated_encoding(s);
+ return;
+ }
+
+ handle_fpfpcvt(s, rd, rn, opcode, itof, FPROUNDING_ZERO, scale, sf, type);
}
static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof)