[PATCH 04/11] target/i386: cleanup PAUSE helpers

[Paolo Bonzini <pbonzini@redhat.com>]

Use decode.c's support for intercepts, doing the check in TCG-generated
code rather than the helper.  This is cleaner because it allows removing
the eip_addend argument to helper_pause(), even though it adds a bit of
bloat for opcode 0x90's new decoding function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/helper.h                 |  2 +-
 target/i386/tcg/helper-tcg.h         |  1 -
 target/i386/tcg/misc_helper.c        | 10 +---------
 target/i386/tcg/sysemu/misc_helper.c |  2 +-
 target/i386/tcg/decode-new.c.inc     | 15 ++++++++++++++-
 target/i386/tcg/emit.c.inc           | 20 ++++++++------------
 6 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/target/i386/helper.h b/target/i386/helper.h
index c244dbb4812..2f46cffabd8 100644
--- a/target/i386/helper.h
+++ b/target/i386/helper.h
@@ -53,7 +53,7 @@ DEF_HELPER_1(sysenter, void, env)
 DEF_HELPER_2(sysexit, void, env, int)
 DEF_HELPER_2(syscall, void, env, int)
 DEF_HELPER_2(sysret, void, env, int)
-DEF_HELPER_FLAGS_2(pause, TCG_CALL_NO_WG, noreturn, env, int)
+DEF_HELPER_FLAGS_1(pause, TCG_CALL_NO_WG, noreturn, env)
 DEF_HELPER_FLAGS_3(raise_interrupt, TCG_CALL_NO_WG, noreturn, env, int, int)
 DEF_HELPER_FLAGS_2(raise_exception, TCG_CALL_NO_WG, noreturn, env, int)
 DEF_HELPER_FLAGS_1(icebp, TCG_CALL_NO_WG, noreturn, env)
diff --git a/target/i386/tcg/helper-tcg.h b/target/i386/tcg/helper-tcg.h
index 6a5505e7b4c..43180b58314 100644
--- a/target/i386/tcg/helper-tcg.h
+++ b/target/i386/tcg/helper-tcg.h
@@ -91,7 +91,6 @@ extern const uint8_t parity_table[256];
 
 /* misc_helper.c */
 void cpu_load_eflags(CPUX86State *env, int eflags, int update_mask);
-G_NORETURN void do_pause(CPUX86State *env);
 
 /* sysemu/svm_helper.c */
 #ifndef CONFIG_USER_ONLY
diff --git a/target/i386/tcg/misc_helper.c b/target/i386/tcg/misc_helper.c
index b0f0f7b893b..8316d42ffcd 100644
--- a/target/i386/tcg/misc_helper.c
+++ b/target/i386/tcg/misc_helper.c
@@ -88,7 +88,7 @@ G_NORETURN void helper_rdpmc(CPUX86State *env)
     raise_exception_err(env, EXCP06_ILLOP, 0);
 }
 
-G_NORETURN void do_pause(CPUX86State *env)
+G_NORETURN void helper_pause(CPUX86State *env)
 {
     CPUState *cs = env_cpu(env);
 
@@ -97,14 +97,6 @@ G_NORETURN void do_pause(CPUX86State *env)
     cpu_loop_exit(cs);
 }
 
-G_NORETURN void helper_pause(CPUX86State *env, int next_eip_addend)
-{
-    cpu_svm_check_intercept_param(env, SVM_EXIT_PAUSE, 0, GETPC());
-    env->eip += next_eip_addend;
-
-    do_pause(env);
-}
-
 uint64_t helper_rdpkru(CPUX86State *env, uint32_t ecx)
 {
     if ((env->cr[4] & CR4_PKE_MASK) == 0) {
diff --git a/target/i386/tcg/sysemu/misc_helper.c b/target/i386/tcg/sysemu/misc_helper.c
index e41c88346cb..093cc2d0f90 100644
--- a/target/i386/tcg/sysemu/misc_helper.c
+++ b/target/i386/tcg/sysemu/misc_helper.c
@@ -547,7 +547,7 @@ G_NORETURN void helper_mwait(CPUX86State *env, int next_eip_addend)
 
     /* XXX: not complete but not completely erroneous */
     if (cs->cpu_index != 0 || CPU_NEXT(cs) != NULL) {
-        do_pause(env);
+        helper_pause(env);
     } else {
         helper_hlt(env);
     }
diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.c.inc
index 376d2bdabe1..c2d8da8d14e 100644
--- a/target/i386/tcg/decode-new.c.inc
+++ b/target/i386/tcg/decode-new.c.inc
@@ -1359,6 +1359,19 @@ static void decode_group11(DisasContext *s, CPUX86State *env, X86OpEntry *entry,
     }
 }
 
+static void decode_90(DisasContext *s, CPUX86State *env, X86OpEntry *entry, uint8_t *b)
+{
+    static X86OpEntry pause = X86_OP_ENTRY0(PAUSE, svm(PAUSE));
+    static X86OpEntry nop = X86_OP_ENTRY0(NOP);
+    static X86OpEntry xchg_ax = X86_OP_ENTRY2(XCHG, 0,v, LoBits,v);
+
+    if (REX_B(s)) {
+        *entry = xchg_ax;
+    } else {
+        *entry = (s->prefix & PREFIX_REPZ) ? pause : nop;
+    }
+}
+
 static const X86OpEntry opcodes_root[256] = {
     [0x00] = X86_OP_ENTRY2(ADD, E,b, G,b, lock),
     [0x01] = X86_OP_ENTRY2(ADD, E,v, G,v, lock),
@@ -1441,7 +1454,7 @@ static const X86OpEntry opcodes_root[256] = {
     [0x86] = X86_OP_ENTRY2(XCHG, E,b, G,b, xchg),
     [0x87] = X86_OP_ENTRY2(XCHG, E,v, G,v, xchg),
 
-    [0x90] = X86_OP_ENTRY2(XCHG, 0,v, LoBits,v),
+    [0x90] = X86_OP_GROUP0(90),
     [0x91] = X86_OP_ENTRY2(XCHG, 0,v, LoBits,v),
     [0x92] = X86_OP_ENTRY2(XCHG, 0,v, LoBits,v),
     [0x93] = X86_OP_ENTRY2(XCHG, 0,v, LoBits,v),
diff --git a/target/i386/tcg/emit.c.inc b/target/i386/tcg/emit.c.inc
index 2e94e8ec56f..f90f3d3c589 100644
--- a/target/i386/tcg/emit.c.inc
+++ b/target/i386/tcg/emit.c.inc
@@ -2350,6 +2350,14 @@ static void gen_PANDN(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
                       decode->op[1].offset, vec_len, vec_len);
 }
 
+static void gen_PAUSE(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
+{
+    gen_update_cc_op(s);
+    gen_update_eip_next(s);
+    gen_helper_pause(tcg_env);
+    s->base.is_jmp = DISAS_NORETURN;
+}
+
 static void gen_PCMPESTRI(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
 {
     TCGv_i32 imm = tcg_constant8u_i32(decode->immediate);
@@ -4014,18 +4022,6 @@ static void gen_WAIT(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
 
 static void gen_XCHG(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
 {
-    if (decode->b == 0x90 && !REX_B(s)) {
-        if (s->prefix & PREFIX_REPZ) {
-            gen_update_cc_op(s);
-            gen_update_eip_cur(s);
-            gen_helper_pause(tcg_env, cur_insn_len_i32(s));
-            s->base.is_jmp = DISAS_NORETURN;
-        }
-        /* No writeback.  */
-        decode->op[0].unit = X86_OP_SKIP;
-        return;
-    }
-
     if (s->prefix & PREFIX_LOCK) {
         tcg_gen_atomic_xchg_tl(s->T0, s->A0, s->T1,
                                s->mem_index, decode->op[0].ot | MO_LE);
-- 
2.45.1