[PATCH] target/i386: clean up AAM/AAD

[PATCH] target/i386: clean up AAM/AAD

[Paolo Bonzini]

The 32-bit AAM/AAD opcodes are using helpers that read and write flags and
env->regs[R_EAX].  Clean them up so that the table correctly includes AX
as a 16-bit input and output.

No real reason to do it to be honest, but they are nice one-output helpers
and it removes the masking of env->regs[R_EAX] that generic load/writeback
code already does.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/helper.h             |  4 ++--
 target/i386/tcg/int_helper.c     | 19 ++++++++-----------
 target/i386/tcg/decode-new.c.inc |  4 ++--
 target/i386/tcg/emit.c.inc       |  8 ++++----
 4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/target/i386/helper.h b/target/i386/helper.h
index 3c207ac62d6..a52a1bf0f21 100644
--- a/target/i386/helper.h
+++ b/target/i386/helper.h
@@ -22,8 +22,8 @@ DEF_HELPER_FLAGS_5(bndstx32, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
 DEF_HELPER_FLAGS_5(bndstx64, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
 DEF_HELPER_1(bnd_jmp, void, env)
 
-DEF_HELPER_2(aam, void, env, int)
-DEF_HELPER_2(aad, void, env, int)
+DEF_HELPER_FLAGS_2(aam, TCG_CALL_NO_RWG_SE, tl, tl, tl)
+DEF_HELPER_FLAGS_2(aad, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_1(aaa, void, env)
 DEF_HELPER_1(aas, void, env)
 DEF_HELPER_1(daa, void, env)
diff --git a/target/i386/tcg/int_helper.c b/target/i386/tcg/int_helper.c
index df16130f5df..4cc59f15203 100644
--- a/target/i386/tcg/int_helper.c
+++ b/target/i386/tcg/int_helper.c
@@ -145,27 +145,24 @@ void helper_idivl_EAX(CPUX86State *env, target_ulong t0)
 
 /* bcd */
 
-/* XXX: exception */
-void helper_aam(CPUX86State *env, int base)
+target_ulong helper_aam(target_ulong al, target_ulong base)
 {
-    int al, ah;
+    int ah;
 
-    al = env->regs[R_EAX] & 0xff;
+    al &= 0xff;
     ah = al / base;
     al = al % base;
-    env->regs[R_EAX] = (env->regs[R_EAX] & ~0xffff) | al | (ah << 8);
-    CC_DST = al;
+    return al | (ah << 8);
 }
 
-void helper_aad(CPUX86State *env, int base)
+target_ulong helper_aad(target_ulong ax, target_ulong base)
 {
     int al, ah;
 
-    al = env->regs[R_EAX] & 0xff;
-    ah = (env->regs[R_EAX] >> 8) & 0xff;
+    al = ax & 0xff;
+    ah = (ax >> 8) & 0xff;
     al = ((ah * base) + al) & 0xff;
-    env->regs[R_EAX] = (env->regs[R_EAX] & ~0xffff) | al;
-    CC_DST = al;
+    return al;
 }
 
 void helper_aaa(CPUX86State *env)
diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.c.inc
index 141ab2bc560..27dc1bb146b 100644
--- a/target/i386/tcg/decode-new.c.inc
+++ b/target/i386/tcg/decode-new.c.inc
@@ -1480,8 +1480,8 @@ static const X86OpEntry opcodes_root[256] = {
     [0xD1] = X86_OP_GROUP1(group2, E,v),
     [0xD2] = X86_OP_GROUP2(group2, E,b, 1,b), /* CL */
     [0xD3] = X86_OP_GROUP2(group2, E,v, 1,b), /* CL */
-    [0xD4] = X86_OP_ENTRYr(AAM, I,b),
-    [0xD5] = X86_OP_ENTRYr(AAD, I,b),
+    [0xD4] = X86_OP_ENTRY2(AAM, 0,w, I,b),
+    [0xD5] = X86_OP_ENTRY2(AAD, 0,w, I,b),
     [0xD6] = X86_OP_ENTRYw(SALC, 0,b),
     [0xD7] = X86_OP_ENTRY1(XLAT, 0,b, zextT0), /* AL read/written */
 
diff --git a/target/i386/tcg/emit.c.inc b/target/i386/tcg/emit.c.inc
index 2dee33dd487..ecfdeb1e668 100644
--- a/target/i386/tcg/emit.c.inc
+++ b/target/i386/tcg/emit.c.inc
@@ -1084,8 +1084,8 @@ static void gen_AAA(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
 
 static void gen_AAD(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
 {
-    gen_helper_aad(tcg_env, tcg_constant_i32(decode->immediate));
-    set_cc_op(s, CC_OP_LOGICB);
+    gen_helper_aad(s->T0, s->T0, s->T1);
+    prepare_update1_cc(decode, s, CC_OP_LOGICB);
 }
 
 static void gen_AAM(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
@@ -1093,8 +1093,8 @@ static void gen_AAM(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
     if (decode->immediate == 0) {
         gen_exception(s, EXCP00_DIVZ);
     } else {
-        gen_helper_aam(tcg_env, tcg_constant_i32(decode->immediate));
-        set_cc_op(s, CC_OP_LOGICB);
+        gen_helper_aam(s->T0, s->T0, s->T1);
+        prepare_update1_cc(decode, s, CC_OP_LOGICB);
     }
 }
 
-- 
2.45.1

Re: [PATCH] target/i386: clean up AAM/AAD

[Richard Henderson]

On 5/22/24 05:39, Paolo Bonzini wrote:
> The 32-bit AAM/AAD opcodes are using helpers that read and write flags and
> env->regs[R_EAX].  Clean them up so that the table correctly includes AX
> as a 16-bit input and output.
> 
> No real reason to do it to be honest, but they are nice one-output helpers
> and it removes the masking of env->regs[R_EAX] that generic load/writeback
> code already does.
> 
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> ---
>   target/i386/helper.h             |  4 ++--
>   target/i386/tcg/int_helper.c     | 19 ++++++++-----------
>   target/i386/tcg/decode-new.c.inc |  4 ++--
>   target/i386/tcg/emit.c.inc       |  8 ++++----
>   4 files changed, 16 insertions(+), 19 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~