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Re: [PATCH, ARM, LRA] Prepare ARM build with LRA
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Yvan Roux <yvan dot roux at linaro dot org>
- Cc: gcc-patches at gcc dot gnu dot org, Vladimir Makarov <vmakarov at redhat dot com>, "rdsandiford at googlemail dot com" <rdsandiford at googlemail dot com>, Richard Earnshaw <rearnsha at arm dot com>, Marcus Shawcroft <marcus dot shawcroft at arm dot com>, Ramana Radhakrishnan <Ramana dot Radhakrishnan at arm dot com>, Matthew Gretton-Dann <matthew dot gretton-dann at linaro dot org>, Patch Tracking <patches at linaro dot org>, Richard Henderson <rth at redhat dot com>
- Date: Tue, 24 Sep 2013 12:35:55 +0200
- Subject: Re: [PATCH, ARM, LRA] Prepare ARM build with LRA
- Authentication-results: sourceware.org; auth=none
- References: <CAD57uCfrF9Ns=jghNJOD07p5wg+_zcTc6wmfOknau3iSg4FvWg at mail dot gmail dot com> <CAD57uCcQrc4ooprKbHj5OjpVK6DGgTsXkh+9EQGrnZUVVYLEog at mail dot gmail dot com> <CAD57uCeb_AqkjU8ptE3aggnnHi+WasrLxMjnR_YGqZ4+XJ6Pgw at mail dot gmail dot com>
> Here is the new patch discussed in the other thread.
>
> Thanks
> Yvan
>
> 2013-09-11 Yvan Roux <yvan.roux@linaro.org>
> Vladimir Makarov <vmakarov@redhat.com>
>
> * rtlanal.c (lsb_bitfield_op_p): New predicate for bitfield operations
> from the least significant bit.
> (strip_address_mutations): Add bitfield operations handling.
> (shift_code_p): New predicate for shifting operations.
> (must_be_index_p): Add shifting operations handling.
> (set_address_index): Likewise.
+/* Return true if X is a sign_extract or zero_extract from the least
+ significant bit. */
+
+static bool
+lsb_bitfield_op_p (rtx x)
+{
+ if (GET_RTX_CLASS (GET_CODE (x)) == RTX_BITFIELD_OPS)
+ {
+ enum machine_mode mode = GET_MODE(x);
+ unsigned HOST_WIDE_INT len = INTVAL (XEXP (x, 1));
+ HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
+
+ return (pos == (BITS_BIG_ENDIAN ? GET_MODE_PRECISION (mode) - len :
0));
It seems strange to use the destination mode to decide whether this is the LSB
of the source.
+/* Return true if X is a shifting operation. */
+
+static bool
+shift_code_p (rtx x)
+{
+ return (GET_CODE (x) == ASHIFT
+ || GET_CODE (x) == ASHIFTRT
+ || GET_CODE (x) == LSHIFTRT
+ || GET_CODE (x) == ROTATE
+ || GET_CODE (x) == ROTATERT);
+}
ROTATE and ROTATERT aren't really shifting operations though, so are they
really needed here?
--
Eric Botcazou