]> git.proxmox.com Git - qemu.git/blobdiff - tcg/optimize.c
main-loop: narrow win32 pollfds_fill() event bitmasks
[qemu.git] / tcg / optimize.c
index 8e5d9180300e4cfe0ebad0876cbb899b22ed784f..b35868afbc2cc884ea8bc85ad05ce2bf89776118 100644 (file)
@@ -46,6 +46,7 @@ struct tcg_temp_info {
     uint16_t prev_copy;
     uint16_t next_copy;
     tcg_target_ulong val;
+    tcg_target_ulong mask;
 };
 
 static struct tcg_temp_info temps[TCG_MAX_TEMPS];
@@ -63,6 +64,17 @@ static void reset_temp(TCGArg temp)
         }
     }
     temps[temp].state = TCG_TEMP_UNDEF;
+    temps[temp].mask = -1;
+}
+
+/* Reset all temporaries, given that there are NB_TEMPS of them.  */
+static void reset_all_temps(int nb_temps)
+{
+    int i;
+    for (i = 0; i < nb_temps; i++) {
+        temps[i].state = TCG_TEMP_UNDEF;
+        temps[i].mask = -1;
+    }
 }
 
 static int op_bits(TCGOpcode op)
@@ -139,33 +151,35 @@ static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
 static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args,
                             TCGArg dst, TCGArg src)
 {
-        reset_temp(dst);
-        assert(temps[src].state != TCG_TEMP_CONST);
-
-        if (s->temps[src].type == s->temps[dst].type) {
-            if (temps[src].state != TCG_TEMP_COPY) {
-                temps[src].state = TCG_TEMP_COPY;
-                temps[src].next_copy = src;
-                temps[src].prev_copy = src;
-            }
-            temps[dst].state = TCG_TEMP_COPY;
-            temps[dst].next_copy = temps[src].next_copy;
-            temps[dst].prev_copy = src;
-            temps[temps[dst].next_copy].prev_copy = dst;
-            temps[src].next_copy = dst;
+    reset_temp(dst);
+    temps[dst].mask = temps[src].mask;
+    assert(temps[src].state != TCG_TEMP_CONST);
+
+    if (s->temps[src].type == s->temps[dst].type) {
+        if (temps[src].state != TCG_TEMP_COPY) {
+            temps[src].state = TCG_TEMP_COPY;
+            temps[src].next_copy = src;
+            temps[src].prev_copy = src;
         }
+        temps[dst].state = TCG_TEMP_COPY;
+        temps[dst].next_copy = temps[src].next_copy;
+        temps[dst].prev_copy = src;
+        temps[temps[dst].next_copy].prev_copy = dst;
+        temps[src].next_copy = dst;
+    }
 
-        gen_args[0] = dst;
-        gen_args[1] = src;
+    gen_args[0] = dst;
+    gen_args[1] = src;
 }
 
 static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val)
 {
-        reset_temp(dst);
-        temps[dst].state = TCG_TEMP_CONST;
-        temps[dst].val = val;
-        gen_args[0] = dst;
-        gen_args[1] = val;
+    reset_temp(dst);
+    temps[dst].state = TCG_TEMP_CONST;
+    temps[dst].val = val;
+    temps[dst].mask = val;
+    gen_args[0] = dst;
+    gen_args[1] = val;
 }
 
 static TCGOpcode op_to_mov(TCGOpcode op)
@@ -470,6 +484,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                                     TCGArg *args, TCGOpDef *tcg_op_defs)
 {
     int i, nb_ops, op_index, nb_temps, nb_globals, nb_call_args;
+    tcg_target_ulong mask, affected;
     TCGOpcode op;
     const TCGOpDef *def;
     TCGArg *gen_args;
@@ -482,12 +497,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
 
     nb_temps = s->nb_temps;
     nb_globals = s->nb_globals;
-    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
+    reset_all_temps(nb_temps);
 
-    nb_ops = tcg_opc_ptr - gen_opc_buf;
+    nb_ops = tcg_opc_ptr - s->gen_opc_buf;
     gen_args = args;
     for (op_index = 0; op_index < nb_ops; op_index++) {
-        op = gen_opc_buf[op_index];
+        op = s->gen_opc_buf[op_index];
         def = &tcg_op_defs[op];
         /* Do copy propagation */
         if (op == INDEX_op_call) {
@@ -539,11 +554,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 args[5] = tcg_invert_cond(args[5]);
             }
             break;
-        case INDEX_op_add2_i32:
+        CASE_OP_32_64(add2):
             swap_commutative(args[0], &args[2], &args[4]);
             swap_commutative(args[1], &args[3], &args[5]);
             break;
-        case INDEX_op_mulu2_i32:
+        CASE_OP_32_64(mulu2):
+        CASE_OP_32_64(muls2):
             swap_commutative(args[0], &args[2], &args[3]);
             break;
         case INDEX_op_brcond2_i32:
@@ -560,7 +576,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             break;
         }
 
-        /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */
+        /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
+           and "sub r, 0, a => neg r, a" case.  */
         switch (op) {
         CASE_OP_32_64(shl):
         CASE_OP_32_64(shr):
@@ -569,13 +586,44 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(rotr):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[1]].val == 0) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tcg_opt_gen_movi(gen_args, args[0], 0);
                 args += 3;
                 gen_args += 2;
                 continue;
             }
             break;
+        CASE_OP_32_64(sub):
+            {
+                TCGOpcode neg_op;
+                bool have_neg;
+
+                if (temps[args[2]].state == TCG_TEMP_CONST) {
+                    /* Proceed with possible constant folding. */
+                    break;
+                }
+                if (op == INDEX_op_sub_i32) {
+                    neg_op = INDEX_op_neg_i32;
+                    have_neg = TCG_TARGET_HAS_neg_i32;
+                } else {
+                    neg_op = INDEX_op_neg_i64;
+                    have_neg = TCG_TARGET_HAS_neg_i64;
+                }
+                if (!have_neg) {
+                    break;
+                }
+                if (temps[args[1]].state == TCG_TEMP_CONST
+                    && temps[args[1]].val == 0) {
+                    s->gen_opc_buf[op_index] = neg_op;
+                    reset_temp(args[0]);
+                    gen_args[0] = args[0];
+                    gen_args[1] = args[2];
+                    args += 3;
+                    gen_args += 2;
+                    continue;
+                }
+            }
+            break;
         default:
             break;
         }
@@ -598,9 +646,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             if (temps[args[2]].state == TCG_TEMP_CONST
                 && temps[args[2]].val == 0) {
                 if (temps_are_copies(args[0], args[1])) {
-                    gen_opc_buf[op_index] = INDEX_op_nop;
+                    s->gen_opc_buf[op_index] = INDEX_op_nop;
                 } else {
-                    gen_opc_buf[op_index] = op_to_mov(op);
+                    s->gen_opc_buf[op_index] = op_to_mov(op);
                     tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
                     gen_args += 2;
                 }
@@ -612,13 +660,120 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             break;
         }
 
+        /* Simplify using known-zero bits */
+        mask = -1;
+        affected = -1;
+        switch (op) {
+        CASE_OP_32_64(ext8s):
+            if ((temps[args[1]].mask & 0x80) != 0) {
+                break;
+            }
+        CASE_OP_32_64(ext8u):
+            mask = 0xff;
+            goto and_const;
+        CASE_OP_32_64(ext16s):
+            if ((temps[args[1]].mask & 0x8000) != 0) {
+                break;
+            }
+        CASE_OP_32_64(ext16u):
+            mask = 0xffff;
+            goto and_const;
+        case INDEX_op_ext32s_i64:
+            if ((temps[args[1]].mask & 0x80000000) != 0) {
+                break;
+            }
+        case INDEX_op_ext32u_i64:
+            mask = 0xffffffffU;
+            goto and_const;
+
+        CASE_OP_32_64(and):
+            mask = temps[args[2]].mask;
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+        and_const:
+                affected = temps[args[1]].mask & ~mask;
+            }
+            mask = temps[args[1]].mask & mask;
+            break;
+
+        CASE_OP_32_64(sar):
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                mask = ((tcg_target_long)temps[args[1]].mask
+                        >> temps[args[2]].val);
+            }
+            break;
+
+        CASE_OP_32_64(shr):
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                mask = temps[args[1]].mask >> temps[args[2]].val;
+            }
+            break;
+
+        CASE_OP_32_64(shl):
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                mask = temps[args[1]].mask << temps[args[2]].val;
+            }
+            break;
+
+        CASE_OP_32_64(neg):
+            /* Set to 1 all bits to the left of the rightmost.  */
+            mask = -(temps[args[1]].mask & -temps[args[1]].mask);
+            break;
+
+        CASE_OP_32_64(deposit):
+            tmp = ((1ull << args[4]) - 1);
+            mask = ((temps[args[1]].mask & ~(tmp << args[3]))
+                    | ((temps[args[2]].mask & tmp) << args[3]));
+            break;
+
+        CASE_OP_32_64(or):
+        CASE_OP_32_64(xor):
+            mask = temps[args[1]].mask | temps[args[2]].mask;
+            break;
+
+        CASE_OP_32_64(setcond):
+            mask = 1;
+            break;
+
+        CASE_OP_32_64(movcond):
+            mask = temps[args[3]].mask | temps[args[4]].mask;
+            break;
+
+        default:
+            break;
+        }
+
+        if (mask == 0) {
+            assert(def->nb_oargs == 1);
+            s->gen_opc_buf[op_index] = op_to_movi(op);
+            tcg_opt_gen_movi(gen_args, args[0], 0);
+            args += def->nb_oargs + def->nb_iargs + def->nb_cargs;
+            gen_args += 2;
+            continue;
+        }
+        if (affected == 0) {
+            assert(def->nb_oargs == 1);
+            if (temps_are_copies(args[0], args[1])) {
+                s->gen_opc_buf[op_index] = INDEX_op_nop;
+            } else if (temps[args[1]].state != TCG_TEMP_CONST) {
+                s->gen_opc_buf[op_index] = op_to_mov(op);
+                tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
+                gen_args += 2;
+            } else {
+                s->gen_opc_buf[op_index] = op_to_movi(op);
+                tcg_opt_gen_movi(gen_args, args[0], temps[args[1]].val);
+                gen_args += 2;
+            }
+            args += def->nb_iargs + 1;
+            continue;
+        }
+
         /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
         switch (op) {
         CASE_OP_32_64(and):
         CASE_OP_32_64(mul):
             if ((temps[args[2]].state == TCG_TEMP_CONST
                 && temps[args[2]].val == 0)) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tcg_opt_gen_movi(gen_args, args[0], 0);
                 args += 3;
                 gen_args += 2;
@@ -635,9 +790,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(and):
             if (temps_are_copies(args[1], args[2])) {
                 if (temps_are_copies(args[0], args[1])) {
-                    gen_opc_buf[op_index] = INDEX_op_nop;
+                    s->gen_opc_buf[op_index] = INDEX_op_nop;
                 } else {
-                    gen_opc_buf[op_index] = op_to_mov(op);
+                    s->gen_opc_buf[op_index] = op_to_mov(op);
                     tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
                     gen_args += 2;
                 }
@@ -654,7 +809,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(sub):
         CASE_OP_32_64(xor):
             if (temps_are_copies(args[1], args[2])) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tcg_opt_gen_movi(gen_args, args[0], 0);
                 gen_args += 2;
                 args += 3;
@@ -672,7 +827,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(mov):
             if (temps_are_copies(args[0], args[1])) {
                 args += 2;
-                gen_opc_buf[op_index] = INDEX_op_nop;
+                s->gen_opc_buf[op_index] = INDEX_op_nop;
                 break;
             }
             if (temps[args[1]].state != TCG_TEMP_CONST) {
@@ -684,7 +839,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             /* Source argument is constant.  Rewrite the operation and
                let movi case handle it. */
             op = op_to_movi(op);
-            gen_opc_buf[op_index] = op;
+            s->gen_opc_buf[op_index] = op;
             args[1] = temps[args[1]].val;
             /* fallthrough */
         CASE_OP_32_64(movi):
@@ -702,7 +857,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         case INDEX_op_ext32s_i64:
         case INDEX_op_ext32u_i64:
             if (temps[args[1]].state == TCG_TEMP_CONST) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tmp = do_constant_folding(op, temps[args[1]].val, 0);
                 tcg_opt_gen_movi(gen_args, args[0], tmp);
                 gen_args += 2;
@@ -729,7 +884,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(nor):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[2]].state == TCG_TEMP_CONST) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tmp = do_constant_folding(op, temps[args[1]].val,
                                           temps[args[2]].val);
                 tcg_opt_gen_movi(gen_args, args[0], tmp);
@@ -742,7 +897,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(deposit):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[2]].state == TCG_TEMP_CONST) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tmp = ((1ull << args[4]) - 1);
                 tmp = (temps[args[1]].val & ~(tmp << args[3]))
                       | ((temps[args[2]].val & tmp) << args[3]);
@@ -756,7 +911,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(setcond):
             tmp = do_constant_folding_cond(op, args[1], args[2], args[3]);
             if (tmp != 2) {
-                gen_opc_buf[op_index] = op_to_movi(op);
+                s->gen_opc_buf[op_index] = op_to_movi(op);
                 tcg_opt_gen_movi(gen_args, args[0], tmp);
                 gen_args += 2;
                 args += 4;
@@ -768,12 +923,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             tmp = do_constant_folding_cond(op, args[0], args[1], args[2]);
             if (tmp != 2) {
                 if (tmp) {
-                    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
-                    gen_opc_buf[op_index] = INDEX_op_br;
+                    reset_all_temps(nb_temps);
+                    s->gen_opc_buf[op_index] = INDEX_op_br;
                     gen_args[0] = args[3];
                     gen_args += 1;
                 } else {
-                    gen_opc_buf[op_index] = INDEX_op_nop;
+                    s->gen_opc_buf[op_index] = INDEX_op_nop;
                 }
                 args += 4;
                 break;
@@ -784,13 +939,13 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             tmp = do_constant_folding_cond(op, args[1], args[2], args[5]);
             if (tmp != 2) {
                 if (temps_are_copies(args[0], args[4-tmp])) {
-                    gen_opc_buf[op_index] = INDEX_op_nop;
+                    s->gen_opc_buf[op_index] = INDEX_op_nop;
                 } else if (temps[args[4-tmp]].state == TCG_TEMP_CONST) {
-                    gen_opc_buf[op_index] = op_to_movi(op);
+                    s->gen_opc_buf[op_index] = op_to_movi(op);
                     tcg_opt_gen_movi(gen_args, args[0], temps[args[4-tmp]].val);
                     gen_args += 2;
                 } else {
-                    gen_opc_buf[op_index] = op_to_mov(op);
+                    s->gen_opc_buf[op_index] = op_to_mov(op);
                     tcg_opt_gen_mov(s, gen_args, args[0], args[4-tmp]);
                     gen_args += 2;
                 }
@@ -820,12 +975,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 }
 
                 /* We emit the extra nop when we emit the add2/sub2.  */
-                assert(gen_opc_buf[op_index + 1] == INDEX_op_nop);
+                assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
 
                 rl = args[0];
                 rh = args[1];
-                gen_opc_buf[op_index] = INDEX_op_movi_i32;
-                gen_opc_buf[++op_index] = INDEX_op_movi_i32;
+                s->gen_opc_buf[op_index] = INDEX_op_movi_i32;
+                s->gen_opc_buf[++op_index] = INDEX_op_movi_i32;
                 tcg_opt_gen_movi(&gen_args[0], rl, (uint32_t)a);
                 tcg_opt_gen_movi(&gen_args[2], rh, (uint32_t)(a >> 32));
                 gen_args += 4;
@@ -843,12 +998,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 TCGArg rl, rh;
 
                 /* We emit the extra nop when we emit the mulu2.  */
-                assert(gen_opc_buf[op_index + 1] == INDEX_op_nop);
+                assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
 
                 rl = args[0];
                 rh = args[1];
-                gen_opc_buf[op_index] = INDEX_op_movi_i32;
-                gen_opc_buf[++op_index] = INDEX_op_movi_i32;
+                s->gen_opc_buf[op_index] = INDEX_op_movi_i32;
+                s->gen_opc_buf[++op_index] = INDEX_op_movi_i32;
                 tcg_opt_gen_movi(&gen_args[0], rl, (uint32_t)r);
                 tcg_opt_gen_movi(&gen_args[2], rh, (uint32_t)(r >> 32));
                 gen_args += 4;
@@ -861,12 +1016,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]);
             if (tmp != 2) {
                 if (tmp) {
-                    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
-                    gen_opc_buf[op_index] = INDEX_op_br;
+                    reset_all_temps(nb_temps);
+                    s->gen_opc_buf[op_index] = INDEX_op_br;
                     gen_args[0] = args[5];
                     gen_args += 1;
                 } else {
-                    gen_opc_buf[op_index] = INDEX_op_nop;
+                    s->gen_opc_buf[op_index] = INDEX_op_nop;
                 }
             } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE)
                        && temps[args[2]].state == TCG_TEMP_CONST
@@ -875,8 +1030,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                        && temps[args[3]].val == 0) {
                 /* Simplify LT/GE comparisons vs zero to a single compare
                    vs the high word of the input.  */
-                memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
-                gen_opc_buf[op_index] = INDEX_op_brcond_i32;
+                reset_all_temps(nb_temps);
+                s->gen_opc_buf[op_index] = INDEX_op_brcond_i32;
                 gen_args[0] = args[1];
                 gen_args[1] = args[3];
                 gen_args[2] = args[4];
@@ -891,7 +1046,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         case INDEX_op_setcond2_i32:
             tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]);
             if (tmp != 2) {
-                gen_opc_buf[op_index] = INDEX_op_movi_i32;
+                s->gen_opc_buf[op_index] = INDEX_op_movi_i32;
                 tcg_opt_gen_movi(gen_args, args[0], tmp);
                 gen_args += 2;
             } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE)
@@ -901,7 +1056,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                        && temps[args[4]].val == 0) {
                 /* Simplify LT/GE comparisons vs zero to a single compare
                    vs the high word of the input.  */
-                gen_opc_buf[op_index] = INDEX_op_setcond_i32;
+                s->gen_opc_buf[op_index] = INDEX_op_setcond_i32;
+                reset_temp(args[0]);
                 gen_args[0] = args[0];
                 gen_args[1] = args[2];
                 gen_args[2] = args[4];
@@ -938,9 +1094,10 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             /* Default case: we know nothing about operation (or were unable
                to compute the operation result) so no propagation is done.
                We trash everything if the operation is the end of a basic
-               block, otherwise we only trash the output args.  */
+               block, otherwise we only trash the output args.  "mask" is
+               the non-zero bits mask for the first output arg.  */
             if (def->flags & TCG_OPF_BB_END) {
-                memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
+                reset_all_temps(nb_temps);
             } else {
                 for (i = 0; i < def->nb_oargs; i++) {
                     reset_temp(args[i]);