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| author | Jakub Jelinek <jakub@redhat.com> | 2010-08-19 19:43:50 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2010-08-19 19:43:50 +0200 |
| commit | a5d8253f7aba67d7a3e05c5e0e361c9057bc5d54 (patch) | |
| tree | efa8e5321c21db9e8b1edf44dcacc6bed954fab5 /gcc/simplify-rtx.c | |
| parent | 0524d2d6623eb2ab287f464e05c206ceeb3839bf (diff) | |
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re PR target/45336 (pextr{b,w,d}, (worse than) redundant extensions)
PR target/45336
* simplify-rtx.c (simplify_unary_operation_1): Optimize nested
SIGN_EXTENDs or ZERO_EXTENDs.
From-SVN: r163384
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index a7a91e5..e3acc41 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -1010,6 +1010,31 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op) && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0)))) return rtl_hooks.gen_lowpart_no_emit (mode, op); + /* (sign_extend:M (sign_extend:N <X>)) is (sign_extend:M <X>). */ + if (GET_CODE (op) == SIGN_EXTEND) + return simplify_gen_unary (SIGN_EXTEND, mode, XEXP (op, 0), + GET_MODE (XEXP (op, 0))); + + /* (sign_extend:M (ashiftrt:N (ashift <X> (const_int I)) (const_int I))) + is (sign_extend:M (subreg:O <X>)) if there is mode with + GET_MODE_BITSIZE (N) - I bits. */ + if (GET_CODE (op) == ASHIFTRT + && GET_CODE (XEXP (op, 0)) == ASHIFT + && CONST_INT_P (XEXP (op, 1)) + && XEXP (XEXP (op, 0), 1) == XEXP (op, 1) + && GET_MODE_BITSIZE (GET_MODE (op)) > INTVAL (XEXP (op, 1))) + { + enum machine_mode tmode + = mode_for_size (GET_MODE_BITSIZE (GET_MODE (op)) + - INTVAL (XEXP (op, 1)), MODE_INT, 1); + if (tmode != BLKmode) + { + rtx inner = + rtl_hooks.gen_lowpart_no_emit (tmode, XEXP (XEXP (op, 0), 0)); + return simplify_gen_unary (SIGN_EXTEND, mode, inner, tmode); + } + } + #if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend) /* As we do not know which address space the pointer is refering to, we can do this only if the target does not support different pointer @@ -1036,6 +1061,11 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op) && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0)))) return rtl_hooks.gen_lowpart_no_emit (mode, op); + /* (zero_extend:M (zero_extend:N <X>)) is (zero_extend:M <X>). */ + if (GET_CODE (op) == ZERO_EXTEND) + return simplify_gen_unary (ZERO_EXTEND, mode, XEXP (op, 0), + GET_MODE (XEXP (op, 0))); + #if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend) /* As we do not know which address space the pointer is refering to, we can do this only if the target does not support different pointer |