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[2/9] target/s390x: Use a single return for helper_divs64/u64

Message ID 20221021073006.2398819-3-richard.henderson@linaro.org
State New
Headers show
Series target/s390x: Use Int128 for float128 and retxl | expand

Commit Message

Richard Henderson Oct. 21, 2022, 7:29 a.m. UTC 
Pack the quotient and remainder into a single Int128.
Use the divu128 primitive to remove the cpu_abort on
32-bit hosts.

This is the first use of Int128 as a return value.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/s390x/helper.h         |  4 ++--
 target/s390x/tcg/int_helper.c | 38 +++++++++--------------------------
 target/s390x/tcg/translate.c  | 14 +++++++++----
 3 files changed, 21 insertions(+), 35 deletions(-)

Comments

Philippe Mathieu-Daudé Oct. 24, 2022, 1:16 p.m. UTC | #1 
On 21/10/22 09:29, Richard Henderson wrote:
> Pack the quotient and remainder into a single Int128.
> Use the divu128 primitive to remove the cpu_abort on
> 32-bit hosts.
> 
> This is the first use of Int128 as a return value.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/s390x/helper.h         |  4 ++--
>   target/s390x/tcg/int_helper.c | 38 +++++++++--------------------------
>   target/s390x/tcg/translate.c  | 14 +++++++++----
>   3 files changed, 21 insertions(+), 35 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Ilya Leoshkevich Oct. 25, 2022, 8:47 p.m. UTC | #2 
On Fri, Oct 21, 2022 at 05:29:59PM +1000, Richard Henderson wrote:
> Pack the quotient and remainder into a single Int128.
> Use the divu128 primitive to remove the cpu_abort on
> 32-bit hosts.
> 
> This is the first use of Int128 as a return value.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
diff mbox series

Patch

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 97a9668eef..29986557ed 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -12,8 +12,8 @@  DEF_HELPER_3(clcl, i32, env, i32, i32)
 DEF_HELPER_FLAGS_4(clm, TCG_CALL_NO_WG, i32, env, i32, i32, i64)
 DEF_HELPER_FLAGS_3(divs32, TCG_CALL_NO_WG, i64, env, s64, s64)
 DEF_HELPER_FLAGS_3(divu32, TCG_CALL_NO_WG, i64, env, i64, i64)
-DEF_HELPER_FLAGS_3(divs64, TCG_CALL_NO_WG, s64, env, s64, s64)
-DEF_HELPER_FLAGS_4(divu64, TCG_CALL_NO_WG, i64, env, i64, i64, i64)
+DEF_HELPER_FLAGS_3(divs64, TCG_CALL_NO_WG, i128, env, s64, s64)
+DEF_HELPER_FLAGS_4(divu64, TCG_CALL_NO_WG, i128, env, i64, i64, i64)
 DEF_HELPER_3(srst, void, env, i32, i32)
 DEF_HELPER_3(srstu, void, env, i32, i32)
 DEF_HELPER_4(clst, i64, env, i64, i64, i64)
diff --git a/target/s390x/tcg/int_helper.c b/target/s390x/tcg/int_helper.c
index 130b8bd4d2..7dc919a102 100644
--- a/target/s390x/tcg/int_helper.c
+++ b/target/s390x/tcg/int_helper.c
@@ -76,46 +76,26 @@  uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
 }
 
 /* 64/64 -> 64 signed division */
-int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
+Int128 HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
 {
     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
     if (b == 0 || (b == -1 && a == (1ll << 63))) {
         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
     }
-    env->retxl = a % b;
-    return a / b;
+    return int128_make128(a % b, a / b);
 }
 
 /* 128 -> 64/64 unsigned division */
-uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
-                        uint64_t b)
+Int128 HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al, uint64_t b)
 {
-    uint64_t ret;
-    /* Signal divide by zero.  */
-    if (b == 0) {
-        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
-    }
-    if (ah == 0) {
-        /* 64 -> 64/64 case */
-        env->retxl = al % b;
-        ret = al / b;
-    } else {
-        /* ??? Move i386 idivq helper to host-utils.  */
-#ifdef CONFIG_INT128
-        __uint128_t a = ((__uint128_t)ah << 64) | al;
-        __uint128_t q = a / b;
-        env->retxl = a % b;
-        ret = q;
-        if (ret != q) {
-            tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
+    if (b != 0) {
+        uint64_t r = divu128(&al, &ah, b);
+        if (ah == 0) {
+            return int128_make128(r, al);
         }
-#else
-        /* 32-bit hosts would need special wrapper functionality - just abort if
-           we encounter such a case; it's very unlikely anyways. */
-        cpu_abort(env_cpu(env), "128 -> 64/64 division not implemented\n");
-#endif
     }
-    return ret;
+    /* divide by zero or overflow */
+    tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
 }
 
 uint64_t HELPER(cvd)(int32_t reg)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 525317c9df..a3f5a55891 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -2411,15 +2411,21 @@  static DisasJumpType op_divu32(DisasContext *s, DisasOps *o)
 
 static DisasJumpType op_divs64(DisasContext *s, DisasOps *o)
 {
-    gen_helper_divs64(o->out2, cpu_env, o->in1, o->in2);
-    return_low128(o->out);
+    TCGv_i128 t = tcg_temp_new_i128();
+
+    gen_helper_divs64(t, cpu_env, o->in1, o->in2);
+    tcg_gen_extr_i128_i64(o->out, o->out2, t);
+    tcg_temp_free_i128(t);
     return DISAS_NEXT;
 }
 
 static DisasJumpType op_divu64(DisasContext *s, DisasOps *o)
 {
-    gen_helper_divu64(o->out2, cpu_env, o->out, o->out2, o->in2);
-    return_low128(o->out);
+    TCGv_i128 t = tcg_temp_new_i128();
+
+    gen_helper_divu64(t, cpu_env, o->out, o->out2, o->in2);
+    tcg_gen_extr_i128_i64(o->out, o->out2, t);
+    tcg_temp_free_i128(t);
     return DISAS_NEXT;
 }