diff options
Diffstat (limited to 'gcc-4.8/gcc/simplify-rtx.c')
| -rw-r--r-- | gcc-4.8/gcc/simplify-rtx.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/gcc-4.8/gcc/simplify-rtx.c b/gcc-4.8/gcc/simplify-rtx.c index 43e794ebd..d6b872b9f 100644 --- a/gcc-4.8/gcc/simplify-rtx.c +++ b/gcc-4.8/gcc/simplify-rtx.c @@ -639,11 +639,16 @@ simplify_truncation (enum machine_mode mode, rtx op, XEXP (op, 0), origmode); } - /* Simplify (truncate:SI (op:DI (x:DI) (y:DI))) - to (op:SI (truncate:SI (x:DI)) (truncate:SI (x:DI))). */ - if (GET_CODE (op) == PLUS + /* If the machine can perform operations in the truncated mode, distribute + the truncation, i.e. simplify (truncate:QI (op:SI (x:SI) (y:SI))) into + (op:QI (truncate:QI (x:SI)) (truncate:QI (y:SI))). */ + if (1 +#ifdef WORD_REGISTER_OPERATIONS + && precision >= BITS_PER_WORD +#endif + && (GET_CODE (op) == PLUS || GET_CODE (op) == MINUS - || GET_CODE (op) == MULT) + || GET_CODE (op) == MULT)) { rtx op0 = simplify_gen_unary (TRUNCATE, mode, XEXP (op, 0), op_mode); if (op0) |