subject:"\[PATCH v4 2\/4\] target\/s390x\: Emulate CVB, CVBY and CVBG"

Re: Re: [PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

2024-02-05 Thread Ilya Leoshkevich

On Mon, Feb 05, 2024 at 06:04:27PM +0100, Thomas Huth wrote:
> On 02/02/2024 15.11, Ilya Leoshkevich wrote:
> > Convert to Binary - counterparts of the already implemented Convert
> > to Decimal (CVD*) instructions.
> > Example from the Principles of Operation: 25594C becomes 63FA.
> > 
> > Co-developed-by: Pavel Zbitskiy 
> > Signed-off-by: Ilya Leoshkevich 
> > ---
> >   target/s390x/helper.h|  2 +
> >   target/s390x/tcg/insn-data.h.inc |  4 ++
> >   target/s390x/tcg/int_helper.c| 72 
> >   target/s390x/tcg/translate.c | 16 +++
> >   4 files changed, 94 insertions(+)

[...]

> > +uint64_t HELPER(cvbg)(CPUS390XState *env, Int128 dec)
> > +{
> > +uint64_t dec64[] = {int128_getlo(dec), int128_gethi(dec)};
> > +int64_t bin = 0, pow10, tmp;
> > +int digit, i, sign;
> > +
> > +sign = dec64[0] & 0xf;
> > +if (sign < 0xa) {
> > +tcg_s390_data_exception(env, 0, GETPC());
> > +}
> > +dec64[0] >>= 4;
> > +pow10 = (sign == 0xb || sign == 0xd) ? -1 : 1;
> > +
> > +for (i = 1; i < 20; i++) {
> > +digit = dec64[i >> 4] & 0xf;
> > +if (digit > 0x9) {
> > +tcg_s390_data_exception(env, 0, GETPC());
> > +}
> > +dec64[i >> 4] >>= 4;
> > +tmp = pow10 * digit;
> > +if (digit && ((tmp ^ pow10) < 0)) {
> 
> That tmp ^ pow10 caused some frowning for me first, but it's just a check
> whether the sign changed, right? ... a comment in front of the line might be
> helpful.

Good point about writing a comment, I tried to elaborate why checking
the sign is justified, and realized that it's actually redundant.
The int64_t bounds are roughly +-9.2E+18, and the last pow10 value in
this loop is +-1E+18. The multiplication cannot overflow.

> > +tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
> > +}
> > +tmp = bin + tmp;
> > +if (bin && ((tmp ^ bin) < 0)) {

The addition, however, can, e.g., bin=9E+17 and tmp=9E+18.
So I'll send a v5 without the first check and with a comment.

[...]

Re: [PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

2024-02-05 Thread Thomas Huth


On 02/02/2024 15.11, Ilya Leoshkevich wrote:

Convert to Binary - counterparts of the already implemented Convert
to Decimal (CVD*) instructions.
Example from the Principles of Operation: 25594C becomes 63FA.

Co-developed-by: Pavel Zbitskiy 
Signed-off-by: Ilya Leoshkevich 
---
  target/s390x/helper.h|  2 +
  target/s390x/tcg/insn-data.h.inc |  4 ++
  target/s390x/tcg/int_helper.c| 72 
  target/s390x/tcg/translate.c | 16 +++
  4 files changed, 94 insertions(+)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 332a9a9c632..cc1c20e9e3f 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -88,6 +88,8 @@ DEF_HELPER_FLAGS_3(tcxb, TCG_CALL_NO_RWG_SE, i32, env, i128, 
i64)
  DEF_HELPER_FLAGS_2(sqeb, TCG_CALL_NO_WG, i64, env, i64)
  DEF_HELPER_FLAGS_2(sqdb, TCG_CALL_NO_WG, i64, env, i64)
  DEF_HELPER_FLAGS_2(sqxb, TCG_CALL_NO_WG, i128, env, i128)
+DEF_HELPER_3(cvb, void, env, i32, i64)
+DEF_HELPER_FLAGS_2(cvbg, TCG_CALL_NO_WG, i64, env, i128)
  DEF_HELPER_FLAGS_1(cvd, TCG_CALL_NO_RWG_SE, i64, s32)
  DEF_HELPER_FLAGS_1(cvdg, TCG_CALL_NO_RWG_SE, i128, s64)
  DEF_HELPER_FLAGS_4(pack, TCG_CALL_NO_WG, void, env, i32, i64, i64)
diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 388dcb8dbbc..e7d61cdec28 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -293,6 +293,10 @@
  D(0xec73, CLFIT,   RIE_a, GIE, r1_32u, i2_16u, 0, 0, ct, 0, 1)
  D(0xec71, CLGIT,   RIE_a, GIE, r1_o, i2_16u, 0, 0, ct, 0, 1)
  
+/* CONVERT TO BINARY */

+C(0x4f00, CVB, RX_a,  Z,   la2, 0, 0, 0, cvb, 0)
+C(0xe306, CVBY,RXY_a, LD,  la2, 0, 0, 0, cvb, 0)
+C(0xe30e, CVBG,RXY_a, Z,   la2, 0, r1, 0, cvbg, 0)
  /* CONVERT TO DECIMAL */
  C(0x4e00, CVD, RX_a,  Z,   r1_o, a2, 0, 0, cvd, 0)
  C(0xe326, CVDY,RXY_a, LD,  r1_o, a2, 0, 0, cvd, 0)
diff --git a/target/s390x/tcg/int_helper.c b/target/s390x/tcg/int_helper.c
index 121e3006a65..17974375e98 100644
--- a/target/s390x/tcg/int_helper.c
+++ b/target/s390x/tcg/int_helper.c
@@ -25,6 +25,7 @@
  #include "exec/exec-all.h"
  #include "qemu/host-utils.h"
  #include "exec/helper-proto.h"
+#include "exec/cpu_ldst.h"
  
  /* #define DEBUG_HELPER */

  #ifdef DEBUG_HELPER
@@ -98,6 +99,77 @@ Int128 HELPER(divu64)(CPUS390XState *env, uint64_t ah, 
uint64_t al, uint64_t b)
  tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  }
  
+void HELPER(cvb)(CPUS390XState *env, uint32_t r1, uint64_t dec)

+{
+int64_t pow10 = 1, bin = 0;
+int digit, sign;
+
+sign = dec & 0xf;
+if (sign < 0xa) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec >>= 4;
+
+while (dec) {
+digit = dec & 0xf;
+if (digit > 0x9) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec >>= 4;
+bin += digit * pow10;
+pow10 *= 10;
+}
+
+if (sign == 0xb || sign == 0xd) {
+bin = -bin;
+}
+
+/* R1 is updated even on fixed-point-divide exception. */
+env->regs[r1] = (env->regs[r1] & 0xULL) | (uint32_t)bin;
+if (bin != (int32_t)bin) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+}
+
+uint64_t HELPER(cvbg)(CPUS390XState *env, Int128 dec)
+{
+uint64_t dec64[] = {int128_getlo(dec), int128_gethi(dec)};
+int64_t bin = 0, pow10, tmp;
+int digit, i, sign;
+
+sign = dec64[0] & 0xf;
+if (sign < 0xa) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec64[0] >>= 4;
+pow10 = (sign == 0xb || sign == 0xd) ? -1 : 1;
+
+for (i = 1; i < 20; i++) {
+digit = dec64[i >> 4] & 0xf;
+if (digit > 0x9) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec64[i >> 4] >>= 4;
+tmp = pow10 * digit;
+if (digit && ((tmp ^ pow10) < 0)) {


That tmp ^ pow10 caused some frowning for me first, but it's just a check 
whether the sign changed, right? ... a comment in front of the line might be 
helpful.



+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+tmp = bin + tmp;
+if (bin && ((tmp ^ bin) < 0)) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+bin = tmp;
+pow10 *= 10;
+}
+
+g_assert(!dec64[0]);
+if (dec64[1]) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+
+return bin;
+}


Patch looks sane to me now, but I'd appreciate if Richard and/or David could 
have a look at this, too!


 Thomas

[PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

2024-02-02 Thread Ilya Leoshkevich

Convert to Binary - counterparts of the already implemented Convert
to Decimal (CVD*) instructions.
Example from the Principles of Operation: 25594C becomes 63FA.

Co-developed-by: Pavel Zbitskiy 
Signed-off-by: Ilya Leoshkevich 
---
 target/s390x/helper.h|  2 +
 target/s390x/tcg/insn-data.h.inc |  4 ++
 target/s390x/tcg/int_helper.c| 72 
 target/s390x/tcg/translate.c | 16 +++
 4 files changed, 94 insertions(+)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 332a9a9c632..cc1c20e9e3f 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -88,6 +88,8 @@ DEF_HELPER_FLAGS_3(tcxb, TCG_CALL_NO_RWG_SE, i32, env, i128, 
i64)
 DEF_HELPER_FLAGS_2(sqeb, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_2(sqdb, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_2(sqxb, TCG_CALL_NO_WG, i128, env, i128)
+DEF_HELPER_3(cvb, void, env, i32, i64)
+DEF_HELPER_FLAGS_2(cvbg, TCG_CALL_NO_WG, i64, env, i128)
 DEF_HELPER_FLAGS_1(cvd, TCG_CALL_NO_RWG_SE, i64, s32)
 DEF_HELPER_FLAGS_1(cvdg, TCG_CALL_NO_RWG_SE, i128, s64)
 DEF_HELPER_FLAGS_4(pack, TCG_CALL_NO_WG, void, env, i32, i64, i64)
diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 388dcb8dbbc..e7d61cdec28 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -293,6 +293,10 @@
 D(0xec73, CLFIT,   RIE_a, GIE, r1_32u, i2_16u, 0, 0, ct, 0, 1)
 D(0xec71, CLGIT,   RIE_a, GIE, r1_o, i2_16u, 0, 0, ct, 0, 1)
 
+/* CONVERT TO BINARY */
+C(0x4f00, CVB, RX_a,  Z,   la2, 0, 0, 0, cvb, 0)
+C(0xe306, CVBY,RXY_a, LD,  la2, 0, 0, 0, cvb, 0)
+C(0xe30e, CVBG,RXY_a, Z,   la2, 0, r1, 0, cvbg, 0)
 /* CONVERT TO DECIMAL */
 C(0x4e00, CVD, RX_a,  Z,   r1_o, a2, 0, 0, cvd, 0)
 C(0xe326, CVDY,RXY_a, LD,  r1_o, a2, 0, 0, cvd, 0)
diff --git a/target/s390x/tcg/int_helper.c b/target/s390x/tcg/int_helper.c
index 121e3006a65..17974375e98 100644
--- a/target/s390x/tcg/int_helper.c
+++ b/target/s390x/tcg/int_helper.c
@@ -25,6 +25,7 @@
 #include "exec/exec-all.h"
 #include "qemu/host-utils.h"
 #include "exec/helper-proto.h"
+#include "exec/cpu_ldst.h"
 
 /* #define DEBUG_HELPER */
 #ifdef DEBUG_HELPER
@@ -98,6 +99,77 @@ Int128 HELPER(divu64)(CPUS390XState *env, uint64_t ah, 
uint64_t al, uint64_t b)
 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
 }
 
+void HELPER(cvb)(CPUS390XState *env, uint32_t r1, uint64_t dec)
+{
+int64_t pow10 = 1, bin = 0;
+int digit, sign;
+
+sign = dec & 0xf;
+if (sign < 0xa) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec >>= 4;
+
+while (dec) {
+digit = dec & 0xf;
+if (digit > 0x9) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec >>= 4;
+bin += digit * pow10;
+pow10 *= 10;
+}
+
+if (sign == 0xb || sign == 0xd) {
+bin = -bin;
+}
+
+/* R1 is updated even on fixed-point-divide exception. */
+env->regs[r1] = (env->regs[r1] & 0xULL) | (uint32_t)bin;
+if (bin != (int32_t)bin) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+}
+
+uint64_t HELPER(cvbg)(CPUS390XState *env, Int128 dec)
+{
+uint64_t dec64[] = {int128_getlo(dec), int128_gethi(dec)};
+int64_t bin = 0, pow10, tmp;
+int digit, i, sign;
+
+sign = dec64[0] & 0xf;
+if (sign < 0xa) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec64[0] >>= 4;
+pow10 = (sign == 0xb || sign == 0xd) ? -1 : 1;
+
+for (i = 1; i < 20; i++) {
+digit = dec64[i >> 4] & 0xf;
+if (digit > 0x9) {
+tcg_s390_data_exception(env, 0, GETPC());
+}
+dec64[i >> 4] >>= 4;
+tmp = pow10 * digit;
+if (digit && ((tmp ^ pow10) < 0)) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+tmp = bin + tmp;
+if (bin && ((tmp ^ bin) < 0)) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+bin = tmp;
+pow10 *= 10;
+}
+
+g_assert(!dec64[0]);
+if (dec64[1]) {
+tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+}
+
+return bin;
+}
+
 uint64_t HELPER(cvd)(int32_t reg)
 {
 /* positive 0 */
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index c2fdc920a50..325b25959d3 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -2223,6 +2223,22 @@ static DisasJumpType op_csp(DisasContext *s, DisasOps *o)
 }
 #endif
 
+static DisasJumpType op_cvb(DisasContext *s, DisasOps *o)
+{
+TCGv_i64 t = tcg_temp_new_i64();
+tcg_gen_qemu_ld_i64(t, o->addr1, get_mem_index(s), MO_TEUQ);
+gen_helper_cvb(tcg_env, tcg_constant_i32(get_field(s, r1)), t);
+return DISAS_NEXT;
+}
+
+static DisasJumpType op_cvbg(DisasContext *s, DisasOps *o)
+{
+TCGv_i128 t = tcg_temp_new_i128();
+tcg_gen_qemu_ld_i128(t,

Re: Re: [PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

Re: [PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

[PATCH v4 2/4] target/s390x: Emulate CVB, CVBY and CVBG

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