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tcg/optimize: Build and use o_bits in fold_bswap

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Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-12-10 15:02:41 -06:00
parent 787190e3f4
commit e6e3733bf1
1 changed files with 24 additions and 25 deletions
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49
tcg/optimize.c
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@ -1671,53 +1671,52 @@ static bool fold_brcond2(OptContext *ctx, TCGOp *op)
static bool fold_bswap(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, s_mask, sign;
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1 = arg_info(op->args[1]);
int flags = op->args[2];
if (ti_is_const(t1)) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
do_constant_folding(op->opc, ctx->type,
ti_const_val(t1),
op->args[2]));
ti_const_val(t1), flags));
}
z_mask = t1->z_mask;
o_mask = t1->o_mask;
s_mask = 0;
switch (op->opc) {
case INDEX_op_bswap16:
z_mask = bswap16(z_mask);
sign = INT16_MIN;
o_mask = bswap16(o_mask);
if (flags & TCG_BSWAP_OS) {
z_mask = (int16_t)z_mask;
o_mask = (int16_t)o_mask;
s_mask = INT16_MIN;
} else if (!(flags & TCG_BSWAP_OZ)) {
z_mask |= MAKE_64BIT_MASK(16, 48);
}
break;
case INDEX_op_bswap32:
z_mask = bswap32(z_mask);
sign = INT32_MIN;
o_mask = bswap32(o_mask);
if (flags & TCG_BSWAP_OS) {
z_mask = (int32_t)z_mask;
o_mask = (int32_t)o_mask;
s_mask = INT32_MIN;
} else if (!(flags & TCG_BSWAP_OZ)) {
z_mask |= MAKE_64BIT_MASK(32, 32);
}
break;
case INDEX_op_bswap64:
z_mask = bswap64(z_mask);
sign = INT64_MIN;
o_mask = bswap64(o_mask);
break;
default:
g_assert_not_reached();
}
s_mask = 0;
switch (op->args[2] & (TCG_BSWAP_OZ | TCG_BSWAP_OS)) {
case TCG_BSWAP_OZ:
break;
case TCG_BSWAP_OS:
/* If the sign bit may be 1, force all the bits above to 1. */
if (z_mask & sign) {
z_mask |= sign;
}
/* The value and therefore s_mask is explicitly sign-extended. */
s_mask = sign;
break;
default:
/* The high bits are undefined: force all bits above the sign to 1. */
z_mask |= sign << 1;
break;
}
return fold_masks_zs(ctx, op, z_mask, s_mask);
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_call(OptContext *ctx, TCGOp *op)