[Qemu-devel] [PATCH v3 14/18] target/s390x: Tidy SRST

[Richard Henderson]

Since we require all registers saved on input, read R0 from ENV instead
of passing it manually.  Recognize the specification exception when R0
contains incorrect data.

Signed-off-by: Richard Henderson <r...@twiddle.net>
---
 target/s390x/helper.h     |  2 +-
 target/s390x/mem_helper.c | 11 ++++++++---
 target/s390x/translate.c  |  2 +-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index c014820..cd51b89 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -12,7 +12,7 @@ DEF_HELPER_FLAGS_3(divs32, TCG_CALL_NO_WG, s64, 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_4(srst, i64, env, i64, i64, i64)
+DEF_HELPER_3(srst, i64, env, i64, i64)
 DEF_HELPER_4(clst, i64, env, i64, i64, i64)
 DEF_HELPER_FLAGS_4(mvn, TCG_CALL_NO_WG, void, env, i32, i64, i64)
 DEF_HELPER_FLAGS_4(mvo, TCG_CALL_NO_WG, void, env, i32, i64, i64)
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index df082f5..990858e 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -538,12 +538,17 @@ static inline void set_length(CPUS390XState *env, int 
reg, uint64_t length)
 }
 
 /* search string (c is byte to search, r2 is string, r1 end of string) */
-uint64_t HELPER(srst)(CPUS390XState *env, uint64_t r0, uint64_t end,
-                      uint64_t str)
+uint64_t HELPER(srst)(CPUS390XState *env, uint64_t end, uint64_t str)
 {
     uintptr_t ra = GETPC();
     uint32_t len;
-    uint8_t v, c = r0;
+    uint8_t v, c = env->regs[0];
+
+    /* Bits 32-55 must contain all 0.  */
+    if (env->regs[0] & 0xffffff00u) {
+        cpu_restore_state(ENV_GET_CPU(env), ra);
+        program_interrupt(env, PGM_SPECIFICATION, 6);
+    }
 
     str = wrap_address(env, str);
     end = wrap_address(env, end);
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index f8989ec..4a860f1 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -4256,7 +4256,7 @@ static ExitStatus op_stpq(DisasContext *s, DisasOps *o)
 
 static ExitStatus op_srst(DisasContext *s, DisasOps *o)
 {
-    gen_helper_srst(o->in1, cpu_env, regs[0], o->in1, o->in2);
+    gen_helper_srst(o->in1, cpu_env, o->in1, o->in2);
     set_cc_static(s);
     return_low128(o->in2);
     return NO_EXIT;
-- 
2.9.4