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Blackfin: change global data register from P5 to P3

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Since the Blackfin ABI favors higher scratch registers by default, use the
last scratch register (P3) for global data rather than the first (P5).
This allows the compiler's register allocator to use higher number scratch
P registers, which in turn better matches the Blackfin instruction set,
which reduces the size of U-Boot by more than 1024 bytes...

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Robin Getz
2009-08-17 15:23:02 +00:00
committed by Mike Frysinger
parent 574b70df03
commit c4db335c2e
5 changed files with 7 additions and 7 deletions
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@@ -3912,10 +3912,10 @@ For PowerPC, the following registers have specific use:
average for all boards 752 bytes for the whole U-Boot image,
624 text + 127 data).
On Blackfin, the normal C ABI (except for P5) is followed as documented here:
On Blackfin, the normal C ABI (except for P3) is followed as documented here:
http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
==> U-Boot will use P5 to hold a pointer to the global data
==> U-Boot will use P3 to hold a pointer to the global data
On ARM, the following registers are used: