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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: pbonzini@redhat.com, f4bug@amsat.org, ehabkost@redhat.com,
	cfontana@suse.de
Subject: [PATCH v2 15/50] target/i386: Introduce REX_PREFIX
Date: Fri, 14 May 2021 10:13:07 -0500	[thread overview]
Message-ID: <20210514151342.384376-16-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210514151342.384376-1-richard.henderson@linaro.org>

The existing flag, x86_64_hregs, does not accurately describe
its setting.  It is true if and only if a REX prefix has been
seen.  Yes, that affects the "h" regs, but that's secondary.

Add PREFIX_REX and include this bit in s->prefix.  Add REX_PREFIX
so that the check folds away when x86_64 is compiled out.

Fold away the reg >= 8 check, because bit 3 of the register
number comes from the REX prefix in the first place.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/i386/tcg/translate.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 7d7ab3e03d..79a37fb1a7 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -39,6 +39,7 @@
 #define PREFIX_DATA   0x08
 #define PREFIX_ADR    0x10
 #define PREFIX_VEX    0x20
+#define PREFIX_REX    0x40
 
 #ifdef TARGET_X86_64
 #define REX_X(s) ((s)->rex_x)
@@ -105,9 +106,6 @@ typedef struct DisasContext {
     int vex_v;  /* vex vvvv register, without 1's complement.  */
     CCOp cc_op;  /* current CC operation */
     bool cc_op_dirty;
-#ifdef TARGET_X86_64
-    bool x86_64_hregs;
-#endif
     int f_st;   /* currently unused */
     int tf;     /* TF cpu flag */
     int jmp_opt; /* use direct block chaining for direct jumps */
@@ -173,6 +171,12 @@ typedef struct DisasContext {
 #define LMA(S)    (((S)->flags & HF_LMA_MASK) != 0)
 #endif
 
+#ifdef TARGET_X86_64
+#define REX_PREFIX(S)  (((S)->prefix & PREFIX_REX) != 0)
+#else
+#define REX_PREFIX(S)  false
+#endif
+
 static void gen_eob(DisasContext *s);
 static void gen_jr(DisasContext *s, TCGv dest);
 static void gen_jmp(DisasContext *s, target_ulong eip);
@@ -336,14 +340,10 @@ static void gen_update_cc_op(DisasContext *s)
  */
 static inline bool byte_reg_is_xH(DisasContext *s, int reg)
 {
-    if (reg < 4) {
+    /* Any time the REX prefix is present, byte registers are uniform */
+    if (reg < 4 || REX_PREFIX(s)) {
         return false;
     }
-#ifdef TARGET_X86_64
-    if (reg >= 8 || s->x86_64_hregs) {
-        return false;
-    }
-#endif
     return true;
 }
 
@@ -4559,7 +4559,6 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
 #ifdef TARGET_X86_64
     s->rex_x = 0;
     s->rex_b = 0;
-    s->x86_64_hregs = false;
 #endif
     s->rip_offset = 0; /* for relative ip address */
     s->vex_l = 0;
@@ -4614,12 +4613,11 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
     case 0x40 ... 0x4f:
         if (CODE64(s)) {
             /* REX prefix */
+            prefixes |= PREFIX_REX;
             rex_w = (b >> 3) & 1;
             rex_r = (b & 0x4) << 1;
             s->rex_x = (b & 0x2) << 2;
             REX_B(s) = (b & 0x1) << 3;
-            /* select uniform byte register addressing */
-            s->x86_64_hregs = true;
             goto next_byte;
         }
         break;
@@ -4643,14 +4641,9 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
 
             /* 4.1.1-4.1.3: No preceding lock, 66, f2, f3, or rex prefixes. */
             if (prefixes & (PREFIX_REPZ | PREFIX_REPNZ
-                            | PREFIX_LOCK | PREFIX_DATA)) {
+                            | PREFIX_LOCK | PREFIX_DATA | PREFIX_REX)) {
                 goto illegal_op;
             }
-#ifdef TARGET_X86_64
-            if (s->x86_64_hregs) {
-                goto illegal_op;
-            }
-#endif
             rex_r = (~vex2 >> 4) & 8;
             if (b == 0xc5) {
                 /* 2-byte VEX prefix: RVVVVlpp, implied 0f leading opcode byte */
-- 
2.25.1



  parent reply	other threads:[~2021-05-14 15:23 UTC|newest]

Thread overview: 106+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-14 15:12 [PATCH v2 00/50] target/i386 translate cleanups Richard Henderson
2021-05-14 15:12 ` [PATCH v2 01/50] target/i386: Split out gen_exception_gpf Richard Henderson
2021-05-18  9:08   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 02/50] target/i386: Split out check_cpl0 Richard Henderson
2021-05-18  9:10   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 03/50] target/i386: Unify code paths for IRET Richard Henderson
2021-05-18  9:11   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 04/50] target/i386: Split out check_vm86_iopl Richard Henderson
2021-05-18  9:48   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 05/50] target/i386: Split out check_iopl Richard Henderson
2021-05-18  9:14   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 06/50] target/i386: Assert PE is set for user-only Richard Henderson
2021-05-18  9:15   ` Paolo Bonzini
2021-05-14 15:12 ` [PATCH v2 07/50] target/i386: Assert CPL is 3 " Richard Henderson
2021-05-18  9:17   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 08/50] target/i386: Assert IOPL is 0 " Richard Henderson
2021-05-18  9:18   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 09/50] target/i386: Assert !VM86 for x86_64 user-only Richard Henderson
2021-05-18  9:19   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 10/50] target/i386: Assert CODE32 " Richard Henderson
2021-05-18  9:20   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 11/50] target/i386: Assert SS32 " Richard Henderson
2021-05-18  9:20   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 12/50] target/i386: Assert CODE64 " Richard Henderson
2021-05-18  9:21   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 13/50] target/i386: Assert LMA " Richard Henderson
2021-05-18  9:21   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 14/50] target/i386: Assert !ADDSEG " Richard Henderson
2021-05-18  9:23   ` Paolo Bonzini
2021-05-14 15:13 ` Richard Henderson [this message]
2021-05-18  9:26   ` [PATCH v2 15/50] target/i386: Introduce REX_PREFIX Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 16/50] target/i386: Tidy REX_B, REX_X definition Richard Henderson
2021-05-18  9:28   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 17/50] target/i386: Move rex_r into DisasContext Richard Henderson
2021-05-18  9:28   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 18/50] target/i386: Move rex_w " Richard Henderson
2021-05-18  9:30   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 19/50] target/i386: Remove DisasContext.f_st as unused Richard Henderson
2021-05-18  9:30   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 20/50] target/i386: Reduce DisasContext.flags to uint32_t Richard Henderson
2021-05-18  9:30   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 21/50] target/i386: Reduce DisasContext.override to int8_t Richard Henderson
2021-05-18  9:31   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 22/50] target/i386: Reduce DisasContext.prefix to uint8_t Richard Henderson
2021-05-18  9:31   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 23/50] target/i386: Reduce DisasContext.vex_[lv] " Richard Henderson
2021-05-18  9:32   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 24/50] target/i386: Reduce DisasContext popl_esp_hack and rip_offset " Richard Henderson
2021-05-18  9:34   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 25/50] target/i386: Leave TF in DisasContext.flags Richard Henderson
2021-05-18  9:36   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 26/50] target/i386: Reduce DisasContext jmp_opt, repz_opt to bool Richard Henderson
2021-05-18  9:36   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 27/50] target/i386: Fix the comment for repz_opt Richard Henderson
2021-05-18  9:48   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 28/50] target/i386: Reorder DisasContext members Richard Henderson
2021-05-18  9:49   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 29/50] target/i386: Add stub generator for helper_set_dr Richard Henderson
2021-05-18  9:49   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 30/50] target/i386: Assert !SVME for user-only Richard Henderson
2021-05-18  9:51   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 31/50] target/i386: Assert !GUEST " Richard Henderson
2021-05-18  9:51   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 32/50] target/i386: Implement skinit in translate.c Richard Henderson
2021-05-18  9:51   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 33/50] target/i386: Eliminate SVM helpers for user-only Richard Henderson
2021-05-18  9:52   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 34/50] target/i386: Mark some helpers as noreturn Richard Henderson
2021-05-18  9:56   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 35/50] target/i386: Simplify gen_debug usage Richard Henderson
2021-05-18  9:56   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 36/50] target/i386: Tidy svm_check_intercept from tcg Richard Henderson
2021-05-18  9:57   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 37/50] target/i386: Remove pc_start argument to gen_svm_check_intercept Richard Henderson
2021-05-18  9:58   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 38/50] target/i386: Remove user stub for cpu_vmexit Richard Henderson
2021-05-18  9:58   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 39/50] target/i386: Cleanup read_crN, write_crN, lmsw Richard Henderson
2021-05-18 10:30   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 40/50] target/i386: Pass env to do_pause and do_hlt Richard Henderson
2021-05-18  9:59   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 41/50] target/i386: Move invlpg, hlt, monitor, mwait to sysemu Richard Henderson
2021-05-18 10:00   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 42/50] target/i386: Unify invlpg, invlpga Richard Henderson
2021-05-18 10:00   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 43/50] target/i386: Inline user cpu_svm_check_intercept_param Richard Henderson
2021-05-18 10:01   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 44/50] target/i386: Eliminate user stubs for read/write_crN, rd/wrmsr Richard Henderson
2021-05-18 10:01   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 45/50] target/i386: Exit tb after wrmsr Richard Henderson
2021-05-18 10:02   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 46/50] target/i386: Tidy gen_check_io Richard Henderson
2021-05-18 10:18   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 47/50] target/i386: Pass in port to gen_check_io Richard Henderson
2021-05-18 10:20   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 48/50] target/i386: Create helper_check_io Richard Henderson
2021-05-18 10:21   ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 49/50] target/i386: Move helper_check_io to sysemu Richard Henderson
2021-05-14 17:45   ` Richard Henderson
2021-05-18 10:22     ` Paolo Bonzini
2021-05-14 15:13 ` [PATCH v2 50/50] target/i386: Remove user-only i/o stubs Richard Henderson
2021-05-18 10:23   ` Paolo Bonzini
2021-05-14 16:09 ` [PATCH v2 00/50] target/i386 translate cleanups no-reply
2021-05-18 10:31 ` Paolo Bonzini
2021-05-18 10:59   ` Richard Henderson
2021-05-18 12:33     ` Paolo Bonzini

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