[Qemu-devel] [PATCH] CRIS: optimize clear insns + other minor updates.

[Edgar E. Iglesias]

Small CRIS patch to:

Optimize clear insns by treating support reg P0 specially.
Add missing micro-op RETURN's.
Minor cleanup.

Best regards
-- 
Edgar E. Iglesias
Axis Communications AB

diff --git a/target-cris/op.c b/target-cris/op.c
index 6e17719..3c50574 100644
--- a/target-cris/op.c
+++ b/target-cris/op.c
@@ -205,6 +205,7 @@ void OPPROTO op_ccs_lshift (void)
        ccs = env->pregs[SR_CCS];
        ccs = (ccs & 0xc0000000) | ((ccs << 12) >> 2);
        env->pregs[SR_CCS] = ccs;
+       RETURN();
 }
 void OPPROTO op_ccs_rshift (void)
 {
@@ -214,6 +215,7 @@ void OPPROTO op_ccs_rshift (void)
        ccs = env->pregs[SR_CCS];
        ccs = (ccs & 0xc0000000) | (ccs >> 10);
        env->pregs[SR_CCS] = ccs;
+       RETURN();
 }
 
 void OPPROTO op_setf (void)
diff --git a/target-cris/translate.c b/target-cris/translate.c
index 44ba804..a05d139 100644
--- a/target-cris/translate.c
+++ b/target-cris/translate.c
@@ -110,15 +110,6 @@ typedef struct DisasContext {
        unsigned int mode;
        unsigned int postinc;
 
-
-       struct
-       {
-               int op;
-               int size;
-               unsigned int mask;
-       } cc_state[3];
-       int cc_i;
-
        int update_cc;
        int cc_op;
        int cc_size;
@@ -183,6 +174,10 @@ static void gen_vr_read(void) {
        gen_op_movl_T0_im(32);
 }
 
+static void gen_movl_T0_p0(void) {
+       gen_op_movl_T0_im(0);
+}
+
 static void gen_ccs_read(void) {
        gen_op_movl_T0_p13();
 }
@@ -209,7 +204,7 @@ static GenOpFunc *gen_movl_preg_T0[16] =
 };
 static GenOpFunc *gen_movl_T0_preg[16] =
 {
-       gen_op_movl_T0_p0,
+       gen_movl_T0_p0,
        gen_vr_read,
        gen_op_movl_T0_p2, gen_op_movl_T0_p3,
        gen_op_movl_T0_p4, gen_op_movl_T0_p5,
@@ -345,6 +340,8 @@ static void cris_cc_mask(DisasContext *dc, unsigned int 
mask)
 {
        uint32_t ovl;
 
+       /* Check if we need to evaluate the condition codes due to 
+          CC overlaying.  */
        ovl = (dc->cc_mask ^ mask) & ~mask;
        if (ovl) {
                /* TODO: optimize this case. It trigs all the time.  */
@@ -987,7 +984,6 @@ static unsigned int dec_btstq(DisasContext *dc)
 {
        dc->op1 = EXTRACT_FIELD(dc->ir, 0, 4);
        DIS(fprintf (logfile, "btstq %u, $r%d\n", dc->op1, dc->op2));
-       cris_evaluate_flags(dc);
        cris_cc_mask(dc, CC_MASK_NZ);
        gen_movl_T0_reg[dc->op2]();
        gen_op_movl_T1_im(dc->op1);
@@ -1333,7 +1329,6 @@ static unsigned int dec_btst_r(DisasContext *dc)
 {
        DIS(fprintf (logfile, "btst $r%u, $r%u\n",
                    dc->op1, dc->op2));
-       cris_evaluate_flags(dc);
        cris_cc_mask(dc, CC_MASK_NZ);
        dec_prep_alu_r(dc, dc->op1, dc->op2, 4, 0);
        crisv32_alu_op(dc, CC_OP_BTST, dc->op2, 4);
@@ -1518,8 +1513,14 @@ static unsigned int dec_move_pr(DisasContext *dc)
 {
        DIS(fprintf (logfile, "move $p%u, $r%u\n", dc->op1, dc->op2));
        cris_cc_mask(dc, 0);
-       gen_movl_T0_preg[dc->op2]();
-       gen_op_movl_T1_T0();
+       /* Support register 0 is hardwired to zero. 
+          Treat it specially. */
+       if (dc->op2 == 0)
+               gen_op_movl_T1_im(0);
+       else {
+               gen_movl_T0_preg[dc->op2]();
+               gen_op_movl_T1_T0();
+       }
        crisv32_alu_op(dc, CC_OP_MOVE, dc->op1, preg_sizes[dc->op2]);
        return 2;
 }
@@ -1846,13 +1847,21 @@ static unsigned int dec_move_pm(DisasContext *dc)
 
        memsize = preg_sizes[dc->op2];
 
-       DIS(fprintf (logfile, "move.%d $p%u, [$r%u%s\n",
-                    memsize, dc->op2, dc->op1, dc->postinc ? "+]" : "]"));
+       DIS(fprintf (logfile, "move.%c $p%u, [$r%u%s\n",
+                    memsize_char(memsize), 
+                    dc->op2, dc->op1, dc->postinc ? "+]" : "]"));
 
        cris_cc_mask(dc, 0);
-       /* prepare store.  */
-       gen_movl_T0_preg[dc->op2]();
-       gen_op_movl_T1_T0();
+       /* prepare store. Address in T0, value in T1.  */
+       /* Support register 0 is hardwired to zero. 
+          Treat it specially. */
+       if (dc->op2 == 0)
+               gen_op_movl_T1_im(0);
+       else
+       {
+               gen_movl_T0_preg[dc->op2]();
+               gen_op_movl_T1_T0();
+       }
        gen_movl_T0_reg[dc->op1]();
        gen_store_T0_T1(dc, memsize);
        if (dc->postinc)