Initial import of qemu-2.4.1HEADmaster

1 files changed, 1330 insertions, 0 deletions

diff --git a/tcg/optimize.c b/tcg/optimize.c
new file mode 100644
index 00000000..18283cfd
--- /dev/null
+++ b/tcg/optimize.c
@@ -0,0 +1,1330 @@
+/*
+ * Optimizations for Tiny Code Generator for QEMU
+ *
+ * Copyright (c) 2010 Samsung Electronics.
+ * Contributed by Kirill Batuzov <batuzovk@ispras.ru>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "qemu-common.h"
+#include "tcg-op.h"
+
+#define CASE_OP_32_64(x)                        \
+        glue(glue(case INDEX_op_, x), _i32):    \
+        glue(glue(case INDEX_op_, x), _i64)
+
+typedef enum {
+    TCG_TEMP_UNDEF = 0,
+    TCG_TEMP_CONST,
+    TCG_TEMP_COPY,
+} tcg_temp_state;
+
+struct tcg_temp_info {
+    tcg_temp_state state;
+    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];
+
+/* Reset TEMP's state to TCG_TEMP_UNDEF.  If TEMP only had one copy, remove
+   the copy flag from the left temp.  */
+static void reset_temp(TCGArg temp)
+{
+    if (temps[temp].state == TCG_TEMP_COPY) {
+        if (temps[temp].prev_copy == temps[temp].next_copy) {
+            temps[temps[temp].next_copy].state = TCG_TEMP_UNDEF;
+        } else {
+            temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
+            temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
+        }
+    }
+    temps[temp].state = TCG_TEMP_UNDEF;
+    temps[temp].mask = -1;
+}
+
+static TCGOp *insert_op_before(TCGContext *s, TCGOp *old_op,
+                                TCGOpcode opc, int nargs)
+{
+    int oi = s->gen_next_op_idx;
+    int pi = s->gen_next_parm_idx;
+    int prev = old_op->prev;
+    int next = old_op - s->gen_op_buf;
+    TCGOp *new_op;
+
+    tcg_debug_assert(oi < OPC_BUF_SIZE);
+    tcg_debug_assert(pi + nargs <= OPPARAM_BUF_SIZE);
+    s->gen_next_op_idx = oi + 1;
+    s->gen_next_parm_idx = pi + nargs;
+
+    new_op = &s->gen_op_buf[oi];
+    *new_op = (TCGOp){
+        .opc = opc,
+        .args = pi,
+        .prev = prev,
+        .next = next
+    };
+    if (prev >= 0) {
+        s->gen_op_buf[prev].next = oi;
+    } else {
+        s->gen_first_op_idx = oi;
+    }
+    old_op->prev = oi;
+
+    return new_op;
+}
+
+/* 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)
+{
+    const TCGOpDef *def = &tcg_op_defs[op];
+    return def->flags & TCG_OPF_64BIT ? 64 : 32;
+}
+
+static TCGOpcode op_to_mov(TCGOpcode op)
+{
+    switch (op_bits(op)) {
+    case 32:
+        return INDEX_op_mov_i32;
+    case 64:
+        return INDEX_op_mov_i64;
+    default:
+        fprintf(stderr, "op_to_mov: unexpected return value of "
+                "function op_bits.\n");
+        tcg_abort();
+    }
+}
+
+static TCGOpcode op_to_movi(TCGOpcode op)
+{
+    switch (op_bits(op)) {
+    case 32:
+        return INDEX_op_movi_i32;
+    case 64:
+        return INDEX_op_movi_i64;
+    default:
+        fprintf(stderr, "op_to_movi: unexpected return value of "
+                "function op_bits.\n");
+        tcg_abort();
+    }
+}
+
+static TCGArg find_better_copy(TCGContext *s, TCGArg temp)
+{
+    TCGArg i;
+
+    /* If this is already a global, we can't do better. */
+    if (temp < s->nb_globals) {
+        return temp;
+    }
+
+    /* Search for a global first. */
+    for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
+        if (i < s->nb_globals) {
+            return i;
+        }
+    }
+
+    /* If it is a temp, search for a temp local. */
+    if (!s->temps[temp].temp_local) {
+        for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
+            if (s->temps[i].temp_local) {
+                return i;
+            }
+        }
+    }
+
+    /* Failure to find a better representation, return the same temp. */
+    return temp;
+}
+
+static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
+{
+    TCGArg i;
+
+    if (arg1 == arg2) {
+        return true;
+    }
+
+    if (temps[arg1].state != TCG_TEMP_COPY
+        || temps[arg2].state != TCG_TEMP_COPY) {
+        return false;
+    }
+
+    for (i = temps[arg1].next_copy ; i != arg1 ; i = temps[i].next_copy) {
+        if (i == arg2) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static void tcg_opt_gen_movi(TCGContext *s, TCGOp *op, TCGArg *args,
+                             TCGArg dst, TCGArg val)
+{
+    TCGOpcode new_op = op_to_movi(op->opc);
+    tcg_target_ulong mask;
+
+    op->opc = new_op;
+
+    reset_temp(dst);
+    temps[dst].state = TCG_TEMP_CONST;
+    temps[dst].val = val;
+    mask = val;
+    if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_movi_i32) {
+        /* High bits of the destination are now garbage.  */
+        mask |= ~0xffffffffull;
+    }
+    temps[dst].mask = mask;
+
+    args[0] = dst;
+    args[1] = val;
+}
+
+static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg *args,
+                            TCGArg dst, TCGArg src)
+{
+    if (temps_are_copies(dst, src)) {
+        tcg_op_remove(s, op);
+        return;
+    }
+
+    if (temps[src].state == TCG_TEMP_CONST) {
+        tcg_opt_gen_movi(s, op, args, dst, temps[src].val);
+        return;
+    }
+
+    TCGOpcode new_op = op_to_mov(op->opc);
+    tcg_target_ulong mask;
+
+    op->opc = new_op;
+
+    reset_temp(dst);
+    mask = temps[src].mask;
+    if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_mov_i32) {
+        /* High bits of the destination are now garbage.  */
+        mask |= ~0xffffffffull;
+    }
+    temps[dst].mask = 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;
+    }
+
+    args[0] = dst;
+    args[1] = src;
+}
+
+static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
+{
+    uint64_t l64, h64;
+
+    switch (op) {
+    CASE_OP_32_64(add):
+        return x + y;
+
+    CASE_OP_32_64(sub):
+        return x - y;
+
+    CASE_OP_32_64(mul):
+        return x * y;
+
+    CASE_OP_32_64(and):
+        return x & y;
+
+    CASE_OP_32_64(or):
+        return x | y;
+
+    CASE_OP_32_64(xor):
+        return x ^ y;
+
+    case INDEX_op_shl_i32:
+        return (uint32_t)x << (y & 31);
+
+    case INDEX_op_shl_i64:
+        return (uint64_t)x << (y & 63);
+
+    case INDEX_op_shr_i32:
+        return (uint32_t)x >> (y & 31);
+
+    case INDEX_op_trunc_shr_i32:
+    case INDEX_op_shr_i64:
+        return (uint64_t)x >> (y & 63);
+
+    case INDEX_op_sar_i32:
+        return (int32_t)x >> (y & 31);
+
+    case INDEX_op_sar_i64:
+        return (int64_t)x >> (y & 63);
+
+    case INDEX_op_rotr_i32:
+        return ror32(x, y & 31);
+
+    case INDEX_op_rotr_i64:
+        return ror64(x, y & 63);
+
+    case INDEX_op_rotl_i32:
+        return rol32(x, y & 31);
+
+    case INDEX_op_rotl_i64:
+        return rol64(x, y & 63);
+
+    CASE_OP_32_64(not):
+        return ~x;
+
+    CASE_OP_32_64(neg):
+        return -x;
+
+    CASE_OP_32_64(andc):
+        return x & ~y;
+
+    CASE_OP_32_64(orc):
+        return x | ~y;
+
+    CASE_OP_32_64(eqv):
+        return ~(x ^ y);
+
+    CASE_OP_32_64(nand):
+        return ~(x & y);
+
+    CASE_OP_32_64(nor):
+        return ~(x | y);
+
+    CASE_OP_32_64(ext8s):
+        return (int8_t)x;
+
+    CASE_OP_32_64(ext16s):
+        return (int16_t)x;
+
+    CASE_OP_32_64(ext8u):
+        return (uint8_t)x;
+
+    CASE_OP_32_64(ext16u):
+        return (uint16_t)x;
+
+    case INDEX_op_ext32s_i64:
+        return (int32_t)x;
+
+    case INDEX_op_ext32u_i64:
+        return (uint32_t)x;
+
+    case INDEX_op_muluh_i32:
+        return ((uint64_t)(uint32_t)x * (uint32_t)y) >> 32;
+    case INDEX_op_mulsh_i32:
+        return ((int64_t)(int32_t)x * (int32_t)y) >> 32;
+
+    case INDEX_op_muluh_i64:
+        mulu64(&l64, &h64, x, y);
+        return h64;
+    case INDEX_op_mulsh_i64:
+        muls64(&l64, &h64, x, y);
+        return h64;
+
+    case INDEX_op_div_i32:
+        /* Avoid crashing on divide by zero, otherwise undefined.  */
+        return (int32_t)x / ((int32_t)y ? : 1);
+    case INDEX_op_divu_i32:
+        return (uint32_t)x / ((uint32_t)y ? : 1);
+    case INDEX_op_div_i64:
+        return (int64_t)x / ((int64_t)y ? : 1);
+    case INDEX_op_divu_i64:
+        return (uint64_t)x / ((uint64_t)y ? : 1);
+
+    case INDEX_op_rem_i32:
+        return (int32_t)x % ((int32_t)y ? : 1);
+    case INDEX_op_remu_i32:
+        return (uint32_t)x % ((uint32_t)y ? : 1);
+    case INDEX_op_rem_i64:
+        return (int64_t)x % ((int64_t)y ? : 1);
+    case INDEX_op_remu_i64:
+        return (uint64_t)x % ((uint64_t)y ? : 1);
+
+    default:
+        fprintf(stderr,
+                "Unrecognized operation %d in do_constant_folding.\n", op);
+        tcg_abort();
+    }
+}
+
+static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y)
+{
+    TCGArg res = do_constant_folding_2(op, x, y);
+    if (op_bits(op) == 32) {
+        res &= 0xffffffff;
+    }
+    return res;
+}
+
+static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c)
+{
+    switch (c) {
+    case TCG_COND_EQ:
+        return x == y;
+    case TCG_COND_NE:
+        return x != y;
+    case TCG_COND_LT:
+        return (int32_t)x < (int32_t)y;
+    case TCG_COND_GE:
+        return (int32_t)x >= (int32_t)y;
+    case TCG_COND_LE:
+        return (int32_t)x <= (int32_t)y;
+    case TCG_COND_GT:
+        return (int32_t)x > (int32_t)y;
+    case TCG_COND_LTU:
+        return x < y;
+    case TCG_COND_GEU:
+        return x >= y;
+    case TCG_COND_LEU:
+        return x <= y;
+    case TCG_COND_GTU:
+        return x > y;
+    default:
+        tcg_abort();
+    }
+}
+
+static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c)
+{
+    switch (c) {
+    case TCG_COND_EQ:
+        return x == y;
+    case TCG_COND_NE:
+        return x != y;
+    case TCG_COND_LT:
+        return (int64_t)x < (int64_t)y;
+    case TCG_COND_GE:
+        return (int64_t)x >= (int64_t)y;
+    case TCG_COND_LE:
+        return (int64_t)x <= (int64_t)y;
+    case TCG_COND_GT:
+        return (int64_t)x > (int64_t)y;
+    case TCG_COND_LTU:
+        return x < y;
+    case TCG_COND_GEU:
+        return x >= y;
+    case TCG_COND_LEU:
+        return x <= y;
+    case TCG_COND_GTU:
+        return x > y;
+    default:
+        tcg_abort();
+    }
+}
+
+static bool do_constant_folding_cond_eq(TCGCond c)
+{
+    switch (c) {
+    case TCG_COND_GT:
+    case TCG_COND_LTU:
+    case TCG_COND_LT:
+    case TCG_COND_GTU:
+    case TCG_COND_NE:
+        return 0;
+    case TCG_COND_GE:
+    case TCG_COND_GEU:
+    case TCG_COND_LE:
+    case TCG_COND_LEU:
+    case TCG_COND_EQ:
+        return 1;
+    default:
+        tcg_abort();
+    }
+}
+
+/* Return 2 if the condition can't be simplified, and the result
+   of the condition (0 or 1) if it can */
+static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
+                                       TCGArg y, TCGCond c)
+{
+    if (temps[x].state == TCG_TEMP_CONST && temps[y].state == TCG_TEMP_CONST) {
+        switch (op_bits(op)) {
+        case 32:
+            return do_constant_folding_cond_32(temps[x].val, temps[y].val, c);
+        case 64:
+            return do_constant_folding_cond_64(temps[x].val, temps[y].val, c);
+        default:
+            tcg_abort();
+        }
+    } else if (temps_are_copies(x, y)) {
+        return do_constant_folding_cond_eq(c);
+    } else if (temps[y].state == TCG_TEMP_CONST && temps[y].val == 0) {
+        switch (c) {
+        case TCG_COND_LTU:
+            return 0;
+        case TCG_COND_GEU:
+            return 1;
+        default:
+            return 2;
+        }
+    } else {
+        return 2;
+    }
+}
+
+/* Return 2 if the condition can't be simplified, and the result
+   of the condition (0 or 1) if it can */
+static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
+{
+    TCGArg al = p1[0], ah = p1[1];
+    TCGArg bl = p2[0], bh = p2[1];
+
+    if (temps[bl].state == TCG_TEMP_CONST
+        && temps[bh].state == TCG_TEMP_CONST) {
+        uint64_t b = ((uint64_t)temps[bh].val << 32) | (uint32_t)temps[bl].val;
+
+        if (temps[al].state == TCG_TEMP_CONST
+            && temps[ah].state == TCG_TEMP_CONST) {
+            uint64_t a;
+            a = ((uint64_t)temps[ah].val << 32) | (uint32_t)temps[al].val;
+            return do_constant_folding_cond_64(a, b, c);
+        }
+        if (b == 0) {
+            switch (c) {
+            case TCG_COND_LTU:
+                return 0;
+            case TCG_COND_GEU:
+                return 1;
+            default:
+                break;
+            }
+        }
+    }
+    if (temps_are_copies(al, bl) && temps_are_copies(ah, bh)) {
+        return do_constant_folding_cond_eq(c);
+    }
+    return 2;
+}
+
+static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2)
+{
+    TCGArg a1 = *p1, a2 = *p2;
+    int sum = 0;
+    sum += temps[a1].state == TCG_TEMP_CONST;
+    sum -= temps[a2].state == TCG_TEMP_CONST;
+
+    /* Prefer the constant in second argument, and then the form
+       op a, a, b, which is better handled on non-RISC hosts. */
+    if (sum > 0 || (sum == 0 && dest == a2)) {
+        *p1 = a2;
+        *p2 = a1;
+        return true;
+    }
+    return false;
+}
+
+static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
+{
+    int sum = 0;
+    sum += temps[p1[0]].state == TCG_TEMP_CONST;
+    sum += temps[p1[1]].state == TCG_TEMP_CONST;
+    sum -= temps[p2[0]].state == TCG_TEMP_CONST;
+    sum -= temps[p2[1]].state == TCG_TEMP_CONST;
+    if (sum > 0) {
+        TCGArg t;
+        t = p1[0], p1[0] = p2[0], p2[0] = t;
+        t = p1[1], p1[1] = p2[1], p2[1] = t;
+        return true;
+    }
+    return false;
+}
+
+/* Propagate constants and copies, fold constant expressions. */
+void tcg_optimize(TCGContext *s)
+{
+    int oi, oi_next, nb_temps, nb_globals;
+
+    /* Array VALS has an element for each temp.
+       If this temp holds a constant then its value is kept in VALS' element.
+       If this temp is a copy of other ones then the other copies are
+       available through the doubly linked circular list. */
+
+    nb_temps = s->nb_temps;
+    nb_globals = s->nb_globals;
+    reset_all_temps(nb_temps);
+
+    for (oi = s->gen_first_op_idx; oi >= 0; oi = oi_next) {
+        tcg_target_ulong mask, partmask, affected;
+        int nb_oargs, nb_iargs, i;
+        TCGArg tmp;
+
+        TCGOp * const op = &s->gen_op_buf[oi];
+        TCGArg * const args = &s->gen_opparam_buf[op->args];
+        TCGOpcode opc = op->opc;
+        const TCGOpDef *def = &tcg_op_defs[opc];
+
+        oi_next = op->next;
+        if (opc == INDEX_op_call) {
+            nb_oargs = op->callo;
+            nb_iargs = op->calli;
+        } else {
+            nb_oargs = def->nb_oargs;
+            nb_iargs = def->nb_iargs;
+        }
+
+        /* Do copy propagation */
+        for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
+            if (temps[args[i]].state == TCG_TEMP_COPY) {
+                args[i] = find_better_copy(s, args[i]);
+            }
+        }
+
+        /* For commutative operations make constant second argument */
+        switch (opc) {
+        CASE_OP_32_64(add):
+        CASE_OP_32_64(mul):
+        CASE_OP_32_64(and):
+        CASE_OP_32_64(or):
+        CASE_OP_32_64(xor):
+        CASE_OP_32_64(eqv):
+        CASE_OP_32_64(nand):
+        CASE_OP_32_64(nor):
+        CASE_OP_32_64(muluh):
+        CASE_OP_32_64(mulsh):
+            swap_commutative(args[0], &args[1], &args[2]);
+            break;
+        CASE_OP_32_64(brcond):
+            if (swap_commutative(-1, &args[0], &args[1])) {
+                args[2] = tcg_swap_cond(args[2]);
+            }
+            break;
+        CASE_OP_32_64(setcond):
+            if (swap_commutative(args[0], &args[1], &args[2])) {
+                args[3] = tcg_swap_cond(args[3]);
+            }
+            break;
+        CASE_OP_32_64(movcond):
+            if (swap_commutative(-1, &args[1], &args[2])) {
+                args[5] = tcg_swap_cond(args[5]);
+            }
+            /* For movcond, we canonicalize the "false" input reg to match
+               the destination reg so that the tcg backend can implement
+               a "move if true" operation.  */
+            if (swap_commutative(args[0], &args[4], &args[3])) {
+                args[5] = tcg_invert_cond(args[5]);
+            }
+            break;
+        CASE_OP_32_64(add2):
+            swap_commutative(args[0], &args[2], &args[4]);
+            swap_commutative(args[1], &args[3], &args[5]);
+            break;
+        CASE_OP_32_64(mulu2):
+        CASE_OP_32_64(muls2):
+            swap_commutative(args[0], &args[2], &args[3]);
+            break;
+        case INDEX_op_brcond2_i32:
+            if (swap_commutative2(&args[0], &args[2])) {
+                args[4] = tcg_swap_cond(args[4]);
+            }
+            break;
+        case INDEX_op_setcond2_i32:
+            if (swap_commutative2(&args[1], &args[3])) {
+                args[5] = tcg_swap_cond(args[5]);
+            }
+            break;
+        default:
+            break;
+        }
+
+        /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
+           and "sub r, 0, a => neg r, a" case.  */
+        switch (opc) {
+        CASE_OP_32_64(shl):
+        CASE_OP_32_64(shr):
+        CASE_OP_32_64(sar):
+        CASE_OP_32_64(rotl):
+        CASE_OP_32_64(rotr):
+            if (temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[1]].val == 0) {
+                tcg_opt_gen_movi(s, op, args, args[0], 0);
+                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 (opc == 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) {
+                    op->opc = neg_op;
+                    reset_temp(args[0]);
+                    args[1] = args[2];
+                    continue;
+                }
+            }
+            break;
+        CASE_OP_32_64(xor):
+        CASE_OP_32_64(nand):
+            if (temps[args[1]].state != TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[2]].val == -1) {
+                i = 1;
+                goto try_not;
+            }
+            break;
+        CASE_OP_32_64(nor):
+            if (temps[args[1]].state != TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[2]].val == 0) {
+                i = 1;
+                goto try_not;
+            }
+            break;
+        CASE_OP_32_64(andc):
+            if (temps[args[2]].state != TCG_TEMP_CONST
+                && temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[1]].val == -1) {
+                i = 2;
+                goto try_not;
+            }
+            break;
+        CASE_OP_32_64(orc):
+        CASE_OP_32_64(eqv):
+            if (temps[args[2]].state != TCG_TEMP_CONST
+                && temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[1]].val == 0) {
+                i = 2;
+                goto try_not;
+            }
+            break;
+        try_not:
+            {
+                TCGOpcode not_op;
+                bool have_not;
+
+                if (def->flags & TCG_OPF_64BIT) {
+                    not_op = INDEX_op_not_i64;
+                    have_not = TCG_TARGET_HAS_not_i64;
+                } else {
+                    not_op = INDEX_op_not_i32;
+                    have_not = TCG_TARGET_HAS_not_i32;
+                }
+                if (!have_not) {
+                    break;
+                }
+                op->opc = not_op;
+                reset_temp(args[0]);
+                args[1] = args[i];
+                continue;
+            }
+        default:
+            break;
+        }
+
+        /* Simplify expression for "op r, a, const => mov r, a" cases */
+        switch (opc) {
+        CASE_OP_32_64(add):
+        CASE_OP_32_64(sub):
+        CASE_OP_32_64(shl):
+        CASE_OP_32_64(shr):
+        CASE_OP_32_64(sar):
+        CASE_OP_32_64(rotl):
+        CASE_OP_32_64(rotr):
+        CASE_OP_32_64(or):
+        CASE_OP_32_64(xor):
+        CASE_OP_32_64(andc):
+            if (temps[args[1]].state != TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[2]].val == 0) {
+                tcg_opt_gen_mov(s, op, args, args[0], args[1]);
+                continue;
+            }
+            break;
+        CASE_OP_32_64(and):
+        CASE_OP_32_64(orc):
+        CASE_OP_32_64(eqv):
+            if (temps[args[1]].state != TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[2]].val == -1) {
+                tcg_opt_gen_mov(s, op, args, args[0], args[1]);
+                continue;
+            }
+            break;
+        default:
+            break;
+        }
+
+        /* Simplify using known-zero bits. Currently only ops with a single
+           output argument is supported. */
+        mask = -1;
+        affected = -1;
+        switch (opc) {
+        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(andc):
+            /* Known-zeros does not imply known-ones.  Therefore unless
+               args[2] is constant, we can't infer anything from it.  */
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                mask = ~temps[args[2]].mask;
+                goto and_const;
+            }
+            /* But we certainly know nothing outside args[1] may be set. */
+            mask = temps[args[1]].mask;
+            break;
+
+        case INDEX_op_sar_i32:
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = temps[args[2]].val & 31;
+                mask = (int32_t)temps[args[1]].mask >> tmp;
+            }
+            break;
+        case INDEX_op_sar_i64:
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = temps[args[2]].val & 63;
+                mask = (int64_t)temps[args[1]].mask >> tmp;
+            }
+            break;
+
+        case INDEX_op_shr_i32:
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = temps[args[2]].val & 31;
+                mask = (uint32_t)temps[args[1]].mask >> tmp;
+            }
+            break;
+        case INDEX_op_shr_i64:
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = temps[args[2]].val & 63;
+                mask = (uint64_t)temps[args[1]].mask >> tmp;
+            }
+            break;
+
+        case INDEX_op_trunc_shr_i32:
+            mask = (uint64_t)temps[args[1]].mask >> args[2];
+            break;
+
+        CASE_OP_32_64(shl):
+            if (temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = temps[args[2]].val & (TCG_TARGET_REG_BITS - 1);
+                mask = temps[args[1]].mask << tmp;
+            }
+            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):
+            mask = deposit64(temps[args[1]].mask, args[3], args[4],
+                             temps[args[2]].mask);
+            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):
+        case INDEX_op_setcond2_i32:
+            mask = 1;
+            break;
+
+        CASE_OP_32_64(movcond):
+            mask = temps[args[3]].mask | temps[args[4]].mask;
+            break;
+
+        CASE_OP_32_64(ld8u):
+            mask = 0xff;
+            break;
+        CASE_OP_32_64(ld16u):
+            mask = 0xffff;
+            break;
+        case INDEX_op_ld32u_i64:
+            mask = 0xffffffffu;
+            break;
+
+        CASE_OP_32_64(qemu_ld):
+            {
+                TCGMemOpIdx oi = args[nb_oargs + nb_iargs];
+                TCGMemOp mop = get_memop(oi);
+                if (!(mop & MO_SIGN)) {
+                    mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1;
+                }
+            }
+            break;
+
+        default:
+            break;
+        }
+
+        /* 32-bit ops generate 32-bit results.  For the result is zero test
+           below, we can ignore high bits, but for further optimizations we
+           need to record that the high bits contain garbage.  */
+        partmask = mask;
+        if (!(def->flags & TCG_OPF_64BIT)) {
+            mask |= ~(tcg_target_ulong)0xffffffffu;
+            partmask &= 0xffffffffu;
+            affected &= 0xffffffffu;
+        }
+
+        if (partmask == 0) {
+            assert(nb_oargs == 1);
+            tcg_opt_gen_movi(s, op, args, args[0], 0);
+            continue;
+        }
+        if (affected == 0) {
+            assert(nb_oargs == 1);
+            tcg_opt_gen_mov(s, op, args, args[0], args[1]);
+            continue;
+        }
+
+        /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
+        switch (opc) {
+        CASE_OP_32_64(and):
+        CASE_OP_32_64(mul):
+        CASE_OP_32_64(muluh):
+        CASE_OP_32_64(mulsh):
+            if ((temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[2]].val == 0)) {
+                tcg_opt_gen_movi(s, op, args, args[0], 0);
+                continue;
+            }
+            break;
+        default:
+            break;
+        }
+
+        /* Simplify expression for "op r, a, a => mov r, a" cases */
+        switch (opc) {
+        CASE_OP_32_64(or):
+        CASE_OP_32_64(and):
+            if (temps_are_copies(args[1], args[2])) {
+                tcg_opt_gen_mov(s, op, args, args[0], args[1]);
+                continue;
+            }
+            break;
+        default:
+            break;
+        }
+
+        /* Simplify expression for "op r, a, a => movi r, 0" cases */
+        switch (opc) {
+        CASE_OP_32_64(andc):
+        CASE_OP_32_64(sub):
+        CASE_OP_32_64(xor):
+            if (temps_are_copies(args[1], args[2])) {
+                tcg_opt_gen_movi(s, op, args, args[0], 0);
+                continue;
+            }
+            break;
+        default:
+            break;
+        }
+
+        /* Propagate constants through copy operations and do constant
+           folding.  Constants will be substituted to arguments by register
+           allocator where needed and possible.  Also detect copies. */
+        switch (opc) {
+        CASE_OP_32_64(mov):
+            tcg_opt_gen_mov(s, op, args, args[0], args[1]);
+            break;
+        CASE_OP_32_64(movi):
+            tcg_opt_gen_movi(s, op, args, args[0], args[1]);
+            break;
+
+        CASE_OP_32_64(not):
+        CASE_OP_32_64(neg):
+        CASE_OP_32_64(ext8s):
+        CASE_OP_32_64(ext8u):
+        CASE_OP_32_64(ext16s):
+        CASE_OP_32_64(ext16u):
+        case INDEX_op_ext32s_i64:
+        case INDEX_op_ext32u_i64:
+            if (temps[args[1]].state == TCG_TEMP_CONST) {
+                tmp = do_constant_folding(opc, temps[args[1]].val, 0);
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+                break;
+            }
+            goto do_default;
+
+        case INDEX_op_trunc_shr_i32:
+            if (temps[args[1]].state == TCG_TEMP_CONST) {
+                tmp = do_constant_folding(opc, temps[args[1]].val, args[2]);
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+                break;
+            }
+            goto do_default;
+
+        CASE_OP_32_64(add):
+        CASE_OP_32_64(sub):
+        CASE_OP_32_64(mul):
+        CASE_OP_32_64(or):
+        CASE_OP_32_64(and):
+        CASE_OP_32_64(xor):
+        CASE_OP_32_64(shl):
+        CASE_OP_32_64(shr):
+        CASE_OP_32_64(sar):
+        CASE_OP_32_64(rotl):
+        CASE_OP_32_64(rotr):
+        CASE_OP_32_64(andc):
+        CASE_OP_32_64(orc):
+        CASE_OP_32_64(eqv):
+        CASE_OP_32_64(nand):
+        CASE_OP_32_64(nor):
+        CASE_OP_32_64(muluh):
+        CASE_OP_32_64(mulsh):
+        CASE_OP_32_64(div):
+        CASE_OP_32_64(divu):
+        CASE_OP_32_64(rem):
+        CASE_OP_32_64(remu):
+            if (temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = do_constant_folding(opc, temps[args[1]].val,
+                                          temps[args[2]].val);
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+                break;
+            }
+            goto do_default;
+
+        CASE_OP_32_64(deposit):
+            if (temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[2]].state == TCG_TEMP_CONST) {
+                tmp = deposit64(temps[args[1]].val, args[3], args[4],
+                                temps[args[2]].val);
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+                break;
+            }
+            goto do_default;
+
+        CASE_OP_32_64(setcond):
+            tmp = do_constant_folding_cond(opc, args[1], args[2], args[3]);
+            if (tmp != 2) {
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+                break;
+            }
+            goto do_default;
+
+        CASE_OP_32_64(brcond):
+            tmp = do_constant_folding_cond(opc, args[0], args[1], args[2]);
+            if (tmp != 2) {
+                if (tmp) {
+                    reset_all_temps(nb_temps);
+                    op->opc = INDEX_op_br;
+                    args[0] = args[3];
+                } else {
+                    tcg_op_remove(s, op);
+                }
+                break;
+            }
+            goto do_default;
+
+        CASE_OP_32_64(movcond):
+            tmp = do_constant_folding_cond(opc, args[1], args[2], args[5]);
+            if (tmp != 2) {
+                tcg_opt_gen_mov(s, op, args, args[0], args[4-tmp]);
+                break;
+            }
+            goto do_default;
+
+        case INDEX_op_add2_i32:
+        case INDEX_op_sub2_i32:
+            if (temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[3]].state == TCG_TEMP_CONST
+                && temps[args[4]].state == TCG_TEMP_CONST
+                && temps[args[5]].state == TCG_TEMP_CONST) {
+                uint32_t al = temps[args[2]].val;
+                uint32_t ah = temps[args[3]].val;
+                uint32_t bl = temps[args[4]].val;
+                uint32_t bh = temps[args[5]].val;
+                uint64_t a = ((uint64_t)ah << 32) | al;
+                uint64_t b = ((uint64_t)bh << 32) | bl;
+                TCGArg rl, rh;
+                TCGOp *op2 = insert_op_before(s, op, INDEX_op_movi_i32, 2);
+                TCGArg *args2 = &s->gen_opparam_buf[op2->args];
+
+                if (opc == INDEX_op_add2_i32) {
+                    a += b;
+                } else {
+                    a -= b;
+                }
+
+                rl = args[0];
+                rh = args[1];
+                tcg_opt_gen_movi(s, op, args, rl, (uint32_t)a);
+                tcg_opt_gen_movi(s, op2, args2, rh, (uint32_t)(a >> 32));
+
+                /* We've done all we need to do with the movi.  Skip it.  */
+                oi_next = op2->next;
+                break;
+            }
+            goto do_default;
+
+        case INDEX_op_mulu2_i32:
+            if (temps[args[2]].state == TCG_TEMP_CONST
+                && temps[args[3]].state == TCG_TEMP_CONST) {
+                uint32_t a = temps[args[2]].val;
+                uint32_t b = temps[args[3]].val;
+                uint64_t r = (uint64_t)a * b;
+                TCGArg rl, rh;
+                TCGOp *op2 = insert_op_before(s, op, INDEX_op_movi_i32, 2);
+                TCGArg *args2 = &s->gen_opparam_buf[op2->args];
+
+                rl = args[0];
+                rh = args[1];
+                tcg_opt_gen_movi(s, op, args, rl, (uint32_t)r);
+                tcg_opt_gen_movi(s, op2, args2, rh, (uint32_t)(r >> 32));
+
+                /* We've done all we need to do with the movi.  Skip it.  */
+                oi_next = op2->next;
+                break;
+            }
+            goto do_default;
+
+        case INDEX_op_brcond2_i32:
+            tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]);
+            if (tmp != 2) {
+                if (tmp) {
+            do_brcond_true:
+                    reset_all_temps(nb_temps);
+                    op->opc = INDEX_op_br;
+                    args[0] = args[5];
+                } else {
+            do_brcond_false:
+                    tcg_op_remove(s, op);
+                }
+            } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE)
+                       && temps[args[2]].state == TCG_TEMP_CONST
+                       && temps[args[3]].state == TCG_TEMP_CONST
+                       && temps[args[2]].val == 0
+                       && temps[args[3]].val == 0) {
+                /* Simplify LT/GE comparisons vs zero to a single compare
+                   vs the high word of the input.  */
+            do_brcond_high:
+                reset_all_temps(nb_temps);
+                op->opc = INDEX_op_brcond_i32;
+                args[0] = args[1];
+                args[1] = args[3];
+                args[2] = args[4];
+                args[3] = args[5];
+            } else if (args[4] == TCG_COND_EQ) {
+                /* Simplify EQ comparisons where one of the pairs
+                   can be simplified.  */
+                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                               args[0], args[2], TCG_COND_EQ);
+                if (tmp == 0) {
+                    goto do_brcond_false;
+                } else if (tmp == 1) {
+                    goto do_brcond_high;
+                }
+                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                               args[1], args[3], TCG_COND_EQ);
+                if (tmp == 0) {
+                    goto do_brcond_false;
+                } else if (tmp != 1) {
+                    goto do_default;
+                }
+            do_brcond_low:
+                reset_all_temps(nb_temps);
+                op->opc = INDEX_op_brcond_i32;
+                args[1] = args[2];
+                args[2] = args[4];
+                args[3] = args[5];
+            } else if (args[4] == TCG_COND_NE) {
+                /* Simplify NE comparisons where one of the pairs
+                   can be simplified.  */
+                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                               args[0], args[2], TCG_COND_NE);
+                if (tmp == 0) {
+                    goto do_brcond_high;
+                } else if (tmp == 1) {
+                    goto do_brcond_true;
+                }
+                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                               args[1], args[3], TCG_COND_NE);
+                if (tmp == 0) {
+                    goto do_brcond_low;
+                } else if (tmp == 1) {
+                    goto do_brcond_true;
+                }
+                goto do_default;
+            } else {
+                goto do_default;
+            }
+            break;
+
+        case INDEX_op_setcond2_i32:
+            tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]);
+            if (tmp != 2) {
+            do_setcond_const:
+                tcg_opt_gen_movi(s, op, args, args[0], tmp);
+            } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE)
+                       && temps[args[3]].state == TCG_TEMP_CONST
+                       && temps[args[4]].state == TCG_TEMP_CONST
+                       && temps[args[3]].val == 0
+                       && temps[args[4]].val == 0) {
+                /* Simplify LT/GE comparisons vs zero to a single compare
+                   vs the high word of the input.  */
+            do_setcond_high:
+                reset_temp(args[0]);
+                temps[args[0]].mask = 1;
+                op->opc = INDEX_op_setcond_i32;
+                args[1] = args[2];
+                args[2] = args[4];
+                args[3] = args[5];
+            } else if (args[5] == TCG_COND_EQ) {
+                /* Simplify EQ comparisons where one of the pairs
+                   can be simplified.  */
+                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                               args[1], args[3], TCG_COND_EQ);
+                if (tmp == 0) {
+                    goto do_setcond_const;
+                } else if (tmp == 1) {
+                    goto do_setcond_high;
+                }
+                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                               args[2], args[4], TCG_COND_EQ);
+                if (tmp == 0) {
+                    goto do_setcond_high;
+                } else if (tmp != 1) {
+                    goto do_default;
+                }
+            do_setcond_low:
+                reset_temp(args[0]);
+                temps[args[0]].mask = 1;
+                op->opc = INDEX_op_setcond_i32;
+                args[2] = args[3];
+                args[3] = args[5];
+            } else if (args[5] == TCG_COND_NE) {
+                /* Simplify NE comparisons where one of the pairs
+                   can be simplified.  */
+                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                               args[1], args[3], TCG_COND_NE);
+                if (tmp == 0) {
+                    goto do_setcond_high;
+                } else if (tmp == 1) {
+                    goto do_setcond_const;
+                }
+                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                               args[2], args[4], TCG_COND_NE);
+                if (tmp == 0) {
+                    goto do_setcond_low;
+                } else if (tmp == 1) {
+                    goto do_setcond_const;
+                }
+                goto do_default;
+            } else {
+                goto do_default;
+            }
+            break;
+
+        case INDEX_op_call:
+            if (!(args[nb_oargs + nb_iargs + 1]
+                  & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
+                for (i = 0; i < nb_globals; i++) {
+                    reset_temp(i);
+                }
+            }
+            goto do_reset_output;
+
+        default:
+        do_default:
+            /* 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.  "mask" is
+               the non-zero bits mask for the first output arg.  */
+            if (def->flags & TCG_OPF_BB_END) {
+                reset_all_temps(nb_temps);
+            } else {
+        do_reset_output:
+                for (i = 0; i < nb_oargs; i++) {
+                    reset_temp(args[i]);
+                    /* Save the corresponding known-zero bits mask for the
+                       first output argument (only one supported so far). */
+                    if (i == 0) {
+                        temps[args[i]].mask = mask;
+                    }
+                }
+            }
+            break;
+        }
+    }
+}