diff options
| -rw-r--r-- | simplify.c | 30 |
1 files changed, 28 insertions, 2 deletions
@@ -247,14 +247,19 @@ static int simplify_constant_rightside(struct instruction *insn) /* Fallthrough */ case OP_ADD: case OP_OR: case OP_XOR: + case OP_OR_BOOL: case OP_SHL: case OP_LSR: case OP_ASR: if (!value) return replace_with_pseudo(insn, insn->src1); return 0; - case OP_AND: case OP_MULU: case OP_MULS: + case OP_AND_BOOL: + if (value == 1) + return replace_with_pseudo(insn, insn->src1); + /* Fallthrough */ + case OP_AND: if (!value) return replace_with_pseudo(insn, insn->src2); return 0; @@ -559,6 +564,19 @@ static int simplify_memop(struct instruction *insn) return ret; } +static long long get_cast_value(long long val, int old_size, int new_size, int sign) +{ + long long mask; + + if (sign && new_size > old_size) { + mask = 1 << (old_size-1); + if (val & mask) + val |= ~(mask | (mask-1)); + } + mask = 1 << (new_size-1); + return val & (mask | (mask-1)); +} + static int simplify_cast(struct instruction *insn) { struct symbol *orig_type; @@ -575,6 +593,14 @@ static int simplify_cast(struct instruction *insn) size = insn->size; src = insn->src; + /* A cast of a constant? */ + if (constant(src)) { + int sign = orig_type->ctype.modifiers & MOD_SIGNED; + long long val = get_cast_value(src->value, orig_size, size, sign); + src = value_pseudo(val); + goto simplify; + } + /* A cast of a "and" might be a no-op.. */ if (src->type == PSEUDO_REG) { struct instruction *def = src->def; @@ -597,7 +623,7 @@ static int simplify_cast(struct instruction *insn) return 0; simplify: - return replace_with_pseudo(insn, insn->src); + return replace_with_pseudo(insn, src); } static int simplify_select(struct instruction *insn) |