target/s390x: fix COMPARE LOGICAL LONG EXTENDED

There are multiple issues with the COMPARE LOGICAL LONG EXTENDED
instruction:
- The test between the two operands is inverted, leading to an inversion
  of the cc values 1 and 2.
- The address and length of an operand continue to be decreased after
  reaching the end of this operand. These values are then wrong write
  back to the registers.
- We should limit the amount of bytes to process, so that interrupts can
  be served correctly.

At the same time rename dest into src1 and src into src3 to match the
operand names and make the code less confusing.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170531220129.27724-18-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 15 insertions, 5 deletions

diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index a21de0967a..ecd0a91c04 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -1922,11 +1922,21 @@ static ExitStatus op_clc(DisasContext *s, DisasOps *o)
 
 static ExitStatus op_clcle(DisasContext *s, DisasOps *o)
 {
-    TCGv_i32 r1 = tcg_const_i32(get_field(s->fields, r1));
-    TCGv_i32 r3 = tcg_const_i32(get_field(s->fields, r3));
-    gen_helper_clcle(cc_op, cpu_env, r1, o->in2, r3);
-    tcg_temp_free_i32(r1);
-    tcg_temp_free_i32(r3);
+    int r1 = get_field(s->fields, r1);
+    int r3 = get_field(s->fields, r3);
+    TCGv_i32 t1, t3;
+
+    /* r1 and r3 must be even.  */
+    if (r1 & 1 || r3 & 1) {
+        gen_program_exception(s, PGM_SPECIFICATION);
+        return EXIT_NORETURN;
+    }
+
+    t1 = tcg_const_i32(r1);
+    t3 = tcg_const_i32(r3);
+    gen_helper_clcle(cc_op, cpu_env, t1, o->in2, t3);
+    tcg_temp_free_i32(t1);
+    tcg_temp_free_i32(t3);
     set_cc_static(s);
     return NO_EXIT;
 }