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target/sparc: Remove CC_OP_DIV
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Return both result and overflow from helper_[us]div.
Compute all flags explicitly in gen_op_[us]divcc.

Marginally improve the INT64_MIN special case in helper_sdiv.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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@rth7680
rth7680 committed Nov 5, 2023
1 parent 2a45b73 commit 1326010
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Showing 5 changed files with 93 additions and 110 deletions.
33 changes: 0 additions & 33 deletions target/sparc/cc_helper.c
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Original file line number Diff line number Diff line change
Expand Up @@ -47,30 +47,6 @@ static inline uint32_t get_NZ_xcc(target_long dst)
}
#endif

static inline uint32_t get_V_div_icc(target_ulong src2)
{
uint32_t ret = 0;

if (src2 != 0) {
ret = PSR_OVF;
}
return ret;
}

static uint32_t compute_all_div(CPUSPARCState *env)
{
uint32_t ret;

ret = get_NZ_icc(CC_DST);
ret |= get_V_div_icc(CC_SRC2);
return ret;
}

static uint32_t compute_C_div(CPUSPARCState *env)
{
return 0;
}

static inline uint32_t get_C_add_icc(uint32_t dst, uint32_t src1)
{
uint32_t ret = 0;
Expand Down Expand Up @@ -378,21 +354,13 @@ static uint32_t compute_all_tsubtv(CPUSPARCState *env)
return ret;
}

#ifdef TARGET_SPARC64
static uint32_t compute_all_logic_xcc(CPUSPARCState *env)
{
return get_NZ_xcc(CC_DST);
}
#endif

typedef struct CCTable {
uint32_t (*compute_all)(CPUSPARCState *env); /* return all the flags */
uint32_t (*compute_c)(CPUSPARCState *env); /* return the C flag */
} CCTable;

static const CCTable icc_table[CC_OP_NB] = {
/* CC_OP_DYNAMIC should never happen */
[CC_OP_DIV] = { compute_all_div, compute_C_div },
[CC_OP_ADD] = { compute_all_add, compute_C_add },
[CC_OP_ADDX] = { compute_all_addx, compute_C_addx },
[CC_OP_TADD] = { compute_all_tadd, compute_C_add },
Expand All @@ -406,7 +374,6 @@ static const CCTable icc_table[CC_OP_NB] = {
#ifdef TARGET_SPARC64
static const CCTable xcc_table[CC_OP_NB] = {
/* CC_OP_DYNAMIC should never happen */
[CC_OP_DIV] = { compute_all_logic_xcc, compute_C_div },
[CC_OP_ADD] = { compute_all_add_xcc, compute_C_add_xcc },
[CC_OP_ADDX] = { compute_all_addx_xcc, compute_C_addx_xcc },
[CC_OP_TADD] = { compute_all_add_xcc, compute_C_add_xcc },
Expand Down
1 change: 0 additions & 1 deletion target/sparc/cpu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,6 @@ enum {
enum {
CC_OP_DYNAMIC, /* must use dynamic code to get cc_op */
CC_OP_FLAGS, /* all cc are back in cc_*_[NZCV] registers */
CC_OP_DIV, /* modify N, Z and V, C = 0*/
CC_OP_ADD, /* modify all flags, CC_DST = res, CC_SRC = src1 */
CC_OP_ADDX, /* modify all flags, CC_DST = res, CC_SRC = src1 */
CC_OP_TADD, /* modify all flags, CC_DST = res, CC_SRC = src1 */
Expand Down
93 changes: 33 additions & 60 deletions target/sparc/helper.c
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Original file line number Diff line number Diff line change
Expand Up @@ -81,79 +81,52 @@ void helper_tick_set_limit(void *opaque, uint64_t limit)
}
#endif

static target_ulong do_udiv(CPUSPARCState *env, target_ulong a,
target_ulong b, int cc, uintptr_t ra)
uint64_t helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
{
int overflow = 0;
uint64_t x0;
uint32_t x1;
uint64_t a64 = (uint32_t)a | ((uint64_t)env->y << 32);
uint32_t b32 = b;
uint32_t r;

x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
x1 = (b & 0xffffffff);

if (x1 == 0) {
cpu_raise_exception_ra(env, TT_DIV_ZERO, ra);
}

x0 = x0 / x1;
if (x0 > UINT32_MAX) {
x0 = UINT32_MAX;
overflow = 1;
if (b32 == 0) {
cpu_raise_exception_ra(env, TT_DIV_ZERO, GETPC());
}

if (cc) {
env->cc_src2 = overflow;
a64 /= b32;
r = a64;
if (unlikely(a64 > UINT32_MAX)) {
return -1; /* r = UINT32_MAX, v = 1 */
}
return x0;
return r;
}

target_ulong helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
uint64_t helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
{
return do_udiv(env, a, b, 0, GETPC());
}
int64_t a64 = (uint32_t)a | ((uint64_t)env->y << 32);
int32_t b32 = b;
int32_t r;

target_ulong helper_udiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
{
return do_udiv(env, a, b, 1, GETPC());
}

static target_ulong do_sdiv(CPUSPARCState *env, target_ulong a,
target_ulong b, int cc, uintptr_t ra)
{
int overflow = 0;
int64_t x0;
int32_t x1;

x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
x1 = (b & 0xffffffff);

if (x1 == 0) {
cpu_raise_exception_ra(env, TT_DIV_ZERO, ra);
} else if (x1 == -1 && x0 == INT64_MIN) {
x0 = INT32_MAX;
overflow = 1;
} else {
x0 = x0 / x1;
if ((int32_t) x0 != x0) {
x0 = x0 < 0 ? INT32_MIN : INT32_MAX;
overflow = 1;
}
if (b32 == 0) {
cpu_raise_exception_ra(env, TT_DIV_ZERO, GETPC());
}

if (cc) {
env->cc_src2 = overflow;
if (unlikely(a64 == INT64_MIN)) {
/*
* Special case INT64_MIN / -1 is required to avoid trap on x86 host.
* However, with a dividend of INT64_MIN, there is no 32-bit divisor
* which can yield a 32-bit result:
* INT64_MIN / INT32_MIN = 0x1_0000_0000
* INT64_MIN / INT32_MAX = -0x1_0000_0002
* Therefore we know we must overflow and saturate.
*/
return (uint32_t)(b32 < 0 ? INT32_MAX : INT32_MIN) | (-1ull << 32);
}
return x0;
}

target_ulong helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
{
return do_sdiv(env, a, b, 0, GETPC());
}

target_ulong helper_sdiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
{
return do_sdiv(env, a, b, 1, GETPC());
a64 /= b;
r = a64;
if (unlikely(r != a64)) {
return (uint32_t)(a64 < 0 ? INT32_MIN : INT32_MAX) | (-1ull << 32);
}
return (uint32_t)r;
}

#ifdef TARGET_SPARC64
Expand Down
6 changes: 2 additions & 4 deletions target/sparc/helper.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,10 +27,8 @@ DEF_HELPER_FLAGS_2(tick_set_limit, TCG_CALL_NO_RWG, void, ptr, i64)
DEF_HELPER_1(debug, void, env)
DEF_HELPER_1(save, void, env)
DEF_HELPER_1(restore, void, env)
DEF_HELPER_3(udiv, tl, env, tl, tl)
DEF_HELPER_3(udiv_cc, tl, env, tl, tl)
DEF_HELPER_3(sdiv, tl, env, tl, tl)
DEF_HELPER_3(sdiv_cc, tl, env, tl, tl)
DEF_HELPER_FLAGS_3(udiv, TCG_CALL_NO_WG, i64, env, tl, tl)
DEF_HELPER_FLAGS_3(sdiv, TCG_CALL_NO_WG, i64, env, tl, tl)
DEF_HELPER_3(taddcctv, tl, env, tl, tl)
DEF_HELPER_3(tsubcctv, tl, env, tl, tl)
#ifdef TARGET_SPARC64
Expand Down
70 changes: 58 additions & 12 deletions target/sparc/translate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -693,22 +693,76 @@ static void gen_op_sdivx(TCGv dst, TCGv src1, TCGv src2)

static void gen_op_udiv(TCGv dst, TCGv src1, TCGv src2)
{
#ifdef TARGET_SPARC64
gen_helper_udiv(dst, tcg_env, src1, src2);
tcg_gen_ext32u_tl(dst, dst);
#else
TCGv_i64 t64 = tcg_temp_new_i64();
gen_helper_udiv(t64, tcg_env, src1, src2);
tcg_gen_trunc_i64_tl(dst, t64);
#endif
}

static void gen_op_sdiv(TCGv dst, TCGv src1, TCGv src2)
{
#ifdef TARGET_SPARC64
gen_helper_sdiv(dst, tcg_env, src1, src2);
tcg_gen_ext32s_tl(dst, dst);
#else
TCGv_i64 t64 = tcg_temp_new_i64();
gen_helper_sdiv(t64, tcg_env, src1, src2);
tcg_gen_trunc_i64_tl(dst, t64);
#endif
}

static void gen_op_udivcc(TCGv dst, TCGv src1, TCGv src2)
{
gen_helper_udiv_cc(dst, tcg_env, src1, src2);
TCGv_i64 t64;

#ifdef TARGET_SPARC64
t64 = cpu_cc_V;
#else
t64 = tcg_temp_new_i64();
#endif

gen_helper_udiv(t64, tcg_env, src1, src2);

#ifdef TARGET_SPARC64
tcg_gen_ext32u_tl(cpu_cc_N, t64);
tcg_gen_shri_tl(cpu_cc_V, t64, 32);
tcg_gen_mov_tl(cpu_icc_Z, cpu_cc_N);
tcg_gen_movi_tl(cpu_icc_C, 0);
#else
tcg_gen_extr_i64_tl(cpu_cc_N, cpu_cc_V, t64);
#endif
tcg_gen_mov_tl(cpu_cc_Z, cpu_cc_N);
tcg_gen_movi_tl(cpu_cc_C, 0);
tcg_gen_mov_tl(dst, cpu_cc_N);
}

static void gen_op_sdivcc(TCGv dst, TCGv src1, TCGv src2)
{
gen_helper_sdiv_cc(dst, tcg_env, src1, src2);
TCGv_i64 t64;

#ifdef TARGET_SPARC64
t64 = cpu_cc_V;
#else
t64 = tcg_temp_new_i64();
#endif

gen_helper_sdiv(t64, tcg_env, src1, src2);

#ifdef TARGET_SPARC64
tcg_gen_ext32s_tl(cpu_cc_N, t64);
tcg_gen_shri_tl(cpu_cc_V, t64, 32);
tcg_gen_mov_tl(cpu_icc_Z, cpu_cc_N);
tcg_gen_movi_tl(cpu_icc_C, 0);
#else
tcg_gen_extr_i64_tl(cpu_cc_N, cpu_cc_V, t64);
#endif
tcg_gen_mov_tl(cpu_cc_Z, cpu_cc_N);
tcg_gen_movi_tl(cpu_cc_C, 0);
tcg_gen_mov_tl(dst, cpu_cc_N);
}

static void gen_op_taddcctv(TCGv dst, TCGv src1, TCGv src2)
Expand Down Expand Up @@ -3717,8 +3771,8 @@ TRANS(SMUL, MUL, do_logic, a, gen_op_smul, NULL)

TRANS(UDIVX, 64, do_arith, a, -1, gen_op_udivx, NULL, NULL)
TRANS(SDIVX, 64, do_arith, a, -1, gen_op_sdivx, NULL, NULL)
TRANS(UDIV, DIV, do_arith, a, CC_OP_DIV, gen_op_udiv, NULL, gen_op_udivcc)
TRANS(SDIV, DIV, do_arith, a, CC_OP_DIV, gen_op_sdiv, NULL, gen_op_sdivcc)
TRANS(UDIV, DIV, do_arith, a, CC_OP_FLAGS, gen_op_udiv, NULL, gen_op_udivcc)
TRANS(SDIV, DIV, do_arith, a, CC_OP_FLAGS, gen_op_sdiv, NULL, gen_op_sdivcc)

/* TODO: Should have feature bit -- comes in with UltraSparc T2. */
TRANS(POPC, 64, do_arith, a, -1, gen_op_popc, NULL, NULL)
Expand All @@ -3743,10 +3797,6 @@ static bool trans_OR(DisasContext *dc, arg_r_r_ri_cc *a)
static bool trans_ADDC(DisasContext *dc, arg_r_r_ri_cc *a)
{
switch (dc->cc_op) {
case CC_OP_DIV:
/* Carry is known to be zero. Fall back to plain ADD. */
return do_arith(dc, a, CC_OP_ADD,
tcg_gen_add_tl, tcg_gen_addi_tl, gen_op_add_cc);
case CC_OP_ADD:
case CC_OP_TADD:
case CC_OP_TADDTV:
Expand All @@ -3766,10 +3816,6 @@ static bool trans_ADDC(DisasContext *dc, arg_r_r_ri_cc *a)
static bool trans_SUBC(DisasContext *dc, arg_r_r_ri_cc *a)
{
switch (dc->cc_op) {
case CC_OP_DIV:
/* Carry is known to be zero. Fall back to plain SUB. */
return do_arith(dc, a, CC_OP_SUB,
tcg_gen_sub_tl, tcg_gen_subi_tl, gen_op_sub_cc);
case CC_OP_ADD:
case CC_OP_TADD:
case CC_OP_TADDTV:
Expand Down

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