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target/hppa: Fix addition '</<=' conditions 

These conditions include the signed overflow bit.  See page 5-3
of the Parisc 1.1 Architecture Reference Manual for details.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
[rth: More changes for c == 3, to compute (N^V)|Z properly.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Sven Schnelle 2019-02-11 17:12:54 -08:00 committed by Richard Henderson
parent df0232fe3d
commit b47a4a0290
1 changed files with 58 additions and 37 deletions
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95
target/hppa/translate.c
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@ -452,15 +452,19 @@ static DisasCond cond_make_n(void)
};
}
static DisasCond cond_make_0_tmp(TCGCond c, TCGv_reg a0)
{
assert (c != TCG_COND_NEVER && c != TCG_COND_ALWAYS);
return (DisasCond){
.c = c, .a0 = a0, .a1_is_0 = true
};
}
static DisasCond cond_make_0(TCGCond c, TCGv_reg a0)
{
DisasCond r = { .c = c, .a1 = NULL, .a1_is_0 = true };
assert (c != TCG_COND_NEVER && c != TCG_COND_ALWAYS);
r.a0 = tcg_temp_new();
tcg_gen_mov_reg(r.a0, a0);
return r;
TCGv_reg tmp = tcg_temp_new();
tcg_gen_mov_reg(tmp, a0);
return cond_make_0_tmp(c, tmp);
}
static DisasCond cond_make(TCGCond c, TCGv_reg a0, TCGv_reg a1)
@ -849,12 +853,20 @@ static void gen_goto_tb(DisasContext *ctx, int which,
}
}
/* The parisc documentation describes only the general interpretation of
the conditions, without describing their exact implementation. The
interpretations do not stand up well when considering ADD,C and SUB,B.
However, considering the Addition, Subtraction and Logical conditions
as a whole it would appear that these relations are similar to what
a traditional NZCV set of flags would produce. */
static bool cond_need_sv(int c)
{
return c == 2 || c == 3 || c == 6;
}
static bool cond_need_cb(int c)
{
return c == 4 || c == 5;
}
/*
* Compute conditional for arithmetic. See Page 5-3, Table 5-1, of
* the Parisc 1.1 Architecture Reference Manual for details.
*/
static DisasCond do_cond(unsigned cf, TCGv_reg res,
TCGv_reg cb_msb, TCGv_reg sv)
@ -863,17 +875,32 @@ static DisasCond do_cond(unsigned cf, TCGv_reg res,
TCGv_reg tmp;
switch (cf >> 1) {
case 0: /* Never / TR */
case 0: /* Never / TR (0 / 1) */
cond = cond_make_f();
break;
case 1: /* = / <> (Z / !Z) */
cond = cond_make_0(TCG_COND_EQ, res);
break;
case 2: /* < / >= (N / !N) */
cond = cond_make_0(TCG_COND_LT, res);
case 2: /* < / >= (N ^ V / !(N ^ V) */
tmp = tcg_temp_new();
tcg_gen_xor_reg(tmp, res, sv);
cond = cond_make_0_tmp(TCG_COND_LT, tmp);
break;
case 3: /* <= / > (N | Z / !N & !Z) */
cond = cond_make_0(TCG_COND_LE, res);
case 3: /* <= / > (N ^ V) | Z / !((N ^ V) | Z) */
/*
* Simplify:
* (N ^ V) | Z
* ((res < 0) ^ (sv < 0)) | !res
* ((res ^ sv) < 0) | !res
* (~(res ^ sv) >= 0) | !res
* !(~(res ^ sv) >> 31) | !res
* !(~(res ^ sv) >> 31 & res)
*/
tmp = tcg_temp_new();
tcg_gen_eqv_reg(tmp, res, sv);
tcg_gen_sari_reg(tmp, tmp, TARGET_REGISTER_BITS - 1);
tcg_gen_and_reg(tmp, tmp, res);
cond = cond_make_0_tmp(TCG_COND_EQ, tmp);
break;
case 4: /* NUV / UV (!C / C) */
cond = cond_make_0(TCG_COND_EQ, cb_msb);
@ -882,8 +909,7 @@ static DisasCond do_cond(unsigned cf, TCGv_reg res,
tmp = tcg_temp_new();
tcg_gen_neg_reg(tmp, cb_msb);
tcg_gen_and_reg(tmp, tmp, res);
cond = cond_make_0(TCG_COND_EQ, tmp);
tcg_temp_free(tmp);
cond = cond_make_0_tmp(TCG_COND_EQ, tmp);
break;
case 6: /* SV / NSV (V / !V) */
cond = cond_make_0(TCG_COND_LT, sv);
@ -891,8 +917,7 @@ static DisasCond do_cond(unsigned cf, TCGv_reg res,
case 7: /* OD / EV */
tmp = tcg_temp_new();
tcg_gen_andi_reg(tmp, res, 1);
cond = cond_make_0(TCG_COND_NE, tmp);
tcg_temp_free(tmp);
cond = cond_make_0_tmp(TCG_COND_NE, tmp);
break;
default:
g_assert_not_reached();
@ -930,7 +955,7 @@ static DisasCond do_sub_cond(unsigned cf, TCGv_reg res,
cond = cond_make(TCG_COND_LEU, in1, in2);
break;
default:
return do_cond(cf, res, sv, sv);
return do_cond(cf, res, NULL, sv);
}
if (cf & 1) {
cond.c = tcg_invert_cond(cond.c);
@ -1129,7 +1154,7 @@ static void do_add(DisasContext *ctx, unsigned rt, TCGv_reg in1,
in1 = tmp;
}
if (!is_l || c == 4 || c == 5) {
if (!is_l || cond_need_cb(c)) {
TCGv_reg zero = tcg_const_reg(0);
cb_msb = get_temp(ctx);
tcg_gen_add2_reg(dest, cb_msb, in1, zero, in2, zero);
@ -1151,7 +1176,7 @@ static void do_add(DisasContext *ctx, unsigned rt, TCGv_reg in1,
/* Compute signed overflow if required. */
sv = NULL;
if (is_tsv || c == 6) {
if (is_tsv || cond_need_sv(c)) {
sv = do_add_sv(ctx, dest, in1, in2);
if (is_tsv) {
/* ??? Need to include overflow from shift. */
@ -1242,7 +1267,7 @@ static void do_sub(DisasContext *ctx, unsigned rt, TCGv_reg in1,
/* Compute signed overflow if required. */
sv = NULL;
if (is_tsv || c == 6) {
if (is_tsv || cond_need_sv(c)) {
sv = do_sub_sv(ctx, dest, in1, in2);
if (is_tsv) {
gen_helper_tsv(cpu_env, sv);
@ -1314,7 +1339,7 @@ static void do_cmpclr(DisasContext *ctx, unsigned rt, TCGv_reg in1,
/* Compute signed overflow if required. */
sv = NULL;
if ((cf >> 1) == 6) {
if (cond_need_sv(cf >> 1)) {
sv = do_sub_sv(ctx, dest, in1, in2);
}
@ -2781,7 +2806,7 @@ static bool trans_ds(DisasContext *ctx, arg_rrr_cf *a)
/* Install the new nullification. */
if (a->cf) {
TCGv_reg sv = NULL;
if (a->cf >> 1 == 6) {
if (cond_need_sv(a->cf >> 1)) {
/* ??? The lshift is supposed to contribute to overflow. */
sv = do_add_sv(ctx, dest, add1, add2);
}
@ -2982,7 +3007,7 @@ static bool do_cmpb(DisasContext *ctx, unsigned r, TCGv_reg in1,
tcg_gen_sub_reg(dest, in1, in2);
sv = NULL;
if (c == 6) {
if (cond_need_sv(c)) {
sv = do_sub_sv(ctx, dest, in1, in2);
}
@ -3013,19 +3038,15 @@ static bool do_addb(DisasContext *ctx, unsigned r, TCGv_reg in1,
sv = NULL;
cb_msb = NULL;
switch (c) {
default:
tcg_gen_add_reg(dest, in1, in2);
break;
case 4: case 5:
if (cond_need_cb(c)) {
cb_msb = get_temp(ctx);
tcg_gen_movi_reg(cb_msb, 0);
tcg_gen_add2_reg(dest, cb_msb, in1, cb_msb, in2, cb_msb);
break;
case 6:
} else {
tcg_gen_add_reg(dest, in1, in2);
}
if (cond_need_sv(c)) {
sv = do_add_sv(ctx, dest, in1, in2);
break;
}
cond = do_cond(c * 2 + f, dest, cb_msb, sv);