From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 24 Apr 2024 10:20:17 +0000 (+0200)
Subject: target/i386/tcg: reuse gen_helper_fp_arith_ST0_FT0 for undocumented fcom/fcomp variants
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dcc2b436c1f94a28760e20fad4eb050e79d187cc;p=thirdparty%2Fqemu.git

target/i386/tcg: reuse gen_helper_fp_arith_ST0_FT0 for undocumented fcom/fcomp variants

For 0x32 hack the op to be fcomp; for the others there isn't even anything special
to do.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 32a371e2d9..cf5e2c158c 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -2777,10 +2777,18 @@ static void gen_x87(DisasContext *s, X86DecodedInsn *decode)
                 break;
             }
             break;
+            /* map to fcomp; op & 7 == 2 would not pop  */
+            op = 0x03;
+            /* fallthrough */
         case 0x00 ... 0x07: /* fxxx st, sti */
+        case 0x22 ... 0x23: /* fcom2 and fcomp3, undocumented ops */
+        case 0x32: /* fcomp5, undocumented op */
             gen_helper_fmov_FT0_STN(tcg_env,
                                     tcg_constant_i32(opreg));
             gen_helper_fp_arith_ST0_FT0(op & 7);
+            if (op >= 0x30) {
+                gen_helper_fpop(tcg_env);
+            }
             break;
 
         case 0x20: case 0x21: case 0x24 ... 0x27: /* fxxx sti, st */
@@ -2790,16 +2798,6 @@ static void gen_x87(DisasContext *s, X86DecodedInsn *decode)
                 gen_helper_fpop(tcg_env);
             }
             break;
-        case 0x22: /* fcom2, undocumented op */
-            gen_helper_fmov_FT0_STN(tcg_env, tcg_constant_i32(opreg));
-            gen_helper_fcom_ST0_FT0(tcg_env);
-            break;
-        case 0x23: /* fcomp3, undocumented op */
-        case 0x32: /* fcomp5, undocumented op */
-            gen_helper_fmov_FT0_STN(tcg_env, tcg_constant_i32(opreg));
-            gen_helper_fcom_ST0_FT0(tcg_env);
-            gen_helper_fpop(tcg_env);
-            break;
         case 0x15: /* da/5 */
             switch (rm) {
             case 1: /* fucompp */