[PATCH 1/2] target/s390x: Fix MXDB and MXDBR

[Ilya Leoshkevich <iii@linux.ibm.com>]

These instructions multiply 64 bits by 64 bits, not 128 bits by 64 bits.

Reported-by: Tulio Magno Quites Machado Filho <tuliom@redhat.com>
Fixes: 2b91240f95fd ("target/s390x: Use Int128 for passing float128")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 target/s390x/helper.h            | 2 +-
 target/s390x/tcg/fpu_helper.c    | 5 +++--
 target/s390x/tcg/insn-data.h.inc | 4 ++--
 target/s390x/tcg/translate.c     | 8 +-------
 4 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 7529e725f29..6bc01df73d7 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -50,7 +50,7 @@ DEF_HELPER_FLAGS_3(meeb, TCG_CALL_NO_WG, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(mdeb, TCG_CALL_NO_WG, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(mdb, TCG_CALL_NO_WG, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(mxb, TCG_CALL_NO_WG, i128, env, i128, i128)
-DEF_HELPER_FLAGS_3(mxdb, TCG_CALL_NO_WG, i128, env, i128, i64)
+DEF_HELPER_FLAGS_3(mxdb, TCG_CALL_NO_WG, i128, env, i64, i64)
 DEF_HELPER_FLAGS_2(ldeb, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_3(ldxb, TCG_CALL_NO_WG, i64, env, i128, i32)
 DEF_HELPER_FLAGS_2(lxdb, TCG_CALL_NO_WG, i128, env, i64)
diff --git a/target/s390x/tcg/fpu_helper.c b/target/s390x/tcg/fpu_helper.c
index 0bdab5bcf71..57e58292833 100644
--- a/target/s390x/tcg/fpu_helper.c
+++ b/target/s390x/tcg/fpu_helper.c
@@ -321,10 +321,11 @@ Int128 HELPER(mxb)(CPUS390XState *env, Int128 a, Int128 b)
 }
 
 /* 128/64-bit FP multiplication */
-Int128 HELPER(mxdb)(CPUS390XState *env, Int128 a, uint64_t f2)
+Int128 HELPER(mxdb)(CPUS390XState *env, uint64_t f1, uint64_t f2)
 {
+    float128 f1_128 = float64_to_float128(f1, &env->fpu_status);
     float128 ret = float64_to_float128(f2, &env->fpu_status);
-    ret = float128_mul(ARG128(a), ret, &env->fpu_status);
+    ret = float128_mul(f1_128, ret, &env->fpu_status);
     handle_exceptions(env, false, GETPC());
     return RET128(ret);
 }
diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 937e18ea9d9..0a45dbbcda8 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -668,11 +668,11 @@
     F(0xb31c, MDBR,    RRE,   Z,   f1, f2, new, f1, mdb, 0, IF_BFP)
     F(0xb34c, MXBR,    RRE,   Z,   x1, x2, new_x, x1, mxb, 0, IF_BFP)
     F(0xb30c, MDEBR,   RRE,   Z,   f1, e2, new, f1, mdeb, 0, IF_BFP)
-    F(0xb307, MXDBR,   RRE,   Z,   0, f2, x1, x1, mxdb, 0, IF_BFP)
+    F(0xb307, MXDBR,   RRE,   Z,   f1, f2, new_x, x1, mxdb, 0, IF_BFP)
     F(0xed17, MEEB,    RXE,   Z,   e1, m2_32u, new, e1, meeb, 0, IF_BFP)
     F(0xed1c, MDB,     RXE,   Z,   f1, m2_64, new, f1, mdb, 0, IF_BFP)
     F(0xed0c, MDEB,    RXE,   Z,   f1, m2_32u, new, f1, mdeb, 0, IF_BFP)
-    F(0xed07, MXDB,    RXE,   Z,   0, m2_64, x1, x1, mxdb, 0, IF_BFP)
+    F(0xed07, MXDB,    RXE,   Z,   f1, m2_64, new_x, x1, mxdb, 0, IF_BFP)
 /* MULTIPLY HALFWORD */
     C(0x4c00, MH,      RX_a,  Z,   r1_o, m2_16s, new, r1_32, mul, 0)
     C(0xe37c, MHY,     RXY_a, GIE, r1_o, m2_16s, new, r1_32, mul, 0)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 3eb3708d551..3ac573dfce5 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -3421,7 +3421,7 @@ static DisasJumpType op_mxb(DisasContext *s, DisasOps *o)
 
 static DisasJumpType op_mxdb(DisasContext *s, DisasOps *o)
 {
-    gen_helper_mxdb(o->out_128, cpu_env, o->in1_128, o->in2);
+    gen_helper_mxdb(o->out_128, cpu_env, o->in1, o->in2);
     return DISAS_NEXT;
 }
 
@@ -5183,12 +5183,6 @@ static void prep_r1_P(DisasContext *s, DisasOps *o)
 }
 #define SPEC_prep_r1_P SPEC_r1_even
 
-static void prep_x1(DisasContext *s, DisasOps *o)
-{
-    o->out_128 = load_freg_128(get_field(s, r1));
-}
-#define SPEC_prep_x1 SPEC_r1_f128
-
 /* ====================================================================== */
 /* The "Write OUTput" generators.  These generally perform some non-trivial
    copy of data to TCG globals, or to main memory.  The trivial cases are
-- 
2.40.1