target-i386: make it clearer that op table accesses don't overrun

Rephrase some of the expressions used to select an entry
in the SSE op table arrays so that it's clearer that they
don't overrun the op table array size.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

diff --git a/target-i386/translate.c b/target-i386/translate.c
index 5899e09245267c7bb18dd76126c5ff6ca773c7f1..1988dae2908becea7db17fd892182bca4f9431ce 100644 (file)
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -2964,16 +2964,16 @@ static const SSEFunc_0_pl sse_op_table3aq[] = {
 
 static const SSEFunc_i_p sse_op_table3bi[] = {
     gen_helper_cvttss2si,
-    gen_helper_cvttsd2si,
     gen_helper_cvtss2si,
+    gen_helper_cvttsd2si,
     gen_helper_cvtsd2si
 };
 
 #ifdef TARGET_X86_64
 static const SSEFunc_l_p sse_op_table3bq[] = {
     gen_helper_cvttss2sq,
-    gen_helper_cvttsd2sq,
     gen_helper_cvtss2sq,
+    gen_helper_cvttsd2sq,
     gen_helper_cvtsd2sq
 };
 #endif
@@ -3571,12 +3571,12 @@ static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
             op1_offset = offsetof(CPUX86State,xmm_regs[reg]);
             tcg_gen_addi_ptr(cpu_ptr0, cpu_env, op1_offset);
             if (ot == OT_LONG) {
-                SSEFunc_0_pi sse_fn_pi = sse_op_table3ai[(b >> 8) - 2];
+                SSEFunc_0_pi sse_fn_pi = sse_op_table3ai[(b >> 8) & 1];
                 tcg_gen_trunc_tl_i32(cpu_tmp2_i32, cpu_T[0]);
                 sse_fn_pi(cpu_ptr0, cpu_tmp2_i32);
             } else {
 #ifdef TARGET_X86_64
-                SSEFunc_0_pl sse_fn_pl = sse_op_table3aq[(b >> 8) - 2];
+                SSEFunc_0_pl sse_fn_pl = sse_op_table3aq[(b >> 8) & 1];
                 sse_fn_pl(cpu_ptr0, cpu_T[0]);
 #else
                 goto illegal_op;
@@ -3635,13 +3635,13 @@ static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
             tcg_gen_addi_ptr(cpu_ptr0, cpu_env, op2_offset);
             if (ot == OT_LONG) {
                 SSEFunc_i_p sse_fn_i_p =
-                    sse_op_table3bi[(b >> 8) - 2 + (b & 1) * 2];
+                    sse_op_table3bi[((b >> 7) & 2) | (b & 1)];
                 sse_fn_i_p(cpu_tmp2_i32, cpu_ptr0);
                 tcg_gen_extu_i32_tl(cpu_T[0], cpu_tmp2_i32);
             } else {
 #ifdef TARGET_X86_64
                 SSEFunc_l_p sse_fn_l_p =
-                    sse_op_table3bq[(b >> 8) - 2 + (b & 1) * 2];
+                    sse_op_table3bq[((b >> 7) & 2) | (b & 1)];
                 sse_fn_l_p(cpu_T[0], cpu_ptr0);
 #else
                 goto illegal_op;